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Sample records for electrical neuroimaging evidence

  1. Neuroimaging Evidence of Comprehension Monitoring

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    Linda Baker

    2014-04-01

    Full Text Available The purpose of this article is to synthesize the emerging neuroimaging literature that reveals how the brain responds when readers and listeners encounter texts that demand monitoring of their ongoing comprehension processes. Much of this research has been undertaken by cognitive scientists who do not frame their work in metacognitive terms, and therefore it is less likely to be familiar to psychologists who study metacognition in educational contexts. The important role of metacognition in the development and use of academic skills is widely recognized. Metacognition is typically defined as the awareness and control of one's own cognitive processes. In the domain of reading, the most important metacognitive skill is comprehension monitoring, the evaluation and regulation of comprehension. Readers who monitor their understanding realize when they have encountered difficulty making sense of the text, and they apply error correction procedures to attempt to resolve the difficulty. Metacognition depends on executive control skills that continue to develop into early adulthood, in parallel with the maturation of the executive control regions of the prefrontal cortex. Functional magnetic resonance imaging (fMRI and event-related potentials (ERP have been used for some time to study neural correlates of basic reading processes such as word identification, but it is only within recent years that researchers have turned to the higher-level processes of text comprehension. The article describes illustrative studies that reveal changes in neural activity when adults apply lexical, syntactic, or semantic standards to evaluate their understanding.

  2. Understanding the impact of TV commercials: electrical neuroimaging.

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    Vecchiato, Giovanni; Kong, Wanzeng; Maglione, Anton Giulio; Wei, Daming

    2012-01-01

    Today, there is a greater interest in the marketing world in using neuroimaging tools to evaluate the efficacy of TV commercials. This field of research is known as neuromarketing. In this article, we illustrate some applications of electrical neuroimaging, a discipline that uses electroencephalography (EEG) and intensive signal processing techniques for the evaluation of marketing stimuli. We also show how the proper usage of these methodologies can provide information related to memorization and attention while people are watching marketing-relevant stimuli. We note that temporal and frequency patterns of EEG signals are able to provide possible descriptors that convey information about the cognitive process in subjects observing commercial advertisements (ads). Such information could be unobtainable through common tools used in standard marketing research. Evidence of this research shows how EEG methodologies could be employed to better design new products that marketers are going to promote and to analyze the global impact of video commercials already broadcast on TV.

  3. Attention to spoken word planning: Chronometric and neuroimaging evidence

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    Roelofs, A.P.A.

    2008-01-01

    This article reviews chronometric and neuroimaging evidence on attention to spoken word planning, using the WEAVER++ model as theoretical framework. First, chronometric studies on the time to initiate vocal responding and gaze shifting suggest that spoken word planning may require some attention,

  4. Linking Essential Tremor to the Cerebellum-Neuroimaging Evidence.

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    Cerasa, Antonio; Quattrone, Aldo

    2016-06-01

    Essential tremor (ET) is the most common pathological tremor disorder in the world, and post-mortem evidence has shown that the cerebellum is the most consistent area of pathology in ET. In the last few years, advanced neuroimaging has tried to confirm this evidence. The aim of the present review is to discuss to what extent the evidence provided by this field of study may be generalised. We performed a systematic literature search combining the terms ET with the following keywords: MRI, VBM, MRS, DTI, fMRI, PET and SPECT. We summarised and discussed each study and placed the results in the context of existing knowledge regarding the cerebellar involvement in ET. A total of 51 neuroimaging studies met our search criteria, roughly divided into 19 structural and 32 functional studies. Despite clinical and methodological differences, both functional and structural imaging studies showed similar findings but without defining a clear topography of neurodegeneration. Indeed, the vast majority of studies found functional and structural abnormalities in several parts of the anterior and posterior cerebellar lobules, but it remains to be established to what degree these neural changes contribute to clinical symptoms of ET. Currently, advanced neuroimaging has confirmed the involvement of the cerebellum in pathophysiological processes of ET, although a high variability in results persists. For this reason, the translation of this knowledge into daily clinical practice is again partially limited, although new advanced multivariate neuroimaging approaches (machine-learning) are proving interesting changes of perspective.

  5. Neural mechanisms of mindfulness and meditation: Evidence from neuroimaging studies

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    William; R; Marchand

    2014-01-01

    Mindfulness is the dispassionate,moment-by-moment awareness of sensations,emotions and thoughts.Mindfulness-based interventions are being increasingly used for stress,psychological well being,coping with chronic illness as well as adjunctive treatments for psychiatric disorders.However,the neural mechanisms associated with mindfulness have not been well characterized.Recent functional and structural neuroimaging studies are beginning to provide insights into neural processes associated with the practice of mindfulness.A review of this literature revealed compelling evidence that mindfulness impacts the function of the medial cortex and associated default mode network as well as insula and amygdala.Additionally,mindfulness practice appears to effect lateral frontal regions and basal ganglia,at least in some cases.Structural imaging studies are consistent with these findings and also indicate changes in the hippocampus.While many questions remain unanswered,the current literature provides evidence of brain regions and networks relevant for understanding neural processes associated with mindfulness.

  6. Insulin action in the human brain: evidence from neuroimaging studies.

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    Kullmann, S; Heni, M; Fritsche, A; Preissl, H

    2015-06-01

    Thus far, little is known about the action of insulin in the human brain. Nonetheless, recent advances in modern neuroimaging techniques, such as functional magnetic resonance imaging (fMRI) or magnetoencephalography (MEG), have made it possible to investigate the action of insulin in the brain in humans, providing new insights into the pathogenesis of brain insulin resistance and obesity. Using MEG, the clinical relevance of the action of insulin in the brain was first identified, linking cerebral insulin resistance with peripheral insulin resistance, genetic predisposition and weight loss success in obese adults. Although MEG is a suitable tool for measuring brain activity mainly in cortical areas, fMRI provides high spatial resolution for cortical as well as subcortical regions. Thus, the action of insulin can be detected within all eating behaviour relevant regions, which include regions deeply located within the brain, such as the hypothalamus, midbrain and brainstem, as well as regions within the striatum. In this review, we outline recent advances in the field of neuroimaging aiming to investigate the action of insulin in the human brain using different routes of insulin administration. fMRI studies have shown a significant insulin-induced attenuation predominantly in the occipital and prefrontal cortical regions and the hypothalamus, successfully localising insulin-sensitive brain regions in healthy, mostly normal-weight individuals. However, further studies are needed to localise brain areas affected by insulin resistance in obese individuals, which is an important prerequisite for selectively targeting brain insulin resistance in obesity. © 2015 British Society for Neuroendocrinology.

  7. The neuroimaging evidence for chronic brain damage due to boxing

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    Moseley, I.F. [Lysholm Radiological Department, National Hospital for Neurology and Neurosurgery, London (United Kingdom)

    2000-01-01

    A number of imaging techniques have been used to investigate changes produced in the brain by boxing. Most morphological studies have failed to show significant correlations between putative abnormalities on imaging and clinical evidence of brain damage. Fenestration of the septum pellucidum, with formation of a cavum, one of the most frequent observations, does not appear to correlate with neurological or physiological evidence of brain damage. Serial studies on large groups may be more informative. Magnetic resonance spectroscopy and cerebral blood flow studies have been reported in only small numbers of boxers; serial studies are not available to date. (orig.)

  8. The speed of passionate love, as a subliminal prime: A high-density electrical neuroimaging stud

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    Cacioppo Stephanie; Grafton Scott T.; Bianchi-Demicheli F

    2012-01-01

    In line with the psychological model of self expansion recent neuroimaging evidence shows an overlap between the brain network mediating passionate love and that involved in self representation. Nevertheless little remains known about the temporal dynamics of these brain areas. To address this question we recorded brain activity from 20 healthy participants using high density electrophysiological recordings while participants were performing a cognitive priming paradigm known to activate the ...

  9. GENE X ENVIRONMENT INTERACTIONS IN SCHIZOPHRENIA AND BIPOLAR DISORDER:EVIDENCE FROM NEUROIMAGING

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    Pierre Alexis Geoffroy

    2013-10-01

    Full Text Available Introduction: Schizophrenia (SZ and Bipolar disorder (BD are considered as severe multifactorial diseases, stemming from genetic and environmental influences. Growing evidence supports gene x environment (GxE interactions in these disorders and neuroimaging studies can help us to understand how those factors mechanistically interact. No reviews synthesized the existing data of neuroimaging studies in these issues.Methods: We conduct a systematic review on the neuroimaging studies exploring GxE interactions relative to SZ or BD in PubMed.Results: First results of the influence of genetic and environmental risks on brain structures came from monozygotic twin pairs concordant and discordant for SZ or BD. Few structural magnetic resonance imaging (sMRI studies have explored the GxE interactions. No other imaging methods were found. Two main GxE interactions on brain volumes have arisen. First, an interaction between genetic liability to SZ and obstetric complications on gray matter, cerebrospinal fluid and hippocampal volumes. Second, cannabis use and genetic liability interaction effects on cortical thickness and white matter volumes.Conclusion: Combining GxE interactions and neuroimaging domains is a promising approach. Genetic risk and environmental exposures such as cannabis or obstetrical complications seem to interact leading to specific neuroimaging cerebral alterations in SZ. They are suggestive of GxE interactions that confer phenotypic abnormalities in SZ and possibly BD. We need further, larger neuroimaging studies of GxE interactions for which we may propose a framework focusing on GxE interactions data already known to have a clinical effect such as infections, early stress, urbanicity and substance abuse.

  10. Neuroimaging evidence of deficient axon myelination in Wolfram syndrome.

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    Lugar, Heather M; Koller, Jonathan M; Rutlin, Jerrel; Marshall, Bess A; Kanekura, Kohsuke; Urano, Fumihiko; Bischoff, Allison N; Shimony, Joshua S; Hershey, Tamara

    2016-02-18

    Wolfram syndrome is a rare autosomal recessive genetic disease characterized by insulin dependent diabetes and vision, hearing and brain abnormalities which generally emerge in childhood. Mutations in the WFS1 gene predispose cells to endoplasmic reticulum stress-mediated apoptosis and may induce myelin degradation in neuronal cell models. However, in vivo evidence of this phenomenon in humans is lacking. White matter microstructure and regional volumes were measured using magnetic resonance imaging in children and young adults with Wolfram syndrome (n = 21) and healthy and diabetic controls (n = 50). Wolfram patients had lower fractional anisotropy and higher radial diffusivity in major white matter tracts and lower volume in the basilar (ventral) pons, cerebellar white matter and visual cortex. Correlations were found between key brain findings and overall neurological symptoms. This pattern of findings suggests that reduction in myelin is a primary neuropathological feature of Wolfram syndrome. Endoplasmic reticulum stress-related dysfunction in Wolfram syndrome may interact with the development of myelin or promote degeneration of myelin during the progression of the disease. These measures may provide objective indices of Wolfram syndrome pathophysiology that will be useful in unraveling the underlying mechanisms and in testing the impact of treatments on the brain.

  11. Neurobiological Foundations of Acupuncture: The Relevance and Future Prospect Based on Neuroimaging Evidence

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    Lijun Bai

    2013-01-01

    Full Text Available Acupuncture is currently gaining popularity as an important modality of alternative and complementary medicine in the western world. Modern neuroimaging techniques such as functional magnetic resonance imaging, positron emission tomography, and magnetoencephalography open a window into the neurobiological foundations of acupuncture. In this review, we have summarized evidence derived from neuroimaging studies and tried to elucidate both neurophysiological correlates and key experimental factors involving acupuncture. Converging evidence focusing on acute effects of acupuncture has revealed significant modulatory activities at widespread cerebrocerebellar brain regions. Given the delayed effect of acupuncture, block-designed analysis may produce bias, and acupuncture shared a common feature that identified voxels that coded the temporal dimension for which multiple levels of their dynamic activities in concert cause the processing of acupuncture. Expectation in acupuncture treatment has a physiological effect on the brain network, which may be heterogeneous from acupuncture mechanism. “Deqi” response, bearing clinical relevance and association with distinct nerve fibers, has the specific neurophysiology foundation reflected by neural responses to acupuncture stimuli. The type of sham treatment chosen is dependent on the research question asked and the type of acupuncture treatment to be tested. Due to the complexities of the therapeutic mechanisms of acupuncture, using multiple controls is an optimal choice.

  12. Clocking the social mind by identifying mental processes in the IAT with electrical neuroimaging.

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    Schiller, Bastian; Gianotti, Lorena R R; Baumgartner, Thomas; Nash, Kyle; Koenig, Thomas; Knoch, Daria

    2016-03-08

    Why do people take longer to associate the word "love" with outgroup words (incongruent condition) than with ingroup words (congruent condition)? Despite the widespread use of the implicit association test (IAT), it has remained unclear whether this IAT effect is due to additional mental processes in the incongruent condition, or due to longer duration of the same processes. Here, we addressed this previously insoluble issue by assessing the spatiotemporal evolution of brain electrical activity in 83 participants. From stimulus presentation until response production, we identified seven processes. Crucially, all seven processes occurred in the same temporal sequence in both conditions, but participants needed more time to perform one early occurring process (perceptual processing) and one late occurring process (implementing cognitive control to select the motor response) in the incongruent compared with the congruent condition. We also found that the latter process contributed to individual differences in implicit bias. These results advance understanding of the neural mechanics of response time differences in the IAT: They speak against theories that explain the IAT effect as due to additional processes in the incongruent condition and speak in favor of theories that assume a longer duration of specific processes in the incongruent condition. More broadly, our data analysis approach illustrates the potential of electrical neuroimaging to illuminate the temporal organization of mental processes involved in social cognition.

  13. Medial Temporal Lobe Contributions to Future Thinking: Evidence from Neuroimaging and Amnesia

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    Mieke Verfaellie

    2012-09-01

    Full Text Available Following early amnesic case reports, there is now considerable evidence suggesting a link between remembering the past and envisioning the future. This link is evident in the overlap in neural substrates as well as cognitive processes involved in both kinds of tasks. While constructing a future narrative requires multiple processes, neuroimaging and lesion data converge on a critical role for the medial temporal lobes (MTL in retrieving and recombining details from memory in the service of novel simulations. Deficient detail retrieval and recombination may lead to impairments not only in episodic, but also in semantic prospection. MTL contributions to scene construction and mental time travel may further compound impairments in amnesia on tasks that pose additional demands on these processes, but are unlikely to form the core deficit underlying amnesics' cross-domain future thinking impairment. Future studies exploring the role of episodic memory in other forms of self-projection or future-oriented behaviour may elucidate further the adaptive role of memory.

  14. Noninvasive biomarkers in normal pressure hydrocephalus: evidence for the role of neuroimaging.

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    Tarnaris, Andrew; Kitchen, Neil D; Watkins, Laurence D

    2009-05-01

    Normal pressure hydrocephalus (NPH) represents a treatable form of dementia. Recent estimates of the incidence of this condition are in the region of 5% of patients with dementia. The symptoms of NPH can vary among individuals and may be confused with those of patients with multi-infarct dementia, dementia of the Alzheimer type, or even Parkinson disease. Traditionally the diagnosis of NPH could only be confirmed postoperatively by a favorable outcome to surgical diversion of CSF. The object of this literature review was to examine the role of structural and functional imaging in providing biomarkers of favorable surgical outcome. A Medline search was undertaken for the years 1980-2006, using the following terms: normal pressure hydrocephalus, adult hydrocephalus, chronic hydrocephalus, imaging, neuroimaging, imaging studies, outcomes, surgical outcomes, prognosis, prognostic value, sensitivity, specificity, positive predictive value, negative predictive value, and accuracy. The query revealed 16 studies that correlated imaging with surgical outcomes offering accuracy results. Three studies fulfilled the statistical criteria of a biomarker. A dementia Alzheimer-type pattern on SPECT in patients with idiopathic NPH, the presence of CSF flow void on MR imaging, and the N-acetylaspartate/choline ratio in patients with the secondary form are able to predict surgical outcomes with high accuracy. There is at present Level A evidence for using MR spectroscopy in patients with secondary NPH, and Level B evidence for using SPECT and phase-contrast MR imaging to select patients with idiopathic NPH for shunt placement. The studies, however, need to be repeated by other groups. The current work should act as a platform to design further studies with larger sample sizes.

  15. Dreaming as mind wandering: evidence from functional neuroimaging and first-person content reports.

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    Fox, Kieran C R; Nijeboer, Savannah; Solomonova, Elizaveta; Domhoff, G William; Christoff, Kalina

    2013-01-01

    Isolated reports have long suggested a similarity in content and thought processes across mind wandering (MW) during waking, and dream mentation during sleep. This overlap has encouraged speculation that both "daydreaming" and dreaming may engage similar brain mechanisms. To explore this possibility, we systematically examined published first-person experiential reports of MW and dreaming and found many similarities: in both states, content is largely audiovisual and emotional, follows loose narratives tinged with fantasy, is strongly related to current concerns, draws on long-term memory, and simulates social interactions. Both states are also characterized by a relative lack of meta-awareness. To relate first-person reports to neural evidence, we compared meta-analytic data from numerous functional neuroimaging (PET, fMRI) studies of the default mode network (DMN, with high chances of MW) and rapid eye movement (REM) sleep (with high chances of dreaming). Our findings show large overlaps in activation patterns of cortical regions: similar to MW/DMN activity, dreaming and REM sleep activate regions implicated in self-referential thought and memory, including medial prefrontal cortex (PFC), medial temporal lobe structures, and posterior cingulate. Conversely, in REM sleep numerous PFC executive regions are deactivated, even beyond levels seen during waking MW. We argue that dreaming can be understood as an "intensified" version of waking MW: though the two share many similarities, dreams tend to be longer, more visual and immersive, and to more strongly recruit numerous key hubs of the DMN. Further, whereas MW recruits fewer PFC regions than goal-directed thought, dreaming appears to be characterized by an even deeper quiescence of PFC regions involved in cognitive control and metacognition, with a corresponding lack of insight and meta-awareness. We suggest, then, that dreaming amplifies the same features that distinguish MW from goal-directed waking thought.

  16. Sleep Deprivation Promotes Habitual Control over Goal-Directed Control: Behavioral and Neuroimaging Evidence.

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    Chen, Jie; Liang, Jie; Lin, Xiao; Zhang, Yang; Zhang, Yan; Lu, Lin; Shi, Jie

    2017-12-06

    Sleep is one of the most fundamental processes of life, playing an important role in the regulation of brain function. The long-term lack of sleep can cause memory impairments, declines in learning ability, and executive dysfunction. In the present study, we evaluated the effects of sleep deprivation on instrumental learning behavior, particularly goal-directed and habitual actions in humans, and investigated the underlying neural mechanisms. Healthy college students of either gender were enrolled and randomly divided into sleep deprivation group and sleep control group. fMRI data were collected. We found that one night of sleep deprivation led to greater responsiveness to stimuli that were associated with devalued outcomes in the slips-of-action test, indicating a deficit in the formation of goal-directed control and an overreliance on habits. Furthermore, sleep deprivation had no effect on the expression of acquired goal-directed action. The level of goal-directed action after sleep deprivation was positively correlated with baseline working memory capacity. The neuroimaging data indicated that goal-directed learning mainly recruited the ventromedial PFC (vmPFC), the activation of which was less pronounced during goal-directed learning after sleep deprivation. Activation of the vmPFC during goal-directed learning during training was positively correlated with the level of goal-directed action performance. The present study suggests that people rely predominantly on habits at the expense of goal-directed control after sleep deprivation, and this process involves the vmPFC. These results contribute to a better understanding of the effects of sleep loss on decision-making. SIGNIFICANCE STATEMENT Understanding the cognitive consequences of sleep deprivation has become extremely important over the past half century, given the continued decline in sleep duration in industrialized societies. Our results provide novel evidence that goal-directed action may be

  17. Disorders of Consciousness: Painless or Painful Conditions?—Evidence from Neuroimaging Studies

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    Francesca Pistoia

    2016-10-01

    Full Text Available The experience of pain in disorders of consciousness is still debated. Neuroimaging studies, using functional Magnetic Resonance Imaging (fMRI, Positron Emission Tomography (PET, multichannel electroencephalography (EEG and laser-evoked potentials, suggest that the perception of pain increases with the level of consciousness. Brain activation in response to noxious stimuli has been observed in patients with unresponsive wakefulness syndrome (UWS, which is also referred to as a vegetative state (VS, as well as those in a minimally conscious state (MCS. However, all of these techniques suggest that pain-related brain activation patterns of patients in MCS more closely resemble those of healthy subjects. This is further supported by fMRI findings showing a much greater functional connectivity within the structures of the so-called pain matrix in MCS as compared to UWS/VS patients. Nonetheless, when interpreting the results, a distinction is necessary between autonomic responses to potentially harmful stimuli and conscious experience of the unpleasantness of pain. Even more so if we consider that the degree of residual functioning and cortical connectivity necessary for the somatosensory, affective and cognitive-evaluative components of pain processing are not yet clear. Although procedurally challenging, the particular value of the aforementioned techniques in the assessment of pain in disorders of consciousness has been clearly demonstrated. The study of pain-related brain activation and functioning can contribute to a better understanding of the networks underlying pain perception while addressing clinical and ethical questions concerning patient care. Further development of technology and methods should aim to increase the availability of neuroimaging, objective assessment of functional connectivity and analysis at the level of individual cases as well as group comparisons. This will enable neuroimaging to truly become a clinical tool to

  18. Neuroimaging of love: fMRI meta-analysis evidence toward new perspectives in sexual medicine.

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    Ortigue, Stephanie; Bianchi-Demicheli, Francesco; Patel, Nisa; Frum, Chris; Lewis, James W

    2010-11-01

    Brain imaging is becoming a powerful tool in the study of human cerebral functions related to close personal relationships. Outside of subcortical structures traditionally thought to be involved in reward-related systems, a wide range of neuroimaging studies in relationship science indicate a prominent role for different cortical networks and cognitive factors. Thus, the field needs a better anatomical/network/whole-brain model to help translate scientific knowledge from lab bench to clinical models and ultimately to the patients suffering from disorders associated with love and couple relationships. The aim of the present review is to provide a review across wide range of functional magnetic resonance imaging (fMRI) studies to critically identify the cortical networks associated with passionate love, and to compare and contrast it with other types of love (such as maternal love and unconditional love for persons with intellectual disabilities). Retrospective review of pertinent neuroimaging literature. Review of published literature on fMRI studies of love illustrating brain regions associated with different forms of love. Although all fMRI studies of love point to the subcortical dopaminergic reward-related brain systems (involving dopamine and oxytocin receptors) for motivating individuals in pair-bonding, the present meta-analysis newly demonstrated that different types of love involve distinct cerebral networks, including those for higher cognitive functions such as social cognition and bodily self-representation. These metaresults provide the first stages of a global neuroanatomical model of cortical networks involved in emotions related to different aspects of love. Developing this model in future studies should be helpful for advancing clinical approaches helpful in sexual medicine and couple therapy. © 2010 International Society for Sexual Medicine.

  19. Drug Addiction and Its Underlying Neurobiological Basis: Neuroimaging Evidence for the Involvement of the Frontal Cortex

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    Goldstein, Rita Z.; Volkow, Nora D.

    2005-01-01

    Objective Studies of the neurobiological processes underlying drug addiction primarily have focused on limbic subcortical structures. Here the authors evaluated the role of frontal cortical structures in drug addiction. Method An integrated model of drug addiction that encompasses intoxication, bingeing, withdrawal, and craving is proposed. This model and findings from neuroimaging studies on the behavioral, cognitive, and emotional processes that are at the core of drug addiction were used to analyze the involvement of frontal structures in drug addiction. Results The orbitofrontal cortex and the anterior cingulate gyrus, which are regions neuroanatomically connected with limbic structures, are the frontal cortical areas most frequently implicated in drug addiction. They are activated in addicted subjects during intoxication, craving, and bingeing, and they are deactivated during withdrawal. These regions are also involved in higher-order cognitive and motivational functions, such as the ability to track, update, and modulate the salience of a reinforcer as a function of context and expectation and the ability to control and inhibit prepotent responses. Conclusions These results imply that addiction connotes cortically regulated cognitive and emotional processes, which result in the overvaluing of drug reinforcers, the undervaluing of alternative reinforcers, and deficits in inhibitory control for drug responses. These changes in addiction, which the authors call I-RISA (impaired response inhibition and salience attribution), expand the traditional concepts of drug dependence that emphasize limbic-regulated responses to pleasure and reward. PMID:12359667

  20. Differential Motor and Prefrontal Cerebello-Cortical Network Development: Evidence from Multimodal Neuroimaging

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    Bernard, Jessica A.; Orr, Joseph M.; Mittal, Vijay A.

    2015-01-01

    While our understanding of cerebellar structural development through adolescence and young adulthood has expanded, we still lack knowledge of the developmental patterns of cerebellar networks during this critical portion of the lifespan. Volume in lateral posterior cerebellar regions associated with cognition and the prefrontal cortex develops more slowly, reaching their peak volume in adulthood, particularly as compared to motor Lobule V. We predicted that resting state functional connectivity of the lateral posterior regions would show a similar pattern of development during adolescence and young adulthood. That is, we expected to see changes over time in Crus I and Crus II connectivity with the cortex, but no changes in Lobule V connectivity. Additionally, we were interested in how structural connectivity changes in cerebello-thalamo-cortical white matter are related to changes in functional connectivity. A sample of 23 individuals between 12 and 21 years old underwent neuroimaging scans at baseline and 12-months later. Functional networks of Crus I and Crus II showed significant connectivity decreases over 12-months, though there were no differences in Lobule V. Furthermore, these functional connectivity changes were correlated with increases in white matter structural integrity in the corresponding cerebello-thalamo-cortical white matter tract. We suggest that these functional network changes are due to both later pruning in the prefrontal cortex as well as further development of the white matter tracts linking these brain regions. PMID:26391125

  1. The semantic variant of primary progressive aphasia: clinical and neuroimaging evidence in single subjects.

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    Leonardo Iaccarino

    Full Text Available We present a clinical-neuroimaging study in a series of patients with a clinical diagnosis of semantic variant of primary progressive aphasia (svPPA, with the aim to provide clinical-functional correlations of the cognitive and behavioral manifestations at the single-subject level.We performed neuropsychological investigations, 18F-FDG-PET single-subject and group analysis, with an optimized SPM voxel-based approach, and correlation analyses. A measurement of white matter integrity by means of diffusion tensor imaging (DTI was also available for a subgroup of patients.Cognitive assessment confirmed the presence of typical semantic memory deficits in all patients, with a relative sparing of executive, attentional, visuo-constructional, and episodic memory domains. 18F-FDG-PET showed a consistent pattern of cerebral hypometabolism across all patients, which correlated with performance in semantic memory tasks. In addition, a majority of patients also presented with behavioral disturbances associated with metabolic dysfunction in limbic structures. In a subgroup of cases the DTI analysis showed FA abnormalities in the inferior longitudinal and uncinate fasciculi.Each svPPA individual had functional derangement involving an extended, connected system within the left temporal lobe, a crucial part of the verbal semantic network, as well as an involvement of limbic structures. The latter was associated with behavioral manifestations and extended beyond the area of atrophy shown by CT scan.Single-subject 18F-FDG-PET analysis can account for both cognitive and behavioral alterations in svPPA. This provides useful support to the clinical diagnosis.

  2. Noninvasive Electrical Neuroimaging of the Human Brain during Mobile Tasks including Walking and Running

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    2012-01-01

    experiment. All procedures were approved by the University of Michigan Internal Review Board and complied with the standards defined in the...subjects performed two experimental blocks. In the first block, subjects were asked to press a button on a wireless Wii controller (Nintendo, Kyoto...evidence of cortical involvement in human locomotion. Dual-task experiments have demonstrated that balance during walking can be negatively affected by

  3. Face and gaze perception in borderline personality disorder: An electrical neuroimaging study.

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    Berchio, Cristina; Piguet, Camille; Gentsch, Kornelia; Küng, Anne-Lise; Rihs, Tonia A; Hasler, Roland; Aubry, Jean-Michel; Dayer, Alexandre; Michel, Christoph M; Perroud, Nader

    2017-11-30

    Humans are sensitive to gaze direction from early life, and gaze has social and affective values. Borderline personality disorder (BPD) is a clinical condition characterized by emotional dysregulation and enhanced sensitivity to affective and social cues. In this study we wanted to investigate the temporal-spatial dynamics of spontaneous gaze processing in BPD. We used a 2-back-working-memory task, in which neutral faces with direct and averted gaze were presented. Gaze was used as an emotional modulator of event-related-potentials to faces. High density EEG data were acquired in 19 females with BPD and 19 healthy women, and analyzed with a spatio-temporal microstates analysis approach. Independently of gaze direction, BPD patients showed altered N170 and P200 topographies for neutral faces. Source localization revealed that the anterior cingulate and other prefrontal regions were abnormally activated during the N170 component related to face encoding, while middle temporal deactivations were observed during the P200 component. Post-task affective ratings showed that BPD patients had difficulty to disambiguate neutral gaze. This study provides first evidence for an early neural bias toward neutral faces in BPD independent of gaze direction and also suggests the importance of considering basic aspects of social cognition in identifying biological risk factors of BPD. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  4. Evolving Evidence for the Value of Neuroimaging Methods and Biological Markers in Subjects Categorized with Subjective Cognitive Decline.

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    Lista, Simone; Molinuevo, Jose L; Cavedo, Enrica; Rami, Lorena; Amouyel, Philippe; Teipel, Stefan J; Garaci, Francesco; Toschi, Nicola; Habert, Marie-Odile; Blennow, Kaj; Zetterberg, Henrik; O'Bryant, Sid E; Johnson, Leigh; Galluzzi, Samantha; Bokde, Arun L W; Broich, Karl; Herholz, Karl; Bakardjian, Hovagim; Dubois, Bruno; Jessen, Frank; Carrillo, Maria C; Aisen, Paul S; Hampel, Harald

    2015-09-24

    There is evolving evidence that individuals categorized with subjective cognitive decline (SCD) are potentially at higher risk for developing objective and progressive cognitive impairment compared to cognitively healthy individuals without apparent subjective complaints. Interestingly, SCD, during advancing preclinical Alzheimer's disease (AD), may denote very early, subtle cognitive decline that cannot be identified using established standardized tests of cognitive performance. The substantial heterogeneity of existing SCD-related research data has led the Subjective Cognitive Decline Initiative (SCD-I) to accomplish an international consensus on the definition of a conceptual research framework on SCD in preclinical AD. In the area of biological markers, the cerebrospinal fluid signature of AD has been reported to be more prevalent in subjects with SCD compared to healthy controls; moreover, there is a pronounced atrophy, as demonstrated by magnetic resonance imaging, and an increased hypometabolism, as revealed by positron emission tomography, in characteristic brain regions affected by AD. In addition, SCD individuals carrying an apolipoprotein ɛ4 allele are more likely to display AD-phenotypic alterations. The urgent requirement to detect and diagnose AD as early as possible has led to the critical examination of the diagnostic power of biological markers, neurophysiology, and neuroimaging methods for AD-related risk and clinical progression in individuals defined with SCD. Observational studies on the predictive value of SCD for developing AD may potentially be of practical value, and an evidence-based, validated, qualified, and fully operationalized concept may inform clinical diagnostic practice and guide earlier designs in future therapy trials.

  5. Evidence from neuroimaging for the role of the menstrual cycle in the interplay of emotion and cognition.

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    Julia eSacher

    2013-07-01

    Full Text Available Women show increased predisposition for certain psychiatric disorders, such as depression, that are associated with disturbances in the integration of emotion and cognition. While this suggests that sex hormones need to be considered as modulating factors in the regulation of emotion, we still lack a sound understanding of how the menstrual cycle impacts emotional states and cognitive function. Though signals for the influence of the menstrual cycle on the integration of emotion and cognition have appeared as secondary findings in numerous behavioral and neuroimaging studies, this has only very rarely been the primary research goal. This review summarizes evidence: (1 that the menstrual cycle modulates the integration of emotional and cognitive processing on a behavioral level, and (2 that this change in behavior can be associated with functional, molecular and structural changes in the brain during a specific menstrual cycle phase. The growing evidence for menstrual cycle-specific differences suggests a modulating role for sex hormones on the neural networks supporting the integration of emotional and cognitive information. It will further be discussed what methodological aspects need to be considered to capture the role of the menstrual cycle in the emotion-cognition interplay more systematically.

  6. Neural signatures of Trail Making Test performance: Evidence from lesion-mapping and neuroimaging studies.

    Science.gov (United States)

    Varjacic, Andreja; Mantini, Dante; Demeyere, Nele; Gillebert, Celine R

    2018-03-27

    The Trail Making Test (TMT) is an extensively used neuropsychological instrument for the assessment of set-switching ability across a wide range of neurological conditions. However, the exact nature of the cognitive processes and associated brain regions contributing to the performance on the TMT remains unclear. In this review, we first introduce the TMT by discussing its administration and scoring approaches. We then examine converging evidence and divergent findings concerning the brain regions related to TMT performance, as identified by lesion-symptom mapping studies conducted in brain-injured patients and functional magnetic resonance imaging studies conducted in healthy participants. After addressing factors that may account for the heterogeneity in the brain regions reported by these studies, we identify future research endeavours that may permit disentangling the different processes contributing to TMT performance and relating them to specific brain circuits. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  7. Investigating emotion in moral cognition: a review of evidence from functional neuroimaging and neuropsychology.

    Science.gov (United States)

    Young, Liane; Koenigs, Michael

    2007-01-01

    Human moral decision-making has long been a topic of philosophical debate, and, more recently, a topic for empirical investigation. Central to this investigation is the extent to which emotional processes underlie our decisions about moral right and wrong. Neuroscience offers a unique perspective on this question by addressing whether brain regions associated with emotional processing are involved in moral cognition. We conduct a narrative review of neuroscientific studies focused on the role of emotion in morality. Specifically, we describe evidence implicating the ventromedial prefrontal cortex (VMPC), a brain region known to be important for emotional processing. Functional imaging studies demonstrate VMPC activation during tasks probing moral cognition. Studies of clinical populations, including patients with VMPC damage, reveal an association between impairments in emotional processing and impairments in moral judgement and behaviour. Considered together, these studies indicate that not only are emotions engaged during moral cognition, but that emotions, particularly those mediated by VMPC, are in fact critical for human morality.

  8. Behavioral and neuroimaging evidence for overreliance on habit learning in alcohol-dependent patients.

    Science.gov (United States)

    Sjoerds, Z; de Wit, S; van den Brink, W; Robbins, T W; Beekman, A T F; Penninx, B W J H; Veltman, D J

    2013-12-17

    Substance dependence is characterized by compulsive drug-taking despite negative consequences. Animal research suggests an underlying imbalance between goal-directed and habitual action control with chronic drug use. However, this imbalance, and its associated neurophysiological mechanisms, has not yet been experimentally investigated in human drug abusers. The aim of the present study therefore was to assess the balance between goal-directed and habit-based learning and its neural correlates in abstinent alcohol-dependent (AD) patients. A total of 31 AD patients and 19 age, gender and education matched healthy controls (HC) underwent functional magnetic resonance imaging (fMRI) during completion of an instrumental learning task designed to study the balance between goal-directed and habit learning. Task performance and task-related blood oxygen level-dependent activations in the brain were compared between AD patients and healthy matched controls. Findings were additionally associated with duration and severity of alcohol dependence. The results of this study provide evidence for an overreliance on stimulus-response habit learning in AD compared with HC, which was accompanied by decreased engagement of brain areas implicated in goal-directed action (ventromedial prefrontal cortex and anterior putamen) and increased recruitment of brain areas implicated in habit learning (posterior putamen) in AD patients. In conclusion, this is the first human study to provide experimental evidence for a disturbed balance between goal-directed and habitual control by use of an instrumental learning task, and to directly implicate cortical dysfunction to overreliance on inflexible habits in AD patients.

  9. Multimodal neuroimaging evidence linking memory and attention systems during visual search cued by context.

    Science.gov (United States)

    Kasper, Ryan W; Grafton, Scott T; Eckstein, Miguel P; Giesbrecht, Barry

    2015-03-01

    Visual search can be facilitated by the learning of spatial configurations that predict the location of a target among distractors. Neuropsychological and functional magnetic resonance imaging (fMRI) evidence implicates the medial temporal lobe (MTL) memory system in this contextual cueing effect, and electroencephalography (EEG) studies have identified the involvement of visual cortical regions related to attention. This work investigated two questions: (1) how memory and attention systems are related in contextual cueing; and (2) how these systems are involved in both short- and long-term contextual learning. In one session, EEG and fMRI data were acquired simultaneously in a contextual cueing task. In a second session conducted 1 week later, EEG data were recorded in isolation. The fMRI results revealed MTL contextual modulations that were correlated with short- and long-term behavioral context enhancements and attention-related effects measured with EEG. An fMRI-seeded EEG source analysis revealed that the MTL contributed the most variance to the variability in the attention enhancements measured with EEG. These results support the notion that memory and attention systems interact to facilitate search when spatial context is implicitly learned. © 2015 New York Academy of Sciences.

  10. Attention and Emotion-Enhanced Memory: A Systematic Review and Meta-Analysis of Behavioural and Neuroimaging Evidence

    OpenAIRE

    Kohler, Mark; Cross, Zachariah; Santamaria, Amanda

    2018-01-01

    The interaction between attention and emotion is posited to influence long-term memory consolidation. We systematically reviewed experiments investigating the influence of attention on emotional memory to determine: (i) the reported effect of attention on memory for emotional stimuli, and (ii) whether there is homogeneity between behavioural and neuroimaging based effects. Over half of the 47 included experiments found a moderate-to-large effect of attention on emotional memory as measured be...

  11. Developmental neuroimaging

    Energy Technology Data Exchange (ETDEWEB)

    Dehaene-Lambertz, G. [Service Hospitalier Frederic Joliot (CEA/DSV/DRM), INSERM U562, 91 - Orsay (France)

    2006-07-01

    Cognitive capacities, such as language, mathematics, music, etc... are highly developed in humans as compared to animals. Numerous studies have found precursors of these capacities in infants: For example, infants are able to discriminate sentences in different languages (Mehler et al., 1988), distinguish sets of objects based on their numerosity (Feigenson et al., 2002) or recognize known faces (Bushnell, 1982). These abilities are not very different from those of other animals. Monkeys are also able to discriminate two human languages (Ramus et al., 2000), two quantities of items (Hauser et al., 2002), or respond to particular faces (Parr et al., 2000). In a few years, however, children surpass these animals. To explain the development of the cognitive capacities of our species, our approach consists in studying the initial stages of cerebral organization during the first months of life in order to characterize the critical parameters that allow infants to take advantage of their environment to achieve the adults' cognitive sophistication. Thanks to the recent progress of brain imaging, it is now possible to examine cerebral functioning of the very young child in entire security. In our team, we used two complementary methods: event-related potentials (ERPs) and functional magnetic resonance imaging (f MRI). ERPs, used since numerous years in infants, consist of the recording of the brain electrical activity consecutive to the presentation of a stimulus. By using a careful experimental design, it is possible to infer the succession of processing stages that the stimulus follows and to measure their latency (Dehaene-Lambertz and Dehaene, 1994; Gliga and Dehaene-Lambertz, 2006). High-density ERPs system allows also to record even small topographical differences between conditions and thus to infer that the underlying network s involved in the tested conditions are different. With this method, we have decomposed syllable perception in infants and underscore a

  12. Developmental neuroimaging

    International Nuclear Information System (INIS)

    Dehaene-Lambertz, G.

    2006-01-01

    Cognitive capacities, such as language, mathematics, music, etc... are highly developed in humans as compared to animals. Numerous studies have found precursors of these capacities in infants: For example, infants are able to discriminate sentences in different languages (Mehler et al., 1988), distinguish sets of objects based on their numerosity (Feigenson et al., 2002) or recognize known faces (Bushnell, 1982). These abilities are not very different from those of other animals. Monkeys are also able to discriminate two human languages (Ramus et al., 2000), two quantities of items (Hauser et al., 2002), or respond to particular faces (Parr et al., 2000). In a few years, however, children surpass these animals. To explain the development of the cognitive capacities of our species, our approach consists in studying the initial stages of cerebral organization during the first months of life in order to characterize the critical parameters that allow infants to take advantage of their environment to achieve the adults' cognitive sophistication. Thanks to the recent progress of brain imaging, it is now possible to examine cerebral functioning of the very young child in entire security. In our team, we used two complementary methods: event-related potentials (ERPs) and functional magnetic resonance imaging (f MRI). ERPs, used since numerous years in infants, consist of the recording of the brain electrical activity consecutive to the presentation of a stimulus. By using a careful experimental design, it is possible to infer the succession of processing stages that the stimulus follows and to measure their latency (Dehaene-Lambertz and Dehaene, 1994; Gliga and Dehaene-Lambertz, 2006). High-density ERPs system allows also to record even small topographical differences between conditions and thus to infer that the underlying network s involved in the tested conditions are different. With this method, we have decomposed syllable perception in infants and underscore a

  13. Cycles in deregulated electricity markets: Empirical evidence from two decades

    International Nuclear Information System (INIS)

    Arango, Santiago; Larsen, Erik

    2011-01-01

    In this article, we discuss the 'cycle hypothesis' in electricity generation, which states that the introduction of deregulation in an electricity system might lead to sustained fluctuations of over- and under-capacity. The occurrence of cycles is one of the major threats for electricity markets as it affects the security of supply, and creates uncertainty in both the profitability of electricity companies and in consumer prices. We discuss the background for these cycles using analogies with other capital-intensive industries, along with evidence from the analysis of behavioral simulation models as well as from experimental electricity markets. Using data from the oldest deregulated markets we find support for the hypothesis in the case of the English and Chilean markets, based on an autocorrelation analysis. Evidence from the Nordpool market is more ambiguous, although we might be observing the first half of a cycle in generation capacity. Comparing a simulation of the English market performed in 1992 with the actual performance we can observe that the qualitative behavior of the model is consistent with the actual evolution. Finally, we discuss possible mechanisms for damping cycles in electricity generation, such as mothballing, capacity payments, and reliability markets. - Research highlights: → We explore the emergence of cycles in the electricity generation capacity after deregulation. → We discuss the reason for cycles in generation capacity and compare different theories. → Analysis of England and Chile data show strong indications that cycles have emerged.

  14. Visual attention and the neuroimage bias.

    Directory of Open Access Journals (Sweden)

    D A Baker

    Full Text Available Several highly-cited experiments have presented evidence suggesting that neuroimages may unduly bias laypeople's judgments of scientific research. This finding has been especially worrisome to the legal community in which neuroimage techniques may be used to produce evidence of a person's mental state. However, a more recent body of work that has looked directly at the independent impact of neuroimages on layperson decision-making (both in legal and more general arenas, and has failed to find evidence of bias. To help resolve these conflicting findings, this research uses eye tracking technology to provide a measure of attention to different visual representations of neuroscientific data. Finding an effect of neuroimages on the distribution of attention would provide a potential mechanism for the influence of neuroimages on higher-level decisions. In the present experiment, a sample of laypeople viewed a vignette that briefly described a court case in which the defendant's actions might have been explained by a neurological defect. Accompanying these vignettes was either an MRI image of the defendant's brain, or a bar graph depicting levels of brain activity-two competing visualizations that have been the focus of much of the previous research on the neuroimage bias. We found that, while laypeople differentially attended to neuroimagery relative to the bar graph, this did not translate into differential judgments in a way that would support the idea of a neuroimage bias.

  15. Neuroimaging of neurotic disorders

    International Nuclear Information System (INIS)

    Okubo, Yoshiro; Yahata, Noriaki

    2006-01-01

    Neuroimaging has been involved in recent biological approaches with evidence for neurotic disorders in place of diagnostic criteria on Freud theory hitherto. This review describes the present states of brain imaging in those disorders. Emotion has such three bases for environmental stimuli as recognition/evaluation of causable factors, manifestation, and its control, each of which occurs in various different regions connected by neuro-net work in the brain. The disorders are regarded as abnormality of the circuit that can be imaged. Documented and discussed are the actual regions imaged by MRI and PET in panic disorder, social phobia, phobias to specified things, posttraumatic stress disorder and obsessive-compulsive disorder. The approach is thought important for elucidating not only the pathogenesis of the disorders but also the human emotional functions and mechanism of the mind, which may lead to a better treatment of the disorders in future. (T.I)

  16. Where do bright ideas occur in our brain? Meta-analytic evidence from neuroimaging studies of domain-specific creativity

    Science.gov (United States)

    Boccia, Maddalena; Piccardi, Laura; Palermo, Liana; Nori, Raffaella; Palmiero, Massimiliano

    2015-01-01

    Many studies have assessed the neural underpinnings of creativity, failing to find a clear anatomical localization. We aimed to provide evidence for a multi-componential neural system for creativity. We applied a general activation likelihood estimation (ALE) meta-analysis to 45 fMRI studies. Three individual ALE analyses were performed to assess creativity in different cognitive domains (Musical, Verbal, and Visuo-spatial). The general ALE revealed that creativity relies on clusters of activations in the bilateral occipital, parietal, frontal, and temporal lobes. The individual ALE revealed different maximal activation in different domains. Musical creativity yields activations in the bilateral medial frontal gyrus, in the left cingulate gyrus, middle frontal gyrus, and inferior parietal lobule and in the right postcentral and fusiform gyri. Verbal creativity yields activations mainly located in the left hemisphere, in the prefrontal cortex, middle and superior temporal gyri, inferior parietal lobule, postcentral and supramarginal gyri, middle occipital gyrus, and insula. The right inferior frontal gyrus and the lingual gyrus were also activated. Visuo-spatial creativity activates the right middle and inferior frontal gyri, the bilateral thalamus and the left precentral gyrus. This evidence suggests that creativity relies on multi-componential neural networks and that different creativity domains depend on different brain regions. PMID:26322002

  17. Behavioral and multimodal neuroimaging evidence for a deficit in brain timing networks in stuttering: A hypothesis and theory

    Directory of Open Access Journals (Sweden)

    Andrew C Etchell

    2014-06-01

    Full Text Available The fluent production of speech requires accurately timed movements. In this article, we propose that a deficit in brain timing networks is the core neurophysiological deficit in stuttering. We first discuss the experimental evidence supporting the involvement of the basal ganglia and supplementary motor area in stuttering and the involvement of the cerebellum as a mechanism for compensating for the neural deficits that underlie stuttering. Next, we outline the involvement of the right inferior frontal gyrus as another putative compensatory locus in stuttering and suggest a role for this structure in an expanded core timing-network. Subsequently, we review behavioral studies of timing in people who stutter and examine their behavioral performance as compared to people who do not stutter. Finally, we highlight challenges to existing research and provide avenues for future research with specific hypotheses.

  18. The Brain Basis of Positive and Negative Affect: Evidence from a Meta-Analysis of the Human Neuroimaging Literature.

    Science.gov (United States)

    Lindquist, Kristen A; Satpute, Ajay B; Wager, Tor D; Weber, Jochen; Barrett, Lisa Feldman

    2016-05-01

    The ability to experience pleasant or unpleasant feelings or to represent objects as "positive" or "negative" is known as representing hedonic "valence." Although scientists overwhelmingly agree that valence is a basic psychological phenomenon, debate continues about how to best conceptualize it scientifically. We used a meta-analysis of 397 functional magnetic resonance imaging (fMRI) and positron emission tomography studies (containing 914 experimental contrasts and 6827 participants) to test 3 competing hypotheses about the brain basis of valence: the bipolarity hypothesis that positive and negative affect are supported by a brain system that monotonically increases and/or decreases along the valence dimension, the bivalent hypothesis that positive and negative affect are supported by independent brain systems, and the affective workspace hypothesis that positive and negative affect are supported by a flexible set of valence-general regions. We found little evidence for the bipolar or bivalent hypotheses. Findings instead supported the hypothesis that, at the level of brain activity measurable by fMRI, valence is flexibly implemented across instances by a set of valence-general limbic and paralimbic brain regions. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  19. Neuromarketing: the hope and hype of neuroimaging in business.

    Science.gov (United States)

    Ariely, Dan; Berns, Gregory S

    2010-04-01

    The application of neuroimaging methods to product marketing - neuromarketing - has recently gained considerable popularity. We propose that there are two main reasons for this trend. First, the possibility that neuroimaging will become cheaper and faster than other marketing methods; and second, the hope that neuroimaging will provide marketers with information that is not obtainable through conventional marketing methods. Although neuroimaging is unlikely to be cheaper than other tools in the near future, there is growing evidence that it may provide hidden information about the consumer experience. The most promising application of neuroimaging methods to marketing may come before a product is even released - when it is just an idea being developed.

  20. Demand Response in U.S. Electricity Markets: Empirical Evidence

    OpenAIRE

    Cappers, Peter

    2009-01-01

    Empirical evidence concerning demand response (DR) resources is needed in order to establish baseline conditions, develop standardized methods to assess DR availability and performance, and to build confidence among policymakers, utilities, system operators, and stakeholders that DR resources do offer a viable, cost-effective alternative to supply-side investments. This paper summarizes the existing contribution of DR resources in U.S. electric power markets. In 2008, customers enrolled in ...

  1. The electricity consumption and economic growth nexus: Evidence from Greece

    International Nuclear Information System (INIS)

    Polemis, Michael L.; Dagoumas, Athanasios S.

    2013-01-01

    This paper attempts to cast light into the relationship between electricity consumption and economic growth in Greece in a multivariate framework. For this purpose we used cointegration techniques and the vector error correction model in order to capture short-run and long-run dynamics over the sample period 1970–2011. The empirical results reveal that in the long-run electricity demand appears to be price inelastic and income elastic, while in the short-run the relevant elasticities are below unity. We also argue that the causal relationship between electricity consumption and economic growth in Greece is bi-directional. Our results strengthen the notion that Greece is an energy dependent country and well directed energy conservation policies could even boost economic growth. Furthermore, the implementation of renewable energy sources should provide significant benefits ensuring sufficient security of supply in the Greek energy system. This evidence can provide a new basis for discussion on the appropriate design and implementation of environmental and energy policies for Greece and other medium sized economies with similar characteristics. -- Highlights: •We examine the causality between electricity consumption and economic growth. •We used cointegration techniques to capture short-run and long-run dynamics. •The relationship between electricity consumption and GDP is bi-directional. •Residential energy switching in Greece is still limited. •The implementation of renewable energy sources should ensure security of supply

  2. The blood-brain barrier is intact after levodopa-induced dyskinesias in parkinsonian primates--evidence from in vivo neuroimaging studies

    DEFF Research Database (Denmark)

    Astradsson, Arnar; Jenkins, Bruce G; Choi, Ji-Kyung

    2009-01-01

    It has been suggested, based on rodent studies, that levodopa (L-dopa) induced dyskinesia is associated with a disrupted blood-brain barrier (BBB). We have investigated BBB integrity with in vivo neuroimaging techniques in six 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) lesioned primates...

  3. Three-dimensional neuroimaging

    International Nuclear Information System (INIS)

    Toga, A.W.

    1990-01-01

    This book reports on new neuroimaging technologies that are revolutionizing the study of the brain be enabling investigators to visualize its structure and entire pattern of functional activity in three dimensions. The book provides a theoretical and practical explanation of the new science of creating three-dimensional computer images of the brain. The coverage includes a review of the technology and methodology of neuroimaging, the instrumentation and procedures, issues of quantification, analytic protocols, and descriptions of neuroimaging systems. Examples are given to illustrate the use of three-dimensional enuroimaging to quantitate spatial measurements, perform analysis of autoradiographic and histological studies, and study the relationship between brain structure and function

  4. Neuroimaging studies of practice-related change: fMRI and meta-analytic evidence of a domain-general control network for learning.

    Science.gov (United States)

    Chein, Jason M; Schneider, Walter

    2005-12-01

    Functional magnetic resonance imaging and a meta-analysis of prior neuroimaging studies were used to characterize cortical changes resulting from extensive practice and to evaluate a dual-processing account of the neural mechanisms underlying human learning. Three core predictions of the dual processing theory are evaluated: 1) that practice elicits generalized reductions in regional activity by reducing the load on the cognitive control mechanisms that scaffold early learning; 2) that these control mechanisms are domain-general; and 3) that no separate processing pathway emerges as skill develops. To evaluate these predictions, a meta-analysis of prior neuroimaging studies and a within-subjects fMRI experiment contrasting unpracticed to practiced performance in a paired-associate task were conducted. The principal effect of practice was found to be a reduction in the extent and magnitude of activity in a cortical network spanning bilateral dorsal prefrontal, left ventral prefrontal, medial frontal (anterior cingulate), left insular, bilateral parietal, and occipito-temporal (fusiform) areas. These activity reductions are shown to occur in common regions across prior neuroimaging studies and for both verbal and nonverbal paired-associate learning in the present fMRI experiment. The implicated network of brain regions is interpreted as a domain-general system engaged specifically to support novice, but not practiced, performance.

  5. Turner syndrome: neuroimaging findings: structural and functional.

    LENUS (Irish Health Repository)

    Mullaney, Ronan

    2009-01-01

    Neuroimaging studies of Turner syndrome can advance our understanding of the X chromosome in brain development, and the modulatory influence of endocrine factors. There is increasing evidence from neuroimaging studies that TX individuals have significant differences in the anatomy, function, and metabolism of a number of brain regions; including the parietal lobe; cerebellum, amygdala, hippocampus; and basal ganglia; and perhaps differences in "connectivity" between frontal and parieto-occipital regions. Finally, there is preliminary evidence that genomic imprinting, sex hormones and growth hormone have significant modulatory effects on brain maturation in TS.

  6. Food addiction and neuroimaging.

    Science.gov (United States)

    Zhang, Yi; von Deneen, Karen M; Tian, Jie; Gold, Mark S; Liu, Yijun

    2011-01-01

    Obesity has become a serious epidemic and one of the leading global health problems. However, much of the current debate has been fractious, and etiologies of obesity have been attributed to eating behavior (i.e. fast food consumption), personality, depression, addiction or genetics. One of the interesting new hypotheses for explaining the development of obesity involves a food addiction model, which suggests that food is not eaten as much for survival as pleasure and that hedonic overeating is relevant to both substance-related disorders and eating disorders. Accumulating evidence has shown that there are a number of shared neural and hormonal pathways as well as distinct differences in these pathways that may help researchers discover why certain individuals continue to overeat despite health and other consequences, and becomes more and more obese. Functional neuroimaging studies have further revealed that pleasant smelling, looking, and tasting food has reinforcing characteristics similar to drugs of abuse. Many of the brain changes reported for hedonic eating and obesity are also seen in various types of addictions. Most importantly, overeating and obesity may have an acquired drive similar to drug addiction with respect to motivation and incentive craving. In both cases, the desire and continued satisfaction occur after early and repeated exposure to stimuli. The acquired drive for eating food and relative weakness of the satiety signal would cause an imbalance between the drive and hunger/reward centers in the brain and their regulation. In the current paper, we first provide a summary of literature on food addition from eight different perspectives, and then we proposed a research paradigm that may allow screening of new pharmacological treatment on the basis of functional magnetic resonance imaging (fMRI).

  7. Turner Syndrome: Neuroimaging Findings--Structural and Functional

    Science.gov (United States)

    Mullaney, Ronan; Murphy, Declan

    2009-01-01

    Neuroimaging studies of Turner syndrome can advance our understanding of the X chromosome in brain development, and the modulatory influence of endocrine factors. There is increasing evidence from neuroimaging studies that TX individuals have significant differences in the anatomy, function, and metabolism of a number of brain regions; including…

  8. Traumatic Brain Injury: Nuclear Medicine Neuroimaging

    NARCIS (Netherlands)

    Sánchez-Catasús, Carlos A; Vállez Garcia, David; Le Riverend Morales, Eloísa; Galvizu Sánchez, Reinaldo; Dierckx, Rudi; Dierckx, Rudi AJO; Otte, Andreas; de Vries, Erik FJ; van Waarde, Aren; Leenders, Klaus L

    2014-01-01

    This chapter provides an up-to-date review of nuclear medicine neuroimaging in traumatic brain injury (TBI). 18F-FDG PET will remain a valuable tool in researching complex mechanisms associated with early metabolic dysfunction in TBI. Although evidence-based imaging studies are needed, 18F-FDG PET

  9. Neuroimaging in dementia

    Energy Technology Data Exchange (ETDEWEB)

    Barkhof, Frederik [VU Univ. Medical Center, Amsterdam (NL). Dept. of Radiology and Image Analysis Center (IAC); Fox, Nick C. [UCL Institute of Neurology, London (United Kingdom). Dementia Research Centre; VU Univ. Medical Center, Amsterdam (Netherlands); Bastos-Leite, Antonio J. [Porto Univ. (Portugal). Dept. of Medical Imaging; Scheltens, Philip [VU Univ. Medical Center, Amsterdam (Netherlands). Dept. of Neurology and Alzheimer Center

    2011-07-01

    Against a background of an ever-increasing number of patients, new management options, and novel imaging modalities, neuroimaging is playing an increasingly important role in the diagnosis of dementia. This up-to-date, superbly illustrated book aims to provide a practical guide to the effective use of neuroimaging in the patient with cognitive decline. It sets out the key clinical and imaging features of the wide range of causes of dementia and directs the reader from clinical presentation to neuroimaging and on to an accurate diagnosis whenever possible. After an introductory chapter on the clinical background, the available ''toolbox'' of structural and functional neuroimaging techniques is reviewed in detail, including CT, MRI and advanced MR techniques, SPECT and PET, and image analysis methods. The imaging findings in normal ageing are then discussed, followed by a series of chapters that carefully present and analyze the key imaging findings in patients with dementias. A structured path of analysis follows the main presenting feature: disorders associated with primary gray matter loss, with white matter changes, with brain swelling, etc. Throughout, a practical approach is adopted, geared specifically to the needs of clinicians (neurologists, radiologists, psychiatrists, geriatricians) working in the field of dementia, for whom this book should prove an invaluable resource. (orig.)

  10. Introduction to neuroimaging

    International Nuclear Information System (INIS)

    Orrison, W.W.

    1989-01-01

    The author focuses on neuroradiology with emphasis on the current imaging modalities. There are chapters on angiography, myelography, nuclear medicine, ultrasonography, computer tomography (CT), and magnetic resonance (MR) imaging. The other chapters are dedicated to the spine, skull, head and neck, and pediatric neuroimaging

  11. Motives to adopt renewable electricity technologies: Evidence from Sweden

    International Nuclear Information System (INIS)

    Bergek, Anna; Mignon, Ingrid

    2017-01-01

    The diffusion of renewable electricity technologies (RETs) has to speed up for countries to reach their, often ambitious, targets for renewable energy generation. This requires a large number of actors – including individuals, companies and other organizations – to adopt RETs. Policies will most likely be needed to induce adoption, but there is limited knowledge about what motivates RET adoption. The purpose of this paper is to complement and expand the available empirical evidence regarding motives to adopt RETs through a survey to over 600 RET adopters in Sweden. The main finding of the study is that there are many different motives to adopt RETs and that RET adopters are a heterogeneous group with regard to motives. Although environmental concerns, interest in the technology, access to an RE resource and prospects to generate economic revenues are important motives in general, adopters differ with regard to how large importance they attach to the same motive and each adopter can also have several different motives to adopt. There are also differences in motives between adopter categories (especially independent power producers vs. individuals and diversified companies) and between RETs (especially wind power vs. solar power). This implies that a variety of policy instruments might be needed to induce further adoption of a variety of RETs by a variety of adopter categories. - Highlights: • There are many different motives to adopt renewable electricity technologies (RETs). • Adopters attach different levels of importance to the same motive. • Adopters can have several different motives to adopt a particular RET. • Motives to adopt RETs differ between wind power, solar PV and small-scale hydro. • Motives to adopt RETs differ between IPPs, individuals and diversified companies.

  12. Electricity consumption and economic growth: evidence from Korea

    International Nuclear Information System (INIS)

    Yoo, Seung-Hoon

    2005-01-01

    This paper investigates the short- and long-run causality issues between electricity consumption and economic growth in Korea by using the co-integration and error-correction models. It employs annual data covering the period 1970-2002. The overall results show that there exists bi-directional causality between electricity consumption and economic growth. This means that an increase in electricity consumption directly affects economic growth and that economic growth also stimulates further electricity consumption

  13. Demand response in U.S. electricity markets: Empirical evidence

    International Nuclear Information System (INIS)

    Cappers, Peter; Goldman, Charles; Kathan, David

    2010-01-01

    Empirical evidence concerning demand response (DR) resources is needed in order to establish baseline conditions, develop standardized methods to assess DR availability and performance, and to build confidence among policymakers, utilities, system operators, and stakeholders that DR resources do offer a viable, cost-effective alternative to supply-side investments. This paper summarizes the existing contribution of DR resources in U.S. electric power markets. In 2008, customers enrolled in existing wholesale and retail DR programs were capable of providing ∝38,000 MW of potential peak load reductions in the United States. Participants in organized wholesale market DR programs, though, have historically overestimated their likely performance during declared curtailments events, but appear to be getting better as they and their agents gain experience. In places with less developed organized wholesale market DR programs, utilities are learning how to create more flexible DR resources by adapting legacy load management programs to fit into existing wholesale market constructs. Overall, the development of open and organized wholesale markets coupled with direct policy support by the Federal Energy Regulatory Commission has facilitated new entry by curtailment service providers, which has likely expanded the demand response industry and led to product and service innovation. (author)

  14. Big Data and Neuroimaging.

    Science.gov (United States)

    Webb-Vargas, Yenny; Chen, Shaojie; Fisher, Aaron; Mejia, Amanda; Xu, Yuting; Crainiceanu, Ciprian; Caffo, Brian; Lindquist, Martin A

    2017-12-01

    Big Data are of increasing importance in a variety of areas, especially in the biosciences. There is an emerging critical need for Big Data tools and methods, because of the potential impact of advancements in these areas. Importantly, statisticians and statistical thinking have a major role to play in creating meaningful progress in this arena. We would like to emphasize this point in this special issue, as it highlights both the dramatic need for statistical input for Big Data analysis and for a greater number of statisticians working on Big Data problems. We use the field of statistical neuroimaging to demonstrate these points. As such, this paper covers several applications and novel methodological developments of Big Data tools applied to neuroimaging data.

  15. Neuroimaging in eating disorders

    Directory of Open Access Journals (Sweden)

    Jáuregui-Lobera I

    2011-09-01

    Full Text Available Ignacio Jáuregui-LoberaBehavioral Sciences Institute and Pablo de Olavide University, Seville, SpainAbstract: Neuroimaging techniques have been useful tools for accurate investigation of brain structure and function in eating disorders. Computed tomography, magnetic resonance imaging, positron emission tomography, single photon emission computed tomography, magnetic resonance spectroscopy, and voxel-based morphometry have been the most relevant technologies in this regard. The purpose of this review is to update the existing data on neuroimaging in eating disorders. The main brain changes seem to be reversible to some extent after adequate weight restoration. Brain changes in bulimia nervosa seem to be less pronounced than in anorexia nervosa and are mainly due to chronic dietary restrictions. Different subtypes of eating disorders might be correlated with specific brain functional changes. Moreover, anorectic patients who binge/purge may have different functional brain changes compared with those who do not binge/purge. Functional changes in the brain might have prognostic value, and different changes with respect to the binding potential of 5-HT1A, 5-HT2A, and D2/D3 receptors may be persistent after recovering from an eating disorder.Keywords: neuroimaging, brain changes, brain receptors, anorexia nervosa, bulimia nervosa, eating disorders

  16. Industrial companies' demand for electricity. Evidence from a micropanel

    International Nuclear Information System (INIS)

    Bjoerner, T.B.; Togeby, M.; Jensen, H.H.

    2001-01-01

    The paper presents a micro-econometric analysis of industrial companies' demand for electricity. Previous studies on electricity consumption in the industrial sector have relied on aggregate data or cross-section observations. Here we present an econometric study on electricity demand based on a panel of 2949 Danish companies followed from 1983 to 1996. It is found that estimators of electricity demand that take account of the panel structure (fixed effect models) yield considerably lower price and production elasticities compared to estimators that do not (like cross-section models). It is also investigated how various company characteristics like size, type of industrial sub-sector and electricity intensity in production influence price and production elasticities. It appears that companies with a high electricity intensity also have a high own-price elasticity

  17. Neuroimaging of consciousness

    Energy Technology Data Exchange (ETDEWEB)

    Cavanna, Andrea Eugenio [Birmingham Univ. (United Kingdom). Dept. of Neuropsychiatry; UCL Institute of Neurology, London (United Kingdom). Sobell Dept. of Motor, Neuroscience and Movement Disorders; Nani, Andrea [Birmingham Univ. (United Kingdom). Research Group BSMHFT; Blumenfeld, Hal [Yale University School of Medicine, New Haven, CT (United States). Depts. of Neurology, Neurobiology and Neurosurgery; Laureys, Steven (ed.) [Liege Univ. (Belgium). Cyclotron Research Centre

    2013-07-01

    An important reference work on a multidisciplinary and rapidly expanding area. Particular focus on the relevance of neuroimaging for the diagnosis and treatment of common neuropsychiatric disorders affecting consciousness. Written by world-class experts in the field. Relevant for clinicians, researchers, and scholars across different specialties. Within the field of neuroscience, the past few decades have witnessed an exponential growth of research into the brain mechanisms underlying both normal and pathological states of consciousness in humans. The development of sophisticated imaging techniques (above all fMRI and PET) to visualize and map brain activity in vivo has opened new avenues in our understanding of the pathological processes involved in common neuropsychiatric disorders affecting consciousness, such as epilepsy, coma, vegetative states, dissociative disorders, and dementia. This book presents the state of the art in neuroimaging exploration of the brain correlates of the alterations in consciousness across these conditions, with a particular focus on the potential applications for diagnosis and management. Although the book has a practical approach and is primarily targeted at neurologists, neuroradiologists, and psychiatrists, a wide range of researchers and health care professionals will find it an essential reference that explains the significance of neuroimaging of consciousness for clinical practice. Within the field of neuroscience, the past few decades have witnessed an exponential growth of research into the brain mechanisms underlying both normal and pathological states of consciousness in humans. The development of sophisticated imaging techniques (above all fMRI and PET) to visualize and map brain activity in vivo has opened new avenues in our understanding of the pathological processes involved in common neuropsychiatric disorders affecting consciousness, such as epilepsy, coma, vegetative states, dissociative disorders, and dementia. This

  18. Neuroimaging of consciousness

    International Nuclear Information System (INIS)

    Cavanna, Andrea Eugenio; UCL Institute of Neurology, London; Nani, Andrea; Blumenfeld, Hal; Laureys, Steven

    2013-01-01

    An important reference work on a multidisciplinary and rapidly expanding area. Particular focus on the relevance of neuroimaging for the diagnosis and treatment of common neuropsychiatric disorders affecting consciousness. Written by world-class experts in the field. Relevant for clinicians, researchers, and scholars across different specialties. Within the field of neuroscience, the past few decades have witnessed an exponential growth of research into the brain mechanisms underlying both normal and pathological states of consciousness in humans. The development of sophisticated imaging techniques (above all fMRI and PET) to visualize and map brain activity in vivo has opened new avenues in our understanding of the pathological processes involved in common neuropsychiatric disorders affecting consciousness, such as epilepsy, coma, vegetative states, dissociative disorders, and dementia. This book presents the state of the art in neuroimaging exploration of the brain correlates of the alterations in consciousness across these conditions, with a particular focus on the potential applications for diagnosis and management. Although the book has a practical approach and is primarily targeted at neurologists, neuroradiologists, and psychiatrists, a wide range of researchers and health care professionals will find it an essential reference that explains the significance of neuroimaging of consciousness for clinical practice. Within the field of neuroscience, the past few decades have witnessed an exponential growth of research into the brain mechanisms underlying both normal and pathological states of consciousness in humans. The development of sophisticated imaging techniques (above all fMRI and PET) to visualize and map brain activity in vivo has opened new avenues in our understanding of the pathological processes involved in common neuropsychiatric disorders affecting consciousness, such as epilepsy, coma, vegetative states, dissociative disorders, and dementia. This

  19. Electricity demand and basic needs: Empirical evidence from China's households

    International Nuclear Information System (INIS)

    He, Xiaoping; Reiner, David

    2016-01-01

    An increasing block tariff (IBT) has been implemented nationwide in the residential sector in China since 2012. However, knowledge about IBT design is still limited, particularly how to determine the electricity volume for the first block of an IBT scheme. Assuming the first block should be set based on some measure of electricity poverty; we attempt to model household electricity demand such that the range of basic needs can be established. We show that in Chinese households there exists a threshold for electricity consumption with respect to income, which could be considered a measure of electricity poverty, and the threshold differs between rural and urban areas. For rural (urban) families, electricity consumption at the level of 7th (5th) income decile households can be considered the threshold for basic needs or a measure of electricity poverty since household electricity demand in rural (urban) areas does not respond to income changes until after 7th (5th) income decile. Accordingly, the first IBT block for some provinces (e.g., Beijing) appears to have been set at a level that is too high. Over time however, given continued rapid growth, the IBT will begin to better reflect actual basic needs. - Highlights: • Basic electricity needs of a household are investigated with survey data. • The Basic electricity needs differ between the rural and urban households. • The first block of the IBTs in China has proven too high and beyond the basic needs. • The initial policy targets of the IBTs in China will be difficult to achieve.

  20. Labor demand effects of rising electricity prices: Evidence for Germany

    International Nuclear Information System (INIS)

    Cox, Michael; Peichl, Andreas; Pestel, Nico; Siegloch, Sebastian

    2014-01-01

    Germany continues to play a pioneering role in replacing conventional power plants with renewable energy sources. While this might be beneficial with respect to environmental quality, it also implies increasing electricity prices. The extent to which this is associated with negative impacts on employment depends on the interrelationship between labor and electricity as input factors in the production process. In this paper, we estimate cross-price elasticities between electricity and heterogeneous labor for the German manufacturing sector. We use administrative linked employer–employee micro-data combined with information on sector-level electricity prices and usage over the period 2003–2007. We find positive, but small conditional cross-price elasticities of labor demand with respect to electricity prices, which means that electricity as an input factor can be replaced by labor to a limited extent when the production level is held constant. In the case of adjustable output, we find negative unconditional cross-price elasticities, implying that higher electricity prices lead to output reductions and to lower labor demand, with low- and high-skilled workers being affected more than medium-skilled. Resulting adverse distributional effects and potential overall job losses may pose challenges for policy-makers in securing public support for the German energy turnaround. - Highlights: • We estimate cross-price elasticities for electricity and labor in manufacturing. • We use linked employer–employee micro-data from Germany for 2003 to 2007. • We find a weak substitutability between electricity and labor for constant output. • We find complementarity between electricity and labor for adjustable output. • Low- and high-skilled workers are more affected than medium-skilled

  1. Electricity consumption and economic growth nexus in Bangladesh: Revisited evidences

    Energy Technology Data Exchange (ETDEWEB)

    Ahamad, Mazbahul Golam, E-mail: mg.ahamad@gmail.com [Research Division, Centre for Policy Dialogue (CPD), House: 40C, Road: 11, Dhanmondi, Dhaka 1209 (Bangladesh); Islam, A.K.M. Nazrul, E-mail: nazrul2002@yahoo.com [Research Division, Centre for Policy Dialogue (CPD), House: 40C, Road: 11, Dhanmondi, Dhaka 1209 (Bangladesh)

    2011-10-15

    In this paper, an attempt is being made to examine the causal relationship between per capita electricity consumption and per capita GDP of Bangladesh using the vector error correction specified Granger causality test to search their short-run, long-run and joint causal relationships for the period of 1971-2008. Empirical findings reveal that there is a short-run unidirectional causal flow running from per capita electricity consumption to per capita GDP without feedback. The presence of a positive short-run causality explains that an increase in electricity consumption directly affects economic activity in Bangladesh. Likewise, results from joint causality exhibit the same as in short-run. By contrast, long-run results show a bi-directional causality running from electricity consumption to economic growth with feedback. These findings can provide essential policy insights to design immediate and long-term growth prospect for Bangladesh keeping in mind its present planned growth strategy and dismal power and energy sector. - Highlights: > Short-run causality running from electricity consumption to economic growth. > Positive SR causality explains electricity generation directly affects economic growth. > For long run, causality runs from electricity consumption to economic growth with feedback. > Joint causality implies the same as in short-run.

  2. Electricity consumption and economic growth nexus in Bangladesh: Revisited evidences

    International Nuclear Information System (INIS)

    Ahamad, Mazbahul Golam; Islam, A.K.M. Nazrul

    2011-01-01

    In this paper, an attempt is being made to examine the causal relationship between per capita electricity consumption and per capita GDP of Bangladesh using the vector error correction specified Granger causality test to search their short-run, long-run and joint causal relationships for the period of 1971-2008. Empirical findings reveal that there is a short-run unidirectional causal flow running from per capita electricity consumption to per capita GDP without feedback. The presence of a positive short-run causality explains that an increase in electricity consumption directly affects economic activity in Bangladesh. Likewise, results from joint causality exhibit the same as in short-run. By contrast, long-run results show a bi-directional causality running from electricity consumption to economic growth with feedback. These findings can provide essential policy insights to design immediate and long-term growth prospect for Bangladesh keeping in mind its present planned growth strategy and dismal power and energy sector. - Highlights: → Short-run causality running from electricity consumption to economic growth. → Positive SR causality explains electricity generation directly affects economic growth. → For long run, causality runs from electricity consumption to economic growth with feedback. → Joint causality implies the same as in short-run.

  3. Cross-subsidy in electricity tariffs: evidence from India

    International Nuclear Information System (INIS)

    Chattopadhyay, P.

    2004-01-01

    The recent reforms in India have been equated to the reduction of cross-subsidization in electricity tariffs. Examining the usefulness of cross subsidies in electricity tariffs in India, I have argued that they are prone to considerable inefficiencies and should be discontinued. I have also formally examined the viability of above-cost tariffs in the industrial sector to allow subsidized domestic and agricultural consumption. Finally, I have used data from a distribution company in the state of Uttar Pradesh, India to estimate industrial demand for electricity and have found that the policy of cross-subsidy may have indeed gone overboard in India. (author)

  4. Functional Neuroimaging in Psychopathy.

    Science.gov (United States)

    Del Casale, Antonio; Kotzalidis, Georgios D; Rapinesi, Chiara; Di Pietro, Simone; Alessi, Maria Chiara; Di Cesare, Gianluigi; Criscuolo, Silvia; De Rossi, Pietro; Tatarelli, Roberto; Girardi, Paolo; Ferracuti, Stefano

    2015-01-01

    Psychopathy is associated with cognitive and affective deficits causing disruptive, harmful and selfish behaviour. These have considerable societal costs due to recurrent crime and property damage. A better understanding of the neurobiological bases of psychopathy could improve therapeutic interventions, reducing the related social costs. To analyse the major functional neural correlates of psychopathy, we reviewed functional neuroimaging studies conducted on persons with this condition. We searched the PubMed database for papers dealing with functional neuroimaging and psychopathy, with a specific focus on how neural functional changes may correlate with task performances and human behaviour. Psychopathy-related behavioural disorders consistently correlated with dysfunctions in brain areas of the orbitofrontal-limbic (emotional processing and somatic reaction to emotions; behavioural planning and responsibility taking), anterior cingulate-orbitofrontal (correct assignment of emotional valence to social stimuli; violent/aggressive behaviour and challenging attitude) and prefrontal-temporal-limbic (emotional stimuli processing/response) networks. Dysfunctional areas more consistently included the inferior frontal, orbitofrontal, dorsolateral prefrontal, ventromedial prefrontal, temporal (mainly the superior temporal sulcus) and cingulated cortices, the insula, amygdala, ventral striatum and other basal ganglia. Emotional processing and learning, and several social and affective decision-making functions are impaired in psychopathy, which correlates with specific changes in neural functions. © 2015 S. Karger AG, Basel.

  5. Neuroimaging of Alzheimer's disease

    International Nuclear Information System (INIS)

    Matsuda, Hiroshi

    2005-01-01

    Main purposes of neuroimaging in Alzheimer's disease have been moved from diagnosis of advanced Alzheimer's disease to diagnosis of very early Alzheimer's disease at a prodromal stage of mild cognitive impairment, prediction of conversion from mild cognitive impairment to Alzheimer's disease, and differential diagnosis from other diseases causing dementia. Structural MRI studies and functional studies using fluorodeoxyglucose (FDG)-PET and brain perfusion SPECT are widely used in diagnosis of Alzheimer's disease. Outstanding progress in diagnostic accuracy of these neuroimaging modalities has been obtained using statistical analysis on a voxel-by-voxel basis after spatial normalization of individual scans to a standardized brain-volume template instead of visual inspection or a conventional region of interest technique. In a very early stage of Alzheimer's disease, this statistical approach revealed gray matter loss in the entorhinal and hippocampal areas and hypometabolism or hypoperfusion in the posterior cingulate cortex. These two findings might be related in view of anatomical knowledge that the regions are linked through the circuit of Papez. This statistical approach also offers accurate evaluation of therapeutical effects on brain metabolism or perfusion. The latest development in functional imaging relates to the final pathological hallmark of Alzheimer's disease-amyloid plaques. Amyloid imaging might be an important surrogate marker for trials of disease-modifying agents. (author)

  6. Effects of the South American psychoactive beverage ayahuasca on regional brain electrical activity in humans: a functional neuroimaging study using low-resolution electromagnetic tomography.

    Science.gov (United States)

    Riba, Jordi; Anderer, Peter; Jané, Francesc; Saletu, Bernd; Barbanoj, Manel J

    2004-01-01

    Ayahuasca, a South American psychotropic plant tea obtained from Banisteriopsis caapi and Psychotria viridis, combines monoamine oxidase-inhibiting beta-carboline alkaloids with N,N-dimethyltryptamine (DMT), a psychedelic agent showing 5-HT(2A) agonist activity. In a clinical research setting, ayahuasca has demonstrated a combined stimulatory and psychedelic effect profile, as measured by subjective effect self-assessment instruments and dose-dependent changes in spontaneous brain electrical activity, which parallel the time course of subjective effects. In the present study, the spatial distribution of ayahuasca-induced changes in brain electrical activity was investigated by means of low-resolution electromagnetic tomography (LORETA). Electroencephalography recordings were obtained from 18 volunteers after the administration of a dose of encapsulated freeze-dried ayahuasca containing 0.85 mg DMT/kg body weight and placebo. The intracerebral power density distribution was computed with LORETA from spectrally analyzed data, and subjective effects were measured by means of the Hallucinogen Rating Scale (HRS). Statistically significant differences compared to placebo were observed for LORETA power 60 and 90 min after dosing, together with increases in all six scales of the HRS. Ayahuasca decreased power density in the alpha-2, delta, theta and beta-1 frequency bands. Power decreases in the delta, alpha-2 and beta-1 bands were found predominantly over the temporo-parieto-occipital junction, whereas theta power was reduced in the temporomedial cortex and in frontomedial regions. The present results suggest the involvement of unimodal and heteromodal association cortex and limbic structures in the psychological effects elicited by ayahuasca. Copyright 2004 S. Karger AG, Basel

  7. Neuroimaging in Antisocial Personality Disorder

    Directory of Open Access Journals (Sweden)

    Abdullah Yildirim

    2015-03-01

    Full Text Available Neuroimaging has been used in antisocial personality disorder since the invention of computed tomography and new modalities are introduced as technology advances. Magnetic resonance imaging, diffusion tensor imaging, functional magnetic resonance imaging and radionuclide imaging are such techniques that are currently used in neuroimaging. Although neuroimaging is an indispensible tool for psychiatric reseach, its clinical utility is questionable until new modalities become more accessible and regularly used in clinical practice. The aim of this paper is to provide clinicians with an introductory knowledge on neuroimaging in antisocial personality disorder including basic physics principles, current contributions to general understanding of pathophysiology in antisocial personality disorder and possible future applications of neuroimaging. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2015; 7(1: 98-108

  8. Neuroimaging of autism

    Energy Technology Data Exchange (ETDEWEB)

    Verhoeven, Judith S; Cock, Paul de; Lagae, Lieven [University Hospitals of the Catholic University of Leuven, Department of Pediatrics, Leuven (Belgium); Sunaert, Stefan [University Hospitals of the Catholic University of Leuven, Department of Radiology, Leuven (Belgium)

    2010-01-15

    Neuroimaging studies done by means of magnetic resonance imaging (MRI) have provided important insights into the neurobiological basis for autism. The aim of this article is to review the current state of knowledge regarding brain abnormalities in autism. Results of structural MRI studies dealing with total brain volume, the volume of the cerebellum, caudate nucleus, thalamus, amygdala and the area of the corpus callosum are summarised. In the past 5 years also new MRI applications as functional MRI and diffusion tensor imaging brought considerable new insights in the pathophysiological mechanisms of autism. Dysfunctional activation in key areas of verbal and non-verbal communication, social interaction, and executive functions are revised. Finally, we also discuss white matter alterations in important communication pathways in the brain of autistic patients. (orig.)

  9. Neuroimaging of autism

    International Nuclear Information System (INIS)

    Verhoeven, Judith S.; Cock, Paul de; Lagae, Lieven; Sunaert, Stefan

    2010-01-01

    Neuroimaging studies done by means of magnetic resonance imaging (MRI) have provided important insights into the neurobiological basis for autism. The aim of this article is to review the current state of knowledge regarding brain abnormalities in autism. Results of structural MRI studies dealing with total brain volume, the volume of the cerebellum, caudate nucleus, thalamus, amygdala and the area of the corpus callosum are summarised. In the past 5 years also new MRI applications as functional MRI and diffusion tensor imaging brought considerable new insights in the pathophysiological mechanisms of autism. Dysfunctional activation in key areas of verbal and non-verbal communication, social interaction, and executive functions are revised. Finally, we also discuss white matter alterations in important communication pathways in the brain of autistic patients. (orig.)

  10. Neuroimaging and electroconvulsive therapy

    DEFF Research Database (Denmark)

    Bolwig, Tom G

    2014-01-01

    BACKGROUND: Since the 1970s, a number of neuroimaging studies of electroconvulsive therapy (ECT) have been conducted to elucidate the working action of this highly efficacious treatment modality. The technologies used are single photon emission tomography, positron emission tomography, magnetic...... in localized cortical and subcortical areas of the brain and have revealed differences in neurophysiology and metabolism between the hyperactive ictal state and the restorative interictal/postictal periods. Recent magnetic resonance imaging studies seem to pave way for new insights into ECT's effects...... on increased connectivity in the brain during depression. CONCLUSION: The existing data reveal considerable variations among studies and therefore do not yet allow the formulation of a unified hypothesis for the mechanism of ECT. The rapid developments in imaging technology, however, hold promises for further...

  11. Job Satisfaction for Employees: Evidence from Karachi Electric Supply Corporation

    OpenAIRE

    Frukh, Nousjheen; Herani, Gobind M.; Mohammad, Mahmud; Mohammad, Tariq

    2009-01-01

    Research has been conducted in order to critically evaluate and examine the level of employees’ satisfaction as well as the factors of dissatisfaction among the employees of Karachi Electric supply Corporation (KESC). The purpose of this study is also to observe and analyze the factors which create job dissatisfaction especially among the hardworking managers, and to find out the reasons which make them realize that they don not have a clear career path along working with KESC. The primary da...

  12. Long-term memory in electricity prices: Czech market evidence

    Czech Academy of Sciences Publication Activity Database

    Krištoufek, Ladislav; Luňáčková, P.

    2013-01-01

    Roč. 63, č. 5 (2013), s. 407-424 ISSN 0015-1920 R&D Projects: GA ČR GA402/09/0965 Grant - others:GA ČR(CZ) GAP402/11/0948 Program:GA Institutional support: RVO:67985556 Keywords : electricity * long-term memory Subject RIV: AH - Economics Impact factor: 0.358, year: 2013 http://library.utia.cas.cz/separaty/2014/E/kristoufek-0427660.pdf

  13. The impact of hearing aids and age-related hearing loss on auditory plasticity across three months - An electrical neuroimaging study.

    Science.gov (United States)

    Giroud, Nathalie; Lemke, Ulrike; Reich, Philip; Matthes, Katarina L; Meyer, Martin

    2017-09-01

    The present study investigates behavioral and electrophysiological auditory and cognitive-related plasticity in three groups of healthy older adults (60-77 years). Group 1 was moderately hearing-impaired, experienced hearing aid users, and fitted with new hearing aids using non-linear frequency compression (NLFC on); Group 2, also moderately hearing-impaired, used the same type of hearing aids but NLFC was switched off during the entire period of study duration (NLFC off); Group 3 represented individuals with age-appropriate hearing (NHO) as controls, who were not different in IQ, gender, or age from Group 1 and 2. At five measurement time points (M1-M5) across three months, a series of active oddball tasks were administered while EEG was recorded. The stimuli comprised syllables consisting of naturally high-pitched fricatives (/sh/, /s/, and /f/), which are hard to distinguish for individuals with presbycusis. By applying a data-driven microstate approach to obtain global field power (GFP) as a measure of processing effort, the modulations of perceptual (P50, N1, P2) and cognitive-related (N2b, P3b) auditory evoked potentials were calculated and subsequently related to behavioral changes (accuracy and reaction time) across time. All groups improved their performance across time, but NHO showed consistently higher accuracy and faster reaction times than the hearing-impaired groups, especially under difficult conditions. Electrophysiological results complemented this finding by demonstrating longer latencies in the P50 and the N1 peak in hearing aid users. Furthermore, the GFP of cognitive-related evoked potentials decreased from M1 to M2 in the NHO group, while a comparable decrease in the hearing-impaired group was only evident at M5. After twelve weeks of hearing aid use of eight hours each day, we found a significantly lower GFP in the P3b of the group with NLFC on as compared to the group with NLFC off. These findings suggest higher processing effort, as

  14. Functional neuroimaging in Alzheimer's disease

    International Nuclear Information System (INIS)

    Matsuda, Hiroshi

    2006-01-01

    Recent progress in the title is reviewed often referring to authors' investigations. The method eZIS developed by them is for automated diagnosis of brain perfusion SPECT, where voxel-based analysis can be done using a Z-score map calculable from patient's data and standard database with 3D-stereotactic surface projection. Decreases of regional cerebral blood flow (rCBF) and of glucose metabolism detectable in specified brain regions by PET or SPECT in patients with mild cognitive impairment (MCI), are found useful for predicting the stage progression of MCI to Alzheimer disease (AD) in future. Partial volume correction method, essentially the division of images of a gray matter SPECT by MR, has elevated the precision of cerebral image analysis. Differential diagnosis of AD and dementia with Lewy bodies, the second most common form of dementia, is possible by the difference of occipital perfusion or glucose metabolism. Evidences by rCBF SPECT as well as by symptomatic ones have been accumulated recently for the therapeutic effect of donepezil, an inhibitor of acetylcholine esterase used for AD treatment. PET and SPECT imaging for the assessment of rCBF and metabolism has thus played very important roles in AD diagnosis, staging, differentiation, prediction and drug effect assessment. Recent advance in voxel-based statistical analysis of PET and SPECT images has raised the value of neuroimaging in dementia. (T.I.)

  15. Ownership and environmental regulation: Evidence from the European electricity industry

    International Nuclear Information System (INIS)

    Clò, Stefano; Ferraris, Matteo; Florio, Massimo

    2017-01-01

    The paper investigates how ownership affects the environmental performance in developed countries where environmental regulation is introduced in the form of market-based instrument. By looking at a cross-country panel dataset of 29 power markets around Europe over the period 1990–2012, we find empirical evidence that an increase of public ownership, as measured by the OECD ETCR index, is associated with a reduction of both greenhouse gas emissions and carbon intensity. We also find that the implementation of the European Emissions Trading Scheme (ETS) had a limited impact on emissions' reduction due to lax allocation of allowances. The positive effect of public ownership on environmental performance has been significant even after the introduction of the ETS, giving additional incentives to mitigate emissions when the ETS cap was not stringent enough. This evidence suggests that government control over power companies in Europe can has created idiosyncratic incentives to improve environmental quality, complementing environmental regulation in the achievement of environmental goals when the latter was absent or sub-optimal. - Highlights: • We analyse the power industry's environmental performance in 29 European countries. • Public ownership is associated with lower emissions than private ownership. • Mixed oligopoly is superior to private oligopoly in environmental terms. • The ETS had a limited impact on emissions' reduction due to over-allocation. • Public ownership mitigates the effects of sub-optimal environmental regulation.

  16. Portfolio selection using ELECTRE III: Evidence from Tehran Stock Exchange

    Directory of Open Access Journals (Sweden)

    Aazam Shabani Vezmelai

    2015-04-01

    Full Text Available Ranking the companies can be a useful guide for investors to select an optimum portfolio. Tehran stock exchange (TSE uses liquidity criterion to rank the companies; however, this study shows that preferences of investors, the criteria they use to evaluate companies’ performances, and the extent to which ranking of companies based on investors’ criteria are in line with the ranking announced by the stock exchange. Since the criteria used for ranking the companies are various and often conflicting and because each multiple criteria technique has its own specific characteristics, various rankings are offered. Therefore, it is required to utilize multiple criteria decision making models to avoid confusion of investors. For this purpose, some companies were selected from 50 top companies listed in 2011 in TSE, which maintained the reliability of their ranks and finally, 20 companies were selected and were ranked based on investors’ criteria using EECTRE III Technique. The obtained ranking was then compared with the ranking offered by stock exchange. Research results indicate that ELECTRE III technique was a useful and efficient method to select a portfolio. Moreover, value-based criteria as well as accounting criteria are suitable and useful bases for investors to select a portfolio.

  17. Occipital headaches and neuroimaging in children.

    Science.gov (United States)

    Bear, Joshua J; Gelfand, Amy A; Goadsby, Peter J; Bass, Nancy

    2017-08-01

    To investigate the common thinking, as reinforced by the International Classification of Headache Disorders, 3rd edition (beta), that occipital headaches in children are rare and suggestive of serious intracranial pathology. We performed a retrospective chart review cohort study of all patients ≤18 years of age referred to a university child neurology clinic for headache in 2009. Patients were stratified by headache location: solely occipital, occipital plus other area(s) of head pain, or no occipital involvement. Children with abnormal neurologic examinations were excluded. We assessed location as a predictor of whether neuroimaging was ordered and whether intracranial pathology was found. Analyses were performed with cohort study tools in Stata/SE 13.0 (StataCorp, College Station, TX). A total of 308 patients were included. Median age was 12 years (32 months-18 years), and 57% were female. Headaches were solely occipital in 7% and occipital-plus in 14%. Patients with occipital head pain were more likely to undergo neuroimaging than those without occipital involvement (solely occipital: 95%, relative risk [RR] 10.5, 95% confidence interval [CI] 1.4-77.3; occipital-plus: 88%, RR 3.7, 95% CI 1.5-9.2; no occipital pain: 63%, referent). Occipital pain alone or with other locations was not significantly associated with radiographic evidence of clinically significant intracranial pathology. Children with occipital headache are more likely to undergo neuroimaging. In the absence of concerning features on the history and in the setting of a normal neurologic examination, neuroimaging can be deferred in most pediatric patients when occipital pain is present. © 2017 American Academy of Neurology.

  18. Evidence of prompt penetration electric fields during HILDCAA events

    Science.gov (United States)

    Pereira Silva, Regia; Sobral, Jose Humberto Andrade; Koga, Daiki; Rodrigues Souza, Jonas

    2017-10-01

    High-intensity, long-duration continuous auroral electrojet (AE) activity (HILDCAA) events may occur during a long-lasting recovery phase of a geomagnetic storm. They are a special kind of geomagnetic activity, different from magnetic storms or substorms. Ionized particles are pumped into the auroral region by the action of Alfvén waves, increasing the auroral current system. The Dst index, however, does not present a significant downward swing as it occurs during geomagnetic storms. During the HILDCAA occurrence, the AE index presents an intense and continuous activity. In this paper, the response of Brazilian equatorial ionosphere is studied during three HILDCAA events that occurred in the year of 2006 (the descending phase of solar cycle 23) using the digisonde data located at São Luís, Brazil (2.33° S, 44.2° W; dip latitude 1.75° S). Geomagnetic indices and interplanetary parameters were used to calculate a cross-correlation coefficient between the Ey component of the interplanetary electric field and the F2 electron density peak height variations during two situations: the first of them for two sets daytime and nighttime ranges, and the second one for the time around the pre-reversal enhancement (PRE) peak. The results showed that the pumping action of particle precipitation into the auroral zone has moderately modified the equatorial F2 peak height. However, F2 peak height seems to be more sensitive to HILDCAA effects during PRE time, showing the highest variations and sinusoidal oscillations in the cross-correlation indices.

  19. Evidence of prompt penetration electric fields during HILDCAA events

    Directory of Open Access Journals (Sweden)

    R. P. Silva

    2017-10-01

    Full Text Available High-intensity, long-duration continuous auroral electrojet (AE activity (HILDCAA events may occur during a long-lasting recovery phase of a geomagnetic storm. They are a special kind of geomagnetic activity, different from magnetic storms or substorms. Ionized particles are pumped into the auroral region by the action of Alfvén waves, increasing the auroral current system. The Dst index, however, does not present a significant downward swing as it occurs during geomagnetic storms. During the HILDCAA occurrence, the AE index presents an intense and continuous activity. In this paper, the response of Brazilian equatorial ionosphere is studied during three HILDCAA events that occurred in the year of 2006 (the descending phase of solar cycle 23 using the digisonde data located at São Luís, Brazil (2.33° S, 44.2° W; dip latitude 1.75° S. Geomagnetic indices and interplanetary parameters were used to calculate a cross-correlation coefficient between the Ey component of the interplanetary electric field and the F2 electron density peak height variations during two situations: the first of them for two sets daytime and nighttime ranges, and the second one for the time around the pre-reversal enhancement (PRE peak. The results showed that the pumping action of particle precipitation into the auroral zone has moderately modified the equatorial F2 peak height. However, F2 peak height seems to be more sensitive to HILDCAA effects during PRE time, showing the highest variations and sinusoidal oscillations in the cross-correlation indices.

  20. Do acquisitions by electric utility companies create value? Evidence from deregulated markets

    International Nuclear Information System (INIS)

    Kishimoto, Jo; Goto, Mika; Inoue, Kotaro

    2017-01-01

    In the early 1990s, the United Kingdom (the UK) initiated widespread reforms in the electricity industry through a series of market liberalization policies. Several other countries have subsequently followed the lead and restructured their electricity industry. A major outcome of the deregulation effort is the spate of takeovers, both domestic and global, by electric utility companies. With the entry of new players and increasing competition, the business environment of the electricity industry has changed dramatically. This study analyzes the economic impact of mergers and acquisitions (M&As) in the electric utility industry after deregulation. We have examined acquisitions that took place between 1998 and 2013 in the United States, Canada, the UK, Germany, and France. Although previous studies showed no evidence of a positive effect on acquiring firms through M&As, we find that acquisitions by electric utility companies increased the acquiring firms’ share value and improved their operating performance, primarily through efficiency gains after the deregulation. These results are consistent with the empirical evidence and implications presented by Andrade et al. (2001) that M&A created value for the shareholders of the acquiring and target combined firms. - Highlights: • This study examined mergers and acquisitions (M&A) in electric utility industry. • The sample covered M&A between 1998 and 2013 in North America and Europe. • We found M&A significantly increased acquiring firms’ share value and operating performance. • Deregulation policy realized gains for shareholders without incurring costs for consumers.

  1. Electric fields in the magnetosphere - the evidence from ISEE, S3-3, GEOS and Viking

    International Nuclear Information System (INIS)

    Faelthammar, C.G.

    1988-08-01

    Electric field measurements on the satellites S3-3, GEOS-1, GEOS-2, ISEE-1 and Viking have extended the empirical knowledge of electric fields in space so as to include the outer regions of the magnetosphere. While the measurements confirm some of the theoretically expected properties of the electric fields, they also reveal unexpected features and a high degree of complexity and variability. The existence of a magnetospheric dawn-to-dusk electric field, as expected on the basis of extrapolation from low altitude measurements, is confirmed in an average sense. However, the actual field exhibits large spatial and temporal variations, including strong fields of inductive origin. At the magnetopause the average (dawn to dusk directed) tangential electric field component is typically obscured by irregular fluctuations of large amplitude. The magnetic-field aligned component of the electric field, which is of particular importance for ionosphere-magnetosphere coupling and for auroral acceleration is even now very difficult to measure directly. However, the data from electric field measurements provide further support for the conclusion, based on a variety of evidence, that a non-vanishing magnetic-field aligned electric field exists in the auroral acceleration region. (93 refs.) (author)

  2. Neuroimaging findings in movement disorders

    International Nuclear Information System (INIS)

    Topalov, N.

    2015-01-01

    Full text: Neuroimaging methods are of great importance for the differential diagnostic delimitation of movement disorders associated with structural damage (neoplasms, ischemic lesions, neuroinfections) from those associated with specific pathophysiological mechanisms (dysmetabolic disorders, neurotransmitter disorders). Learning objective: Presentation of typical imaging findings contributing to nosological differentiation in groups of movement disorders with similar clinical signs. In this presentation are discussed neuroimaging findings in Parkinson‘s disease, atypical parkinsonian syndromes (multiple system atrophy, progressive supranuclear palsy, corticobasal degeneration), parkinsonism in genetically mediated diseases (Wilson’s disease, pantothenate kinase-associated neurodegeneration – PKAN), vascular parkinsonism, hyperkinetic movement disorders (palatal tremor, Huntington‘s chorea, symptomatic chorea in ischemic stroke and diabetes, rubral tremor, ballismus, hemifacial spasm). Contemporary neuroimaging methods enable support for diagnostic and differential diagnostic precision of a number of hypo- and hyperkinetic movement disorders, which is essential for neurological clinical practice

  3. Neuroimaging, nuclear medicine

    International Nuclear Information System (INIS)

    Kato, Takashi; Ito, Kengo; Arahata, Yutaka

    2007-01-01

    This chapter describes radionuclide imaging as it related to neurodegenerative dementias like Alzheimer's disease (AD), idiopathic Parkinson's disease (PD), and normal aging, among the various diseases of the elderly. The role of neuroimaging with nuclear medicine is to detect changes in neural activities that are caused by these diseases. Such changes may be indirect phenomena, but the imaging of neural functions provides physicians with useful, objective information regarding pathophysiology in the brain. Brain activities change with age, with the elderly showing decreased brain function in memory, execution, and attention. Age-dependent reduction in the global mean of cerebral blood flow (CBF) has been reported in many studies that have used X-133 and O-15 labeled gas, the spatial resolution of which is low. Partial volume correction (PVC) is available through the segmentation of grey matter from high-resolution T1-weighted magnetic resonance imaging. Meltzer reported that age-related change disappeared after PVC. The relative distribution of CBF and glucose metabolism has been examined on a voxel-by-voxel basis in many studies. The areas negatively correlated with age are the anterior part of the brain, especially the dorsolateral and medial frontal areas, anterior cingulate cortices, frontolateral and perisylvian cortices, and basal ganglia. The areas positively correlated with age are the occipital lobe, temporal lobe, sensorimotor cortex, and primary visual cortex. It is not easy to define ''normal aging''. Aged people tend to have the potential for diseases like cerebral ischemia caused by arteriosclerosis. Ischemia results in volume loss of the gray matter and CBF. The ApoE e4 gene is a risk factor for AD, and carriers of the ApoE e4 allel show CBF-like AD even at a relatively young age. Hypo-glucose metabolism in the posterior cingulate cortex is seen in 5% of normal people over 50 years of age. This Alzheimer-like CBF/metabolic pattern needs further

  4. Identifying electricity-saving potential in rural China: Empirical evidence from a household survey

    International Nuclear Information System (INIS)

    Yu, Yihua; Guo, Jin

    2016-01-01

    In recent years, there has been a fast-growing body of literature examining energy-saving potential in relation to electricity. However, empirical studies focusing on non-Western nations are limited. To fill this gap, this study intends to examine the electricity-saving potential of rural households in China using a unique data set from the China Residential Electricity Consumption Survey (CRECS) in collaboration with the China General Social Survey (CGSS), conducted nationwide at the household level in rural China. We use a stochastic frontier model, which allows us to decompose residential electricity consumption into the minimum necessary amount of consumption based on physical characteristics (e.g. house size, house age, number of televisions or refrigerators) and estimate the consumption slack (i.e. the amount of electricity consumption that could be saved), which depends on various factors. We find that rural households in China are generally efficient in electricity saving and the saving potential is affected by (fast) information feedback and social-demographic characteristics, instead of by the (averaged) electricity price, or energy efficiency labelling signals. In addition, we find no evidence of regional heterogeneity on electricity saving potential for rural households. Policy implications are derived. - Highlights: •Electricity saving potential of rural households in China is examined. •Unique survey data from the CRECS in collaboration with the CGSS are used. •A stochastic frontier model is applied. •Information feedback and social-demographic characteristics matter. •Electricity price or energy efficiency tier rating does not matter.

  5. Finding related functional neuroimaging volumes

    DEFF Research Database (Denmark)

    Nielsen, Finn Årup; Hansen, Lars Kai

    2004-01-01

    We describe a content-based image retrieval technique for finding related functional neuroimaging experiments by voxelization of sets of stereotactic coordinates in Talairach space, comparing the volumes and reporting related volumes in a sorted list. Voxelization is accomplished by convolving ea...

  6. Neuroimaging of child abuse: A critical review

    Directory of Open Access Journals (Sweden)

    Heledd eHart

    2012-03-01

    Full Text Available Childhood maltreatment is a severe stressor that can lead to the development of behaviour problems and affect brain structure and function. This review summarizes the current evidence for the effects of early childhood maltreatment on behavior, cognition and the brain in adults and children. Neuropsychological studies suggest an association between child abuse and deficits in IQ, memory, executive function and emotion discrimination. Structural neuroimaging studies provide evidence for deficits in brain volume, grey and white matter of several regions, most prominently the dorsolateral and ventromedial prefrontal cortex but also hippocampus, amygdala, and corpus callosum. Diffusion tensor imaging studies show evidence for deficits in structural interregional connectivity between these areas, suggesting neural network abnormalities. Functional imaging studies support this evidence by reporting atypical activation in the same brain regions during executive function and emotion processing. There are, however, several limitations of the abuse research literature which are discussed, most prominently the lack of control for co-morbid psychiatric disorders, which make it difficult to disentangle which of the above effects are due to maltreatment, the associated psychiatric conditions or a combination or interaction between both. Overall, the better controlled studies that show a direct correlation between childhood abuse and brain measures suggest that the most prominent deficits associated with early childhood abuse are in the function and structure of lateral and ventromedial fronto-limbic brain areas and networks that mediate behavioural and affect control. Future, large scale multimodal neuroimaging studies in medication-naïve subjects, however, are needed that control for psychiatric co-morbidities in order to elucidate the structural and functional brain sequelae that are associated with early environmental adversity, independently of secondary

  7. Neuroimaging for psychotherapy research: current trends.

    Science.gov (United States)

    Weingarten, Carol P; Strauman, Timothy J

    2015-01-01

    This article reviews neuroimaging studies that inform psychotherapy research. An introduction to neuroimaging methods is provided as background for the increasingly sophisticated breadth of methods and findings appearing in psychotherapy research. We compiled and assessed a comprehensive list of neuroimaging studies of psychotherapy outcome, along with selected examples of other types of studies that also are relevant to psychotherapy research. We emphasized magnetic resonance imaging (MRI) since it is the dominant neuroimaging modality in psychological research. We summarize findings from neuroimaging studies of psychotherapy outcome, including treatment for depression, obsessive compulsive disorder (OCD), and schizophrenia. The increasing use of neuroimaging methods in the study of psychotherapy continues to refine our understanding of both outcome and process. We suggest possible directions for future neuroimaging studies in psychotherapy research.

  8. Consensus paper: combining transcranial stimulation with neuroimaging

    DEFF Research Database (Denmark)

    Siebner, Hartwig R; Bergmann, Til O; Bestmann, Sven

    2009-01-01

    neuroimaging (online approach), TMS can be used to test how focal cortex stimulation acutely modifies the activity and connectivity in the stimulated neuronal circuits. TMS and neuroimaging can also be separated in time (offline approach). A conditioning session of repetitive TMS (rTMS) may be used to induce...... information obtained by neuroimaging can be used to define the optimal site and time point of stimulation in a subsequent experiment in which TMS is used to probe the functional contribution of the stimulated area to a specific task. In this review, we first address some general methodologic issues that need......In the last decade, combined transcranial magnetic stimulation (TMS)-neuroimaging studies have greatly stimulated research in the field of TMS and neuroimaging. Here, we review how TMS can be combined with various neuroimaging techniques to investigate human brain function. When applied during...

  9. Neuroimaging and advanced social living

    DEFF Research Database (Denmark)

    Larsen, Torben

    2012-01-01

    Background: Snow stated in 1959 a modern conflict between classical hermeneutic humanism and natural science which recently has been renewed by Kensei Hiwaki [2011]. However, the last decade has brought a breakthrough in the study of the neural base of mental processes by neuroimaging which may...... patients. Further, this healing principle explains classical relaxation procedures as yoga and meditation as coping techniques. 2. Mental balance between L(x) and NC is not a continued but a discrete variable of general risk attitude differentiating 4 sub-groups corresponding to the classical tempers which...

  10. Neuroimaging of aggressive and violent behaviour in children and adolescents

    Directory of Open Access Journals (Sweden)

    Philipp Sterzer

    2009-10-01

    Full Text Available In recent years, a number of functional and structural neuroimaging studies have investigated the neural bases of aggressive and violent behaviour in children and adolescents. Most functional neuroimaging studies have persued the hypothesis that pathological aggression is a consequence of deficits in the neural circuits involved in emotion processing. There is converging evidence for deficient neural responses to emotional stimuli in youths with a propensity towards aggressive behaviour. In addition, recent neuroimaging work has suggested that aggressive behaviour is also associated with abnormalities in neural processes that subserve both the inhibitory control of behaviour and the flexible adaptation of behaviour in accord with reinforcement information. Structural neuroimaging studies in children and adolescents with conduct problems are still scarce, but point to deficits in brain structures in volved in the processing of social information and in the regulation of social and goal directed behaviour. The indisputable progress that this research field has made in recent years notwithstanding, the overall picture is still rather patchy and there are inconsistencies between studies that await clarification. Despite this, we attempt to provide an integrated view on the neural abnormalities that may contribute to various forms of juvenile aggression and violence, and discuss research strategies that may help to provide a more profound understanding of these important issues in the future.

  11. Contributions of neuroimaging in singing voice studies: a systematic review

    Directory of Open Access Journals (Sweden)

    Geová Oliveira de Amorim

    Full Text Available ABSTRACT It is assumed that singing is a highly complex activity, which requires the activation and interconnection of sensorimotor areas. The aim of the current research was to present the evidence from neuroimaging studies in the performance of the motor and sensory system in the process of singing. Research articles on the characteristics of human singing analyzed by neuroimaging, which were published between 1990 and 2016, and indexed and listed in databases such as PubMed, BIREME, Lilacs, Web of Science, Scopus, and EBSCO were chosen for this systematic review. A total of 9 articles, employing magnetoencephalography, functional magnetic resonance imaging, positron emission tomography, and electrocorticography were chosen. These neuroimaging approaches enabled the identification of a neural network interconnecting the spoken and singing voice, to identify, modulate, and correct pitch. This network changed with the singer's training, variations in melodic structure and harmonized singing, amusia, and the relationship among the brain areas that are responsible for speech, singing, and the persistence of musicality. Since knowledge of the neural networks that control singing is still scarce, the use of neuroimaging methods to elucidate these pathways should be a focus of future research.

  12. Neuroimaging Endophenotypes in Autism Spectrum Disorder

    Science.gov (United States)

    Mahajan, Rajneesh; Mostofsky, Stewart H.

    2015-01-01

    Autism spectrum disorder (ASD) is a neurodevelopmental disorder that has a strong genetic basis, and is heterogeneous in its etiopathogenesis and clinical presentation. Neuroimaging studies, in concert with neuropathological and clinical research, have been instrumental in delineating trajectories of development in children with ASD. Structural neuroimaging has revealed ASD to be a disorder with general and regional brain enlargement, especially in the frontotemporal cortices, while functional neuroimaging studies have highlighted diminished connectivity, especially between frontal-posterior regions. The diverse and specific neuroimaging findings may represent potential neuroendophenotypes, and may offer opportunities to further understand the etiopathogenesis of ASD, predict treatment response and lead to the development of new therapies. PMID:26234701

  13. Market power in the Nordic electricity wholesale market: A survey of the empirical evidence

    International Nuclear Information System (INIS)

    Fridolfsson, Sven-Olof; Tangeras, Thomas P.

    2009-01-01

    We review the recent empirical research assessing market power on the Nordic wholesale market for electricity, Nord Pool. The studies find no evidence of systematic exploitation of system level market power on Nord Pool. Local market power arising from transmission constraints seems to be more problematic in some price areas across the Nordic countries. Market power can manifest itself in a number of ways that have so far escaped empirical scrutiny. We discuss investment incentives, vertical integration and buyer power, as well as withholding of base-load (nuclear) capacity.

  14. Predicting Age Using Neuroimaging: Innovative Brain Ageing Biomarkers.

    Science.gov (United States)

    Cole, James H; Franke, Katja

    2017-12-01

    The brain changes as we age and these changes are associated with functional deterioration and neurodegenerative disease. It is vital that we better understand individual differences in the brain ageing process; hence, techniques for making individualised predictions of brain ageing have been developed. We present evidence supporting the use of neuroimaging-based 'brain age' as a biomarker of an individual's brain health. Increasingly, research is showing how brain disease or poor physical health negatively impacts brain age. Importantly, recent evidence shows that having an 'older'-appearing brain relates to advanced physiological and cognitive ageing and the risk of mortality. We discuss controversies surrounding brain age and highlight emerging trends such as the use of multimodality neuroimaging and the employment of 'deep learning' methods. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Functional Neuro-Imaging and Post-Traumatic Olfactory Impairment

    Science.gov (United States)

    Roberts, Richard J.; Sheehan, William; Thurber, Steven; Roberts, Mary Ann

    2010-01-01

    Objective: To evaluate via a research literature survey the anterior neurological significance of decreased olfactory functioning following traumatic brain injuries. Materials and Methods: A computer literature review was performed to locate all functional neuro-imaging studies on patients with post-traumatic anosmia and other olfactory deficits. Results: A convergence of findings from nine functional neuro-imaging studies indicating evidence for reduced metabolic activity at rest or relative hypo-perfusion during olfactory activations. Hypo-activation of the prefrontal regions was apparent in all nine post-traumatic samples, with three samples yielding evidence of reduced activity in the temporal regions as well. Conclusions: The practical ramifications include the reasonable hypothesis that a total anosmic head trauma patient likely has frontal lobe involvement. PMID:21716782

  16. What's new in neuroimaging methods?

    Science.gov (United States)

    Bandettini, Peter A.

    2009-01-01

    The rapid advancement of neuroimaging methodology and availability has transformed neuroscience research. The answers to many questions that we ask about how the brain is organized depend on the quality of data that we are able to obtain about the locations, dynamics, fluctuations, magnitudes, and types of brain activity and structural changes. In this review, an attempt is made to take a snapshot of the cutting edge of a small component of the very rapidly evolving field of neuroimaging. For each area covered, a brief context is provided along with a summary of a few of the current developments and issues. Then, several outstanding papers, published in the past year or so, are described, providing an example of the directions in which each area is progressing. The areas covered include functional MRI (fMRI), voxel based morphometry (VBM), diffusion tensor imaging (DTI), electroencephalography (EEG), magnetoencephalography (MEG), optical imaging, and positron emission tomography (PET). More detail is included on fMRI, as subsections include: functional MRI interpretation, new functional MRI contrasts, MRI technology, MRI paradigms and processing, and endogenous oscillations in functional MRI. PMID:19338512

  17. Neuroimaging in aging: brain maintenance [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Lars Nyberg

    2017-07-01

    Full Text Available Neuroimaging studies of the aging brain provide support that the strongest predictor of preserved memory and cognition in older age is brain maintenance, or relative lack of brain pathology. Evidence for brain maintenance comes from different levels of examination, but up to now relatively few studies have used a longitudinal design. Examining factors that promote brain maintenance in aging is a critical task for the future and may be combined with the use of new techniques for multimodal imaging.

  18. Guidelines for the ethical use of neuroimages in medical testimony: report of a multidisciplinary consensus conference.

    Science.gov (United States)

    Meltzer, C C; Sze, G; Rommelfanger, K S; Kinlaw, K; Banja, J D; Wolpe, P R

    2014-04-01

    With rapid advances in neuroimaging technology, there is growing concern over potential misuse of neuroradiologic imaging data in legal matters. On December 7 and 8, 2012, a multidisciplinary consensus conference, Use and Abuse of Neuroimaging in the Courtroom, was held at Emory University in Atlanta, Georgia. Through this interactive forum, a highly select group of experts-including neuroradiologists, neurologists, forensic psychiatrists, neuropsychologists, neuroscientists, legal scholars, imaging statisticians, judges, practicing attorneys, and neuroethicists-discussed the complex issues involved in the use of neuroimaging data entered into legal evidence and for associated expert testimony. The specific contexts of criminal cases, child abuse, and head trauma were especially considered. The purpose of the conference was to inform the development of guidelines on expert testimony for the American Society of Neuroradiology and to provide principles for courts on the ethical use of neuroimaging data as evidence. This report summarizes the conference and resulting recommendations.

  19. Neuroimaging Biomarkers of Neurodegenerative Diseases and Dementia

    OpenAIRE

    Risacher, Shannon L.; Saykin, Andrew J.

    2013-01-01

    Neurodegenerative disorders leading to dementia are common diseases that affect many older and some young adults. Neuroimaging methods are important tools for assessing and monitoring pathological brain changes associated with progressive neurodegenerative conditions. In this review, the authors describe key findings from neuroimaging studies (magnetic resonance imaging and radionucleotide imaging) in neurodegenerative disorders, including Alzheimer’s disease (AD) and prodromal stages, famili...

  20. Neuroimaging and Research into Second Language Acquisition

    Science.gov (United States)

    Sabourin, Laura

    2009-01-01

    Neuroimaging techniques are becoming not only more and more sophisticated but are also coming to be increasingly accessible to researchers. One thing that one should take note of is the potential of neuroimaging research within second language acquisition (SLA) to contribute to issues pertaining to the plasticity of the adult brain and to general…

  1. Electricity consumption-real GDP causality nexus: Evidence from a bootstrapped causality test for 30 OECD countries

    International Nuclear Information System (INIS)

    Narayan, Paresh Kumar; Prasad, Arti

    2008-01-01

    The goal of this paper is to examine any causal effects between electricity consumption and real GDP for 30 OECD countries. We use a bootstrapped causality testing approach and unravel evidence in favour of electricity consumption causing real GDP in Australia, Iceland, Italy, the Slovak Republic, the Czech Republic, Korea, Portugal, and the UK. The implication is that electricity conservation policies will negatively impact real GDP in these countries. However, for the rest of the 22 countries our findings suggest that electricity conversation policies will not affect real GDP

  2. Neuroimaging in psychiatry: from bench to bedside

    Directory of Open Access Journals (Sweden)

    David E Linden

    2009-12-01

    Full Text Available This perspective considers the present and the future role of different neuroimaging techniques in the field of psychiatry. After identifying shortcomings of the mainly symptom-focussed diagnostic processes and treatment decisions in modern psychiatry, we suggest topics where neuroimaging methods have the potential to help. These include better understanding of the pathophysiology, improved diagnoses, assistance in therapeutic decisions and the supervision of treatment success by direct assessment of improvement in disease-related brain functions. These different questions are illustrated by examples from neuroimaging studies, with a focus on severe mental and neuropsychiatric illnesses such as schizophrenia, depression and dementia. Despite all reservations addressed in the article, we are optimistic, that neuroimaging has a huge potential with regard to the above-mentioned questions. We expect that neuroimaging will play an increasing role in the future refinement of the diagnostic process and aid in the development of new therapies in the field of psychiatry.

  3. [Exploring dream contents by neuroimaging].

    Science.gov (United States)

    Horikawa, Tomoyasu; Kamitani, Yukiyasu

    2014-04-01

    Dreaming is a subjective experience during sleep that is often accompanied by vivid perceptual and emotional contents. Because of its fundamentally subjective nature, the objective study of dream contents has been challenging. However, since the discovery of rapid eye movements during sleep, scientific knowledge on the relationship between dreaming and physiological measures including brain activity has accumulated. Recent advances in neuroimaging analysis methods have made it possible to uncover direct links between specific dream contents and brain activity patterns. In this review, we first give a historical overview on dream researches with a focus on the neurophysiological and behavioral signatures of dreaming. We then discuss our recent study in which visual dream contents were predicted, or decoded, from brain activity during sleep onset periods using machine learning-based pattern recognition of functional MRI data. We suggest that advanced analytical tools combined with neural and behavioral databases will reveal the relevance of spontaneous brain activity during sleep to waking experiences.

  4. Functional neuroimaging of sleep disorders

    International Nuclear Information System (INIS)

    Qiu Chun; Zhao Jun; Guan Yihui

    2013-01-01

    Sleep disorders may affect the health and normal life of human badly. However, the pathophysiology underlying adult sleep disorders is still unclear. Functional neuroimaging can be used to investigate whether sleep disorders are associated with specific changes in brain structure or regional activity. This paper reviews functional brain imaging findings in major intrinsic sleep disorders (i.e., idiopathic insomnia, narcolepsy, and obstructive sleep apnea) and in abnormal motor behavior during sleep (i.e., periodic limb movement disorder and REM sleep behavior disorder). Metabolic/functional investigations (positron emission tomography, single photon emission computed tomography, functional magnetic resonance imaging) are mainly reviewed, as well as neuroanatomical assessments (voxel-based morphometry, magnetic resonance spectroscopy). Meanwhile, here are some brief introduction of different kinds of sleep disorders. (authors)

  5. Electricity

    CERN Document Server

    Basford, Leslie

    2013-01-01

    Electricity Made Simple covers the fundamental principles underlying every aspect of electricity. The book discusses current; resistance including its measurement, Kirchhoff's laws, and resistors; electroheat, electromagnetics and electrochemistry; and the motor and generator effects of electromagnetic forces. The text also describes alternating current, circuits and inductors, alternating current circuits, and a.c. generators and motors. Other methods of generating electromagnetic forces are also considered. The book is useful for electrical engineering students.

  6. Learning Neuroimaging. 100 essential cases

    International Nuclear Information System (INIS)

    Asis Bravo-Rodriguez, Francisco de; Diaz-Aguilera, Rocio; Hygino da Cruz, Luiz Celso

    2012-01-01

    Neuroradiology is the branch of radiology that comprises both imaging and invasive procedures related to the brain, spine and spinal cord, head, neck, organs of special sense (eyes, ears, nose), cranial and spinal nerves, and cranial, cervical, and spinal vessels. Special training and skills are required to enable the neuroradiologist to function as an expert diagnostic and therapeutic consultant and practitioner. In addition to knowledge of imaging findings, the neuroradiologist is required to learn the fundamentals of structural and functional neuroanatomy, neuropathology, and neuropathophysiology as well as the clinical manifestations of diseases of the brain, spine and spinal cord, head, neck, and organs of special sense. This book is intended as an introduction to neuroradiology and aims to provide the reader with a comprehensive overview of this highly specialized radiological subspecialty. One hundred illustrated cases from clinical practice are presented in a standard way. Each case is supported by representative images and is divided into three parts: a brief summary of the patient's medical history, a discussion of the disease, and a description of the most characteristic imaging features of the disorder. The focus is not only on common neuroradiological entities such as stroke and acute head trauma but also on less frequent disorders that the practitioner should recognize. Learning Neuroimaging: 100 Essential Cases is an ideal resource for neuroradiology and radiology residents, neurology residents, neurosurgery residents, nurses, radiology technicians, and medical students. (orig.)

  7. Learning Neuroimaging. 100 essential cases

    Energy Technology Data Exchange (ETDEWEB)

    Asis Bravo-Rodriguez, Francisco de [Reina Sofia University Hospital, Cordoba (Spain). Diagnostic and Therapeutics Neuroradiology; Diaz-Aguilera, Rocio [Alto Guadalquivir Hospital, Andujar, Jaen (Spain). Dept. of Radiology; Hygino da Cruz, Luiz Celso [Universidade Federal do Rio de Janeiro (Brazil). CDPI and IRM Ressonancia Magnetica

    2012-07-01

    Neuroradiology is the branch of radiology that comprises both imaging and invasive procedures related to the brain, spine and spinal cord, head, neck, organs of special sense (eyes, ears, nose), cranial and spinal nerves, and cranial, cervical, and spinal vessels. Special training and skills are required to enable the neuroradiologist to function as an expert diagnostic and therapeutic consultant and practitioner. In addition to knowledge of imaging findings, the neuroradiologist is required to learn the fundamentals of structural and functional neuroanatomy, neuropathology, and neuropathophysiology as well as the clinical manifestations of diseases of the brain, spine and spinal cord, head, neck, and organs of special sense. This book is intended as an introduction to neuroradiology and aims to provide the reader with a comprehensive overview of this highly specialized radiological subspecialty. One hundred illustrated cases from clinical practice are presented in a standard way. Each case is supported by representative images and is divided into three parts: a brief summary of the patient's medical history, a discussion of the disease, and a description of the most characteristic imaging features of the disorder. The focus is not only on common neuroradiological entities such as stroke and acute head trauma but also on less frequent disorders that the practitioner should recognize. Learning Neuroimaging: 100 Essential Cases is an ideal resource for neuroradiology and radiology residents, neurology residents, neurosurgery residents, nurses, radiology technicians, and medical students. (orig.)

  8. Developments in functional neuroimaging techniques

    International Nuclear Information System (INIS)

    Aine, C.J.

    1995-01-01

    A recent review of neuroimaging techniques indicates that new developments have primarily occurred in the area of data acquisition hardware/software technology. For example, new pulse sequences on standard clinical imagers and high-powered, rapidly oscillating magnetic field gradients used in echo planar imaging (EPI) have advanced MRI into the functional imaging arena. Significant developments in tomograph design have also been achieved for monitoring the distribution of positron-emitting radioactive tracers in the body (PET). Detector sizes, which pose a limit on spatial resolution, have become smaller (e.g., 3--5 mm wide) and a new emphasis on volumetric imaging has emerged which affords greater sensitivity for determining locations of positron annihilations and permits smaller doses to be utilized. Electromagnetic techniques have also witnessed growth in the ability to acquire data from the whole head simultaneously. EEG techniques have increased their electrode coverage (e.g., 128 channels rather than 16 or 32) and new whole-head systems are now in use for MEG. But the real challenge now is in the design and implementation of more sophisticated analyses to effectively handle the tremendous amount of physiological/anatomical data that can be acquired. Furthermore, such analyses will be necessary for integrating data across techniques in order to provide a truly comprehensive understanding of the functional organization of the human brain

  9. ORIGINAL ARTICLE EEG changes and neuroimaging abnormalities ...

    African Journals Online (AJOL)

    salah

    Clinical Genetics Department, Human Genetics & Genome Research Division, ... neuroimaging changes of the brain and EEG abnormalities in correlation to the ... level and by developmental changes2. .... for IQ as a confounding factor.30.

  10. Making Individual Prognoses in Psychiatry Using Neuroimaging and Machine Learning.

    Science.gov (United States)

    Janssen, Ronald J; Mourão-Miranda, Janaina; Schnack, Hugo G

    2018-04-22

    Psychiatric prognosis is a difficult problem. Making a prognosis requires looking far into the future, as opposed to making a diagnosis, which is concerned with the current state. During the follow-up period, many factors will influence the course of the disease. Combined with the usually scarcer longitudinal data and the variability in the definition of outcomes/transition, this makes prognostic predictions a challenging endeavor. Employing neuroimaging data in this endeavor introduces the additional hurdle of high dimensionality. Machine-learning techniques are especially suited to tackle this challenging problem. This review starts with a brief introduction to machine learning in the context of its application to clinical neuroimaging data. We highlight a few issues that are especially relevant for prediction of outcome and transition using neuroimaging. We then review the literature that discusses the application of machine learning for this purpose. Critical examination of the studies and their results with respect to the relevant issues revealed the following: 1) there is growing evidence for the prognostic capability of machine-learning-based models using neuroimaging; and 2) reported accuracies may be too optimistic owing to small sample sizes and the lack of independent test samples. Finally, we discuss options to improve the reliability of (prognostic) prediction models. These include new methodologies and multimodal modeling. Paramount, however, is our conclusion that future work will need to provide properly (cross-)validated accuracy estimates of models trained on sufficiently large datasets. Nevertheless, with the technological advances enabling acquisition of large databases of patients and healthy subjects, machine learning represents a powerful tool in the search for psychiatric biomarkers. Copyright © 2018 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  11. Molecular neuroimaging in degenerative dementias.

    Science.gov (United States)

    Jiménez Bonilla, J F; Carril Carril, J M

    2013-01-01

    In the context of the limitations of structural imaging, brain perfusion and metabolism using SPECT and PET have provided relevant information for the study of cognitive decline. The introduction of the radiotracers for cerebral amyloid imaging has changed the diagnostic strategy regarding Alzheimer's disease, which is currently considered to be a "continuum." According to this new paradigm, the increasing amyloid load would be associated to the preclinical phase and mild cognitive impairment. It has been possible to observe "in vivo" images using 11C-PIB and PET scans. The characteristics of the 11C-PIB image include specific high brain cortical area retention in the positive cases with typical distribution pattern and no retention in the negative cases. This, in combination with 18F-FDG PET, is the basis of molecular neuroimaging as a biomarker. At present, its prognostic value is being evaluated in longitudinal studies. 11C-PIB-PET has become the reference radiotracer to evaluate the presence of cerebral amyloid. However, its availability is limited due to the need for a nearby cyclotron. Therefore, 18F labeled radiotracers are being introduced. Our experience in the last two years with 11C-PIB, first in the research phase and then as being clinically applied, has shown the utility of the technique in the clinical field, either alone or in combination with FDG. Thus, amyloid image is a useful tool for the differential diagnosis of dementia and it is a potentially useful method for early diagnosis and evaluation of future treatments. Copyright © 2013 Elsevier España, S.L. and SEMNIM. All rights reserved.

  12. Can renewable energy be financed with higher electricity prices? evidence from Spain

    OpenAIRE

    Barreiro Hurlé, Jesús; Gracia Royo, Azucena; Pérez y Pérez, Luis

    2011-01-01

    The aim of this paper is to assess willingness to pay for renewable energy electricity. We used a choice experiment to elicit willingness-to-pay for different electricity service attributes: renewable sources (wind, solar and biomass) and the regional origin of the electricity with data from a survey conducted in Spain in 2010. Findings indicate that a majority of consumers are not willing to pay a premium for increases in the renewable component of their electricity mix. Moreover, they would...

  13. Electricity consumption, employment and real income in Australia evidence from multivariate Granger causality tests

    International Nuclear Information System (INIS)

    Narayan, P.K.; Smyth, Russell

    2005-01-01

    This paper examines the relationship between electricity consumption, employment and real income in Australia within a cointegration and causality framework. We find that electricity consumption, employment and real income are cointegrated and that in the long-run employment and real income Granger cause electricity consumption, while in the short run there is weak unidirectional Granger causality running from income to electricity consumption and from income to employment

  14. Electricity and the Technology–Skill Complementarity: Evidence from the Swedish Industrial Census of 1931

    Directory of Open Access Journals (Sweden)

    Svante Prado

    2017-04-01

    Full Text Available Notwithstanding the popularity among economists of attributing the surging inequality of recent decades to technology–skill complementarity, researchers with a keen eye on history have been reluctant to pick up this thread. This paper joins Claudia Goldin and Lawrence Katz’s attempt to examine the role of electrification as an example of a technology that is complementary to workers’ rising skill levels. Sweden electrified manufacturing processes rapidly in the first quarter of the twentieth century, while the supply of skills through secondary education only increased significantly in the 1950s. We use industry-specific information from the Swedish Industrial Census of 1931 to establish whether electricity and the use of white-collar workers correlated positively. The results indicate that the correlation was positive, but the estimated effect was rather small. Moreover, the available evidence for skill ratios does not suggest that inequality, thus measured, increased. We conclude that labor market institutions prevented—and also overturned—the inequality push emanating from technology.

  15. Does employee safety influence customer satisfaction? Evidence from the electric utility industry.

    Science.gov (United States)

    Willis, P Geoffrey; Brown, Karen A; Prussia, Gregory E

    2012-12-01

    Research on workplace safety has not examined implications for business performance outcomes such as customer satisfaction. In a U.S. electric utility company, we surveyed 821 employees in 20 work groups, and also had access to archival safety data and the results of a customer satisfaction survey (n=341). In geographically-based work units where there were more employee injuries (based on archival records), customers were less satisfied with the service they received. Safety climate, mediated by safety citizenship behaviors (SCBs), added to the predictive power of the group-level model, but these two constructs exerted their influence independently from actual injuries. In combination, two safety-related predictor paths (injuries and climate/SCB) explained 53% of the variance in customer satisfaction. Results offer preliminary evidence that workplace safety influences customer satisfaction, suggesting that there are likely spillover effects between the safety environment and the service environment. Additional research will be needed to assess the specific mechanisms that convert employee injuries into palpable results for customers. Better safety climate and reductions in employee injuries have the potential to offer payoffs in terms of what customers experience. Copyright © 2012 National Safety Council and Elsevier Ltd. All rights reserved.

  16. What do customers want from improved residential electricity services? Evidence from a choice experiment

    International Nuclear Information System (INIS)

    Huh, Sung-Yoon; Woo, JongRoul; Lim, Sesil; Lee, Yong-Gil; Kim, Chang Seob

    2015-01-01

    Improvements in customer satisfaction as well as product/service quality represent a common objective of all businesses, and electricity services are no exception. Using choice experiments and a mixed logit model, this study quantitatively analyzes customers' preferences and their marginal willingness to pay for improved residential electricity services. The study provides an ex ante evaluation of customers' acceptance of hypothetical electricity services. According to the results, customers consider the electricity bill and the electricity mix as the two most important attributes when choosing their electricity services. Customers are willing to pay 2.2% more in the average electricity bill (an additional monthly electricity bill of KRW 1,064; USD 0.96) for a significant increase in the share of renewable energy, which is far less than the actual cost of achieving this renewable target. Therefore, it is better to maintain the current electricity mix in principle, and the renewable share should be gradually expanded instead of making a sudden change in the electricity mix. In addition, customers are willing to pay KRW 6,793 (USD 6.15) more to reduce blackouts once in a year and KRW 64/year (USD 0.06/year) to reduce a minute of each blackout. -- Highlights: •Customers' preferences for improved residential electricity services are analyzed. •Empirical setting is a sample of residents in South Korea. •The electricity bills and electricity mix are important to customers. •Increase in electricity bill of different electricity mix is considered

  17. The dynamics of sectoral electricity demand for a panel of US states: New evidence on the consumption–growth nexus

    International Nuclear Information System (INIS)

    Saunoris, James W.; Sheridan, Brandon J.

    2013-01-01

    In this paper, we use a panel of the 48 contiguous US states over the period 1970–2009 to examine the dynamics of electricity demand in addressing the four hypotheses set forth in the literature: growth, conservation, neutrality, and feedback. In doing so we provide both short-run and long-run elasticity estimates for electricity demand. Recent developments in nonstationary panel estimation techniques allow for heterogeneity in the coefficients while examining the direction of causality among electricity consumption, electricity prices, and income growth. In addition to the full sample, we also disaggregate the sample into three sectors: commercial, industrial, and residential. The short-run results provide evidence in favor of the growth hypothesis for the aggregate sample, as well as for the industrial sector. For the residential and commercial sectors, the conservation hypothesis is supported. Long-run results favor the conservation hypothesis. To ascertain differences in electricity demand relating to electricity intensity we also examine states based on their efficiency in electricity consumption. Overall, the results yield in favor of the growth hypothesis for low intensity states and conservation hypothesis for high intensity states. - Highlights: • We use dynamic panel techniques to model electricity demand by sector for US states. • The conservation hypothesis is supported in the long run; short-run results are mixed. • The conservation hypothesis is supported in the high-electricity-intensity subsample. • The growth hypothesis is supported in the low-electricity-intensity subsample. • Policies aimed at energy conservation should be long-run in nature

  18. A structural VAR analysis of electricity consumption and real GDP: Evidence from the G7 countries

    International Nuclear Information System (INIS)

    Narayan, Paresh Kumar; Narayan, Seema; Prasad, Arti

    2008-01-01

    In this paper, we depart from the literature on electricity consumption-real GDP in that for the first time we examine the reaction of real GDP to shocks in electricity consumption. To achieve this goal, we use the structural vector autoregressive (SVAR) model and examine the impact of electricity consumption shocks on real GDP for the G7 countries. We find that except for the USA, electricity consumption has a statistically significant positive impact on real GDP over short horizons. This finding implies that except for the USA, electricity conservation policies will hurt real GDP in the G7 countries

  19. Household electricity access, availability and human well-being: Evidence from India

    International Nuclear Information System (INIS)

    Ahmad, Sohail; Mathai, Manu V.; Parayil, Govindan

    2014-01-01

    According to the 2011 Census of India, over 31% of India's 1.2 billion people lived in nearly 8000 towns and cities; the remaining 830 million people lived in over 638,000 villages. About 55% of rural households and 93% of urban households had access to electricity. The 2005 Indian Human Development Survey showed that on average, electricity availability (hours of supply per day) in rural and urban households were 14 and 19 h, respectively (Desai et al., 2007). Using nationally representative data from Indian Human Development Survey, this study estimated the impact of electricity access and availability on two attributes of human well-being, viz. education and health attainment. It found a significant positive relationship between electricity availability and well-being in rural and urban households. Electricity accessibility, revealed a significant positive relationship only for rural households. The paper concludes with implications for electricity policy and infrastructure choices. - Graphical abstract: Impact of electricity security on the attributes of human well-being. - Highlights: • Nexus between well-being, and electricity access and availability is quantified. • Electricity access is positively associated with well-being in rural but not urban. • Electricity availability negatively associates with morbidity and absenteeism. • Electricity security as human well-being enabler seeks nuanced policy attention. • Decentralized rapidly deployable modular technologies and microgrids are advocated

  20. Economic growth and electricity consumption in Cote d'Ivoire: Evidence from time series analysis

    International Nuclear Information System (INIS)

    Kouakou, Auguste K.

    2011-01-01

    This paper examines the causal relationship between the electric power industry and the economic growth of Cote d'Ivoire. Using the data from 1971 to 2008, a test was conducted for the cointegration and Granger causality within an error correction model. Results from these tests reveal a bidirectional causality between per capita electricity consumption and per capita GDP. A unidirectional causality running from electricity consumption to industry value added appears in the short run. Economic growth is found to have great effects on electricity consumption and a reverse causality from electricity to economic growth may also appear. In the long run, there is a unidirectional causality between electricity and both GDP and industry value added. From these findings, we conclude that the country will be energy dependent in the long run and must therefore secure the production network from shortfalls to ensure a sustainable development path. Accordingly, government should adopt policies aimed at increasing the investment in the sector by stepping up electricity production from existing and new energy sources. - Highlights: → We analyze the electricity-growth nexus for Cote d'Ivoire using causality tests. → Short run bi-directional causality appears between electricity and GDP. → We found a unidirectional causality running from electricity to industry and GDP. → Economic activities are electricity dependent and require appropriate policies.

  1. Determinants and policy implications for household electricity-saving behaviour: Evidence from Beijing, China

    International Nuclear Information System (INIS)

    Wang Zhaohua; Zhang Bin; Yin Jianhua; Zhang Yixiang

    2011-01-01

    This research sets out to explore the possibilities for further saving in household electricity consumption through a study of the residents' willingness and behavioural characteristics in electricity saving, as applied within a Chinese context. Based on an extensive literature review, the authors argue that economic benefits, policy and social norms, and past experience may have a positive correlation with household electricity-saving behaviour, while the discomfort caused by electricity-saving activities, may exert a negative effect on it. Through a sample of 816 randomly selected residents in Beijing, the propositions are examined using logit regression analysis. The conclusions support the ideas, concerning both the positive influence of economic benefits, policy and social norms, and past experience as they affect broader electricity-saving behaviour, and the negative influence of the discomfort caused by electricity-saving activities. Finally, some inferences are drawn, and suggestions are offered for policy makers and further studies. - Highlights: → We develop a logistic regression to investigate household electricity saving behaviour. → Determinants for household electricity saving are verified with a questionnaire survey. → Environmental awareness does not impact on household electricity saving directly. → It is prerequisite to focus on both financial subsidy and technology improvement. → Tiered price reform is considered an effective policy for electricity saving.

  2. Measuring and testing natural gas and electricity markets volatility : evidence from Alberta's deregulated markets

    International Nuclear Information System (INIS)

    Serletis, A.; Shahmoradi, A.

    2005-01-01

    A number of innovative methods for modelling spot wholesale electricity prices have recently been developed. However, these models have primarily used a univariate time series approach to the analysis of electricity prices. This paper specified and estimated a multivariate GARCH-M model of natural gas and electricity price changes and their volatilities, using data over the deregulated period between January 1996 to November 2004 from Alberta's spot power and natural gas markets. The primary objective of the model was to investigate the relationship between electricity and natural gas prices. It was noted that the model allows for the possibilities of spillovers and asymmetries in the variance-covariance structure for natural gas and electricity price changes, and also for the separate examination of the effects of the volatility of anticipated and unanticipated changes in natural gas and electricity prices. Section 2 of the paper provided a description of the model used to test for causality between natural gas and electricity price changes, while section 3 discussed the data and presented the empirical results. It was concluded that there is a bidirectional causality between natural gas and electricity price changes. However, neither anticipated nor unanticipated natural gas price volatility causes electricity price changes. Anticipated electricity price volatility has a causal effect on natural gas. 10 refs., 2 tabs., 3 figs

  3. Evidence that dirty electricity is causing the worldwide epidemics of obesity and diabetes.

    Science.gov (United States)

    Milham, Samuel

    2014-01-01

    The epidemics of obesity and diabetes most apparent in recent years had their origins with Thomas Edison's development of distributed electricity in New York City in 1882. His original direct current (DC) generators suffered serious commutator brush arcing which is a major source of high-frequency voltage transients (dirty electricity). From the onset of the electrical grid, electrified populations have been exposed to dirty electricity. Diesel generator sets are a major source of dirty electricity today and are used almost universally to electrify small islands and places unreachable by the conventional electric grid. This accounts for the fact that diabetes prevalence, fasting plasma glucose and obesity are highest on small islands and other places electrified by generator sets and lowest in places with low levels of electrification like sub-Saharan Africa and east and Southeast Asia.

  4. Electricity supply, employment and real GDP in India: evidence from cointegration and Granger-causality tests

    International Nuclear Information System (INIS)

    Ghosh, Sajal

    2009-01-01

    This study probes nexus between electricity supply, employment and real GDP for India within a multivariate framework using autoregressive distributed lag (ARDL) bounds testing approach of cointegration. Long-run equilibrium relationship has been established among these variables for the time span 1970-71 to 2005-06. The study further establishes long- and short-run Granger causality running from real GDP and electricity supply to employment without any feedback effect. Thus, growth in real GDP and electricity supply are responsible for the high level of employment in India. The absence of causality running from electricity supply to real GDP implies that electricity demand and supply side measures can be adopted to reduce the wastage of electricity, which would not affect future economic growth of India.

  5. The Effects of Competition Policy on TFP Growth: Some Evidence from the Malaysian Electricity Supply Industry

    OpenAIRE

    Kok Fong See; Tim Coelli

    2009-01-01

    The main objectives of this paper are to measure total factor productivity (TFP) growth in the electricity supply industry in Peninsular Malaysia from 1975 to 2005 and to assess the impact of private entry reforms upon TFP in this industry. Prior to 1995, a government-linked, vertically-integrated electricity utility, Tenaga Nasional Berhad (TNB), was essentially the sole operator. However, since 1995 privately-owned Independent Power Producers (IPPs) have also begun generating electricity, a...

  6. Analyse Risk-Return Paradox: Evidence from Electricity Sector of Pakistan

    OpenAIRE

    Naqi Shah, Sadia; Qayyum, Abdul

    2016-01-01

    This study analyse risk return relationship of the electricity companies of Pakistan by using the log return series of these electricity companies. Financial time series data have the property of autoregressive heteroscedasticity so move towards the GARCH family test. As the study want to analyse the risk return relationship so, GARCH-M Model of Engel et al (1987) is used, who empirically found relationship between risk and return. Results show that risk return in case of Pakistan electricity...

  7. Does electricity consumption panel Granger cause GDP? A new global evidence

    Energy Technology Data Exchange (ETDEWEB)

    Narayan, Paresh Kumar [School of Accounting, Economics and Finance, Faculty of Business and Economics, Deakin University, Melbourne (Australia); Narayan, Seema [School of Economics, Finance, and Marketing, RMIT University, Melbourne (Australia); Popp, Stephan [Department of Economics, University of Duisburg-Essen (Germany)

    2010-10-15

    The goal of this paper is to undertake a panel data investigation of long-run Granger causality between electricity consumption and real GDP for seven panels, which together consist of 93 countries. We use a new panel causality test and find that in the long-run both electricity consumption and real GDP have a bidirectional Granger causality relationship except for the Middle East where causality runs only from GDP to electricity consumption. Finally, for the G6 panel the estimates reveal a negative sign effect, implying that increasing electricity consumption in the six most industrialised nations will reduce GDP. (author)

  8. Economic analysis of price premiums in the presence of non-convexities. Evidence from German electricity markets

    International Nuclear Information System (INIS)

    Paschmann, Martin

    2017-01-01

    Analyzing price data from sequential German electricity markets, namely the day-ahead and intraday auction, a puzzling but apparently systematic pattern of price premiums can be identified. The price premiums are highly correlated with the underlying demand profile. As there is evidence that widespread models for electricity forward premiums are not applicable to the market dynamics under analysis, a theoretical model is developed within this article which reveals that non-convexities in only a subset of sequential markets with differing product granularity may cause systematic price premiums at equilibrium. These price premiums may be bidirectional and reflect a value for additional short-term power supply system flexibility.

  9. Economic analysis of price premiums in the presence of non-convexities. Evidence from German electricity markets

    Energy Technology Data Exchange (ETDEWEB)

    Paschmann, Martin

    2017-11-15

    Analyzing price data from sequential German electricity markets, namely the day-ahead and intraday auction, a puzzling but apparently systematic pattern of price premiums can be identified. The price premiums are highly correlated with the underlying demand profile. As there is evidence that widespread models for electricity forward premiums are not applicable to the market dynamics under analysis, a theoretical model is developed within this article which reveals that non-convexities in only a subset of sequential markets with differing product granularity may cause systematic price premiums at equilibrium. These price premiums may be bidirectional and reflect a value for additional short-term power supply system flexibility.

  10. [How to start a neuroimaging study].

    Science.gov (United States)

    Narumoto, Jin

    2012-06-01

    In order to help researchers understand how to start a neuroimaging study, several tips are described in this paper. These include 1) Choice of an imaging modality, 2) Statistical method, and 3) Interpretation of the results. 1) There are several imaging modalities available in clinical research. Advantages and disadvantages of each modality are described. 2) Statistical Parametric Mapping, which is the most common statistical software for neuroimaging analysis, is described in terms of parameter setting in normalization and level of significance. 3) In the discussion section, the region which shows a significant difference between patients and normal controls should be discussed in relation to the neurophysiology of the disease, making reference to previous reports from neuroimaging studies in normal controls, lesion studies and animal studies. A typical pattern of discussion is described.

  11. Mathematical modeling and visualization of functional neuroimages

    DEFF Research Database (Denmark)

    Rasmussen, Peter Mondrup

    This dissertation presents research results regarding mathematical modeling in the context of the analysis of functional neuroimages. Specifically, the research focuses on pattern-based analysis methods that recently have become popular analysis tools within the neuroimaging community. Such methods...... neuroimaging data sets are characterized by relatively few data observations in a high dimensional space. The process of building models in such data sets often requires strong regularization. Often, the degree of model regularization is chosen in order to maximize prediction accuracy. We focus on the relative...... be carefully selected, so that the model and its visualization enhance our ability to interpret brain function. The second part concerns interpretation of nonlinear models and procedures for extraction of ‘brain maps’ from nonlinear kernel models. We assess the performance of the sensitivity map as means...

  12. Molecular neuroimaging of emotional decision-making.

    Science.gov (United States)

    Takahashi, Hidehiko

    2013-04-01

    With the dissemination of non-invasive human neuroimaging techniques such as fMRI and the advancement of cognitive science, neuroimaging studies focusing on emotions and social cognition have become established. Along with this advancement, behavioral economics taking emotional and social factors into account for economic decisions has been merged with neuroscientific studies, and this interdisciplinary approach is called neuroeconomics. Past neuroeconomics studies have demonstrated that subcortical emotion-related brain structures play an important role in "irrational" decision-making. The research field that investigates the role of central neurotransmitters in this process is worthy of further development. Here, we provide an overview of recent molecular neuroimaging studies to further the understanding of the neurochemical basis of "irrational" or emotional decision-making and the future direction, including clinical implications, of the field. Copyright © 2013 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

  13. A novel machine learning approach for estimation of electricity demand: An empirical evidence from Thailand

    International Nuclear Information System (INIS)

    Mostafavi, Elham Sadat; Mostafavi, Seyyed Iman; Jaafari, Arefeh; Hosseinpour, Fariba

    2013-01-01

    Highlights: • A hybrid approach is presented for the estimation of the electricity demand. • The proposed method integrates the capabilities of GP and SA. • The GSA model makes accurate predictions of the electricity demand. - Abstract: This study proposes an innovative hybrid approach for the estimation of the long-term electricity demand. A new prediction equation was developed for the electricity demand using an integrated search method of genetic programming and simulated annealing, called GSA. The annual electricity demand was formulated in terms of population, gross domestic product (GDP), stock index, and total revenue from exporting industrial products of the same year. A comprehensive database containing total electricity demand in Thailand from 1986 to 2009 was used to develop the model. The generalization of the model was verified using a separate testing data. A sensitivity analysis was conducted to investigate the contribution of the parameters affecting the electricity demand. The GSA model provides accurate predictions of the electricity demand. Furthermore, the proposed model outperforms a regression and artificial neural network-based models

  14. Is Power Production Flexibility a Substitute for Storability? Evidence from Electricity Futures Prices

    NARCIS (Netherlands)

    M. Kilic (Mehtap); R. Huisman (Ronald)

    2010-01-01

    textabstractElectricity is not storable. As a consequence, electricity demand and supply need to be in balance at any moment in time as a shortage in production volume cannot be compensated with supply from inventories. However, if the installed power supply capacity is very flexible, variation in

  15. Electricity

    International Nuclear Information System (INIS)

    Tombs, F.

    1983-01-01

    The subject is discussed, with particular reference to the electricity industry in the United Kingdom, under the headings; importance and scope of the industry's work; future fuel supplies (estimated indigenous fossil fuels reserves); outlook for UK energy supplies; problems of future generating capacity and fuel mix (energy policy; construction programme; economics and pricing; contribution of nuclear power - thermal and fast reactors; problems of conversion of oil-burning to coal-burning plant). (U.K.)

  16. Estimating short and long-term residential demand for electricity. New evidence from Sri Lanka

    International Nuclear Information System (INIS)

    Athukorala, P.P.A Wasantha; Wilson, Clevo

    2010-01-01

    This study investigates the short-run dynamics and long-run equilibrium relationship between residential electricity demand and factors influencing demand - per capita income, price of electricity, price of kerosene oil and price of liquefied petroleum gas - using annual data for Sri Lanka for the period, 1960-2007. The study uses unit root, cointegration and error-correction models. The long-run demand elasticities of income, own price and price of kerosene oil (substitute) were estimated to be 0.78, - 0.62, and 0.14 respectively. The short-run elasticities for the same variables were estimated to be 0.32, - 0.16 and 0.10 respectively. Liquefied petroleum (LP) gas is a substitute for electricity only in the short-run with an elasticity of 0.09. The main findings of the paper support the following (1) increasing the price of electricity is not the most effective tool to reduce electricity consumption (2) existing subsidies on electricity consumption can be removed without reducing government revenue (3) the long-run income elasticity of demand shows that any future increase in household incomes is likely to significantly increase the demand for electricity and (4) any power generation plans which consider only current per capita consumption and population growth should be revised taking into account the potential future income increases in order to avoid power shortages in the country. (author)

  17. Exploring the relationship between agricultural electricity consumption and output: New evidence from Turkish regional data

    International Nuclear Information System (INIS)

    Dogan, Eyup; Sebri, Maamar; Turkekul, Berna

    2016-01-01

    This study investigates the relationship between agricultural electricity consumption and agricultural output for a panel of 12 regions of Turkey for the period 1995–2013. In order to reveal the possible heterogeneity between regions, empirical analyses are conducted for the whole panel data and two sub-groups within the panel data; namely, coastal regions and non-coastal regions. The results from several panel unit root tests indicate that electricity consumption and output are stationary process at their levels for overall panel and the two specific groups. By using the OLS with regional fixed effects, this study finds that coefficient estimate of electricity consumption on output is statistically significant and positive for overall regions, coastal regions and non-coastal regions. In addition, the results from the Dumitrescu-Hurlin Granger causality test show that there is unidirectional causality running from agricultural output to electricity consumption for non-coastal regions, and there is bidirectional causality between agricultural electricity consumption and output for overall panel and coastal regions. Findings and policy implications are further discussed. - Highlights: •This study uses the recently developed Dumitrescu-Hurlin Granger causality test. •There is unidirectional causality running from agricultural output to electricity consumption for non-coastal regions. •Bidirectional causality runs between the analyzed variables for coastal regions. •Electricity consumption increases agricultural output.

  18. Estimating short and long-term residential demand for electricity. New evidence from Sri Lanka

    Energy Technology Data Exchange (ETDEWEB)

    Athukorala, P.P.A Wasantha; Wilson, Clevo [School of Economics and Finance, Queensland University of Technology, Brisbane (Australia)

    2010-09-15

    This study investigates the short-run dynamics and long-run equilibrium relationship between residential electricity demand and factors influencing demand - per capita income, price of electricity, price of kerosene oil and price of liquefied petroleum gas - using annual data for Sri Lanka for the period, 1960-2007. The study uses unit root, cointegration and error-correction models. The long-run demand elasticities of income, own price and price of kerosene oil (substitute) were estimated to be 0.78, - 0.62, and 0.14 respectively. The short-run elasticities for the same variables were estimated to be 0.32, - 0.16 and 0.10 respectively. Liquefied petroleum (LP) gas is a substitute for electricity only in the short-run with an elasticity of 0.09. The main findings of the paper support the following (1) increasing the price of electricity is not the most effective tool to reduce electricity consumption (2) existing subsidies on electricity consumption can be removed without reducing government revenue (3) the long-run income elasticity of demand shows that any future increase in household incomes is likely to significantly increase the demand for electricity and (4) any power generation plans which consider only current per capita consumption and population growth should be revised taking into account the potential future income increases in order to avoid power shortages in the country. (author)

  19. Paediatric population neuroimaging and the Generation R Study

    DEFF Research Database (Denmark)

    White, Tonya; Muetzel, Ryan L.; El Marroun, Hanan

    2018-01-01

    Paediatric population neuroimaging is an emerging field that falls at the intersection between developmental neuroscience and epidemiology. A key feature of population neuroimaging studies involves large-scale recruitment that is representative of the general population. One successful approach f...

  20. Cross-border integration in the European electricity market. Evidence from the pricing behavior of Norwegian and Swiss exporters

    International Nuclear Information System (INIS)

    Balaguer, Jacint

    2011-01-01

    This paper examines the electricity market integration process in two European areas based on the pricing behavior of Norwegian and Swiss exporters. The aim is to gain evidence for the period after the adoption of the 'Second Legislative Package' (2003). The pricing behavior of Norwegian exporters indicates that the wholesale markets for Denmark and Sweden are highly integrated. Moreover, results are fully compatible with the existence of a very competitive marketplace for electricity. This clearly contrasts with the evidence provided by Swiss exporters. In this last case, analysis revealed differences in pricing-to-market behavior between Italy, France and Germany, which indicates that exporters take advantage of international market segmentation and divergences between market structures. This outcome provides a reasonable explanation as to why price differences between countries cannot be fully attributed to transmission costs, as has been claimed in previous research. We also found cross-country convergence in levels of markups and in pricing-to-market behavior of the Swiss exporters for the first part of the period that was analyzed. The evidence is fully consistent with an initial impulse toward market integration originated by reforms implemented at the beginning of the last decade. - Highlights: → We exploit a model based on pricing-to-market behavior. → Price discrimination by Swiss exporters is found. → Nordic electricity markets are found to be already highly integrated. → Market integration was recently improved in continental area. → Results are consistent with reforms under the 'Second Legislative Package'.

  1. Cross-border integration in the European electricity market. Evidence from the pricing behavior of Norwegian and Swiss exporters

    Energy Technology Data Exchange (ETDEWEB)

    Balaguer, Jacint, E-mail: jacint.balaguer@eco.uji.es [Department of Economics, Universitat Jaume I, 12071 Castellon (Spain)

    2011-09-15

    This paper examines the electricity market integration process in two European areas based on the pricing behavior of Norwegian and Swiss exporters. The aim is to gain evidence for the period after the adoption of the 'Second Legislative Package' (2003). The pricing behavior of Norwegian exporters indicates that the wholesale markets for Denmark and Sweden are highly integrated. Moreover, results are fully compatible with the existence of a very competitive marketplace for electricity. This clearly contrasts with the evidence provided by Swiss exporters. In this last case, analysis revealed differences in pricing-to-market behavior between Italy, France and Germany, which indicates that exporters take advantage of international market segmentation and divergences between market structures. This outcome provides a reasonable explanation as to why price differences between countries cannot be fully attributed to transmission costs, as has been claimed in previous research. We also found cross-country convergence in levels of markups and in pricing-to-market behavior of the Swiss exporters for the first part of the period that was analyzed. The evidence is fully consistent with an initial impulse toward market integration originated by reforms implemented at the beginning of the last decade. - Highlights: > We exploit a model based on pricing-to-market behavior. > Price discrimination by Swiss exporters is found. > Nordic electricity markets are found to be already highly integrated. > Market integration was recently improved in continental area. > Results are consistent with reforms under the 'Second Legislative Package'.

  2. Meeting Curation Challenges in a Neuroimaging Group

    Directory of Open Access Journals (Sweden)

    Angus Whyte

    2008-08-01

    Full Text Available The SCARP project is a series of short studies with two aims; firstly to discover more about disciplinary approaches and attitudes to digital curation through ‘immersion’ in selected cases; secondly to apply known good practice, and where possible, identify new lessons from practice in the selected discipline areas. The study summarised here is of the Neuroimaging Group in the University of Edinburgh’s Division of Psychiatry, which plays a leading role in eScience collaborations to improve the infrastructure for neuroimaging data integration and reuse. The Group also aims to address growing data storage and curation needs, given the capabilities afforded by new infrastructure. The study briefly reviews the policy context and current challenges to data integration and sharing in the neuroimaging field. It then describes how curation and preservation risks and opportunities for change were identified throughout the curation lifecycle; and their context appreciated through field study in the research site. The results are consistent with studies of neuroimaging eInfrastructure that emphasise the role of local data sharing and reuse practices. These sustain mutual awareness of datasets and experimental protocols through sharing peer to peer, and among senior researchers and students, enabling continuity in research and flexibility in project work. This “human infrastructure” is taken into account in considering next steps for curation and preservation of the Group’s datasets and a phased approach to supporting data documentation.

  3. The search for neuroimaging and cognitive endophenotypes

    DEFF Research Database (Denmark)

    Miskowiak, Kamilla W.; Kjærstad, Hanne L; Meluken, Iselin

    2017-01-01

    and structural neuroimaging. Seventy-seven cross-sectional studies met the inclusion criteria. The present review revealed that URs in comparison with HCs showed: (i) widespread deficits in verbal memory, sustained attention, and executive function; (ii) abnormalities in the reactivity to and regulation...

  4. PET radioligand injection for pig neuroimaging

    DEFF Research Database (Denmark)

    Alstrup, Aage Kristian Olsen; Munk, Ole Lajord; Landau, Anne M.

    2018-01-01

    Pigs are useful models in neuroimaging studies with positron emission tomography. Radiolabeled ligands are injected intravenously at the start of the scan and in pigs, the most easily accessible route of administration is the ear vein. However, in brain studies the short distance between the brai...

  5. Neuroimaging in childhood headache: a systematic review

    Energy Technology Data Exchange (ETDEWEB)

    Alexiou, George A. [University of Ioannina, Department of Neurosurgery, Medical School, P.O. Box 103, Ioannina (Greece); Argyropoulou, Maria I. [University of Ioannina, Department of Radiology, Medical School, Ioannina (Greece)

    2013-07-15

    Headache is a common complaint in children, one that gives rise to considerable parental concern and fear of the presence of a space-occupying lesion. The evaluation and diagnosis of headache is very challenging for paediatricians, and neuroimaging by means of CT or MRI is often requested as part of the investigation. CT exposes children to radiation, while MRI is costly and sometimes requires sedation or general anaesthesia, especially in children younger than 6 years. This review of the literature on the value of neuroimaging in children with headache showed that the rate of pathological findings is generally low. Imaging findings that led to a change in patient management were in almost all cases reported in children with abnormal signs on neurological examination. Neuroimaging should be limited to children with a suspicious clinical history, abnormal neurological findings or other physical signs suggestive of intracranial pathology. Well-designed prospective studies are needed to better define the clinical findings that warrant neuroimaging in children with headache. (orig.)

  6. Neuroimaging in childhood headache: a systematic review

    International Nuclear Information System (INIS)

    Alexiou, George A.; Argyropoulou, Maria I.

    2013-01-01

    Headache is a common complaint in children, one that gives rise to considerable parental concern and fear of the presence of a space-occupying lesion. The evaluation and diagnosis of headache is very challenging for paediatricians, and neuroimaging by means of CT or MRI is often requested as part of the investigation. CT exposes children to radiation, while MRI is costly and sometimes requires sedation or general anaesthesia, especially in children younger than 6 years. This review of the literature on the value of neuroimaging in children with headache showed that the rate of pathological findings is generally low. Imaging findings that led to a change in patient management were in almost all cases reported in children with abnormal signs on neurological examination. Neuroimaging should be limited to children with a suspicious clinical history, abnormal neurological findings or other physical signs suggestive of intracranial pathology. Well-designed prospective studies are needed to better define the clinical findings that warrant neuroimaging in children with headache. (orig.)

  7. Hirayama disease: diagnostic essentials in neuroimaging.

    Science.gov (United States)

    Kapetanakis, Stylianos; Chourmouzi, Danae; Terzoudi, Aikaterini; Georgiou, Nikiforos; Giovannopoulou, Eirini

    2017-12-01

    A 22-year-old male presented with progressive muscular weakness of the upper extremities. MRI of the cervical spine established the final diagnosis of Hirayama disease (HD). HD is a rare disease with benign progress. Neurologists and radiologists should be aware of the specific neuroimaging signs of this rare clinical entity.

  8. Statistical Challenges in "Big Data" Human Neuroimaging.

    Science.gov (United States)

    Smith, Stephen M; Nichols, Thomas E

    2018-01-17

    Smith and Nichols discuss "big data" human neuroimaging studies, with very large subject numbers and amounts of data. These studies provide great opportunities for making new discoveries about the brain but raise many new analytical challenges and interpretational risks. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Online open neuroimaging mass meta-analysis

    DEFF Research Database (Denmark)

    Nielsen, Finn Årup; Kempton, Matthew J.; Williams, Steven C. R.

    We describe a system for meta-analysis where a wiki stores numerical data in a simple format and a web service performs the numerical computation. We initially apply the system on multiple meta-analyses of structural neuroimaging data results. The described system allows for mass meta-analysis, e...

  10. Causal linkages between electricity consumption and GDP in Thailand: evidence from the bounds test

    OpenAIRE

    Jiranyakul, Komain

    2014-01-01

    This paper investigates the causal relationship between electricity consumption and real GDP by applying the bounds testing for cointegration in a multivariate framework. The error correction mechanism is employed to detect causal relationship in the presence of cointegration among three variables. Empirical results for Thailand during 2001Q1 and 2014Q2 suggest that there is long-run bidirectional causality between electricity consumption and real GDP. The source of causation in the long run ...

  11. Evaluating the market splitting determinants: evidence from the Iberian spot electricity prices

    International Nuclear Information System (INIS)

    Figueiredo, Nuno Carvalho; Silva, Patrícia Pereira da; Cerqueira, Pedro A.

    2015-01-01

    This paper aims to assess the main determinants on the market splitting behaviour of the Iberian electricity spot markets. Iberia stands as an ideal case-study, where the high level deployment of wind power is observed, together with the implementation of the market splitting arrangement between the Portuguese and the Spanish spot electricity markets. Logit and non-parametric models are used to express the probability response for market splitting of day-ahead spot electricity prices as a function of the explanatory variables representing the main technologies in the generation mix: wind, hydro, thermal and nuclear power, together with the available transfer capacity and electricity demand. Logit models give preliminary indications about market splitting behaviour, and then, notwithstanding the demanding computational challenge, a non-parametric model is applied in order to overcome the limitations of the former models. Results show an increase of market splitting probability with higher wind power generation or, more generally, with higher availability of low marginal cost electricity such as nuclear power generation. The European interconnection capacity target of 10% of the peak demand of the smallest interconnected market might be insufficient to maintain electricity market integration. Therefore, pro-active coordination policies, governing both interconnections and renewables deployment, should be further developed. -- Highlights: •Assess determinants on market splitting behaviour of Iberian electricity markets. •Logit and non-parametric models to express market splitting probability response. •Explanatory variables: wind, hydro, thermal and nuclear power; ATC and demand. •Results: increase of market splitting probability with higher availability of low marginal cost electricity. •Coordination policies governing both interconnections and renewables deployment

  12. Evidence that pulsed electric field treatment enhances the cell wall porosity of yeast cells.

    Science.gov (United States)

    Ganeva, Valentina; Galutzov, Bojidar; Teissie, Justin

    2014-02-01

    The application of rectangular electric pulses, with 0.1-2 ms duration and field intensity of 2.5-4.5 kV/cm, to yeast suspension mediates liberation of cytoplasmic proteins without cell lysis. The aim of this study was to evaluate the effect of pulsed electric field with similar parameters on cell wall porosity of different yeast species. We found that electrically treated cells become more susceptible to lyticase digestion. In dependence on the strain and the electrical conditions, cell lysis was obtained at 2-8 times lower enzyme concentration in comparison with control untreated cells. The increase of the maximal lysis rate was between two and nine times. Furthermore, when applied at low concentration (1 U/ml), the lyticase enhanced the rate of protein liberation from electropermeabilized cells without provoking cell lysis. Significant differences in the cell surface of control and electrically treated cells were revealed by scanning electron microscopy. Data presented in this study allow us to conclude that electric field pulses provoke not only plasma membrane permeabilization, but also changes in the cell wall structure, leading to increased wall porosity.

  13. The crucial relationship among energy commodity prices: Evidence from the Spanish electricity market

    International Nuclear Information System (INIS)

    Moutinho, Victor; Vieira, Joel; Carrizo Moreira, Antonio

    2011-01-01

    The main purpose of this article is twofold to analyze: (a) the long-term relation among the commodities prices and between spot electricity market price and commodity prices, and (b) the short-term dynamics among commodity prices and between electricity prices and commodity prices. Data between 2002 and 2005 from the Spanish electricity market was used. Econometric methods were used in the analysis of the commodity spot price, namely the vector autoregression model, the vector error correction model and the granger causality test. The co-integration approach was used to analyze the long-term relationship between the common stochastic trends of four fossil fuel prices. One of the findings in the long-term relation is that the prices of fuel and the prices of Brent are intertwined, though the prices of Brent ten to 'move' to reestablish the price equilibrium. Another finding is that the price of electricity is explained by the evolution of the natural gas series. - Highlights: → We model energy commodity prices in the Spanish electricity market. → We examine the short and long-term relationships among commodities prices. → We examine short and long-term relationships using co-integration techniques. → We found that in the long run the prices of fuel and Brent are intertwined. → The evolution of price of electricity is explained by the evolution of price of gas.

  14. [Functional neuroimaging in the diagnosis of patients with Parkinsonism: Update and recommendations for clinical use].

    Science.gov (United States)

    Arbizu, J; Luquin, M R; Abella, J; de la Fuente-Fernández, R; Fernandez-Torrón, R; García-Solís, D; Garrastachu, P; Jiménez-Hoyuela, J M; Llaneza, M; Lomeña, F; Lorenzo-Bosquet, C; Martí, M J; Martinez-Castrillo, J C; Mir, P; Mitjavila, M; Ruiz-Martínez, J; Vela, L

    2014-01-01

    Functional Neuroimaging has been traditionally used in research for patients with different Parkinsonian syndromes. However, the emergence of commercial radiotracers together with the availability of single photon emission computed tomography (SPECT) and, more recently, positron emission tomography (PET) have made them available for clinical practice. Particularly, the development of clinical evidence achieved by functional neuroimaging techniques over the past two decades have motivated a progressive inclusion of several biomarkers in the clinical diagnostic criteria for neurodegenerative diseases that occur with Parkinsonism. However, the wide range of radiotracers designed to assess the involvement of different pathways in the neurodegenerative process underlying Parkinsonian syndromes (dopaminergic nigrostriatal pathway integrity, basal ganglia and cortical neuronal activity, myocardial sympathetic innervation), and the different neuroimaging techniques currently available (scintigraphy, SPECT and PET), have generated some controversy concerning the best neuroimaging test that should be indicated for the differential diagnosis of Parkinsonism. In this article, a panel of nuclear medicine and neurology experts has evaluated the functional neuroimaging techniques emphazising practical considerations related to the diagnosis of patients with uncertain origin parkinsonism and the assessment Parkinson's disease progression. Copyright © 2014 Elsevier España, S.L. and SEMNIM. All rights reserved.

  15. Neuroimaging in Psychiatry: A Review of the Background and ...

    African Journals Online (AJOL)

    There are two different types of neuroimaging of value in clinical psychiatry, namely: structural neuroimaging techniques (e.g., CT, MRI) which provide static images of the skull, and brain, and funnctional neuroimaging techniques (e.g., single photon emission CT [SPECT], positron emission tomography [PET], functional MRI ...

  16. The impact of daylight saving time on electricity consumption: Evidence from southern Norway and Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Mirza, Faisal Mehmood, E-mail: faisal.mirza@umb.no [Department of Economics and Resource Management, Norwegian University of Life Sciences (UMB), P.O. Box 5003, 1432 As (Norway); Bergland, Olvar, E-mail: olvar.bergland@umb.no [Department of Economics and Resource Management, Norwegian University of Life Sciences (UMB), P.O. Box 5003, 1432 As (Norway)

    2011-06-15

    This paper examines the impact of daylight saving time (DST) on electricity consumption in southern Norway and Sweden. As DST was implemented in both the countries in 1980, we do not have a clear counterfactual in the form of a control period to identify the impact of DST directly with before and after or with and without analysis. This problem in the study is resolved by using 'equivalent day normalization technique' to identify the impact of DST. The difference-in-difference (DID) average treatment effects model suggests an annual reduction of at least 1.0 percent in electricity consumption for both Norway and Sweden due to DST. The average annual electricity consumption reduction corresponding to DST effects equals 519 and 882 GWh for southern Norway and Sweden, resulting in an annual financial saving of 16.1 million Euros and 30.1 million Euros, respectively. The distribution of treatment effects across different hours of the day indicates a small but significant reduction in electricity consumption during the morning and a steep decline during the evening hours in both countries. - Highlights: > We assess the impact of DST on electricity consumption in southern Norway and Sweden. > DST reduces electricity consumption by 1.3 percent in both countries. > The impact is smaller during the morning hours but larger during evening hours. > Respective annual financial savings equal Euro 16.1 and 30.1 million for Norway and Sweden. > Average annual electricity savings equal 519 and 882 GWh for two countries, respectively.

  17. The impact of daylight saving time on electricity consumption: Evidence from southern Norway and Sweden

    International Nuclear Information System (INIS)

    Mirza, Faisal Mehmood; Bergland, Olvar

    2011-01-01

    This paper examines the impact of daylight saving time (DST) on electricity consumption in southern Norway and Sweden. As DST was implemented in both the countries in 1980, we do not have a clear counterfactual in the form of a control period to identify the impact of DST directly with before and after or with and without analysis. This problem in the study is resolved by using 'equivalent day normalization technique' to identify the impact of DST. The difference-in-difference (DID) average treatment effects model suggests an annual reduction of at least 1.0 percent in electricity consumption for both Norway and Sweden due to DST. The average annual electricity consumption reduction corresponding to DST effects equals 519 and 882 GWh for southern Norway and Sweden, resulting in an annual financial saving of 16.1 million Euros and 30.1 million Euros, respectively. The distribution of treatment effects across different hours of the day indicates a small but significant reduction in electricity consumption during the morning and a steep decline during the evening hours in both countries. - Highlights: → We assess the impact of DST on electricity consumption in southern Norway and Sweden. → DST reduces electricity consumption by 1.3 percent in both countries. → The impact is smaller during the morning hours but larger during evening hours. → Respective annual financial savings equal Euro 16.1 and 30.1 million for Norway and Sweden. → Average annual electricity savings equal 519 and 882 GWh for two countries, respectively.

  18. New evidence on the impact of structural reforms on electricity sector performance

    International Nuclear Information System (INIS)

    Polemis, Michael L.

    2016-01-01

    The evolution of electricity industry over the last decades has shown substantial differences between OECD countries. This paper empirically investigates to what extent different structural forms of regulation, competition and privatisation explain these international differences. It distinguishes three modes of electricity performance: a) net generation per capita, b) installed capacity and c) labour productivity. The empirical model spans the period 1975–2011 and uses panel data econometric techniques. Our analysis reveals that there is a strongly significant interaction impact on the level of electricity performance between regulation and competition. The empirical findings do confirm that a robust independent regulatory scheme must be implemented in order to achieve a competitive electricity market. - Highlights: •We assess the impact of structural reforms on OECD electricity sector performance. •Regulation has stronger impact on performance when interaction terms are present. •Privatisation has unambiguous effect on the elements of performance. •The combined effect of reforms on performance is more aggressive in the long run.

  19. Linear and nonlinear causality between sectoral electricity consumption and economic growth: Evidence from Taiwan

    International Nuclear Information System (INIS)

    Yang, Cheng-Lang; Lin, Hung-Pin; Chang, Chih-Heng

    2010-01-01

    This study investigates the linear and nonlinear causality between the total electricity consumption (TEC) and real gross domestic production (RGDP). Unlike previous literature, we solve the undetermined relation between RGDP and electricity consumption by classifying TEC into industrial sector consumption (ISC) and residential sector consumption (RSC) as well as investigating how TEC, ISC, and RSC influence Taiwan's RGDP. By using the Granger's linear causality test, it is shown that (i) there is a bidirectional causality among TEC, ISC, and RGDP, but a neutrality between RSC and RGDP with regard to the linear causality and (ii) there is still a bidirectional causality between TEC and RGDP, but a unidirectional causality between RSC and RGDP with regard to the nonlinear causality. On the basis of (i) and (ii), we suggest that the electricity policy formulators loosen the restriction on ISC and limit RSC in order to achieve the goal of economic growth.

  20. EU Emission Allowances and the stock market Evidence from the electricity industry

    International Nuclear Information System (INIS)

    Oberndorfer, Ulrich

    2009-01-01

    This paper constitutes - to our best knowledge - the first econometric analysis on stock market effects of the EU Emission Trading Scheme (EU ETS). Our results suggest that EU Emission Allowance (EUA) price developments matter to the stock performance of electricity firms: EUA price changes and stock returns of the most important European electricity corporations are shown to be positively related. This effect does not work asymmetrically, so that stock markets do not seem to react differently to EUA appreciations in comparison to depreciations. The carbon market effect is shown to be both time- and country-specific: It is particularly strong for the period of EUA market shock in early 2006, and differs with respect to the countries where the electricity corporations analysed are headquartered. Stock market reactions to EUA volatility could not be shown. (author)

  1. Firm size and productivity. Evidence from the electricity distribution industry in Brazil

    International Nuclear Information System (INIS)

    Tovar, Beatriz; Javier Ramos-Real, Francisco; De Almeida, Edmar Fagundes

    2011-01-01

    In this paper we apply Stochastic Frontier Analysis through a distance function to investigate the impact of firm size on productivity development in electricity distribution. We use a sample of seventeen Brazilian firms from 1998 to 2005 and decompose productivity into technical efficiency, scale efficiency and technical change. Moreover, a further step is to decompose the technical change measurement into several components. The results indicate that firm size is important for industry's productivity, and therefore a key aspect to consider when making decisions that affect the market structure in the electricity distribution industry. (author)

  2. Off-Grid Electricity Access and its Impact on Micro-Enterprises: Evidence from Rural Uganda

    Science.gov (United States)

    Muhoro, Peter N.

    The history of development shows convincingly that no country has substantially reduced poverty without massively increasing the use of electricity. The development of micro-enterprises in rural areas of Uganda is linked with increased access and use of electricity services. In this study, I combine quantitative and qualitative methods, including informal surveys, intra-business energy allocation studies and historical analysis, to analyze off-grid electricity access among micro-enterprises in rural western Uganda. I explore the linkages between of grid electricity access and the influence it has on micro- enterprises. Data is obtained from 56 micro-enterprises located in 11 village-towns within 3 districts in Uganda. In studying the micro-enterprises. the focus is on the services that are provided by electricity from modern energy carriers. The type of equipment used, forms of transportation, technical support, level of understanding and education of the entrepreneur, financing for energy equipment, and the role of donors are discussed in this thesis. Qualitative methods are used to allow for new insights and prioritization of concepts to emerge from the field rattier than from theory. Micro-enterprises in rural Uganda create income for the poor; they are resources for poverty reduction. With price adjustments, it becomes possible for those who live below the poverty line, nominally less than $1 a day, to afford the products and services and therefore mitigating the vicious cycle of poverty. Energy consumption among the micro-enterprises is at an average of 0.13kWh/day. The cost of accessing this amount of electricity attributes to about 50% of total revenue. I find that the "practices" used in off-grid electricity access lead to situations where the entrepreneurs have to evaluate pricing and output of products and services to generate higher profits. Such numbers indicate the need for appropriate technologies and profitable policies to be implemented. The data

  3. PET-based molecular nuclear neuro-imaging

    International Nuclear Information System (INIS)

    Kim, Jong Ho

    2004-01-01

    Molecular nuclear neuro-imaging in CNS drug discovery and development can be divided into four categories that are clearly inter-related. (1) Neuroreceptor mapping to examine the involvement of specific neurotransmitter system in CNS diseases, drug occupancy characteristics and perhaps examine mechanisms of action;(2) Structural and spectroscopic imaging to examine morphological changes and their consequences;(3) Metabolic mapping to provide evidence of central activity and CNS fingerprinting the neuroanatomy of drug effects;(4) Functional mapping to examine disease-drug interactions. In addition, targeted delivery of therapeutic agents could be achieved by modifying stem cells to release specific drugs at the site of transplantation('stem cell pharmacology'). Future exploitation of stem cell biology, including enhanced release of therapeutic factors through genetic stem cell engineering might thus constitute promising pharmaceutical approaches to treating diseases of the nervous system. With continued improvements in instrumentation, identification of better imaging probes by innovative chemistry, molecular nuclear neuro-imaging promise to play increasingly important roles in disease diagnosis and therapy

  4. Cholinergic modulation of cognition: Insights from human pharmacological functional neuroimaging

    Science.gov (United States)

    Bentley, Paul; Driver, Jon; Dolan, Raymond J.

    2011-01-01

    Evidence from lesion and cortical-slice studies implicate the neocortical cholinergic system in the modulation of sensory, attentional and memory processing. In this review we consider findings from sixty-three healthy human cholinergic functional neuroimaging studies that probe interactions of cholinergic drugs with brain activation profiles, and relate these to contemporary neurobiological models. Consistent patterns that emerge are: (1) the direction of cholinergic modulation of sensory cortex activations depends upon top-down influences; (2) cholinergic hyperstimulation reduces top-down selective modulation of sensory cortices; (3) cholinergic hyperstimulation interacts with task-specific frontoparietal activations according to one of several patterns, including: suppression of parietal-mediated reorienting; decreasing ‘effort’-associated activations in prefrontal regions; and deactivation of a ‘resting-state network’ in medial cortex, with reciprocal recruitment of dorsolateral frontoparietal regions during performance-challenging conditions; (4) encoding-related activations in both neocortical and hippocampal regions are disrupted by cholinergic blockade, or enhanced with cholinergic stimulation, while the opposite profile is observed during retrieval; (5) many examples exist of an ‘inverted-U shaped’ pattern of cholinergic influences by which the direction of functional neural activation (and performance) depends upon both task (e.g. relative difficulty) and subject (e.g. age) factors. Overall, human cholinergic functional neuroimaging studies both corroborate and extend physiological accounts of cholinergic function arising from other experimental contexts, while providing mechanistic insights into cholinergic-acting drugs and their potential clinical applications. PMID:21708219

  5. PET-based molecular nuclear neuro-imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Ho [Gil Medical Center, Gachon (Korea, Republic of)

    2004-04-01

    Molecular nuclear neuro-imaging in CNS drug discovery and development can be divided into four categories that are clearly inter-related. (1) Neuroreceptor mapping to examine the involvement of specific neurotransmitter system in CNS diseases, drug occupancy characteristics and perhaps examine mechanisms of action;(2) Structural and spectroscopic imaging to examine morphological changes and their consequences;(3) Metabolic mapping to provide evidence of central activity and CNS fingerprinting the neuroanatomy of drug effects;(4) Functional mapping to examine disease-drug interactions. In addition, targeted delivery of therapeutic agents could be achieved by modifying stem cells to release specific drugs at the site of transplantation('stem cell pharmacology'). Future exploitation of stem cell biology, including enhanced release of therapeutic factors through genetic stem cell engineering might thus constitute promising pharmaceutical approaches to treating diseases of the nervous system. With continued improvements in instrumentation, identification of better imaging probes by innovative chemistry, molecular nuclear neuro-imaging promise to play increasingly important roles in disease diagnosis and therapy.

  6. Neuroimaging of amblyopia and binocular vision: a review.

    Science.gov (United States)

    Joly, Olivier; Frankó, Edit

    2014-01-01

    Amblyopia is a cerebral visual impairment considered to derive from abnormal visual experience (e.g., strabismus, anisometropia). Amblyopia, first considered as a monocular disorder, is now often seen as a primarily binocular disorder resulting in more and more studies examining the binocular deficits in the patients. The neural mechanisms of amblyopia are not completely understood even though they have been investigated with electrophysiological recordings in animal models and more recently with neuroimaging techniques in humans. In this review, we summarize the current knowledge about the brain regions that underlie the visual deficits associated with amblyopia with a focus on binocular vision using functional magnetic resonance imaging. The first studies focused on abnormal responses in the primary and secondary visual areas whereas recent evidence shows that there are also deficits at higher levels of the visual pathways within the parieto-occipital and temporal cortices. These higher level areas are part of the cortical network involved in 3D vision from binocular cues. Therefore, reduced responses in these areas could be related to the impaired binocular vision in amblyopic patients. Promising new binocular treatments might at least partially correct the activation in these areas. Future neuroimaging experiments could help to characterize the brain response changes associated with these treatments and help devise them.

  7. Neuroimaging of amblyopia and binocular vision: a review

    Directory of Open Access Journals (Sweden)

    Olivier eJoly

    2014-08-01

    Full Text Available Amblyopia is a cerebral visual impairment considered to derive from abnormal visual experience (e.g., strabismus, anisometropia. Amblyopia, first considered as a monocular disorder, is now often seen as a primarily binocular disorder resulting in more and more studies examining the binocular deficits in the patients. The neural mechanisms of amblyopia are not completely understood even though they have been investigated with electrophysiological recordings in animal models and more recently with neuroimaging techniques in humans. In this review, we summarise the current knowledge about the brain regions that underlie the visual deficits associated with amblyopia with a focus on binocular vision using functional magnetic resonance imaging (fMRI. The first studies focused on abnormal responses in the primary and secondary visual areas whereas recent evidence show that there are also deficits at higher levels of the visual pathways within the parieto-occipital and temporal cortices. These higher level areas are part of the cortical network involved in 3D vision from binocular cues. Therefore, reduced responses in these areas could be related to the impaired binocular vision in amblyopic patients. Promising new binocular treatments might at least partially correct the activation in these areas. Future neuroimaging experiments could help to characterise the brain response changes associated with these treatments and help devise them.

  8. The Challenge Posed by Geomagnetic Activity to Electric Power Reliability: Evidence From England and Wales

    Science.gov (United States)

    Forbes, Kevin F.; St. Cyr, O. C.

    2017-10-01

    This paper addresses whether geomagnetic activity challenged the reliability of the electric power system during part of the declining phase of solar cycle 23. Operations by National Grid in England and Wales are examined over the period of 11 March 2003 through 31 March 2005. This paper examines the relationship between measures of geomagnetic activity and a metric of challenged electric power reliability known as the net imbalance volume (NIV). Measured in megawatt hours, NIV represents the sum of all energy deployments initiated by the system operator to balance the electric power system. The relationship between geomagnetic activity and NIV is assessed using a multivariate econometric model. The model was estimated using half-hour settlement data over the period of 11 March 2003 through 31 December 2004. The results indicate that geomagnetic activity had a demonstrable effect on NIV over the sample period. Based on the parameter estimates, out-of-sample predictions of NIV were generated for each half hour over the period of 1 January to 31 March 2005. Consistent with the existence of a causal relationship between geomagnetic activity and the electricity market imbalance, the root-mean-square error of the out-of-sample predictions of NIV is smaller; that is, the predictions are more accurate, when the statistically significant estimated effects of geomagnetic activity are included as drivers in the predictions.

  9. Evidence-Based Systematic Review: Effects of Neuromuscular Electrical Stimulation on Swallowing and Neural Activation

    Science.gov (United States)

    Clark, Heather; Lazarus, Cathy; Arvedson, Joan; Schooling, Tracy; Frymark, Tobi

    2009-01-01

    Purpose: To systematically review the literature examining the effects of neuromuscular electrical stimulation (NMES) on swallowing and neural activation. The review was conducted as part of a series examining the effects of oral motor exercises (OMEs) on speech, swallowing, and neural activation. Method: A systematic search was conducted to…

  10. Impact of electricity prices on foreign direct investment: Evidence from the European Union

    NARCIS (Netherlands)

    Bartekova, E.; Ziesemer, T.H.W.

    2015-01-01

    In the course of recent years growing concerns over increasing energy prices have emerged in the context of maintaining Europe’s international competitiveness. In particular, rising electricity price differentials adversely affect firms’ total production costs and ultimately impact their investment

  11. Is green energy expensive? Empirical evidence from the Spanish electricity market

    International Nuclear Information System (INIS)

    Ciarreta, Aitor; Espinosa, Maria Paz; Pizarro-Irizar, Cristina

    2014-01-01

    Renewable energy promotion and its cost are at the heart of the energy policy debate in many countries. The question from an economic perspective is how expensive the promotion of renewable sources through price-based incentive schemes is. This paper addresses this issue empirically. We analyze the Spanish electricity market during the period 2008–2012, where renewable energy production rose by 57%. To determine how expensive it was, we first measure the savings due to the spot price reduction driven by the merit order effect and, second, we compute the amount paid as incentives to green energy by the electricity system; the difference between the two is the net cost of green energy to the electricity markets. We present aggregate results for renewable sources as a whole, as well as individual results for each technology. We show that at the initial stages, when renewable capacity was low, green energy promotion paid for itself (2008–2009); however, from 2010 on, when renewable production reached a relatively high level, it started to impose a positive net cost on the system. Finally, we found substantial differences among technologies: wind energy implied the lowest net cost, while solar photovoltaic was the most expensive. - Highlights: • The combination of feed-in tariffs and premiums has been an effective instrument in the promotion of renewable electricity in Spain. • Significant reduction of the daily market price due to RES-E. • Considering the subsidies to RES-E this energy might seem rather expensive for the Spanish electricity system since 2010. • Substantial differences among technologies: wind energy implied the lowest net cost, while solar photovoltaic was the most expensive

  12. FDI spillovers at different levels of industrial and spatial aggregation: Evidence from the electricity sector

    International Nuclear Information System (INIS)

    Del Bo, Chiara F.

    2013-01-01

    The European electricity sector has undergone significant reforms in recent years, in the direction of market opening, integration and privatization. National and regional markets are now characterized by the presence of domestic and foreign firms, both privately and publicly owned. Did foreign entry induce positive productivity spillovers to domestic firms in the electricity sector, both at the aggregate and disaggregated level, while also controlling for domestic firms' ownership? This paper examines this issue by focusing on regional foreign direct investment (FDI) spillovers in the aggregated electricity sector and in the disaggregated sub-sectors of generation and distribution. The results show the importance of industry aggregation in determining the existence and sign of regional FDI spillovers for domestic firms. FDI spillovers are then calculated based on a purely geographic scale, by considering the distance between each firm's city of location and firms in neighboring cities. The importance and sign of FDI spillovers is different with respect to the analysis based on regional administrative boundaries, suggesting that spatial aggregation, along with industrial aggregation, is relevant in accounting for productivity spillover effects of foreign presence in the EU electricity sector. - Highlights: • Has the post-reform entry of foreign firms in the EU electricity sector induced spillover effects? • Spatial and industrial disaggregation are important when evaluating foreign direct investment (FDI) spillovers. • Positive horizontal spillovers are found only in the distribution segment of the industry. • Vertical spillovers in generation are negative; positive in distribution. • Spillover intensity in distribution decreasing with distance; regional dimension relevant in generation

  13. Evident?

    DEFF Research Database (Denmark)

    Plant, Peter

    2012-01-01

    Quality assurance and evidence in career guidance in Europe are often seen as self-evident approaches, but particular interests lie behind......Quality assurance and evidence in career guidance in Europe are often seen as self-evident approaches, but particular interests lie behind...

  14. Neuroimaging studies of self-reflection

    Institute of Scientific and Technical Information of China (English)

    ZHU Ying

    2004-01-01

    This paper reviews some basic findings and methodological issues in neuroimaging studies of self-referential processing.As a general rule,making judgments about one's self,inclusive of personality trait adjectives or current mental states(person's prefer ences,norms,aesthetic values and feeling)uniformly generates medial prefrontal activations,regardless of stimulus materials(words or pictures)and modality(visual or auditory).Cingulate activations are also observed in association with most self-referential processing.Methodological issues include treating self-referential processing as either representing one's own personality traits or representing one's own current mental states.Finally,self-referential processing could Be considered as implement of "I think therefore I am" approach to neuroimaging the self.

  15. Mathematical modeling and visualization of functional neuroimages

    DEFF Research Database (Denmark)

    Rasmussen, Peter Mondrup

    This dissertation presents research results regarding mathematical modeling in the context of the analysis of functional neuroimages. Specifically, the research focuses on pattern-based analysis methods that recently have become popular within the neuroimaging community. Such methods attempt...... sets are characterized by relatively few data observations in a high dimensional space. The process of building models in such data sets often requires strong regularization. Often, the degree of model regularization is chosen in order to maximize prediction accuracy. We focus on the relative influence...... be carefully selected, so that the model and its visualization enhance our ability to interpret the brain. The second part concerns interpretation of nonlinear models and procedures for extraction of ‘brain maps’ from nonlinear kernel models. We assess the performance of the sensitivity map as means...

  16. Neuroimaging Measures as Endophenotypes in Alzheimer's Disease

    Directory of Open Access Journals (Sweden)

    Meredith N. Braskie

    2011-01-01

    Full Text Available Late onset Alzheimer's disease (AD is moderately to highly heritable. Apolipoprotein E allele ε4 (APOE4 has been replicated consistently as an AD risk factor over many studies, and recently confirmed variants in other genes such as CLU, CR1, and PICALM each increase the lifetime risk of AD. However, much of the heritability of AD remains unexplained. AD is a complex disease that is diagnosed largely through neuropsychological testing, though neuroimaging measures may be more sensitive for detecting the incipient disease stages. Difficulties in early diagnosis and variable environmental contributions to the disease can obscure genetic relationships in traditional case-control genetic studies. Neuroimaging measures may be used as endophenotypes for AD, offering a reliable, objective tool to search for possible genetic risk factors. Imaging measures might also clarify the specific mechanisms by which proposed risk factors influence the brain.

  17. Neuroimaging in nuclear medicine: drug addicted brain

    Energy Technology Data Exchange (ETDEWEB)

    Chung, Yong-An; Kim, Dae-Jin [The Catholic University of Korea, Seoul (Korea, Republic of)

    2006-02-15

    Addiction to illicit drugs in one of today's most important social issues. Most addictive drugs lead to irreversible parenchymal changes in the human brain. Neuroimaging data bring to light the pharmacodynamics and pharmacokinetics of the abused drugs, and demonstrate that addiction is a disease of the brain. Continuous researches better illustrate the neurochemical alterations in brain function, and attempt to discover the links to consequent behavioral changes. Newer hypotheses and theories follow the numerous results, and more rational methods of approaching therapy are being developed. Substance abuse is on the rise in Korea, and social interest in the matter as well. On the other hand, diagnosis and treatment of drug addiction is still very difficult, because how the abused substance acts in the brain, or how it leads to behavioral problems in not widely known. Therefore, understanding the mechanism of drug addiction can improve the process of diagnosing addict patients, planning therapy, and predicting the prognosis . Neuroimaging approaches by nuclear medicine methods are expected to objectively judge behavioral and neurochemical changes, and response to treatment. In addition, as genes associated with addictive behavior are discovered, functional nuclear medicine images will aid in the assessment of individuals. Reviewing published literature on neuroimaging regarding nuclear medicine is expected to be of assistance to the management of drug addict patients. What's more, means of applying nuclear medicine to the care of drug addict patients should be investigated further.

  18. Neuroimaging in nuclear medicine: drug addicted brain

    International Nuclear Information System (INIS)

    Chung, Yong-An; Kim, Dae-Jin

    2006-01-01

    Addiction to illicit drugs in one of today's most important social issues. Most addictive drugs lead to irreversible parenchymal changes in the human brain. Neuroimaging data bring to light the pharmacodynamics and pharmacokinetics of the abused drugs, and demonstrate that addiction is a disease of the brain. Continuous researches better illustrate the neurochemical alterations in brain function, and attempt to discover the links to consequent behavioral changes. Newer hypotheses and theories follow the numerous results, and more rational methods of approaching therapy are being developed. Substance abuse is on the rise in Korea, and social interest in the matter as well. On the other hand, diagnosis and treatment of drug addiction is still very difficult, because how the abused substance acts in the brain, or how it leads to behavioral problems in not widely known. Therefore, understanding the mechanism of drug addiction can improve the process of diagnosing addict patients, planning therapy, and predicting the prognosis . Neuroimaging approaches by nuclear medicine methods are expected to objectively judge behavioral and neurochemical changes, and response to treatment. In addition, as genes associated with addictive behavior are discovered, functional nuclear medicine images will aid in the assessment of individuals. Reviewing published literature on neuroimaging regarding nuclear medicine is expected to be of assistance to the management of drug addict patients. What's more, means of applying nuclear medicine to the care of drug addict patients should be investigated further

  19. Functional neuroimaging in Tourette syndrome: recent perspectives

    Directory of Open Access Journals (Sweden)

    Debes NM

    2017-04-01

    Full Text Available Nanette Mol Debes, Marie Préel, Liselotte Skov Pediatric Department, Tourette Clinic, Herlev University Hospital, Herlev, DenmarkAbstract: The most recent functional neuroimaging studies on Tourette syndrome (TS are reviewed in this paper. Although it can be difficult to compare functional neuroimaging studies due to differences in methods, differences in age of the included subjects, and differences in the extent to which the presence of comorbidity, medical treatment, and severity of tics are considered in the various studies; most studies show that the cortico-striato-thalamo-cortical circuit seems to be involved in the generation of tics. Changes in this circuit seem to be correlated with tic severity. Correlations have been found between the presence of tics and hypermetabolism in various brain regions. Abnormalities of GABAergic, serotonergic, and dopaminergic neurotransmission in patients with TS have been suggested. During tic suppression, increased activity in the inferior frontal gyrus is seen. The premotor cortex might be involved in inhibition of motor control in subjects with TS. The right anterior insula is suggested to be a part of the urge–tic network. Several studies have shown altered motor network activations and sensorimotor gating deficits in subjects with TS. In future studies, inclusion of more well-defined subjects and further examination of premonitory urge and tic suppression is needed in order to increase the knowledge about the pathophysiology and treatment possibilities of TS. Keywords: functional neuroimaging, Tourette syndrome

  20. Who invests in renewable electricity production? : Empirical evidence and suggestions for further research

    OpenAIRE

    Bergek, Anna; Mignon, Ingrid; Sundberg, Gunnel

    2013-01-01

    Transforming energy systems to fulfill the needs of a low-carbon economy requires large investments in renewable electricity production (RES-E). Recent literature underlines the need to take a closer look at the composition of the RES-E investor group in order to understand the motives and investment processes of different types of investors. However, existing energy policies generally consider RES-E investments made on a regional or national level, and target investors who evaluate their RES...

  1. Beyond black lung: scientific evidence of health effects from coal use in electricity generation.

    Science.gov (United States)

    Buchanan, Susan; Burt, Erica; Orris, Peter

    2014-08-01

    While access to electricity affects health positively, combustion of coal in power plants causes well-documented adverse health effects. We review respiratory, cardiovascular, reproductive, and neurologic health outcomes associated with exposure to coal-fired power plant emissions. We also discuss population-level health effects of coal combustion and its role in climate change. Our review of scientific studies suggests that those we present here can be used to inform energy policy.

  2. What drives people's opinions of electricity infrastructure? Empirical evidence from Ireland

    International Nuclear Information System (INIS)

    Bertsch, Valentin; Hyland, Marie; Mahony, Michael

    2017-01-01

    Across the EU, significant infrastructure investment is needed in both generation from renewable energy sources (RES) and the electricity grid to meet the European targets on emission reduction and RES expansion. Experiences show, however, that citizens may object to new energy infrastructure in their localities which may cause delays in achieving the targets. To avoid delays, it is crucial to understand what drives people's opinions. To explore people's opinions of different electricity generation and transmission technologies in Ireland, we conducted a nationally-representative survey. Concerning the drivers, we distinguish between socio-demographics, technology-specific perceptions, and energy policy preferences. Our results show that people generally have positive views of RES technologies. While this indicates that Irish citizens agree to move towards cleaner electricity sources, we find reluctance amongst people to have these technologies located close to their places of residence. We find that, across most technologies, the tradeoff people make between economic and environmental policy objectives drives their opinions of, and their tendencies to oppose, technology developments. The significance of most socio-demographic variables, however, is largely technology-dependent. This highlights that policy makers need to understand how people make tradeoffs between policy objectives and how these tradeoffs relate to their opinions of different technologies. - Highlights: • Conducted a survey to understand drivers of opinions of electricity infrastructure. • Considered socio-demographic, policy-related and technology-specific drivers. • Irish citizens generally have positive opinions of renewable technologies. • Positive opinions don't rule out local opposition. • Tradeoffs on policy objectives shape opinions most consistently across technologies.

  3. Electric field-induced valley degeneracy lifting in uniaxial strained graphene: evidence from magnetophonon resonance

    OpenAIRE

    Assili, Mohamed; Haddad, Sonia; Kang, Woun

    2015-01-01

    A double peak structure in the magneto-phonon resonance (MPR) spectrum of uniaxial strained graphene, under crossed electric and magnetic fields, is predicted. We focus on the $\\Gamma$ point optical phonon modes coupled to the inter-Landau level transitions $0 \\leftrightarrows \\pm 1$ where MPR is expected to be more pronounced at high magnetic field. We derive the frequency shifts and the broadenings of the longitudinal (LO) and transverse (TO) optical phonon modes taking into account the eff...

  4. Can renewable energy be financed with higher electricity prices? Evidence from a Spanish region

    International Nuclear Information System (INIS)

    Gracia, Azucena; Barreiro-Hurlé, Jesús; Pérez y Pérez, Luis

    2012-01-01

    In this paper we estimate the willingness to pay for mix of renewable sources of electric power by means of a discrete choice experiment survey conducted in Spain in 2010. Two main categories of power supply attributes are explored: source of renewable power (wind, solar and biomass) and the origin of such power. The findings suggest that most consumers are not willing to pay a premium for increases in the shares of renewable in their electricity mix. For two of the three renewable sources considered (wind and biomass) an increase of the renewable mix would require a discount. Instead, we record positive willing to pay for increases in the share of both solar power and locally generated power. However, preferences for types of renewable (solar and wind) are found to be heterogeneous. By classifying respondents in two groups according to the implied importance of the share of renewable sources in their power mix we identify a market segment consisting of 20% of respondents that could promote renewable energy in the absence of subsidies. This is because such a segment shows willingness to pay higher than the current feed-in tariffs. - Highlights: ► We evaluate the WTP for different renewable electricity sources in a Aragon. ► Average positive WTP is found for only some renewable sources. ► Specific market segments are willing to pay for specific renewable sources. ► Geographical origin is more important than renewable source.

  5. Information v. energy efficiency incentives: Evidence from residential electricity consumption in Maryland

    International Nuclear Information System (INIS)

    Alberini, Anna; Towe, Charles

    2015-01-01

    We focus on two utility programs intended to reduce energy usage and the associated CO2 emissions—a home energy audit and rebates on the purchase of high-efficiency air-source heat pumps. We use a unique panel dataset from participating and non-participating households to estimate the average treatment effect of participating in either program on electricity usage. We fit models with household-by-season, season-by-year, and household-by-year fixed effects to account for all possible confounders that might influence energy usage. Since the programs are voluntary, we seek to restore near-exogeneity of the program “treatment” by matching participating households with control households. We deploy coarsened exact matching (CEM; Iacus et al., 2011) as our main matching method. We ask whether it is sufficient to match households based on past electricity usage, or if we gain by adding structural characteristics of the home, including heating system type. We find that the two programs reduce electricity usage by 5% on average. The effects are strong in both winter and summer for the energy audit groups but appear to be stronger in the winter for the heat pump rebate group. Adding house characteristics to the matching variables does seem to affect results, suggesting that using past usage alone, or house characteristics alone, may not be sufficient to identify the effects of program participation.

  6. Electric field of thunderclouds and cosmic rays: evidence for acceleration of particles (runaway electrons)

    CERN Document Server

    Khaerdinov, N S; Petkov, V B; 12th International Conference on Atmospheric Electricity

    2004-01-01

    We present the data on correlations of the intensity of the soft component of cosmic rays with the local electric field of the near-earth atmosphere during thunderstorm periods at the Baksan Valley (North Caucasus, 1700 m a. s. l.). The large-area array for studying the extensive air showers of cosmic rays is used as a particle detector. An electric field meter of the "electric mill" type (rain-protected) is mounted on the roof of the building in the center of this array. The data were obtained in the summer seasons of 2000-2002. We observe strong enhancements of the soft component intensity before some lightning strokes. At the same time, the analysis of the regression curve "intensity versus field" discovers a bump at the field sign that is opposite to the field sign corresponding to acceleration of electrons. It is interpreted as a signature of runaway electrons from the region of the strong field (with opposite sign) overhead.

  7. Electric field-induced valley degeneracy lifting in uniaxial strained graphene: Evidence from magnetophonon resonance

    Science.gov (United States)

    Assili, Mohamed; Haddad, Sonia; Kang, Woun

    2015-03-01

    A double peak structure in the magnetophonon resonance (MPR) spectrum of uniaxial strained graphene, under crossed electric and magnetic fields, is predicted. We focus on the Γ point optical phonon modes coupled to the inter-Landau level transitions 0 ⇆±1 where MPR is expected to be more pronounced at high magnetic field. We derive the frequency shifts and the broadenings of the longitudinal and transverse optical phonon modes taking into account the effect of the strain modified electronic spectrum on the electron-phonon coupling. We show that the MPR line for a given phonon mode acquires a double peak structure originating from the twofold valley degeneracy lifting. The latter is due to the different Landau level spacings in the two Dirac valleys resulting from the simultaneous action of the inplane electric field and the strain-induced Dirac cone tilt. We discuss the role of some key parameters such as disorder, strain, doping, and electric field amplitude on the emergence of the double peak structure.

  8. Do regulatory mechanisms promote competition and mitigate market power? Evidence from Spanish electricity market

    International Nuclear Information System (INIS)

    Moutinho, Victor; Moreira, António C.; Mota, Jorge

    2014-01-01

    This paper estimates the relationships between bidding quantities, marginal cost and market power measures in the Spanish wholesale electricity market for two different regulatory periods: 2002–2005 and 2006–2007. Using panel econometric techniques we find differences in the impacts on bidding strategies for both periods. Hence, the marginal cost and the market power measures affect bid and net quantities. The market power measures also suggest that the coefficient is consistently positive and highly significant for both periods. Moreover, the market power and marginal costs have mixed effects according to the models proposed for both periods. In addition, our results point to the effectiveness of the different effects of mitigating the market power in the Spanish electricity market. For the 2006–2007 period, the proposed causal relationships are partially validated by the cointegration results, which assumes there is a significant causality between the Lerner Index and the marginal cost. - Highlights: • Competition and regulation in the Spanish electricity market. • Net supplier and net demander behavior in the spot market. • Panel cointegration methods used: FMOLS, PMG, MG, DFE and DOLS. • The price cap regulation is effective in mitigating market power. • Market power and marginal cost have positive effects on bidding strategies

  9. Electricity-market price and nuclear power plant shutdown: Evidence from California

    International Nuclear Information System (INIS)

    Woo, C.K.; Ho, T.; Zarnikau, J.; Olson, A.; Jones, R.; Chait, M.; Horowitz, I.; Wang, J.

    2014-01-01

    Japan's Fukushima nuclear disaster, triggered by the March 11, 2011 earthquake, has led to calls for shutting down existing nuclear plants. To maintain resource adequacy for a grid's reliable operation, one option is to expand conventional generation, whose marginal unit is typically fueled by natural-gas. Two timely and relevant questions thus arise for a deregulated wholesale electricity market: (1) what is the likely price increase due to a nuclear plant shutdown? and (2) what can be done to mitigate the price increase? To answer these questions, we perform a regression analysis of a large sample of hourly real-time electricity-market price data from the California Independent System Operator (CAISO) for the 33-month sample period of April 2010–December 2012. Our analysis indicates that the 2013 shutdown of the state's San Onofre plant raised the CAISO real-time hourly market prices by $6/MWH to $9/MWH, and that the price increases could have been offset by a combination of demand reduction, increasing solar generation, and increasing wind generation. - Highlights: • Japan's disaster led to calls for shutting down existing nuclear plants. • We perform a regression analysis of California's real-time electricity-market prices. • We estimate that the San Onofre plant shutdown has raised the market prices by $6/MWH to $9/MWH. • The price increases could be offset by demand reduction and renewable generation increase

  10. The comparative advantages of public ownership : evidence from U.S. electric utilities

    International Nuclear Information System (INIS)

    Kwoka, J.E.Jr.

    2005-01-01

    This paper challenged the conventional economic theory that private enterprises result in higher cost and price performance by indicating that several empirical studies have shown equal or better performance by public enterprises. These divergent findings have prompted renewed theoretical attention to the public-private debate. Recent theory has identified possible benefits of public enterprise in certain circumstances. It has been argued that public owners can better secure the information needed to monitor business behaviour for consistency with social objectives. This study tested the relative benefits of public versus private companies in producing outputs with more specifiable and less specifiable quality. The empirical tests were conducted on the electric power industry in the United States because it has structural characteristics that make it ideal for the study. Also, both ownership types perform the similar tasks of electricity generation, transmission and distribution. In addition, all segments of the electric power industry have at some point been regulated and have been non competitive. The study showed that while privately owned systems achieve lower costs in generation, public systems typically have the advantage in the end-user-oriented distribution function with more non-contractible disposition. The study emphasized the importance of identifying product, market and provider characteristics best suited to each ownership type. It cautioned that the search for better performance is not simply a matter of prescribing privatization. Rather, there are identifiable circumstances in which public enterprise is appropriate. 26 refs., 5 tabs

  11. Key Drivers of PPPs in Electricity Generation in Developing Countries : Cross-Country Evidence of Switching between PPP Investment in Fossil Fuel and Renewable-Based Generation

    OpenAIRE

    Vagliasindi, Maria

    2012-01-01

    This paper presents new global evidence on the key determinants of public-private partnership investment in electricity generated by fossil fuels and renewable energy based on a panel data analysis for 105 developing countries over a period of 16 years from 1993 to 2008. It aims to identify the key factors affecting private investors' decision to enter electricity generation, through probi...

  12. Recent neuroimaging techniques in mild traumatic brain injury.

    Science.gov (United States)

    Belanger, Heather G; Vanderploeg, Rodney D; Curtiss, Glenn; Warden, Deborah L

    2007-01-01

    Mild traumatic brain injury (TBI) is characterized by acute physiological changes that result in at least some acute cognitive difficulties and typically resolve by 3 months postinjury. Because the majority of mild TBI patients have normal structural magnetic resonance imaging (MRI)/computed tomography (CT) scans, there is increasing attention directed at finding objective physiological correlates of persistent cognitive and neuropsychiatric symptoms through experimental neuroimaging techniques. The authors review studies utilizing these techniques in patients with mild TBI; these techniques may provide more sensitive assessment of structural and functional abnormalities following mild TBI. Particular promise is evident with fMRI, PET, and SPECT scanning, as demonstrated by associations between brain activation and clinical outcomes.

  13. The market value and impact of offshore wind on the electricity spot market: Evidence from Germany

    International Nuclear Information System (INIS)

    Ederer, Nikolaus

    2015-01-01

    Highlights: • Market value of offshore wind based on feed-in and weather data is assessed. • Merit order effect caused by wind energy is simulated for 2006–2014. • Results indicate same impact of on- and offshore wind on market price and value. • Steadier wind resource offshore imposes less variability on market price. • Characteristic of variable wind feed-in cannot be blamed for price deterioration. - Abstract: Although the expansion of offshore wind has recently increased in Germany, as in other countries, it is still forced to defend its role in long-term energy policy plans, particularly against its onshore counterpart, to secure future expansion targets and financial support. The objective of this article is to investigate the economic effects of offshore wind on the electricity spot market and thus open up another perspective that has not been part of the debate about offshore vs. onshore wind thus far. A comprehensive assessment based on a large amount of market, feed-in and weather data in Germany revealed that the market value of offshore wind is generally higher than that of onshore wind. Simulating the merit order effect on the German day-ahead electricity market for the short term and long term in the years 2006–2014 aimed to identify the reason for this observation and show whether it is also an indication of a lower impact on the electricity spot market due to a steadier wind resource prevailing offshore. Although the results suggest no difference regarding the impact on market price and value, they indeed reveal that offshore wind imposes less variability on the spot market price than onshore wind. In addition, the long-term simulation proved that the ongoing price deterioration cannot be blamed on the characteristic of variable wind production

  14. Earnings management under price regulation. Empirical evidence from the Spanish electricity industry

    International Nuclear Information System (INIS)

    Gill-de-Albornoz, Belen; Illueca, Manuel

    2005-01-01

    This paper analyses the effect of price regulation on the accounting policy of Spanish electricity companies over the period 1991-2001. As predicted by the political costs hypothesis (Watts and Zimmerman, 1986) (Watts, R.L., Zimmerman, J.L. 1986. Positive accounting theory, Prentice Hall, Englewood Cliffs, NJ), managers artificially reduce reported earnings when the government establishes tariff increases. In this way, companies attempt to diminish their political visibility and counteract social outcry arising from the government's decision. Several abnormal accruals models existent in the literature are used to obtain a proxy for managerial accounting discretion on earnings

  15. Market Power in Power Markets: Evidence from Forward Prices of Electricity

    DEFF Research Database (Denmark)

    Christensen, Bent Jesper; Jensen, Thomas Elgaard; Mølgaard, Rune

    We examine the forward market for electricity for indications of misuse of market power, using a unique data set on OTC price indications posted by Elsam A/S, the dominant producer in Western Denmark, which is one of the price areas under the Nordic power exchange Nord Pool. The Danish Competition...... Council (the regulatory government agency) has ruled that Elsam has used its dominant position to obtain excessive spot prices over a period from July 2003 through December 2006. We show that significant forward premia exist, and that they are related both to spot market volatility and misuse of market...... are consistent across forward premium regressions and structural forward pricing models....

  16. Price freezes, durables and residential electricity demand - Evidence from the Greater Buenos Aires

    Energy Technology Data Exchange (ETDEWEB)

    Casarin, Ariel; Delfino, Maria Eugenia

    2010-09-15

    This paper examines the determinants of residential electricity demand in the Greater Buenos Aires between 1997 and 2006. During the second half of this period, residential tariffs remained nominally fixed, while an income boom boosted up the sales of durables. This study differs from previous works in that it explicitly considers the impact of the stock of air-conditioners on residential demand. The paper reports short- and long-run elasticities and examines the contribution of prices and durables to recent demand growth. Simulations illustrate the impact of prices and durables on future demand.

  17. Evidence of skeletal muscle damage following electrically stimulated isometric muscle contractions in humans

    DEFF Research Database (Denmark)

    Mackey, Abigail; Bojsen-Moller, Jens; Qvortrup, Klaus

    2008-01-01

    and desmin-negative staining in a small percentage of myofibers in five and four individuals, respectively. z-Line disruption was evident at varying magnitudes in all subjects and displayed a trend toward a positive correlation (r = 0.73, P = 0.0663) with the force produced by stimulation. Increased muscle...

  18. When do firms generate? Evidence on in-house electricity supply in Africa

    International Nuclear Information System (INIS)

    Steinbuks, J.; Foster, V.

    2010-01-01

    This paper attempts to identify the underlying causes and costs of own generation of electric power in Africa. Rigorous empirical analysis of 8483 currently operating firms in 25 African countries shows that the prevalence of own generation would remain high (at around 20%) even if power supplies were perfectly reliable, suggesting that other factors such as firms' size, emergency back-up and export regulations play a critical role in the decision to own a generator. The costs of own-generation are about three times as high as the price of purchasing (subsidized) electricity from the public grid. However, because these generators only operate a small fraction of the time, they do not greatly affect the overall average cost of power to industry. The benefits of generator ownership are also substantial. Firms with their own generators report a value of lost load of less than US$50 per hour, compared with more than US$150 per hour for those without. Nevertheless, when costs and benefits are considered side by side, the balance is not found to be significantly positive. (author)

  19. Is Power Production Flexibility a Substitute for Storability? Evidence from Electricity Futures Prices

    Energy Technology Data Exchange (ETDEWEB)

    Kilic, M.; Huisman, R. [Erasmus School of Economics, Erasmus University Rotterdam, Rotterdam (Netherlands)

    2010-07-15

    Electricity is not storable. As a consequence, electricity demand and supply need to be in balance at any moment in time as a shortage in production volume cannot be compensated with supply from inventories. However, if the installed power supply capacity is very flexible, variation in demand can be counterbalanced with flexible adjustment of production volumes. Therefore, supply flexibility can replace the role of inventory. In this paper, we question whether power production flexibility is a substitute for storability. To do so, we examine power futures prices from countries that differ in their power supply and test whether power futures prices contain information about expected future spot prices and risk premiums and examine whether futures prices from a market in which power supply is more flexible would lead to futures prices that are more in line with the theory of storage. We find the opposite; futures prices from markets with flexible power supply behave according to the expectations theory. The implicit view from futures prices is that flexibility is not a substitute for storability.

  20. Consumer-Oriented Policy towards Diffusion of Electric Vehicles: City-Level Evidence from China

    Directory of Open Access Journals (Sweden)

    Guoqiang Zhang

    2016-12-01

    Full Text Available Public policy is crucial for the diffusion of green innovation, and debates exist about the effects of different policies. This paper explores appropriate types of policy instruments by explaining the quick rise in sales of electric vehicles (EVs in China. Based on a three-year longitudinal dataset across 88 cities, the study shows that consumer-oriented policies are able to significantly promote EV diffusion. Consumer-oriented policies target consumers to facilitate their usage of cars and lower the lifecycle cost, and typical examples include electricity charging and traffic management. This paper contributes to the literature of clean technology policy in two ways. Firstly, it reveals and empirically tests the importance of consumer-oriented policy instruments for the deployment of green innovation. Secondly, it is one of very few scholarly works offering a detailed review of city-level policies in China’s EV industry, which will be useful for scholars who are also interested in similar topics.

  1. Electricity intensity across Chinese provinces: New evidence on convergence and threshold effects

    International Nuclear Information System (INIS)

    Herrerias, M.J.; Liu, G.

    2013-01-01

    Energy intensity has gone through different stages across Chinese regions. In this paper, we investigate the stochastic electricity-intensity convergence across the Chinese provinces. Unlike previous work, this paper highlights the relevance of the level of technology of each province and takes into account the economic geography through the examination of club convergence. We perform several unit root tests that introduce structural breaks, nonlinearities and time variation, with the aim to capture the economic transformation of the Chinese economy. Results indicate that the majority of the Chinese regions have converged according to the unit-root tests in time-series analysis, indicating that technological differences diminish over time. However, this convergence pattern occurs within groups of regions, according with club convergence test. Indeed, we find a dominant club and others smaller clubs that few regions belong. However, it is observed that there are regions that still diverge. These findings support our argument that special policy attention is required for those regions displaying divergence. - Highlights: ► Electricity-intensity convergence across the Chinese provinces is investigated. ► We use monthly data. ► We highlight the relevance of the level of technology of each province and the economic geography. ► Recent unit root tests are employed. ► We found club convergence

  2. Is Power Production Flexibility a Substitute for Storability? Evidence from Electricity Futures Prices

    International Nuclear Information System (INIS)

    Kilic, M.; Huisman, R.

    2010-07-01

    Electricity is not storable. As a consequence, electricity demand and supply need to be in balance at any moment in time as a shortage in production volume cannot be compensated with supply from inventories. However, if the installed power supply capacity is very flexible, variation in demand can be counterbalanced with flexible adjustment of production volumes. Therefore, supply flexibility can replace the role of inventory. In this paper, we question whether power production flexibility is a substitute for storability. To do so, we examine power futures prices from countries that differ in their power supply and test whether power futures prices contain information about expected future spot prices and risk premiums and examine whether futures prices from a market in which power supply is more flexible would lead to futures prices that are more in line with the theory of storage. We find the opposite; futures prices from markets with flexible power supply behave according to the expectations theory. The implicit view from futures prices is that flexibility is not a substitute for storability.

  3. The representation of object distance: evidence from neuroimaging and neuropsychology

    Directory of Open Access Journals (Sweden)

    Marian Berryhill

    2009-11-01

    Full Text Available Perceived distance in two-dimensional images relies on monocular distance cues. Here, we examined the representation of perceived object distance using a continuous carry-over adaptation design for fMRI. The task was to look at photographs of objects and make a judgment as to whether or not the item belonged in the kitchen. Importantly, this task was orthogonal to the variable of interest: the object’s perceived distance from the viewer. In Experiment 1, whole brain group analyses identified bilateral clusters in the superior occipital gyrus (approximately area V3/V3A that showed parametric adaptation to relative changes in perceived distance. In Experiment 2, retinotopic analyses confirmed that area V3A/B reflected the greatest magnitude of response to monocular changes in perceived distance. In Experiment 3, we report that the functional activations overlap with the occipito-parietal lesions in a patient with impaired distance perception, showing that the same regions monitor implied (two-dimensional and actual (three-dimensional distance. These data suggest that distance information is automatically processed even when it is task-irrelevant and that this process relies on superior occipital areas in and around area V3A.

  4. [Psychotherapy of Depression as Neurobiological Process - Evidence from Neuroimaging].

    Science.gov (United States)

    Rubart, Antonie; Hohagen, Fritz; Zurowski, Bartosz

    2018-06-01

    Research on neurobiological effects of psychotherapy in depression facilitates the improvement of treatment strategies. The cortico-limbic dysregulation model serves as a framework for numerous studies on neurobiological changes in depression. In this model, depression is described as hypoactivation of dorsal cortical brain regions in conjunction with hyperactivation of ventral paralimbic regions. This assumption has been supported by various studies of structural and functional brain abnormalities in depression. However, also regions not included in the original cortico-limbic dysregulation model, such as the dorsomedial prefrontal cortex, seem to play an important role in depression. Functional connectivity studies of depression have revealed an enhanced connectivity within the so-called default mode network which is involved in self-referential thinking. Studies also point to a normalization of limbic and cortical brain activity, especially in the anterior cingulate cortex, during psychotherapy. Some neurobiological markers like the activity of the anterior cingulate cortex, striatum and insula as well as hippocampal volume have been proposed to predict treatment response on a group-level. The activity of the anterior insula appears to be a candidate bio-marker for differential indication for psychotherapy or pharmacotherapy. The cortico-limbic dysregulation model and following research have inspired new forms of treatment for depression like deep brain stimulation of the subgenual anterior cingulate cortex, repetitive transcranial magnetic stimulation of the dorsolateral prefrontal cortex, neurofeedback and attention training. © Georg Thieme Verlag KG Stuttgart · New York.

  5. How emotion leads to selective memory: neuroimaging evidence.

    Science.gov (United States)

    Waring, Jill D; Kensinger, Elizabeth A

    2011-06-01

    Often memory for emotionally arousing items is enhanced relative to neutral items within complex visual scenes, but this enhancement can come at the expense of memory for peripheral background information. This 'trade-off' effect has been elicited by a range of stimulus valence and arousal levels, yet the magnitude of the effect has been shown to vary with these factors. Using fMRI, this study investigated the neural mechanisms underlying this selective memory for emotional scenes. Further, we examined how these processes are affected by stimulus dimensions of arousal and valence. The trade-off effect in memory occurred for low to high arousal positive and negative scenes. There was a core emotional memory network associated with the trade-off among all the emotional scene types, however, there were additional regions that were uniquely associated with the trade-off for each individual scene type. These results suggest that there is a common network of regions associated with the emotional memory trade-off effect, but that valence and arousal also independently affect the neural activity underlying the effect. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. How emotion leads to selective memory: Neuroimaging evidence

    OpenAIRE

    Waring, Jill D.; Kensinger, Elizabeth A.

    2011-01-01

    Often memory for emotionally arousing items is enhanced relative to neutral items within complex visual scenes, but this enhancement can come at the expense of memory for peripheral background information. This ‘trade-off’ effect has been elicited by a range of stimulus valence and arousal levels, yet the magnitude of the effect has been shown to vary with these factors. Using fMRI, this study investigated the neural mechanisms underlying this selective memory for emotional scenes. Further, w...

  7. Volumetric neuroimaging in Usher syndrome: evidence of global involvement.

    Science.gov (United States)

    Schaefer, G B; Bodensteiner, J B; Thompson, J N; Kimberling, W J; Craft, J M

    1998-08-27

    Usher syndrome is a group of genetic disorders consisting of congenital sensorineural hearing loss and retinitis pigmentosa of variable onset and severity depending on the genetic type. It was suggested that the psychosis of Usher syndrome might be secondary to a metabolic degeneration involving the brain more diffusely. There have been reports of focal and diffuse atrophic changes in the supratentorial brain as well as atrophy of some of the structures of the posterior fossa. We previously performed quantitative analysis of magnetic resonance imaging studies of 19 Usher syndrome patients (12 with type I and 7 with type II) looking at the cerebellum and various cerebellar components. We found atrophy of the cerebellum in both types and sparing of cerebellar vermis lobules I-V in type II Usher syndrome patients only. We now have studied another group of 19 patients (with some overlap in the patients studied from the previous report) with Usher syndrome (8 with type I, 11 with type II). We performed quantitative volumetric measurements of various brain structures compared to age- and sex-matched controls. We found a significant decrease in intracranial volume and in size of the brain and cerebellum with a trend toward an increase in the size of the subarachnoid spaces. These data suggest that the disease process in Usher syndrome involves the entire brain and is not limited to the posterior fossa or auditory and visual systems.

  8. Divergence in technical efficiency of electric utilities: Evidence from the SAPP

    International Nuclear Information System (INIS)

    Jaunky, Vishal Chandr

    2013-01-01

    This paper investigates the convergence pattern of technical efficiency of the South Africa Power Pool (SAPP) utilities over the period April 2003–March 2010 by means of parametric and non-parametric techniques. Technical efficiency scores are computed via both stochastic frontier analysis and data envelopment analysis. Mixed results are obtained from the neoclassical convergence approaches. In addition, distribution dynamics methods reveal some evidence of club-formation and this result is supported with the occurrence of γ-divergence. Taken as a whole, technical efficiency is found to diverge among the utilities operating in the power pool. -- Highlights: •The technical efficiency convergence pattern within the South Africa Power Pool is assessed. •Mixed results are obtained from the parametric neoclassical convergence approaches. •Evidence of divergence is revealed by the non-parametric convergence approaches

  9. The impact of government incentives for hybrid-electric vehicles: Evidence from US states

    International Nuclear Information System (INIS)

    Diamond, David

    2009-01-01

    This paper examines the impact of government incentives policies designed to promote the adoption of hybrid-electric vehicles (HEVs). As a primary methodology, it employs cross-sectional analysis of hybrid registration data over time from US states to test the relationship between hybrid adoption and a variety of socioeconomic and policy variables. It also compares hybrid adoption patterns over time to the US average for specific states that have changed incentive policies, to examine how differences in incentive schemes influence their efficacy. The results of these analyses suggest a strong relationship between gasoline prices and hybrid adoption, but a much weaker relationship between incentive policies and hybrid adoption. Incentives that provide payments upfront also appear to be the most effective

  10. Neural correlates of fear: insights from neuroimaging

    Directory of Open Access Journals (Sweden)

    Garfinkel SN

    2014-12-01

    Full Text Available Sarah N Garfinkel,1,2 Hugo D Critchley1,2 1Sackler Centre for Consciousness Science, 2Department of Psychiatry, Brighton and Sussex Medical School, University of Sussex, Brighton, UK Abstract: Fear anticipates a challenge to one's well-being and is a reaction to the risk of harm. The expression of fear in the individual is a constellation of physiological, behavioral, cognitive, and experiential responses. Fear indicates risk and will guide adaptive behavior, yet fear is also fundamental to the symptomatology of most psychiatric disorders. Neuroimaging studies of normal and abnormal fear in humans extend knowledge gained from animal experiments. Neuroimaging permits the empirical evaluation of theory (emotions as response tendencies, mental states, and valence and arousal dimensions, and improves our understanding of the mechanisms of how fear is controlled by both cognitive processes and bodily states. Within the human brain, fear engages a set of regions that include insula and anterior cingulate cortices, the amygdala, and dorsal brain-stem centers, such as periaqueductal gray matter. This same fear matrix is also implicated in attentional orienting, mental planning, interoceptive mapping, bodily feelings, novelty and motivational learning, behavioral prioritization, and the control of autonomic arousal. The stereotyped expression of fear can thus be viewed as a special construction from combinations of these processes. An important motivator for understanding neural fear mechanisms is the debilitating clinical expression of anxiety. Neuroimaging studies of anxiety patients highlight the role of learning and memory in pathological fear. Posttraumatic stress disorder is further distinguished by impairment in cognitive control and contextual memory. These processes ultimately need to be targeted for symptomatic recovery. Neuroscientific knowledge of fear has broader relevance to understanding human and societal behavior. As yet, only some of

  11. Advances on functional neuroimaging in substance misuse

    International Nuclear Information System (INIS)

    Lv Rongbin; Liu Xingdang; Han Mei

    2009-01-01

    Over the past decade, functional neuroimaging has contributed greatly to our knowledge about the neuropharmacology of substance misuse in man. In this review, discussed the application and the progress of the positron emission tomography, single photon emission computed tomography and functional magnetic resonance imaging in the substance misuse. After reading some papers, found that the dopamine transporter was significantly decreased in the brain of subjects with heroin abuse. Also observed a significant decrease of regional cerebral blood flow in bilateral cerebral frontal lobes, temporal lobes, the insula and the ipsilateral basal nuclei in substance misuse subjects. Taken together, functional images will lead the direction in future research formedication development of addiction treatment. (authors)

  12. Neuroimaging Features of San Luis Valley Syndrome

    Directory of Open Access Journals (Sweden)

    Matthew T. Whitehead

    2015-01-01

    Full Text Available A 14-month-old Hispanic female with a history of double-outlet right ventricle and developmental delay in the setting of recombinant chromosome 8 syndrome was referred for neurologic imaging. Brain MR revealed multiple abnormalities primarily affecting midline structures, including commissural dysgenesis, vermian and brainstem hypoplasia/dysplasia, an interhypothalamic adhesion, and an epidermoid between the frontal lobes that enlarged over time. Spine MR demonstrated hypoplastic C1 and C2 posterior elements, scoliosis, and a borderline low conus medullaris position. Presented herein is the first illustration of neuroimaging findings from a patient with San Luis Valley syndrome.

  13. [Conversion disorder : functional neuroimaging and neurobiological mechanisms].

    Science.gov (United States)

    Lejeune, J; Piette, C; Salmon, E; Scantamburlo, G

    2017-04-01

    Conversion disorder is a psychiatric disorder often encountered in neurology services. This condition without organic lesions was and still is sometimes referred as an imaginary illness or feigning. However, the absence of organic lesions does not exclude the possibility of cerebral dysfunction. The etiologic mechanisms underlying this disorder remain uncertain even today.The advent of cognitive and functional imaging opens up a field of exploration for psychiatry in understanding the neurobiological mechanisms underlying mental disorders and especially the conversion disorder. This article reports several neuroimaging studies of conversion disorder and attempts to generate hypotheses about neurobiological mechanisms.

  14. Functional neuroimaging studies of episodic memory. Functional dissociation in the medial temporal lobe structures

    International Nuclear Information System (INIS)

    Tsukiura, Takashi

    2008-01-01

    Previous functional neuroimaging studies have demonstrated the critical role of the medial temporal lobe (MTL) regions in the encoding and retrieval of episodic memory. It has also been shown that an emotional factor in human memory enhances episodic encoding and retrieval. However, there is little evidence regarding the specific contribution of each MTL region to the relational, contextual, and emotional processes of episodic memory. The goal of this review article is to identify differential activation patterns of the processes between MTL regions. Results from functional neuroimaging studies of episodic memory show that the hippocampus is involved in encoding the relation between memory items, whereas the entorhinal and perirhinal cortices (anterior parahippocampal gyrus) contribute to the encoding of a single item. Additionally, the parahippocampal cortex (posterior parahippocampal gyrus) is selectively activated during the processing of contextual information of episodic memory. A similar pattern of functional dissociation is found in episodic memory retrieval. Functional neuroimaging has also shown that emotional information of episodic memory enhances amygdala-MTL correlations and that this enhancement is observed during both the encoding and retrieval of emotional memories. These findings from pervious neuroimaging studies suggest that different MTL regions could organize memory for personally experienced episodes via the 'relation' and 'context' factors of episodic memory, and that the emotional factor of episodes could modulate the functional organization in the MTL regions. (author)

  15. Towards a model-based cognitive neuroscience of stopping - a neuroimaging perspective.

    Science.gov (United States)

    Sebastian, Alexandra; Forstmann, Birte U; Matzke, Dora

    2018-07-01

    Our understanding of the neural correlates of response inhibition has greatly advanced over the last decade. Nevertheless the specific function of regions within this stopping network remains controversial. The traditional neuroimaging approach cannot capture many processes affecting stopping performance. Despite the shortcomings of the traditional neuroimaging approach and a great progress in mathematical and computational models of stopping, model-based cognitive neuroscience approaches in human neuroimaging studies are largely lacking. To foster model-based approaches to ultimately gain a deeper understanding of the neural signature of stopping, we outline the most prominent models of response inhibition and recent advances in the field. We highlight how a model-based approach in clinical samples has improved our understanding of altered cognitive functions in these disorders. Moreover, we show how linking evidence-accumulation models and neuroimaging data improves the identification of neural pathways involved in the stopping process and helps to delineate these from neural networks of related but distinct functions. In conclusion, adopting a model-based approach is indispensable to identifying the actual neural processes underlying stopping. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  16. Practical management of heterogeneous neuroimaging metadata by global neuroimaging data repositories.

    Science.gov (United States)

    Neu, Scott C; Crawford, Karen L; Toga, Arthur W

    2012-01-01

    Rapidly evolving neuroimaging techniques are producing unprecedented quantities of digital data at the same time that many research studies are evolving into global, multi-disciplinary collaborations between geographically distributed scientists. While networked computers have made it almost trivial to transmit data across long distances, collecting and analyzing this data requires extensive metadata if the data is to be maximally shared. Though it is typically straightforward to encode text and numerical values into files and send content between different locations, it is often difficult to attach context and implicit assumptions to the content. As the number of and geographic separation between data contributors grows to national and global scales, the heterogeneity of the collected metadata increases and conformance to a single standardization becomes implausible. Neuroimaging data repositories must then not only accumulate data but must also consolidate disparate metadata into an integrated view. In this article, using specific examples from our experiences, we demonstrate how standardization alone cannot achieve full integration of neuroimaging data from multiple heterogeneous sources and why a fundamental change in the architecture of neuroimaging data repositories is needed instead.

  17. Functional Neuroimaging of Motor Control inParkinson’s Disease

    DEFF Research Database (Denmark)

    Herz, Damian M; Eickhoff, Simon B; Løkkegaard, Annemette

    2014-01-01

    Functional neuroimaging has been widely used to study the activation patterns of the motor network in patients with Parkinson's disease (PD), but these studies have yielded conflicting results. This meta-analysis of previous neuroimaging studies was performed to identify patterns of abnormal...... movement-related activation in PD that were consistent across studies. We applied activation likelihood estimation (ALE) of functional neuroimaging studies probing motor function in patients with PD. The meta-analysis encompassed data from 283 patients with PD reported in 24 functional neuroimaging studies...

  18. Efficiency effects of observed and unobserved heterogeneity: Evidence from Norwegian electricity distribution networks

    International Nuclear Information System (INIS)

    Growitsch, Christian; Jamasb, Tooraj; Wetzel, Heike

    2012-01-01

    Since the 1990s, efficiency and benchmarking analysis has increasingly been used in network utilities research and regulation. A recurrent concern is the effect of observable environmental factors that are beyond the influence of firms and unobserved factors that are not identifiable on measured cost and quality performance of firms. This paper analyses the effect of observed geographic and weather factors and unobserved heterogeneity on a set of 128 Norwegian electricity distribution utilities for the 2001–2004 period. We utilise data on 78 geographic and weather variables to identify real economic inefficiency while controlling for observed and unobserved heterogeneity. We use the Factor Analysis technique to reduce the number of environmental factors into few composite variables and to avoid the problem of multicollinearity. In order to identify firm-specific inefficiency, we then estimate a pooled version of the established stochastic frontier model of Aigner et al. (1977) and the recent true random effects model of Greene (2004; 2005a,b) without and with environmental variables. The results indicate that the observed environmental factors have a rather limited influence on the utilities' average efficiency and the efficiency rankings. Moreover, the difference between the average efficiency scores and the efficiency rankings among the pooled and the true random effects models imply that the type of SFA model used is highly influencing the efficiency estimates.

  19. Inactivation of Ricin Toxin by Nanosecond Pulsed Electric Fields Including Evidences from Cell and Animal Toxicity

    Science.gov (United States)

    Wei, Kai; Li, Wei; Gao, Shan; Ji, Bin; Zang, Yating; Su, Bo; Wang, Kaile; Yao, Maosheng; Zhang, Jue; Wang, Jinglin

    2016-01-01

    Ricin is one of the most toxic and easily produced plant protein toxin extracted from the castor oil plant, and it has been classified as a chemical warfare agent. Here, nanosecond pulsed electric fields (nsPEFs) at 30 kV/cm (pulse durations: 10 ns, 100 ns, and 300 ns) were applied to inactivating ricin up to 4.2 μg/mL. To investigate the efficacy, cells and mice were tested against the ricin treated by the nsPEFs via direct intraperitoneal injection and inhalation exposure. Results showed that nsPEFs treatments can effectively reduce the toxicity of the ricin. Without the nsPEFs treatment, 100% of mice were killed upon the 4 μg ricin injection on the first day, however 40% of the mice survived the ricin treated by the nsPEFs. Compared to injection, inhalation exposure even with higher ricin dose required longer time to observe mice fatality. Pathological observations revealed damages to heart, lung, kidney, and stomach after the ricin exposure, more pronounced for lung and kidney including severe bleeding. Sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE) and circular dichroism (CD) analyses revealed that although the primary structure of ricin was not altered, its secondary structures (beta-sheet and beta-turn) underwent transition upon the nsPEFs treatment. PMID:26728251

  20. Evidence of Pavlovian conditioned fear following electrical stimulation of the periaqueductal grey in the rat.

    Science.gov (United States)

    Di Scala, G; Mana, M J; Jacobs, W J; Phillips, A G

    1987-01-01

    Stimulation of the periaqueductal grey (PAG) has been used to support aversive conditioning in a variety of species with several experimental paradigms. However, it has not been clearly demonstrated whether the behavioral changes produced by PAG stimulation in these paradigms are mediated by associative or nonassociative mechanisms. The present studies demonstrate that electrical stimulation of the PAG in the rat may be used to support associative learning in a Pavlovian paradigm. In each experiment, a fully controlled conditional emotional response (CER) procedure was used to examine the unconditional aversive properties of PAG stimulation. In Experiment 1a, weak associative conditioning was observed when a light CS was paired with PAG stimulation over 6 conditioning trials. In Experiment 1b, robust associative conditioning was obtained with a light CS when 18 conditioning trials were used. In Experiment 2, robust associative conditioning was demonstrated with a tone CS when 6 conditioning trials were used. The results parallel those found when other aversive stimuli are used as a UCS (e.g., footshock or intraorbital air puff), and because the present experiments included the proper control procedures the results clearly indicate that the behavioral changes produced by PAG stimulation are mediated by associative Pavlovian learning mechanisms rather than nonassociative mechanisms such as sensitization or pseudoconditioning. The present technique may be useful for assessing the neuroanatomical and neurochemical substrates underlying the aversive effects of brain-stimulation, and for screening the effects of drugs on the conditional and unconditional responses produced by such stimulation.

  1. Reproducibility of neuroimaging analyses across operating systems.

    Science.gov (United States)

    Glatard, Tristan; Lewis, Lindsay B; Ferreira da Silva, Rafael; Adalat, Reza; Beck, Natacha; Lepage, Claude; Rioux, Pierre; Rousseau, Marc-Etienne; Sherif, Tarek; Deelman, Ewa; Khalili-Mahani, Najmeh; Evans, Alan C

    2015-01-01

    Neuroimaging pipelines are known to generate different results depending on the computing platform where they are compiled and executed. We quantify these differences for brain tissue classification, fMRI analysis, and cortical thickness (CT) extraction, using three of the main neuroimaging packages (FSL, Freesurfer and CIVET) and different versions of GNU/Linux. We also identify some causes of these differences using library and system call interception. We find that these packages use mathematical functions based on single-precision floating-point arithmetic whose implementations in operating systems continue to evolve. While these differences have little or no impact on simple analysis pipelines such as brain extraction and cortical tissue classification, their accumulation creates important differences in longer pipelines such as subcortical tissue classification, fMRI analysis, and cortical thickness extraction. With FSL, most Dice coefficients between subcortical classifications obtained on different operating systems remain above 0.9, but values as low as 0.59 are observed. Independent component analyses (ICA) of fMRI data differ between operating systems in one third of the tested subjects, due to differences in motion correction. With Freesurfer and CIVET, in some brain regions we find an effect of build or operating system on cortical thickness. A first step to correct these reproducibility issues would be to use more precise representations of floating-point numbers in the critical sections of the pipelines. The numerical stability of pipelines should also be reviewed.

  2. Neuroimaging of herpesvirus infections in children

    Energy Technology Data Exchange (ETDEWEB)

    Baskin, Henry J. [Cincinnati Children' s Medical Center, Department of Radiology, Cincinnati, OH (United States); Hedlund, Gary [Primary Children' s Medical Center, Department of Medical Imaging, Salt Lake City, UT (United States)

    2007-10-15

    Six members of the herpesvirus family cause well-described neurologic disease in children: herpes simplex virus-1 (HSV-1), herpes simplex virus-2 (HSV-2), varicella-zoster (VZV), Epstein-Barr (EBV), cytomegalovirus (CMV), and human herpes virus-6 (HHV-6). When herpesviruses infect the central nervous system (CNS), the clinical presentation is non-specific and often confounding. The clinical urgency is often underscored by progressive neurologic deficits, seizures, or even death, and prompt diagnosis and treatment rely heavily on neuroimaging. This review focuses on the spectrum of cerebral manifestations caused by these viruses, particularly on non-congenital presentations. Recent advances in our understanding of these viruses are discussed, including new polymerase chain reaction techniques that allow parallel detection, which has improved our recognition that the herpesviruses are neurotropic and involve the CNS more often than previously thought. Evolving knowledge has also better elucidated viral neuropathology, particularly the role of VZV vasculitis in the brain, HHV-6 in febrile seizures, and herpesvirus reactivation in immunosuppressed patients. The virology, clinical course, and CNS manifestations of each virus are reviewed, followed by descriptions of neuroimaging findings when these agents infect the brain. Characteristic but often subtle imaging findings are discussed, as well as technical pearls covering appropriate use of MRI and MRI adjuncts to help differentiate viral infection from mimics. (orig.)

  3. Neuroimaging of herpesvirus infections in children

    International Nuclear Information System (INIS)

    Baskin, Henry J.; Hedlund, Gary

    2007-01-01

    Six members of the herpesvirus family cause well-described neurologic disease in children: herpes simplex virus-1 (HSV-1), herpes simplex virus-2 (HSV-2), varicella-zoster (VZV), Epstein-Barr (EBV), cytomegalovirus (CMV), and human herpes virus-6 (HHV-6). When herpesviruses infect the central nervous system (CNS), the clinical presentation is non-specific and often confounding. The clinical urgency is often underscored by progressive neurologic deficits, seizures, or even death, and prompt diagnosis and treatment rely heavily on neuroimaging. This review focuses on the spectrum of cerebral manifestations caused by these viruses, particularly on non-congenital presentations. Recent advances in our understanding of these viruses are discussed, including new polymerase chain reaction techniques that allow parallel detection, which has improved our recognition that the herpesviruses are neurotropic and involve the CNS more often than previously thought. Evolving knowledge has also better elucidated viral neuropathology, particularly the role of VZV vasculitis in the brain, HHV-6 in febrile seizures, and herpesvirus reactivation in immunosuppressed patients. The virology, clinical course, and CNS manifestations of each virus are reviewed, followed by descriptions of neuroimaging findings when these agents infect the brain. Characteristic but often subtle imaging findings are discussed, as well as technical pearls covering appropriate use of MRI and MRI adjuncts to help differentiate viral infection from mimics. (orig.)

  4. Neuroimaging. Recent issues and future progresses

    International Nuclear Information System (INIS)

    Fukuyama, Hidenao

    2002-01-01

    Recent advances in the technology of non-invasive neuroimaging techniques, include X-ray CT, magnetic resonance imaging, positron CT, etc. The trend of neuroimaging is from the diagnosis of the brain structural change to the functional localization of the brain function with accurate topographical data. Brain activation studies disclosed the responsible regions in the brain for various kinds of paradigms, including motor, sensory, cognitive functions. Another aspect of brain imaging shows the pathophysiological changes of the neurological disorders, such as Alzheimer's disease by abnormal CBF or metabolism changes. It is very important to note that the neurotransmitter receptor imaging is now available for various kinds of transmitters. We recently developed a new tracer for nicotinic type acetylcholine receptor, which might be involved in the pathophysiology of Alzheimer's disease and its treatment. In the near future, we will be able to visualize the proteins in the brain such as amyloid protein, which will make us to diagnose Alzheimer's patients accurately, and with respect to neuroscience research, not only neuronal functional localizations but also relationship between them will become important to disclose the functional aspects of the brain. (author)

  5. The regulatory treatment of adverse outcomes: Empirical evidence from the electric utility industry

    International Nuclear Information System (INIS)

    Ryan, N.E.

    1991-01-01

    This dissertation consists of two essays, both of them empirical studies using data from the US electric utility industry. Part I focuses on utilities' investment behavior, while Part II examines regulatory policy toward the industry. The first paper presents an analysis of utilities' decisions about whether to continue or cancel nuclear construction projects. During the seventies and eighties, changes in economic conditions and regulatory policy radically altered the costs and benefits of nuclear power. This study seeks to determine whether regulators pursued policies which induced utilities to employ socially efficient criteria in re-evaluating ongoing projects. The analysis also yields insights into regulators' distributional goals. Results based on data for 1978-84 are consistent with the capture theory hypothesis, which holds that regulators weigh industry interests more heavily than consumer interests. A test for structural change provides no support for the contention that the relative importance of consumer interests increased over this period. These empirical findings are inconsistent with a standard (and essential) assumption of theoretical principal-agent models of rate-of-return regulation, that regulators value consumers' payoffs more than utility profits. The second paper examines regulatory policy toward generating facilities that entered commercial service during the years 1983-88. In a significant departure from past practice, state public utility commissions often denied utilities full recovery of their investments in new plants. Although such ex post disallowances have an important efficiency rationale, they also provide a means for opportunistic regulators to effect transfers between utilities' ratepayers and shareholders. A probit model was used to assess the impact on the probability of a disallowance of firm and project characteristics as well as attributes of a state's political and institutional environment

  6. Dynamic pricing of electricity for residential customers. The evidence from Michigan

    Energy Technology Data Exchange (ETDEWEB)

    Faruqui, A.; Akaba, L. [The Brattle Group, 201 Mission Street, Suite 2800, San Francisco, CA 94105 (United States); Sergici, S. [The Brattle Group, 44 Brattle Street, Cambridge, MA 02138 (United States)

    2013-08-15

    The rollout of smart meters has enabled the provision of dynamic pricing to residential customers. However, doubts remain whether households can respond to time-varying price signals and that is preventing the full-scale rollout of dynamic pricing and the attainment of economic efficiency. Experiments are being conducted to test price responsiveness. We analyze data from a pilot in Michigan which featured two dynamic pricing rates and an enabling technology. Unlike most other pilots, it also included a group of 'information only' customers who were provided information on time-varying prices but billed on standard rates. Similarly, unlike most other pilots, it also included two control groups, one of whom knew they were in the pilot and one of whom did not. This was designed to test for the presence of a Hawthorne effect. Consistent with the large body of experimental literature, we find that customers, including low-income participants, do respond to dynamic pricing. We also find that the response to critical peak pricing rates is similar to the response to peak time rebates, consistent with the finding of one prior experiment but inconsistent with the finding of two prior experiments. We also find that the 'information only' customers respond to the provision of pricing information but at a substantially lower rate than the customers on dynamic pricing. We find that the response to enabling technology is muted. We do not find any evidence to suggest that a Hawthorne effect existed in this experiment.

  7. Retrospective study on structural neuroimaging in first-episode psychosis

    Directory of Open Access Journals (Sweden)

    Ricardo Coentre

    2016-05-01

    Full Text Available Background. No consensus between guidelines exists regarding neuroimaging in first-episode psychosis. The purpose of this study is to assess anomalies found in structural neuroimaging exams (brain computed tomography (CT and magnetic resonance imaging (MRI in the initial medical work-up of patients presenting first-episode psychosis. Methods. The study subjects were 32 patients aged 18–48 years (mean age: 29.6 years, consecutively admitted with first-episode psychosis diagnosis. Socio-demographic and clinical data and neuroimaging exams (CT and MRI were retrospectively studied. Diagnostic assessments were made using the Operational Criteria Checklist +. Neuroimaging images (CT and MRI and respective reports were analysed by an experienced consultant psychiatrist. Results. None of the patients had abnormalities in neuroimaging exams responsible for psychotic symptoms. Thirty-seven percent of patients had incidental brain findings not causally related to the psychosis (brain atrophy, arachnoid cyst, asymmetric lateral ventricles, dilated lateral ventricles, plagiocephaly and falx cerebri calcification. No further medical referral was needed for any of these patients. No significant differences regarding gender, age, diagnosis, duration of untreated psychosis, in-stay and cannabis use were found between patients who had neuroimaging abnormalities versus those without. Discussion. This study suggests that structural neuroimaging exams reveal scarce abnormalities in young patients with first-episode psychosis. Structural neuroimaging is especially useful in first-episode psychosis patients with neurological symptoms, atypical clinical picture and old age.

  8. The progress and clinical application of radionuclide neuroimaging

    International Nuclear Information System (INIS)

    Chen Wenxin; He Pinyu

    2008-01-01

    Development of site-specific brain radiopharmaceuticals extends the the functional neuroimaging applications in the diagnosis and monitoring treatments of various neurologic and psychiatric disorders. This article highlights recent advances and clinical applications of the functional neuroimaging in Parkinson disease, epilepsy, dementia, substance abuse, psychiatric disorders and brain functional research. (authors)

  9. Pituitary gland in psychiatric disorders: a review of neuroimaging findings.

    Science.gov (United States)

    Atmaca, Murad

    2014-08-01

    In this paper, it was reviewed neuroimaging results of the pituitary gland in psychiatric disorders, particularly schizophrenia, mood disorders, anxiety disorders, and somatoform disorders. The author made internet search in detail by using PubMed database including the period between 1980 and 2012 October. It was included in the articles in English, Turkish and French languages on pituitary gland in psychiatric disorders through structural or functional neuroimaging results. After searching mentioned in the Methods section in detail, investigations were obtained on pituitary gland neuroimaging in a variety of psychiatric disorders. There have been so limited investigations on pituitary neuroimaging in psychiatric disorders including major psychiatric illnesses like schizophrenia and mood disorders. Current findings are so far from the generalizability of the results. For this reason, it is required to perform much more neuroimaging studies of pituitary gland in all psychiatric disorders to reach the diagnostic importance of measuring it.

  10. The use of transcutaneous electrical nerve stimulation (TENS) for pain relief in labour: a review of the evidence.

    Science.gov (United States)

    Bedwell, Carol; Dowswell, Therese; Neilson, James P; Lavender, Tina

    2011-10-01

    to assess the effects of transcutaneous electrical nerve stimulation (TENS) for pain relief in labour. studies were identified from a search of the Cochrane Pregnancy and Childbirth Group's Trials Register (November 2008). randomised controlled trials comparing women receiving TENS for pain relief in labour vs routine care or placebo devices. All types of TENS machines were included. two review authors assessed all trials identified by the search strategy, carried out data extraction and assessed risk of bias. 14 studies including 1256 women were included: 11 examined TENS applied to the back, two to acupuncture points and one to the cranium. Overall, there was little difference in satisfaction with pain relief or in pain ratings between TENS and control groups, although women receiving TENS to acupuncture points were less likely to report severe pain (risk ratio 0.41, 95% confidence interval 0.32-0.55). The majority of women using TENS would use it again in a future labour. There was no evidence that TENS had any impact on interventions and outcomes in labour. There was little information on outcomes for mothers and infants. No adverse events were reported. there is only limited evidence that TENS reduces pain in labour and it does not seem to have any impact on other outcomes for mothers or infants. The use of TENS at home in early labour has not been evaluated. Although the guidelines of the National Institute for Health and Clinical Excellence recommend that TENS should not be offered to women in labour, women appear to be choosing it and midwives are supporting them in their choice. Given the absence of adverse effects and the limited evidence base, it seems unreasonable to deny women that choice. More robust studies of effectiveness are needed. Copyright © 2009 Elsevier Ltd. All rights reserved.

  11. Neuroimaging for drug addiction and related behaviors

    International Nuclear Information System (INIS)

    Parvaz, M.A.; Alia-Klein, N.; Woicik, P.A.; Volkow, N.D.; Goldstein, R.Z.

    2011-01-01

    In this review, we highlight the role of neuroimaging techniques in studying the emotional and cognitive-behavioral components of the addiction syndrome by focusing on the neural substrates subserving them. The phenomenology of drug addiction can be characterized by a recurrent pattern of subjective experiences that includes drug intoxication, craving, bingeing, and withdrawal with the cycle culminating in a persistent preoccupation with obtaining, consuming, and recovering from the drug. In the past two decades, imaging studies of drug addiction have demonstrated deficits in brain circuits related to reward and impulsivity. The current review focuses on studies employing positron emission tomography (PET), functional magnetic resonance imaging (fMRI), and electroencephalography (EEG) to investigate these behaviors in drug-addicted human populations. We begin with a brief account of drug addiction followed by a technical account of each of these imaging modalities. We then discuss how these techniques have uniquely contributed to a deeper understanding of addictive behaviors.

  12. Approach to ''Mind'' using functional neuroimaging

    International Nuclear Information System (INIS)

    Matsuda, Hiroshi

    2006-01-01

    This review mainly describes authors' recent investigations concerning neuroimages approaching to even human ''mind'' using techniques of PET, SPECT and functional MRI (fMRI). Progress of such studies greatly owes to the development of image statistics of the brain like statistical parametric mapping (www.fil.ion.ucl.ac.uk/spm/), and brain standards (www.mrc-cbu.cam.ac.uk/Imaging/mnispace.html, and ric.uthscsa.edu/projects/talairach daemon.html). The author discusses and presents images in cases of hallucinations (SPECT and H 2 15 O-PET), autism (SPECT), sleep, depression, and its therapy by transcaranial magnetic stimulation. These studies are expected to contribute to diagnosis and therapy of endogenous neurological disorders. (T.I.)

  13. Approach to ''Mind'' using functional neuroimaging

    Energy Technology Data Exchange (ETDEWEB)

    Matsuda, Hiroshi [Saitama Medical School, Hospital, Moroyama, Saitama (Japan)

    2006-05-15

    This review mainly describes authors' recent investigations concerning neuroimages approaching to even human ''mind'' using techniques of PET, SPECT and functional MRI (fMRI). Progress of such studies greatly owes to the development of image statistics of the brain like statistical parametric mapping (www.fil.ion.ucl.ac.uk/spm/), and brain standards (www.mrc-cbu.cam.ac.uk/Imaging/mnispace.html, and ric.uthscsa.edu/projects/talairach daemon.html). The author discusses and presents images in cases of hallucinations (SPECT and H{sub 2}{sup 15}O-PET), autism (SPECT), sleep, depression, and its therapy by transcaranial magnetic stimulation. These studies are expected to contribute to diagnosis and therapy of endogenous neurological disorders. (T.I.)

  14. The teen brain: insights from neuroimaging.

    Science.gov (United States)

    Giedd, Jay N

    2008-04-01

    Few parents of a teenager are surprised to hear that the brain of a 16-year-old is different from the brain of an 8-year-old. Yet to pin down these differences in a rigorous scientific way has been elusive. Magnetic resonance imaging, with the capacity to provide exquisitely accurate quantifications of brain anatomy and physiology without the use of ionizing radiation, has launched a new era of adolescent neuroscience. Longitudinal studies of subjects from ages 3-30 years demonstrate a general pattern of childhood peaks of gray matter followed by adolescent declines, functional and structural increases in connectivity and integrative processing, and a changing balance between limbic/subcortical and frontal lobe functions, extending well into young adulthood. Although overinterpretation and premature application of neuroimaging findings for diagnostic purposes remains a risk, converging data from multiple imaging modalities is beginning to elucidate the implications of these brain changes on cognition, emotion, and behavior.

  15. Silent stroke and advance in neuroimaging

    Energy Technology Data Exchange (ETDEWEB)

    Okada, Yasushi; Sadoshima, Seizo; Hasuo, Kanehiro; Saku, Yoshisuke; Fujishima, Masatoshi (Kyushu Univ., Fukuoka (Japan). Faculty of Medicine)

    1990-10-01

    Recently, silent strokes are more frequently demonstrated by CT and MRI with the advance of neuroimaging. The infarcted lesions unrelated to the neurological symptoms were detected in 8, 30, 28, 34, 60, 63% of the patients with cerebral infarction in 1977-78, 1982, 1985, 1986, 1987, 1988, respectively, by CT and/or MRI, and the asymptomatic patients with incidentally diagnosed cerebral infarction were amounted to 16% (8 of 51 cases) in 1988. Of the recent 50 patients with cerebral infarction examined by CT and MRI, asymptomatic cerebrovascular lesions were detected in 25 (50%) by CT and in 35 (70%) by MRI. MRI also revealed asymptomatic old hemorrhage in 7 (14%). The clinical significance of silent stroke was discussed. (author).

  16. Neuroimaging for drug addiction and related behaviors

    Energy Technology Data Exchange (ETDEWEB)

    Parvaz M. A.; Parvaz, M.A.; Alia-Klein, N.; Woicik,P.A.; Volkow, N.D.; Goldstein, R.Z.

    2011-10-01

    In this review, we highlight the role of neuroimaging techniques in studying the emotional and cognitive-behavioral components of the addiction syndrome by focusing on the neural substrates subserving them. The phenomenology of drug addiction can be characterized by a recurrent pattern of subjective experiences that includes drug intoxication, craving, bingeing, and withdrawal with the cycle culminating in a persistent preoccupation with obtaining, consuming, and recovering from the drug. In the past two decades, imaging studies of drug addiction have demonstrated deficits in brain circuits related to reward and impulsivity. The current review focuses on studies employing positron emission tomography (PET), functional magnetic resonance imaging (fMRI), and electroencephalography (EEG) to investigate these behaviors in drug-addicted human populations. We begin with a brief account of drug addiction followed by a technical account of each of these imaging modalities. We then discuss how these techniques have uniquely contributed to a deeper understanding of addictive behaviors.

  17. A simple tool for neuroimaging data sharing

    Directory of Open Access Journals (Sweden)

    Christian eHaselgrove

    2014-05-01

    Full Text Available Data sharing is becoming increasingly common, but despite encouragement and facilitation by funding agencies, journals, and some research efforts, most neuroimaging data acquired today is still not shared due to political, financial, social, and technical barriers to sharing data that remain. In particular, technical solutions are few for researchers that are not a part of larger efforts with dedicated sharing infrastructures, and social barriers such as the time commitment required to share can keep data from becoming publicly available.We present a system for sharing neuroimaging data, designed to be simple to use and to provide benefit to the data provider. The system consists of a server at the International Neuroinformatics Coordinating Facility (INCF and user tools for uploading data to the server. The primary design principle for the user tools is ease of use: the user identifies a directory containing DICOM data, provides their INCF Portal authentication, and provides identifiers for the subject and imaging session. The user tool anonymizes the data and sends it to the server. The server then runs quality control routines on the data, and the data and the quality control reports are made public. The user retains control of the data and may change the sharing policy as they need. The result is that in a few minutes of the user’s time, DICOM data can be anonymized and made publicly available, and an initial quality control assessment can be performed on the data. The system is currently functional, and user tools and access to the public image database are available at http://xnat.incf.org/.

  18. Neuroimaging features of Cornelia de Lange syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Whitehead, Matthew T. [Department of Radiology, Washington, DC (United States); Nagaraj, Usha D. [Department of Radiology, Washington, DC (United States); Cincinnati Children' s Hospital, Department of Radiology, Cincinnati, OH (United States); Pearl, Phillip L. [Department of Radiology, Washington, DC (United States); Boston Children' s Hospital, Department of Neurology, Boston, MA (United States)

    2015-08-15

    Cornelia de Lange syndrome is a rare genetic disease characterized by distinctive facial dysmorphia and dwarfism. Multiple organ system involvement is typical. Various central nervous system (CNS) aberrations have been described in the pathology literature; however, the spectrum of neuroimaging manifestations is less well documented. To present neuroimaging findings from a series of eight patients with Cornelia de Lange syndrome. The CT/MR database at a single academic children's hospital was searched for the terms ''Cornelia'', ''Brachmann'' and ''de Lange.'' The search yielded 18 exams from 16 patients. Two non-CNS and six exams without available images were excluded. Ten exams from eight patients were evaluated by a board-certified neuroradiologist. All patients had skull base dysplasia, most with an unusual coronal basioccipital cleft (7/8). All brain MR exams showed microcephaly, volume loss and gyral simplification (5/5). Six patients had an absent massa intermedia. Four patients had small globe anterior segments; three had optic pathway hypoplasia. Basilar artery fenestration was present in two patients; vertebrobasilar hypoplasia was present in one patient. The inner ear vestibules were dysplastic in two patients. One patient had pachymeningeal thickening. Spinal anomalies included scoliosis, segmentation anomalies, endplate irregularities, basilar invagination, foramen magnum stenosis and tethered spinal cord. Typical imaging manifestations of Cornelia de Lange syndrome include skull base dysplasia with coronal clival cleft, cerebral and brainstem volume loss, and gyral simplification. Membranous labyrinth dysplasia, anterior segment and optic pathway hypoplasia, basilar artery fenestration, absent massa intermedia and spinal anomalies may also be present. (orig.)

  19. Neuroimaging features of Cornelia de Lange syndrome

    International Nuclear Information System (INIS)

    Whitehead, Matthew T.; Nagaraj, Usha D.; Pearl, Phillip L.

    2015-01-01

    Cornelia de Lange syndrome is a rare genetic disease characterized by distinctive facial dysmorphia and dwarfism. Multiple organ system involvement is typical. Various central nervous system (CNS) aberrations have been described in the pathology literature; however, the spectrum of neuroimaging manifestations is less well documented. To present neuroimaging findings from a series of eight patients with Cornelia de Lange syndrome. The CT/MR database at a single academic children's hospital was searched for the terms ''Cornelia'', ''Brachmann'' and ''de Lange.'' The search yielded 18 exams from 16 patients. Two non-CNS and six exams without available images were excluded. Ten exams from eight patients were evaluated by a board-certified neuroradiologist. All patients had skull base dysplasia, most with an unusual coronal basioccipital cleft (7/8). All brain MR exams showed microcephaly, volume loss and gyral simplification (5/5). Six patients had an absent massa intermedia. Four patients had small globe anterior segments; three had optic pathway hypoplasia. Basilar artery fenestration was present in two patients; vertebrobasilar hypoplasia was present in one patient. The inner ear vestibules were dysplastic in two patients. One patient had pachymeningeal thickening. Spinal anomalies included scoliosis, segmentation anomalies, endplate irregularities, basilar invagination, foramen magnum stenosis and tethered spinal cord. Typical imaging manifestations of Cornelia de Lange syndrome include skull base dysplasia with coronal clival cleft, cerebral and brainstem volume loss, and gyral simplification. Membranous labyrinth dysplasia, anterior segment and optic pathway hypoplasia, basilar artery fenestration, absent massa intermedia and spinal anomalies may also be present. (orig.)

  20. Using neural networks and extreme value distributions to model electricity pool prices: Evidence from the Australian National Electricity Market 1998–2013

    International Nuclear Information System (INIS)

    Dev, Priya; Martin, Michael A.

    2014-01-01

    Highlights: • Neural nets are unable to properly capture spiky price behavior found in the electricity market. • We modeled electricity price data from the Australian National Electricity Market over 15 years. • Neural nets need to be augmented with other modeling techniques to capture price spikes. • We fit a Generalized Pareto Distribution to price spikes using a peaks-over-thresholds approach. - Abstract: Competitors in the electricity supply industry desire accurate predictions of electricity spot prices to hedge against financial risks. Neural networks are commonly used for forecasting such prices, but certain features of spot price series, such as extreme price spikes, present critical challenges for such modeling. We investigate the predictive capacity of neural networks for electricity spot prices using Australian National Electricity Market data. Following neural net modeling of the data, we explore extreme price spikes through extreme value modeling, fitting a Generalized Pareto Distribution to price peaks over an estimated threshold. While neural nets capture the smoother aspects of spot price data, they are unable to capture local, volatile features that characterize electricity spot price data. Price spikes can be modeled successfully through extreme value modeling

  1. Potential neuroimaging biomarkers of pathologic brain changes in Mild Cognitive Impairment and Alzheimer's disease: a systematic review.

    Science.gov (United States)

    Ruan, Qingwei; D'Onofrio, Grazia; Sancarlo, Daniele; Bao, Zhijun; Greco, Antonio; Yu, Zhuowei

    2016-05-16

    Neuroimaging-biomarkers of Mild Cognitive Impairment (MCI) allow an early diagnosis in preclinical stages of Alzheimer's disease (AD). The goal in this paper was to review of biomarkers for Mild Cognitive Impairment (MCI) and Alzheimer's disease (AD), with emphasis on neuroimaging biomarkers. A systematic review was conducted from existing literature that draws on markers and evidence for new measurement techniques of neuroimaging in AD, MCI and non-demented subjects. Selection criteria included: 1) age ≥ 60 years; 2) diagnosis of AD according to NIAAA criteria, 3) diagnosis of MCI according to NIAAA criteria with a confirmed progression to AD assessed by clinical follow-up, and 4) acceptable clinical measures of cognitive impairment, disability, quality of life, and global clinical assessments. Seventy-two articles were included in the review. With the development of new radioligands of neuroimaging, today it is possible to measure different aspects of AD neuropathology, early diagnosis of MCI and AD become probable from preclinical stage of AD to AD dementia and non-AD dementia. The panel of noninvasive neuroimaging-biomarkers reviewed provides a set methods to measure brain structural and functional pathophysiological changes in vivo, which are closely associated with preclinical AD, MCI and non-AD dementia. The dynamic measures of these imaging biomarkers are used to predict the disease progression in the early stages and improve the assessment of therapeutic efficacy in these diseases in future clinical trials.

  2. Multivariate Cointegration and Causality between Exports, Electricity Consumption and Real Income per Capita: Recent Evidence from Japan

    Directory of Open Access Journals (Sweden)

    Janesh Sami

    2011-01-01

    Full Text Available The current literature on the relationship between electricity, exports and economic growth is mixed. This paper examines the relationship between exports, electricity consumption and real income per capita in Japan using time series data from 1960-2007.We applied bounds testing procedure developed by Pesaran et al(2001 and found that there is cointegrating relationship between electricity consumption ,exports and economic growth. On establishing cointegration, the causal relationship electricity consumption, exports and economic investigation was investigated within a Vector Error Correction Model (VECM framework. We found that in the long run, there is causality from exports and real GDP per capita to electricity consumption.

  3. Determinants of Electricity Demand in Nonmetallic Mineral Products Industry: Evidence from a Comparative Study of Japan and China

    Directory of Open Access Journals (Sweden)

    Gang Du

    2015-06-01

    Full Text Available Electricity intensity is an important indicator for measuring production efficiency. A comparative study could offer a new perspective on investigating determinants of electricity demand. The Japanese non-metallic mineral products industry is chosen as the object for comparison considering its representative position in production efficiency. By adopting the cointegration model, this paper examines influencing factors of electricity demand in Japanese and Chinese non-metallic mineral products industries under the same framework. Results indicate that although economic growth and industrial development stages are different between the two countries, major factors that affect the sectoral energy consumption are the same. Specifically, economic growth and industrial activity contribute to the growth of sectoral electricity consumption, while R&D intensity, per capita productivity and electricity price are contributors to the decline of sectoral electricity consumption. Finally, in order to further investigate the development trend of sectoral electricity demand, future electricity consumption and conservation potential are predicted under different scenarios. Electricity demand of the Chinese non-metallic mineral products industry is predicted to be 680.53 TWh (terawatt-hours in 2020 and the sectoral electricity conservation potentials are estimated to be 118.26 TWh and 216.25 TWh under the moderate and advanced electricity-saving scenarios, respectively.

  4. Neuroimaging of person perception: A social-visual interface.

    Science.gov (United States)

    Brooks, Jeffrey A; Freeman, Jonathan B

    2017-12-21

    The visual system is able to extract an enormous amount of socially relevant information from the face, including social categories, personality traits, and emotion. While facial features may be directly tied to certain perceptions, emerging research suggests that top-down social cognitive factors (e.g., stereotypes, social-conceptual knowledge, prejudice) considerably influence and shape the perceptual process. The rapid integration of higher-order social cognitive processes into visual perception can give rise to systematic biases in face perception and may potentially act as a mediating factor for intergroup behavioral and evaluative biases. Drawing on neuroimaging evidence, we review the ways that top-down social cognitive factors shape visual perception of facial features. This emerging work in social and affective neuroscience builds upon work on predictive coding and perceptual priors in cognitive neuroscience and visual cognition, suggesting domain-general mechanisms that underlie a social-visual interface through which social cognition affects visual perception. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Neuroimage in neuroecthodermic diseases Part II: Tuberous Sclerosis

    International Nuclear Information System (INIS)

    Menor, F.; Marti-Bonmati, L.; Poyatos, C.; Cortina, H.; Esteban, J.M.; Vilar, J.

    1993-01-01

    A prospective clinicoradiological study has been carried out in 36 patients with tuberous sclerosis. The neuroimaging studies detected some type of disorder in 94% of patients, contributing significantly to the positive diagnosis of the disease. CT was better for viewing periventricular nodules, while MR was more reliable in disclosing the number and location of cortical and white matter lesions. The use of gadolinium-DTPA in MR demonstrated frequent uptake by the periventricular nodules which was exceptional in the cortical and subcortical lesions. The use of contrast, both in CT and in MR, enhanced the images of the 7 presumed giant-cell astrocytomas detected in 6 patients. Uptake by the tumors was always much greater than that observed in the nodules, being and important criterion for the differentiation between nodules and small tumors. The appearance and topography of these CNS lesions can be reasonably well explained by considering the disease to be a disorder of the migration of dysgenic cells. We have found no consistent correlation between the neuroradiological findings and the clinical evolution of the patients. MR and CT are similarly useful in the diagnosis of tuberous sclerosis. Given that MR is more effective in the detection of the set of intracranial lesions, it could be used as the initial technique, resorting to CT in those cases in which the clinical evidence is highly suggestive and the MR study is negative. Periodic MR control is not justified unless there is suspicion of tumor implantation or growth

  6. Sturge-Weber syndrome. The current neuro-imaging data

    International Nuclear Information System (INIS)

    Boukobza, M.; Cambra, M.R.; Merland, J.J.; Enjolras, O.

    2000-01-01

    Sturge-Weber syndrome (SWS) is a rare congenital sporadic disease with neuro-ocular and cutaneous vascular findings. Clinically, the full-blown condition consists of a facial port-wine stain (PWS) the V1 facial trigeminal skin area, alone or in combination with V2 and V3 PWS, seizures and ocular abnormalities (glaucoma and choroidal angioma). Radiologically, a leptomeningeal (pial) capillary and venous malformation, mostly located in the parieto-occipital area, cerebral atrophy and calcifications are demonstrated. An ipsilateral enlarged choroid plexus may be an early anatomic symptom. Development neuro-diagnostic technique for the screening of infants with an at-risk V1 PWS, as well as for the follow-up of patients with evidence SWS. Accelerated myelination in the involved hemisphere may be early diagnostic feature before 6 months of age. Later, hyperintensity of white matter on T2 is considered a symptom of gliosis. Clinically, progression of the diseases is associated with anatomic changes and correlates with the extent of the pial vascular anomaly, extent and severity of cerebral atrophy, and white matter abnormalities. A neonatal neuro-imaging work-up, using CT or MRI, may not demonstrate the pial anomaly and should be repeated after 6 to 12 months in an at-risk infant with V1 PWS. (authors)

  7. The 'wet mind': water and functional neuroimaging

    International Nuclear Information System (INIS)

    Le Bihan, Denis

    2007-01-01

    Functional neuroimaging has emerged as an important approach to study the brain and the mind. Surprisingly, although they are based on radically different physical approaches both positron emission tomography (PET) and magnetic resonance imaging (MRI) make brain activation imaging possible through measurements involving water molecules. So far, PET and MRI functional imaging have relied on the principle that neuronal activation and blood flow are coupled through metabolism. However, a new paradigm has emerged to look at brain activity through the observation with MRI of the molecular diffusion of water. In contrast with the former approaches diffusion MRI has the potential to reveal changes in the intrinsic water physical properties during brain activation, which could be more intimately linked to the neuronal activation mechanisms and lead to an improved spatial and temporal resolution. However, this link has yet to be fully confirmed and understood. To shed light on the possible relationship between water and brain activation, this introductory paper reviews the most recent data on the physical properties of water and on the status of water in biological tissues, and evaluates their relevance to brain diffusion MRI. The biophysical mechanisms of brain activation are then reassessed to reveal their intimacy with the physical properties of water, which may come to be regarded as the 'molecule of the mind'. (invited topical review)

  8. Neuroimaging studies in people with gender incongruence.

    Science.gov (United States)

    Kreukels, Baudewijntje P C; Guillamon, Antonio

    2016-01-01

    The current review gives an overview of brain studies in transgender people. First, we describe studies into the aetiology of feelings of gender incongruence, primarily addressing the sexual differentiation hypothesis: does the brain of transgender individuals resemble that of their natal sex, or that of their experienced gender? Findings from neuroimaging studies focusing on brain structure suggest that the brain phenotypes of trans women (MtF) and trans men (FtM) differ in various ways from control men and women with feminine, masculine, demasculinized and defeminized features. The brain phenotypes of people with feelings of gender incongruence may help us to figure out whether sex differentiation of the brain is atypical in these individuals, and shed light on gender identity development. Task-related imaging studies may show whether brain activation and task performance in transgender people is sex-atypical. Second, we review studies that evaluate the effects of cross-sex hormone treatment on the brain. This type of research provides knowledge on how changes in sex hormone levels may affect brain structure and function.

  9. Neuroimaging for spine and spinal cord surgery

    Energy Technology Data Exchange (ETDEWEB)

    Koyanagi, Izumi [Hokkaido Neurosurgical Memorial Hospital (Japan); Iwasaki, Yoshinobu; Hida, Kazutoshi

    2001-01-01

    Recent advances in neuroimaging of the spine and spinal cord are described based upon our clinical experiences with spinal disorders. Preoperative neuroradiological examinations, including magnetic resonance (MR) imaging and computerized tomography (CT) with three-dimensional reconstruction (3D-CT), were retrospectively analyzed in patients with cervical spondylosis or ossification of the posterior longitudinal ligament (130 cases), spinal trauma (43 cases) and intramedullary spinal cord tumors (92 cases). CT scan and 3D-CT were useful in elucidating the spine pathology associated with degenerative and traumatic spine diseases. Visualization of the deformity of the spine or fracture-dislocation of the spinal column with 3D-CT helped to determine the correct surgical treatment. MR imaging was most important in the diagnosis of both spine and spinal cord abnormalities. The axial MR images of the spinal cord were essential in understanding the laterality of the spinal cord compression in spinal column disorders and in determining surgical approaches to the intramedullary lesions. Although non-invasive diagnostic modalities such as MR imaging and CT scans are adequate for deciding which surgical treatment to use in the majority of spine and spinal cord disorders, conventional myelography is still needed in the diagnosis of nerve root compression in some cases of cervical spondylosis. (author)

  10. How Shakespeare tempests the brain: neuroimaging insights.

    Science.gov (United States)

    Keidel, James L; Davis, Philip M; Gonzalez-Diaz, Victorina; Martin, Clara D; Thierry, Guillaume

    2013-04-01

    Shakespeare made extensive use of the functional shift (FS), a rhetorical device involving a change in the grammatical status of words, e.g., using nouns as verbs. Previous work using event-related brain potentials showed how FS triggers a surprise effect inviting mental re-evaluation, seemingly independent of semantic processing. Here, we used functional magnetic resonance imaging to investigate brain activation in participants making judgements on the semantic relationship between sentences -some containing a Shakespearean FS- and subsequently presented words. Behavioural performance in the semantic decision task was high and unaffected by sentence type. However, neuroimaging results showed that sentences featuring FS elicited significant activation beyond regions classically activated by typical language tasks, including the left caudate nucleus, the right inferior frontal gyrus and the right inferior temporal gyrus. These findings show how Shakespeare's grammatical exploration forces the listener to take a more active role in integrating the meaning of what is said. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Neuroimaging in pre-motor Parkinson's disease

    Directory of Open Access Journals (Sweden)

    Thomas R. Barber

    2017-01-01

    Full Text Available The process of neurodegeneration in Parkinson's disease begins long before the onset of clinical motor symptoms, resulting in substantial cell loss by the time a diagnosis can be made. The period between the onset of neurodegeneration and the development of motoric disease would be the ideal time to intervene with disease modifying therapies. This pre-motor phase can last many years, but the lack of a specific clinical phenotype means that objective biomarkers are needed to reliably detect prodromal disease. In recent years, recognition that patients with REM sleep behaviour disorder (RBD are at particularly high risk of future parkinsonism has enabled the development of large prodromal cohorts in which to investigate novel biomarkers, and neuroimaging has generated some of the most promising results to date. Here we review investigations undertaken in RBD and other pre-clinical cohorts, including modalities that are well established in clinical Parkinson's as well as novel imaging methods. Techniques such as high resolution MRI of the substantia nigra and functional imaging of Parkinsonian brain networks have great potential to facilitate early diagnosis. Further longitudinal studies will establish their true value in quantifying prodromal neurodegeneration and predicting future Parkinson's.

  12. Neuroimaging of Fear-Associated Learning

    Science.gov (United States)

    Greco, John A; Liberzon, Israel

    2016-01-01

    Fear conditioning has been commonly used as a model of emotional learning in animals and, with the introduction of functional neuroimaging techniques, has proven useful in establishing the neurocircuitry of emotional learning in humans. Studies of fear acquisition suggest that regions such as amygdala, insula, anterior cingulate cortex, and hippocampus play an important role in acquisition of fear, whereas studies of fear extinction suggest that the amygdala is also crucial for safety learning. Extinction retention testing points to the ventromedial prefrontal cortex as an essential region in the recall of the safety trace, and explicit learning of fear and safety associations recruits additional cortical and subcortical regions. Importantly, many of these findings have implications in our understanding of the pathophysiology of psychiatric disease. Recent studies using clinical populations have lent insight into the changes in regional activity in specific disorders, and treatment studies have shown how pharmaceutical and other therapeutic interventions modulate brain activation during emotional learning. Finally, research investigating individual differences in neurotransmitter receptor genotypes has highlighted the contribution of these systems in fear-associated learning. PMID:26294108

  13. The experience of art: insights from neuroimaging.

    Science.gov (United States)

    Nadal, Marcos

    2013-01-01

    The experience of art is a complex one. It emerges from the interaction of multiple cognitive and affective processes. Neuropsychological and neuroimaging studies are revealing the broadly distributed network of brain regions upon which it relies. This network can be divided into three functional components: (i) prefrontal, parietal, and temporal cortical regions support evaluative judgment, attentional processing, and memory retrieval; (ii) the reward circuit, including cortical, subcortical regions, and some of its regulators, is involved in the generation of pleasurable feelings and emotions, and the valuation and anticipation of reward; and (iii) attentional modulation of activity in low-, mid-, and high-level cortical sensory regions enhances the perceptual processing of certain features, relations, locations, or objects. Understanding how these regions act in concert to produce unique and moving art experiences and determining the impact of personal and cultural meaning and context on this network the biological foundation of the experience of art--remain future challenges. © 2013 Elsevier B.V. All rights reserved.

  14. Neuroimaging revolutionizes therapeutic approaches to chronic pain

    Directory of Open Access Journals (Sweden)

    Borsook David

    2007-09-01

    Full Text Available Abstract An understanding of how the brain changes in chronic pain or responds to pharmacological or other therapeutic interventions has been significantly changed as a result of developments in neuroimaging of the CNS. These developments have occurred in 3 domains : (1 Anatomical Imaging which has demonstrated changes in brain volume in chronic pain; (2 Functional Imaging (fMRI that has demonstrated an altered state in the brain in chronic pain conditions including back pain, neuropathic pain, and complex regional pain syndromes. In addition the response of the brain to drugs has provided new insights into how these may modify normal and abnormal circuits (phMRI or pharmacological MRI; (3 Chemical Imaging (Magnetic Resonance Spectroscopy or MRS has helped our understanding of measures of chemical changes in chronic pain. Taken together these three domains have already changed the way in which we think of pain – it should now be considered an altered brain state in which there may be altered functional connections or systems and a state that has components of degenerative aspects of the CNS.

  15. Neuroimaging with functional near infrared spectroscopy: From formation to interpretation

    Science.gov (United States)

    Herrera-Vega, Javier; Treviño-Palacios, Carlos G.; Orihuela-Espina, Felipe

    2017-09-01

    Functional Near Infrared Spectroscopy (fNIRS) is gaining momentum as a functional neuroimaging modality to investigate the cerebral hemodynamics subsequent to neural metabolism. As other neuroimaging modalities, it is neuroscience's tool to understand brain systems functions at behaviour and cognitive levels. To extract useful knowledge from functional neuroimages it is critical to understand the series of transformations applied during the process of the information retrieval and how they bound the interpretation. This process starts with the irradiation of the head tissues with infrared light to obtain the raw neuroimage and proceeds with computational and statistical analysis revealing hidden associations between pixels intensities and neural activity encoded to end up with the explanation of some particular aspect regarding brain function.To comprehend the overall process involved in fNIRS there is extensive literature addressing each individual step separately. This paper overviews the complete transformation sequence through image formation, reconstruction and analysis to provide an insight of the final functional interpretation.

  16. Structural neuroimaging in neuropsychology: History and contemporary applications.

    Science.gov (United States)

    Bigler, Erin D

    2017-11-01

    Neuropsychology's origins began long before there were any in vivo methods to image the brain. That changed with the advent of computed tomography in the 1970s and magnetic resonance imaging in the early 1980s. Now computed tomography and magnetic resonance imaging are routinely a part of neuropsychological investigations with an increasing number of sophisticated methods for image analysis. This review examines the history of neuroimaging utilization in neuropsychological investigations, highlighting the basic methods that go into image quantification and the various metrics that can be derived. Neuroimaging methods and limitations for identify what constitutes a lesion are discussed. Likewise, the influence of various demographic and developmental factors that influence quantification of brain structure are reviewed. Neuroimaging is an integral part of 21st Century neuropsychology. The importance of neuroimaging to advancing neuropsychology is emphasized. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  17. Terminology development towards harmonizing multiple clinical neuroimaging research repositories.

    Science.gov (United States)

    Turner, Jessica A; Pasquerello, Danielle; Turner, Matthew D; Keator, David B; Alpert, Kathryn; King, Margaret; Landis, Drew; Calhoun, Vince D; Potkin, Steven G; Tallis, Marcelo; Ambite, Jose Luis; Wang, Lei

    2015-07-01

    Data sharing and mediation across disparate neuroimaging repositories requires extensive effort to ensure that the different domains of data types are referred to by commonly agreed upon terms. Within the SchizConnect project, which enables querying across decentralized databases of neuroimaging, clinical, and cognitive data from various studies of schizophrenia, we developed a model for each data domain, identified common usable terms that could be agreed upon across the repositories, and linked them to standard ontological terms where possible. We had the goal of facilitating both the current user experience in querying and future automated computations and reasoning regarding the data. We found that existing terminologies are incomplete for these purposes, even with the history of neuroimaging data sharing in the field; and we provide a model for efforts focused on querying multiple clinical neuroimaging repositories.

  18. Measuring and testing natural gas and electricity markets volatility : evidence from Alberta's deregulated markets

    Energy Technology Data Exchange (ETDEWEB)

    Serletis, A.; Shahmoradi, A. [Calgary Univ., AB (Canada). Dept. of Economics

    2005-03-01

    A number of innovative methods for modelling spot wholesale electricity prices have recently been developed. However, these models have primarily used a univariate time series approach to the analysis of electricity prices. This paper specified and estimated a multivariate GARCH-M model of natural gas and electricity price changes and their volatilities, using data over the deregulated period between January 1996 to November 2004 from Alberta's spot power and natural gas markets. The primary objective of the model was to investigate the relationship between electricity and natural gas prices. It was noted that the model allows for the possibilities of spillovers and asymmetries in the variance-covariance structure for natural gas and electricity price changes, and also for the separate examination of the effects of the volatility of anticipated and unanticipated changes in natural gas and electricity prices. Section 2 of the paper provided a description of the model used to test for causality between natural gas and electricity price changes, while section 3 discussed the data and presented the empirical results. It was concluded that there is a bidirectional causality between natural gas and electricity price changes. However, neither anticipated nor unanticipated natural gas price volatility causes electricity price changes. Anticipated electricity price volatility has a causal effect on natural gas. 10 refs., 2 tabs., 3 figs.

  19. Neuroimaging findings in pediatric sports-related concussion.

    Science.gov (United States)

    Ellis, Michael J; Leiter, Jeff; Hall, Thomas; McDonald, Patrick J; Sawyer, Scott; Silver, Norm; Bunge, Martin; Essig, Marco

    2015-09-01

    The goal in this review was to summarize the results of clinical neuroimaging studies performed in patients with sports-related concussion (SRC) who were referred to a multidisciplinar ypediatric concussion program. The authors conducted a retrospective review of medical records and neuroimaging findings for all patients referred to a multidisciplinary pediatric concussion program between September 2013 and July 2014. Inclusion criteria were as follows: 1) age ≤ 19 years; and 2) physician-diagnosed SRC. All patients underwent evaluation and follow-up by the same neurosurgeon. The 2 outcomes examined in this review were the frequency of neuroimaging studies performed in this population (including CT and MRI) and the findings of those studies. Clinical indications for neuroimaging and the impact of neuroimaging findings on clinical decision making were summarized where available. This investigation was approved by the local institutional ethics review board. A total of 151 patients (mean age 14 years, 59% female) were included this study. Overall, 36 patients (24%) underwent neuroimaging studies, the results of which were normal in 78% of cases. Sixteen percent of patients underwent CT imaging; results were normal in 79% of cases. Abnormal CT findings included the following: arachnoid cyst (1 patient), skull fracture (2 patients), suspected intracranial hemorrhage (1 patient), and suspected hemorrhage into an arachnoid cyst (1 patient). Eleven percent of patients underwent MRI; results were normal in 75% of cases. Abnormal MRI findings included the following: intraparenchymal hemorrhage and sylvian fissure arachnoid cyst (1 patient); nonhemorrhagic contusion (1 patient); demyelinating disease (1 patient); and posterior fossa arachnoid cyst, cerebellar volume loss, and nonspecific white matter changes (1 patient). Results of clinical neuroimaging studies are normal in the majority of pediatric patients with SRC. However, in selected cases neuroimaging can provide

  20. When Should Neuroimaging be Applied in the Criminal Court?

    DEFF Research Database (Denmark)

    Ryberg, Jesper

    2014-01-01

    When does neuroimaging constitute a sufficiently developed technology to be put into use in the work of determining whether or not a defendant is guilty of crime? This question constitutes the starting point of the present paper. First, it is suggested that an overall answer is provided by what i......-suited for delivering the sort of theoretical guidance that is required for assessing the desirability of using neuroimaging in the work of the criminal court....

  1. On the dynamics of aggregate output, electricity consumption and exports in Malaysia: Evidence from multivariate Granger causality tests

    International Nuclear Information System (INIS)

    Lean, Hooi Hooi; Smyth, Russell

    2010-01-01

    This paper employs annual data from 1971 to 2006 to examine the causal relationship between aggregate output, electricity consumption, exports, labor and capital in a multivariate model for Malaysia. We find that there is bidirectional Granger causality running between aggregate output and electricity consumption. The policy implication of this result is that Malaysia should adopt the dual strategy of increasing investment in electricity infrastructure and stepping up electricity conservation policies to reduce unnecessary wastage of electricity, in order to avoid the negative effect of reducing electricity consumption on aggregate output. We also find support for the export-led hypothesis which states Granger causality runs from exports to aggregate output. This result is consistent with Malaysia pursuing a successful export-orientated strategy. (author)

  2. Neuropsychological and neuroimaging underpinnings of schizoaffective disorder: a systematic review.

    Science.gov (United States)

    Madre, M; Canales-Rodríguez, E J; Ortiz-Gil, J; Murru, A; Torrent, C; Bramon, E; Perez, V; Orth, M; Brambilla, P; Vieta, E; Amann, B L

    2016-07-01

    The neurobiological basis and nosological status of schizoaffective disorder remains elusive and controversial. This study provides a systematic review of neurocognitive and neuroimaging findings in the disorder. A comprehensive literature search was conducted via PubMed, ScienceDirect, Scopus and Web of Knowledge (from 1949 to 31st March 2015) using the keyword 'schizoaffective disorder' and any of the following terms: 'neuropsychology', 'cognition', 'structural neuroimaging', 'functional neuroimaging', 'multimodal', 'DTI' and 'VBM'. Only studies that explicitly examined a well defined sample, or subsample, of patients with schizoaffective disorder were included. Twenty-two of 43 neuropsychological and 19 of 51 neuroimaging articles fulfilled inclusion criteria. We found a general trend towards schizophrenia and schizoaffective disorder being related to worse cognitive performance than bipolar disorder. Grey matter volume loss in schizoaffective disorder is also more comparable to schizophrenia than to bipolar disorder which seems consistent across further neuroimaging techniques. Neurocognitive and neuroimaging abnormalities in schizoaffective disorder resemble more schizophrenia than bipolar disorder. This is suggestive for schizoaffective disorder being a subtype of schizophrenia or being part of the continuum spectrum model of psychosis, with schizoaffective disorder being more skewed towards schizophrenia than bipolar disorder. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. A systematic literature review of neuroimaging research on developmental stuttering between 1995 and 2016.

    Science.gov (United States)

    Etchell, Andrew C; Civier, Oren; Ballard, Kirrie J; Sowman, Paul F

    2018-03-01

    Stuttering is a disorder that affects millions of people all over the world. Over the past two decades, there has been a great deal of interest in investigating the neural basis of the disorder. This systematic literature review is intended to provide a comprehensive summary of the neuroimaging literature on developmental stuttering. It is a resource for researchers to quickly and easily identify relevant studies for their areas of interest and enable them to determine the most appropriate methodology to utilize in their work. The review also highlights gaps in the literature in terms of methodology and areas of research. We conducted a systematic literature review on neuroimaging studies on developmental stuttering according to the PRISMA guidelines. We searched for articles in the pubmed database containing "stuttering" OR "stammering" AND either "MRI", "PET", "EEG", "MEG", "TMS"or "brain" that were published between 1995/​01/​01 and 2016/​01/​01. The search returned a total of 359 items with an additional 26 identified from a manual search. Of these, there were a total of 111 full text articles that met criteria for inclusion in the systematic literature review. We also discuss neuroimaging studies on developmental stuttering published throughout 2016. The discussion of the results is organized first by methodology and second by population (i.e., adults or children) and includes tables that contain all items returned by the search. There are widespread abnormalities in the structural architecture and functional organization of the brains of adults and children who stutter. These are evident not only in speech tasks, but also non-speech tasks. Future research should make greater use of functional neuroimaging and noninvasive brain stimulation, and employ structural methodologies that have greater sensitivity. Newly planned studies should also investigate sex differences, focus on augmenting treatment, examine moments of dysfluency and longitudinally or

  4. Single Subject Prediction of Brain Disorders in Neuroimaging: Promises and Pitfalls

    Science.gov (United States)

    Arbabshirani, Mohammad R.; Plis, Sergey; Sui, Jing; Calhoun, Vince D.

    2016-01-01

    Neuroimaging-based single subject prediction of brain disorders has gained increasing attention in recent years. Using a variety of neuroimaging modalities such as structural, functional and diffusion MRI, along with machine learning techniques, hundreds of studies have been carried out for accurate classification of patients with heterogeneous mental and neurodegenerative disorders such as schizophrenia and Alzheimer's disease. More than 500 studies have been published during the past quarter century on single subject prediction focused on a multiple brain disorders. In the first part of this study, we provide a survey of more than 200 reports in this field with a focus on schizophrenia, mild cognitive impairment (MCI), Alzheimer's disease (AD), depressive disorders, autism spectrum disease (ASD) and attention-deficit hyperactivity disorder (ADHD). Detailed information about those studies such as sample size, type and number of extracted features and reported accuracy are summarized and discussed. To our knowledge, this is by far the most comprehensive review of neuroimaging-based single subject prediction of brain disorders. In the second part, we present our opinion on major pitfalls of those studies from a machine learning point of view. Common biases are discussed and suggestions are provided. Moreover, emerging trends such as decentralized data sharing, multimodal brain imaging, differential diagnosis, disease subtype classification and deep learning are also discussed. Based on this survey, there are extensive evidences showing the great potential of neuroimaging data for single subject prediction of various disorders. However, the main bottleneck of this exciting field is still the limited sample size, which could be potentially addressed by modern data sharing models such as the ones discussed in this paper. Emerging big data technologies and advanced data-intensive machine learning methodologies such as deep learning have coincided with an increasing need

  5. How do urban households in China respond to increasing block pricing in electricity? Evidence from a fuzzy regression discontinuity approach

    International Nuclear Information System (INIS)

    Zhang, Zibin; Cai, Wenxin; Feng, Xiangzhao

    2017-01-01

    China is the largest electricity consumption country after it has passed the United States in 2011. Residential electricity consumption in China grew by 381.35% (12.85% per annum) between 2000 and 2013. In order to deal with rapid growth in residential electricity consumption, an increasing block pricing policy was introduced for residential electricity consumers in China on July 1st, 2012. Using difference-in-differences models with a fuzzy regression discontinuity design, we estimate a causal effect of price on electricity consumption for urban households during the introduction of increasing block pricing policy in Guangdong province of China. We find that consumers do not respond to a smaller (approximately 8%) increase in marginal price. However, consumers do respond to a larger increase in marginal price. An approximately 40% increase in marginal price induces an approximately 35% decrease in electricity use (284 kW h per month). Our results suggest that although the increasing block pricing could affect the behavior of households with higher electricity use, there is only a limit potential to overall energy conservation. - Highlights: • Estimate electricity consumption changes in response to the IBP in China. • Employ quasi-experimental approach and micro household level data in China. • Households do not respond to a smaller increase in marginal price. • 40% increase in marginal price induces a 35% decrease in electricity use.

  6. Neural, cognitive, and neuroimaging markers of the suicidal brain

    Directory of Open Access Journals (Sweden)

    Sobanski T

    2015-05-01

    Full Text Available Thomas Sobanski,1 Karl-Jürgen Bär,2 Gerd Wagner2 1Department of Psychiatry, Psychotherapy and Psychosomatic Medicine, Thüringen-Kliniken "Georgius Agricola" GmbH, Saalfeld, Germany; 2Department of Psychiatry and Psychotherapy, Psychiatric Brain and Body Research Group Jena, Jena University Hospital, Jena, GermanyAbstract: Suicidal behavior (SB is characterized by the occurrence of suicide attempts with substantial intent to die. SB is a major health problem worldwide. In the great majority of cases, SB occurs in patients suffering from psychiatric disorders, mainly from affective disorders or schizophrenia. Despite this high association, there is growing evidence from genetic studies that SB might represent a psychiatric condition on its own. This review provides an overview of the most significant neurobiological and neurocognitive findings in SB. We provide evidence for specific dysfunctions within the serotonergic system, for distinct morphological abnormalities in the gray and white matter composition as well as for neurofunctional alterations in the fronto-striatal network. Additionally, the putative role of impulsivity and hopelessness as trait-like risk factors for SB is outlined. Both the personality traits are associated with altered prefrontal cortex function and deficits in cognitive and affective control similar to the findings in SB. Given the difficulties of clinical risk assessment, there is a need to identify specific markers that can predict SB more reliably. Some recent neurocognitive and functional/structural neuroimaging findings might be appropriate to use as SB indicators in the close future.Keywords: suicidal behavior, biological markers, serotonin, hopelessness, impulsivity, major depressive disorder, fMRI, PET, SPECT

  7. Neuroimaging Studies Of Striatum In Cognition, Part I: Healthy Individuals

    Directory of Open Access Journals (Sweden)

    Jean-Sebastien eProvost

    2015-10-01

    Full Text Available The striatum has traditionally mainly been associated with playing a key role in the modulation of motor functions. Indeed, lesion studies in animals and studies of some neurological conditions in humans have brought further evidence to this idea. However, better methods of investigation have raised concerns about this notion, and it was proposed that the striatum could also be involved in different types of functions including cognitive ones. Although the notion was originally a matter of debate, it is now well accepted that the caudate nucleus contributes to cognition, while the putamen could be involved in motor functions, and to some extent in cognitive functions as well. With the arrival of modern neuroimaging techniques in the early 1990, knowledge supporting the cognitive aspect of the striatum has greatly increased, and a substantial number of scientific papers were published studying the role of the striatum in healthy individuals. For the first time, it was possible to assess the contribution of specific areas of the brain during the execution of a cognitive task. Neuroanatomical studies have described functional loops involving the striatum and the prefrontal cortex suggesting a specific interaction between these two structures. This review examines the data up to date and provides strong evidence for a specific contribution of the fronto-striatal regions in different cognitive processes, such as set-shifting, self-initiated responses, rule learning, action-contingency, and planning. Finally, a new two-level functional model involving the prefrontal cortex and the dorsal striatum is proposed suggesting an essential role of the dorsal striatum in selecting between competing potential responses or actions, and in resolving a high level of ambiguity.

  8. The Effect of Feedback by SMS-text messages and email on Household Electricity Consumption: Experimental Evidence

    DEFF Research Database (Denmark)

    Larsen, Anders

    2010-01-01

    This paper analyzes the effect of supplying online feedback by SMS-text messages and email about electricity consumption on the level of total household electricity consumption. An experiment was conducted in which 1,452 households were randomly allocated to three experimental groups and two...

  9. Nipype: A flexible, lightweight and extensible neuroimaging data processing framework

    Directory of Open Access Journals (Sweden)

    Krzysztof eGorgolewski

    2011-08-01

    Full Text Available Current neuroimaging software offer users an incredible opportunity to analyze their data in different ways, with different underlying assumptions. Several sophisticated software packages (e.g., AFNI, BrainVoyager, FSL, FreeSurfer, Nipy, R, SPM are used to process and analyze large and often diverse (highly multi-dimensional data. However, this heterogeneous collection of specialized applications creates several issues that hinder replicable, efficient and optimal use of neuroimaging analysis approaches: 1 No uniform access to neuroimaging analysis software and usage information; 2 No framework for comparative algorithm development and dissemination; 3 Personnel turnover in laboratories often limits methodological continuity and training new personnel takes time; 4 Neuroimaging software packages do not address computational efficiency; and 5 Methods sections in journal articles are inadequate for reproducing results. To address these issues, we present Nipype (Neuroimaging in Python: Pipelines and Interfaces; http://nipy.org/nipype, an open-source, community-developed, software package and scriptable library. Nipype solves the issues by providing Interfaces to existing neuroimaging software with uniform usage semantics and by facilitating interaction between these packages using Workflows. Nipype provides an environment that encourages interactive exploration of algorithms, eases the design of Workflows within and between packages, allows rapid comparative development of algorithms and reduces the learning curve necessary to use different packages. Nipype supports both local and remote execution on multi-core machines and clusters, without additional scripting. Nipype is BSD licensed, allowing anyone unrestricted usage. An open, community-driven development philosophy allows the software to quickly adapt and address the varied needs of the evolving neuroimaging community, especially in the context of increasing demand for reproducible research.

  10. Culture-sensitive neural substrates of human cognition: a transcultural neuroimaging approach.

    Science.gov (United States)

    Han, Shihui; Northoff, Georg

    2008-08-01

    Our brains and minds are shaped by our experiences, which mainly occur in the context of the culture in which we develop and live. Although psychologists have provided abundant evidence for diversity of human cognition and behaviour across cultures, the question of whether the neural correlates of human cognition are also culture-dependent is often not considered by neuroscientists. However, recent transcultural neuroimaging studies have demonstrated that one's cultural background can influence the neural activity that underlies both high- and low-level cognitive functions. The findings provide a novel approach by which to distinguish culture-sensitive from culture-invariant neural mechanisms of human cognition.

  11. Linking variability in brain chemistry and circuit function through multimodal human neuroimaging

    DEFF Research Database (Denmark)

    Fisher, Patrick M; Hariri, A R

    2012-01-01

    and dopamine system and its effects on threat- and reward-related brain function, we review evidence for how such a multimodal neuroimaging strategy can be successfully implemented. Furthermore, we discuss how multimodal PET-fMRI can be integrated with techniques such as imaging genetics, pharmacological......Identifying neurobiological mechanisms mediating the emergence of individual differences in behavior is critical for advancing our understanding of relative risk for psychopathology. Neuroreceptor positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) can be used...

  12. Neuroimaging in Mental Health Care: Voices in Translation

    Directory of Open Access Journals (Sweden)

    Emily L. Borgelt

    2012-10-01

    Full Text Available Images of brain function, popularly called neuroimages, have become a mainstay of contemporary communication about neuroscience and mental health. Paralleling media coverage of neuroimaging research and the high visibility of clinics selling scans is pressure from sponsors to move basic research about brain function along the translational pathway. Indeed, neuroimaging benefit mental health care with early or tailored intervention, opportunities for education and planning, and access to resources afforded by objectification of disorder. However, risks of premature technology transfer, such as misinterpretation, misrepresentation, and increased stigmatization, could compromise patient care.Stakeholder views on neuroimaging for mental health care are a largely untapped resource of information and guidance for translational efforts. We argue that the insights of key stakeholders – researchers, healthcare providers, patients, and families - have an essential role to play upstream in professional, critical, and ethical discourse about neuroimaging in mental health. Here we integrate previously orthogonal lines of inquiry involving stakeholder research to describe the translational landscape as well as challenges on its horizon.

  13. The Co-evolution of Neuroimaging and Psychiatric Neurosurgery.

    Science.gov (United States)

    Dyster, Timothy G; Mikell, Charles B; Sheth, Sameer A

    2016-01-01

    The role of neuroimaging in psychiatric neurosurgery has evolved significantly throughout the field's history. Psychiatric neurosurgery initially developed without the benefit of information provided by modern imaging modalities, and thus lesion targets were selected based on contemporary theories of frontal lobe dysfunction in psychiatric disease. However, by the end of the 20th century, the availability of structural and functional magnetic resonance imaging (fMRI) allowed for the development of mechanistic theories attempting to explain the anatamofunctional basis of these disorders, as well as the efficacy of stereotactic neuromodulatory treatments. Neuroimaging now plays a central and ever-expanding role in the neurosurgical management of psychiatric disorders, by influencing the determination of surgical candidates, allowing individualized surgical targeting and planning, and identifying network-level changes in the brain following surgery. In this review, we aim to describe the coevolution of psychiatric neurosurgery and neuroimaging, including ways in which neuroimaging has proved useful in elucidating the therapeutic mechanisms of neuromodulatory procedures. We focus on ablative over stimulation-based procedures given their historical precedence and the greater opportunity they afford for post-operative re-imaging, but also discuss important contributions from the deep brain stimulation (DBS) literature. We conclude with a discussion of how neuroimaging will transition the field of psychiatric neurosurgery into the era of precision medicine.

  14. Near-infrared neuroimaging with NinPy

    Directory of Open Access Journals (Sweden)

    Gary E Strangman

    2009-05-01

    Full Text Available There has been substantial recent growth in the use of non-invasive optical brain imaging in studies of human brain function in health and disease. Near-infrared neuroimaging (NIN is one of the most promising of these techniques and, although NIN hardware continues to evolve at a rapid pace, software tools supporting optical data acquisition, image processing, statistical modeling and visualization remain less refined. Python, a modular and computationally efficient development language, can support functional neuroimaging studies of diverse design and implementation. In particular, Python's easily readable syntax and modular architecture allow swift prototyping followed by efficient transition to stable production systems. As an introduction to our ongoing efforts to develop Python software tools for structural and functional neuroimaging, we discuss: (i the role of noninvasive diffuse optical imaging in measuring brain function, (ii the key computational requirements to support NIN experiments, (iii our collection of software tools to support near-infrared neuroimaging, called NinPy, and (iv future extensions of these tools that will allow integration of optical with other structural and functional neuroimaging data sources. Source code for the software discussed here will be made available at www.nmr.mgh.harvard.edu/Neural_SystemsGroup/software.html.

  15. Postfatigue potentiation of the paralyzed soleus muscle: evidence for adaptation with long-term electrical stimulation training

    OpenAIRE

    Shields, Richard K.; Dudley-Javoroski, Shauna; Littmann, Andrew E.

    2006-01-01

    Understanding the torque output behavior of paralyzed muscle has important implications for the use of functional neuromuscular electrical stimulation systems. Postfatigue potentiation is an augmentation of peak muscle torque during repetitive activation after a fatigue protocol. The purposes of this study were 1) to quantify postfatigue potentiation in the acutely and chronically paralyzed soleus and 2) to determine the effect of long-term soleus electrical stimulation training on the potent...

  16. Neuroimaging assessment of early and late neurobiological sequelae of traumatic brain injury: implications for CTE

    Directory of Open Access Journals (Sweden)

    Mark eSundman

    2015-09-01

    Full Text Available Traumatic brain injury (TBI has been increasingly accepted as a major external risk factor for neurodegenerative morbidity and mortality. Recent evidence indicates that the resultant chronic neurobiological sequelae following head trauma may, at least in part, contribute to a pathologically distinct disease known as Chronic Traumatic Encephalopathy (CTE. The clinical manifestation of CTE is variable, but the symptoms of this progressive disease include impaired memory and cognition, affective disorders (i.e., impulsivity, aggression, depression, suicidality, etc., and diminished motor control. Notably, mounting evidence suggests that the pathology contributing to CTE may be caused by repetitive exposure to subconcussive hits to the head, even in those with no history of a clinically evident head injury. Given the millions of athletes and military personnel with potential exposure to repetitive subconcussive insults and TBI, CTE represents an important public health issue. However, the incidence rates and pathological mechanisms are still largely unknown, primarily due to the fact that there is no in vivo diagnostic tool. The primary objective of this manuscript is to address this limitation and discuss potential neuroimaging modalities that may be capable of diagnosing CTE in vivo through the detection of tau and other known pathological features. Additionally, we will discuss the challenges of TBI research, outline the known pathology of CTE (with an emphasis on Tau, review current neuroimaging modalities to assess the potential routes for in vivo diagnosis, and discuss the future directions of CTE research.

  17. Multivariate granger causality between electricity consumption, exports and GDP: Evidence from a panel of Middle Eastern countries

    International Nuclear Information System (INIS)

    Narayan, Paresh Kumar; Smyth, Russell

    2009-01-01

    This paper examines the causal relationship between electricity consumption, exports and gross domestic product (GDP) for a panel of Middle Eastern countries. We find that for the panel as a whole there are statistically significant feedback effects between these variables. A 1 per cent increase in electricity consumption increases GDP by 0.04 per cent, a 1 per cent increase in exports increases GDP by 0.17 per cent and a 1 per cent increase in GDP generates a 0.95 per cent increase in electricity consumption. The policy implications are that for the panel as a whole these countries should invest in electricity infrastructure and step up electricity conservation policies to avoid a reduction in electricity consumption adversely affecting economic growth. Further policy implications are that for the panel as a whole promoting exports, particularly non-oil exports, is a means to promote economic growth and that expansion of exports can be realized without having adverse effects on energy conservation policies

  18. Differentiating emotional processing and attention in psychopathy with functional neuroimaging.

    Science.gov (United States)

    Anderson, Nathaniel E; Steele, Vaughn R; Maurer, J Michael; Rao, Vikram; Koenigs, Michael R; Decety, Jean; Kosson, David S; Calhoun, Vince D; Kiehl, Kent A

    2017-06-01

    Individuals with psychopathy are often characterized by emotional processing deficits, and recent research has examined the specific contexts and cognitive mechanisms that underlie these abnormalities. Some evidence suggests that abnormal features of attention are fundamental to emotional deficits in persons with psychopathy, but few studies have demonstrated the neural underpinnings responsible for such effects. Here, we use functional neuroimaging to examine attention-emotion interactions among incarcerated individuals (n = 120) evaluated for psychopathic traits using the Hare Psychopathy Checklist-Revised (PCL-R). Using a task designed to manipulate attention to emotional features of visual stimuli, we demonstrate effects representing implicit emotional processing, explicit emotional processing, attention-facilitated emotional processing, and vigilance for emotional content. Results confirm the importance of considering mechanisms of attention when evaluating emotional processing differences related to psychopathic traits. The affective-interpersonal features of psychopathy (PCL-R Factor 1) were associated with relatively lower emotion-dependent augmentation of activity in visual processing areas during implicit emotional processing, while antisocial-lifestyle features (PCL-R Factor 2) were associated with elevated activity in the amygdala and related salience network regions. During explicit emotional processing, psychopathic traits were associated with upregulation in the medial prefrontal cortex, insula, and superior frontal regions. Isolating the impact of explicit attention to emotional content, only Factor 1 was related to upregulation of activity in the visual processing stream, which was accompanied by increased activity in the angular gyrus. These effects highlight some important mechanisms underlying abnormal features of attention and emotional processing that accompany psychopathic traits.

  19. Neuroimaging Studies of Essential Tremor: How Well Do These Studies Support/Refute the Neurodegenerative Hypothesis?

    Directory of Open Access Journals (Sweden)

    Elan D. Louis

    2014-05-01

    Full Text Available Background: Tissue‐based research has recently led to a new patho‐mechanistic model of essential tremor (ET—the cerebellar degenerative model. We are not aware of a study that has reviewed the current neuroimaging evidence, focusing on whether the studies support or refute the neurodegenerative hypothesis of ET. This was our aim.Methods: References for this review were identified by searches of PubMed (1966 to February 2014.Results: Several neuroimaging methods have been used to study ET, most of them based on magnetic resonance imaging (MRI. The methods most specific to address the question of neurodegeneration are MRI‐based volumetry, magnetic resonance spectroscopy, and diffusion‐weighted imaging. Studies using each of these methods provide support for the presence of cerebellar degeneration in ET, finding reduced cerebellar brain volumes, consistent decreases in cerebellar N‐acetylaspartate, and increased mean diffusivity. Other neuroimaging techniques, such as functional MRI and positron emission tomography (PET are less specific, but still sensitive to potential neurodegeneration. These techniques are used for measuring a variety of brain functions and their impairment. Studies using these modalities also largely support cerebellar neuronal impairment. In particular, changes in 11C‐flumazenil binding in PET studies and changes in iron deposition in an MRI study provide evidence along these lines. The composite data point to neuronal impairment and likely neuronal degeneration in ET.Discussion: Recent years have seen a marked increase in the number of imaging studies of ET. As a whole, the combined data provide support for the presence of cerebellar neuronal degeneration in this disease.

  20. Machine Learning for Neuroimaging with Scikit-Learn

    Directory of Open Access Journals (Sweden)

    Alexandre eAbraham

    2014-02-01

    Full Text Available Statistical machine learning methods are increasingly used for neuroimaging data analysis. Their main virtue is their ability to model high-dimensional datasets, e.g. multivariate analysis of activation images or resting-state time series. Supervised learning is typically used in decoding or encoding settings to relate brain images to behavioral or clinical observations, while unsupervised learning can uncover hidden structures in sets of images (e.g. resting state functional MRI or find sub-populations in large cohorts. By considering different functional neuroimaging applications, we illustrate how scikit-learn, a Python machine learning library, can be used to perform some key analysis steps. Scikit-learn contains a very large set of statistical learning algorithms, both supervised and unsupervised, and its application to neuroimaging data provides a versatile tool to study the brain.

  1. Looking inside the brain the power of neuroimaging

    CERN Document Server

    Le Bihan, Denis

    2014-01-01

    It is now possible to witness human brain activity while we are talking, reading, or thinking, thanks to revolutionary neuroimaging techniques like magnetic resonance imaging (MRI). These groundbreaking advances have opened infinite fields of investigation—into such areas as musical perception, brain development in utero, and faulty brain connections leading to psychiatric disorders—and have raised unprecedented ethical issues. In Looking Inside the Brain, one of the leading pioneers of the field, Denis Le Bihan, offers an engaging account of the sophisticated interdisciplinary research in physics, neuroscience, and medicine that have led to the remarkable neuroimaging methods that give us a detailed look into the human brain. Introducing neurological anatomy and physiology, Le Bihan walks readers through the historical evolution of imaging technology—from the x-ray and CT scan to the PET scan and MRI—and he explains how neuroimaging uncovers afflictions like stroke or cancer and the workings of high...

  2. Imperial College near infrared spectroscopy neuroimaging analysis framework.

    Science.gov (United States)

    Orihuela-Espina, Felipe; Leff, Daniel R; James, David R C; Darzi, Ara W; Yang, Guang-Zhong

    2018-01-01

    This paper describes the Imperial College near infrared spectroscopy neuroimaging analysis (ICNNA) software tool for functional near infrared spectroscopy neuroimaging data. ICNNA is a MATLAB-based object-oriented framework encompassing an application programming interface and a graphical user interface. ICNNA incorporates reconstruction based on the modified Beer-Lambert law and basic processing and data validation capabilities. Emphasis is placed on the full experiment rather than individual neuroimages as the central element of analysis. The software offers three types of analyses including classical statistical methods based on comparison of changes in relative concentrations of hemoglobin between the task and baseline periods, graph theory-based metrics of connectivity and, distinctively, an analysis approach based on manifold embedding. This paper presents the different capabilities of ICNNA in its current version.

  3. Machine learning for neuroimaging with scikit-learn.

    Science.gov (United States)

    Abraham, Alexandre; Pedregosa, Fabian; Eickenberg, Michael; Gervais, Philippe; Mueller, Andreas; Kossaifi, Jean; Gramfort, Alexandre; Thirion, Bertrand; Varoquaux, Gaël

    2014-01-01

    Statistical machine learning methods are increasingly used for neuroimaging data analysis. Their main virtue is their ability to model high-dimensional datasets, e.g., multivariate analysis of activation images or resting-state time series. Supervised learning is typically used in decoding or encoding settings to relate brain images to behavioral or clinical observations, while unsupervised learning can uncover hidden structures in sets of images (e.g., resting state functional MRI) or find sub-populations in large cohorts. By considering different functional neuroimaging applications, we illustrate how scikit-learn, a Python machine learning library, can be used to perform some key analysis steps. Scikit-learn contains a very large set of statistical learning algorithms, both supervised and unsupervised, and its application to neuroimaging data provides a versatile tool to study the brain.

  4. Impacts of subsidized renewable electricity generation on spot market prices in Germany: evidence from a Garch model with panel data

    International Nuclear Information System (INIS)

    Pham, Thao; Lemoine, Killian

    2015-01-01

    Electricity generated by renewable energy sources creates a downward pressure on wholesale prices through - the so-called 'merit order effect'. This effect tends to lower average power prices and average market revenue that renewables producers should have received, making integration costs of renewables very high at large penetration rate. It is therefore crucial to determine the amplitude of this merit order effect particularly in the context of increasing burden of renewable support policies borne by final consumers. Using hourly data for the period 2009-2012 in German electricity wholesale market for GARCH model under panel data framework, we find that wind and solar power generation injected into German electricity network during this period induces a decrease of electricity spot prices and a slight increase of their volatility. The model-based results suggest that the merit-order effect created by renewable production ranges from 3.86 to 8.34 euro/MWh which implies to the annual volume of consumers' surplus from 1.89 to 3.92 billion euros. However this surplus has not been re-distributed equally among different types of electricity consumers. (authors)

  5. Incidental Findings in Neuroimaging: Ethical and Medicolegal Considerations.

    Science.gov (United States)

    Leung, Lawrence

    2013-01-01

    With the rapid advances in neurosciences in the last three decades, there has been an exponential increase in the use of neuroimaging both in basic sciences and clinical research involving human subjects. During routine neuroimaging, incidental findings that are not part of the protocol or scope of research agenda can occur and they often pose a challenge as to how they should be handled to abide by the medicolegal principles of research ethics. This paper reviews the issue from various ethical (do no harm, general duty to rescue, and mutual benefits and owing) and medicolegal perspectives (legal liability, fiduciary duties, Law of Tort, and Law of Contract) with a suggested protocol of approach.

  6. Linear and non-linear impact of Internet usage and financial deepening on electricity consumption for Turkey: empirical evidence from asymmetric causality.

    Science.gov (United States)

    Faisal, Faisal; Tursoy, Turgut; Berk, Niyazi

    2018-04-01

    This study investigates the relationship between Internet usage, financial development, economic growth, capital and electricity consumption using quarterly data from 1993Q1 to 2014Q4. The integration order of the series is analysed using the structural break unit root test. The ARDL bounds test for cointegration in addition to the Bayer-Hanck (2013) combined cointegration test is applied to analyse the existence of cointegration among the variables. The study found strong evidence of a long-run relationship between the variables. The long-run results under the ARDL framework confirm the existence of an inverted U-shaped relationship between financial development and electricity consumption, not only in the long-run, but also in the short-run. The study also confirms the existence of a U-shaped relationship between Internet usage and electricity consumption; however, the effect is insignificant. Additionally, the influence of trade, capital and economic growth is examined in both the long run and short run (ARDL-ECM). Finally, the results of asymmetric causality suggest a positive shock in electricity consumption that has a positive causal impact on Internet usage. The authors recommend that the Turkish Government should direct financial institutions to moderate the investment in the ICT sector by advancing credits at lower cost for purchasing energy-efficient technologies. In doing so, the Turkish Government can increase productivity in order to achieve sustainable growth, while simultaneously reducing emissions to improve environmental quality.

  7. On the construct validity of measures of willingness to pay for green electricity : Evidence from a South African case

    NARCIS (Netherlands)

    Chan, A.; Oerlemans, Leon; Volschenk, J.

    2015-01-01

    The price consumers are willing to pay (WTP) extra for green electricity (GE) is one of the uncertainties possibly impacting on the overall feasibility of its market introduction. In the literature, several measurements of WTP are used. However, the number of studies comparing WTP measures is

  8. Institutional and Regulatory Economics of Electricity Market Reforms: the Evidence from India, Pakistan, Bangladesh, Nepal, and Sri Lanka

    Science.gov (United States)

    Singh, Bipulendu

    Five South Asian countries-- India, Pakistan, Bangladesh, Nepal and Sri Lanka -- embarked on electricity market reforms in the 1990's. The dissertation uses the framework of New Institutional Economics to assess the effects on electricity sector performance of both observables elements of reform (i.e. privatization, unbundling, establishment of independent regulatory agencies etc.) as well as the unobservable elements (informal beliefs, habit, norms and culture of the actors involved in reforms). The first part of the dissertation -- econometric analysis of the relationship between observable electricity market reform measures and performance indicators -- finds that for the most part electricity market reforms in South Asia are having a positive impact on the performance of the sector. This is particularly the case for reforms that have increased private sector participation in generation and distribution and have vertically unbundled utilities into generation, transmission and distribution entities. Many of the reforms are positively correlated with higher tariffs, indicating a cost to the consumers from the reforms. The relationship between independent regulation and performance indicators , however, is not established. The second part of the dissertation - analytical narrative of the reform experiences of Gujarat and Nepal -- examines the informal elements (such as beliefs, norms, culture) that motivate behavior and explains how and why reform outcomes differed in these two places. The dissertation finds that the strength of formal institutions rules and the nature of social norms and customs have a significant influence on the outcome of reforms. Aided by the strength of its formal institutional framework and more evolved social norms and customs that encouraged people to follow formal rules, reforms in the Indian state of Gujarat were a success. The weakness of the formal institutional framework and the predominance of relation-based norms and customs in

  9. Efeitos cerebrais da maconha: resultados dos estudos de neuroimagem Brain effects of cannabis: neuroimaging findings

    Directory of Open Access Journals (Sweden)

    José Alexandre Crippa

    2005-03-01

    Full Text Available A maconha é a droga ilícita mais utilizada. Apesar disto, apenas um pequeno número de estudos investigaram as conseqüências neurotóxicas de longo prazo do uso de cannabis. As técnicas de neuroimagem se constituem em poderosos instrumentos para investigar alterações neuroanatômicas e neurofuncionais e suas correlações clínicas e neuropsicológicas. Uma revisão computadorizada da literatura foi conduzida nos indexadores MEDLINE e PsycLIT entre 1966 e novembro de 2004 com os termos 'cannabis', 'marijuana', 'neuroimaging', 'magnetic resonance', 'computed tomography', 'positron emission tomography', 'single photon emission computed tomography", 'SPET', 'MRI' e 'CT'. Estudos de neuroimagem estrutural apresentam resultados conflitantes, com a maioria dos estudos não relatando atrofia cerebral ou alterações volumétricas regionais. Contudo, há uma pequena evidência de que usuários de longo prazo que iniciaram um uso regular no início da adolescência apresentam atrofia cerebral assim como redução na substância cinzenta. Estudos de neuroimagem funcional relatam aumento na atividade neural em regiões que podem estar relacionadas com intoxicação por cannabis e alteração do humor (lobos frontais mesial e orbital e redução na atividade de regiões relacionadas com funções cognitivas prejudicadas durante a intoxicação aguda. A questão crucial se efeitos neurotóxicos residuais ocorrem após o uso prolongado e regular de maconha permanece obscura, não existindo até então estudo endereçando esta questão diretamente. Estudos de neuroimagem com melhores desenhos, combinados com avaliação cognitiva, podem ser elucidativos neste aspecto.Cannabis is the most widely used illicit drug. Despite this, only a small number of studies have investigated the long-term neurotoxic consequences of cannabis use. Structural and functional neuroimaging techniques are powerful research tools to investigate possible cannabis

  10. EEG changes and neuroimaging abnormalities in relevance to ...

    African Journals Online (AJOL)

    Background: Autism is currently viewed as a genetically determined neurodevelopmental disorder although its defi nite underlying etiology remains to be established. Aim of the Study: Our purpose was to assess autism related morphological neuroimaging changes of the brain and EEG abnormalities in correlation to the ...

  11. Imaging stress effects on memory: a review of neuroimaging studies

    NARCIS (Netherlands)

    van Stegeren, A.H.

    2009-01-01

    Objective: To review and give an overview of neuroimaging studies that look at the role of stress (hormones) on memory. Method: An overview will be given of imaging studies that looked at the role of stress (hormones) on memory. Stress is here defined as the acute provocation of the sympathetic

  12. SHIWA workflow interoperability solutions for neuroimaging data analysis

    NARCIS (Netherlands)

    Korkhov, Vladimir; Krefting, Dagmar; Montagnat, Johan; Truong Huu, Tram; Kukla, Tamas; Terstyanszky, Gabor; Manset, David; Caan, Matthan; Olabarriaga, Silvia

    2012-01-01

    Neuroimaging is a field that benefits from distributed computing infrastructures (DCIs) to perform data- and compute-intensive processing and analysis. Using grid workflow systems not only automates the processing pipelines, but also enables domain researchers to implement their expertise on how to

  13. Porcupine : A visual pipeline tool for neuroimaging analysis

    NARCIS (Netherlands)

    van Mourik, Tim; Snoek, Lukas; Knapen, T; Norris, David G

    The field of neuroimaging is rapidly adopting a more reproducible approach to data acquisition and analysis. Data structures and formats are being standardised and data analyses are getting more automated. However, as data analysis becomes more complicated, researchers often have to write longer

  14. Update on neuroimaging phenotypes of mid-hindbrain malformations

    Energy Technology Data Exchange (ETDEWEB)

    Jissendi-Tchofo, Patrice [University Hospital of Lille (CHRU), Department of Neuroradiology, MRI 3T Research, Plateforme Imagerie du vivant, IMPRT-IFR 114, Lille-Cedex (France); CHU Saint-Pierre, Radiology Department, Pediatric Neuroradiology Section, Brussels (Belgium); Severino, Mariasavina [Istituto Giannina Gaslini, Neuroradiology Unit, Genoa (Italy); Nguema-Edzang, Beatrice; Toure, Cisse; Soto Ares, Gustavo [University Hospital of Lille (CHRU), Department of Neuroradiology, MRI 3T Research, Plateforme Imagerie du vivant, IMPRT-IFR 114, Lille-Cedex (France); Barkovich, Anthony James [University of California, Neuroradiology Section, Department of Radiology and Biomedical Imaging, San Francisco, CA (United States)

    2014-10-23

    Neuroimaging techniques including structural magnetic resonance imaging (MRI) and functional positron emission tomography (PET) are useful in categorizing various midbrain-hindbrain (MHB) malformations, both in allowing diagnosis and in helping to understand the developmental processes that were disturbed. Brain imaging phenotypes of numerous malformations are characteristic features that help in guiding the genetic testing in case of direct neuroimaging-genotype correlation or, at least, to differentiate among MHB malformations entities. The present review aims to provide the reader with an update of the use of neuroimaging applications in the fine analysis of MHB malformations, using a comprehensive, recently proposed developmental and genetic classification. We have performed an extensive systematic review of the literature, from the embryology main steps of MHB development through the malformations entities, with regard to their molecular and genetic basis, conventional MRI features, and other neuroimaging characteristics. We discuss disorders in which imaging features are distinctive and how these features reflect the structural and functional impairment of the brain. Recognition of specific MRI phenotypes, including advanced imaging features, is useful to recognize the MHB malformation entities, to suggest genetic investigations, and, eventually, to monitor the disease outcome after supportive therapies. (orig.)

  15. 25 years of neuroimaging in amyotrophic lateral sclerosis

    Science.gov (United States)

    Foerster, Bradley R.; Welsh, Robert C.; Feldman, Eva L.

    2014-01-01

    Amyotrophic lateral sclerosis (ALS) is a fatal motor neuron disease for which a precise cause has not yet been identified. Standard CT or MRI evaluation does not demonstrate gross structural nervous system changes in ALS, so conventional neuroimaging techniques have provided little insight into the pathophysiology of this disease. Advanced neuroimaging techniques—such as structural MRI, diffusion tensor imaging and proton magnetic resonance spectroscopy—allow evaluation of alterations of the nervous system in ALS. These alterations include focal loss of grey and white matter and reductions in white matter tract integrity, as well as changes in neural networks and in the chemistry, metabolism and receptor distribution in the brain. Given their potential for investigation of both brain structure and function, advanced neuroimaging methods offer important opportunities to improve diagnosis, guide prognosis, and direct future treatment strategies in ALS. In this article, we review the contributions made by various advanced neuroimaging techniques to our understanding of the impact of ALS on different brain regions, and the potential role of such measures in biomarker development. PMID:23917850

  16. Diagnostic and therapeutic utility of neuroimaging in depression: an overview.

    Science.gov (United States)

    Wise, Toby; Cleare, Anthony J; Herane, Andrés; Young, Allan H; Arnone, Danilo

    2014-01-01

    A growing number of studies have used neuroimaging to further our understanding of how brain structure and function are altered in major depression. More recently, these techniques have begun to show promise for the diagnosis and treatment of depression, both as aids to conventional methods and as methods in their own right. In this review, we describe recent neuroimaging findings in the field that might aid diagnosis and improve treatment accuracy. Overall, major depression is associated with numerous structural and functional differences in neural systems involved in emotion processing and mood regulation. Furthermore, several studies have shown that the structure and function of these systems is changed by pharmacological and psychological treatments of the condition and that these changes in candidate brain regions might predict clinical response. More recently, "machine learning" methods have used neuroimaging data to categorize individual patients according to their diagnostic status and predict treatment response. Despite being mostly limited to group-level comparisons at present, with the introduction of new methods and more naturalistic studies, neuroimaging has the potential to become part of the clinical armamentarium and may improve diagnostic accuracy and inform treatment choice at the patient level.

  17. Neuroimaging in psychiatric pharmacogenetics research: the promise and pitfalls.

    Science.gov (United States)

    Falcone, Mary; Smith, Ryan M; Chenoweth, Meghan J; Bhattacharjee, Abesh Kumar; Kelsoe, John R; Tyndale, Rachel F; Lerman, Caryn

    2013-11-01

    The integration of research on neuroimaging and pharmacogenetics holds promise for improving treatment for neuropsychiatric conditions. Neuroimaging may provide a more sensitive early measure of treatment response in genetically defined patient groups, and could facilitate development of novel therapies based on an improved understanding of pathogenic mechanisms underlying pharmacogenetic associations. This review summarizes progress in efforts to incorporate neuroimaging into genetics and treatment research on major psychiatric disorders, such as schizophrenia, major depressive disorder, bipolar disorder, attention-deficit/hyperactivity disorder, and addiction. Methodological challenges include: performing genetic analyses in small study populations used in imaging studies; inclusion of patients with psychiatric comorbidities; and the extensive variability across studies in neuroimaging protocols, neurobehavioral task probes, and analytic strategies. Moreover, few studies use pharmacogenetic designs that permit testing of genotype × drug effects. As a result of these limitations, few findings have been fully replicated. Future studies that pre-screen participants for genetic variants selected a priori based on drug metabolism and targets have the greatest potential to advance the science and practice of psychiatric treatment.

  18. Functional neuroimaging of emotional learning and autonomic reactions.

    Science.gov (United States)

    Peper, Martin; Herpers, Martin; Spreer, Joachim; Hennig, Jürgen; Zentner, Josef

    2006-06-01

    This article provides a selective overview of the functional neuroimaging literature with an emphasis on emotional activation processes. Emotions are fast and flexible response systems that provide basic tendencies for adaptive action. From the range of involved component functions, we first discuss selected automatic mechanisms that control basic adaptational changes. Second, we illustrate how neuroimaging work has contributed to the mapping of the network components associated with basic emotion families (fear, anger, disgust, happiness), and secondary dimensional concepts that organise the meaning space for subjective experience and verbal labels (emotional valence, activity/intensity, approach/withdrawal, etc.). Third, results and methodological difficulties are discussed in view of own neuroimaging experiments that investigated the component functions involved in emotional learning. The amygdala, prefrontal cortex, and striatum form a network of reciprocal connections that show topographically distinct patterns of activity as a correlate of up and down regulation processes during an emotional episode. Emotional modulations of other brain systems have attracted recent research interests. Emotional neuroimaging calls for more representative designs that highlight the modulatory influences of regulation strategies and socio-cultural factors responsible for inhibitory control and extinction. We conclude by emphasising the relevance of the temporal process dynamics of emotional activations that may provide improved prediction of individual differences in emotionality.

  19. Uncovering the etiology of conversion disorder: insights from functional neuroimaging

    Science.gov (United States)

    Ejareh dar, Maryam; Kanaan, Richard AA

    2016-01-01

    Conversion disorder (CD) is a syndrome of neurological symptoms arising without organic cause, arguably in response to emotional stress, but the exact neural substrates of these symptoms and the underlying mechanisms remain poorly understood with the hunt for a biological basis afoot for centuries. In the past 15 years, novel insights have been gained with the advent of functional neuroimaging studies in patients suffering from CDs in both motor and nonmotor domains. This review summarizes recent functional neuroimaging studies including functional magnetic resonance imaging (fMRI), single photon emission computerized tomography (SPECT), and positron emission tomography (PET) to see whether they bring us closer to understanding the etiology of CD. Convergent functional neuroimaging findings suggest alterations in brain circuits that could point to different mechanisms for manifesting functional neurological symptoms, in contrast with feigning or healthy controls. Abnormalities in emotion processing and in emotion-motor processing suggest a diathesis, while differential reactions to certain stressors implicate a specific response to trauma. No comprehensive theory emerges from these clues, and all results remain preliminary, but functional neuroimaging has at least given grounds for hope that a model for CD may soon be found. PMID:26834476

  20. Visualization of nonlinear kernel models in neuroimaging by sensitivity maps

    DEFF Research Database (Denmark)

    Rasmussen, Peter Mondrup; Madsen, Kristoffer Hougaard; Lund, Torben Ellegaard

    2011-01-01

    There is significant current interest in decoding mental states from neuroimages. In this context kernel methods, e.g., support vector machines (SVM) are frequently adopted to learn statistical relations between patterns of brain activation and experimental conditions. In this paper we focus on v...

  1. The impact of ownership unbundling on cost efficiency: Empirical evidence from the New Zealand electricity distribution sector

    International Nuclear Information System (INIS)

    Filippini, Massimo; Wetzel, Heike

    2014-01-01

    Several countries around the world have introduced reforms to the electric power sector. One important element of these reforms is the introduction of an unbundling process, i.e., the separation of the competitive activities of supply and production from the monopole activity of transmission and distribution of electricity. There are several forms of unbundling: functional, legal and ownership. New Zealand, for instance, adopted an ownership unbundling in 1998. As discussed in the literature, ownership unbundling produces benefits and costs. One of the benefits may be an improvement in the level of the productive efficiency of the companies due to the use of the inputs in just one activity and a greater level of transparency for the regulator. This paper analyzes the cost efficiency of 28 electricity distribution companies in New Zealand for the period between 1996 and 2011. Using a stochastic frontier panel data model, a total cost function and a variable cost function are estimated in order to evaluate the impact of ownership unbundling on the level of cost efficiency. The results indicate that ownership separation of electricity generation and retail operations from the distribution network has a positive effect on the cost efficiency of distribution companies in New Zealand. The estimated effect of ownership separation suggests a positive average one-off shift in the level of cost efficiency by 0.242 in the short-run and 0.144 in the long-run. - Highlights: • We analyze the impact of ownership unbundling on the level of cost efficiency. • A variable cost frontier function and a total cost frontier function are estimated. • The results suggest a positive one-off shift in the level of cost efficiency

  2. Are electricity risk premia affected by emission allowance prices? Evidence from the EEX, Nord Pool and Powernext

    International Nuclear Information System (INIS)

    Daskalakis, George; Markellos, Raphael N.

    2009-01-01

    The links between emission and energy markets are of great interest to practitioners, academics and policy makers. In this paper, it is conjectured that a positive relationship exists between emission allowance spot returns and electricity risk premia within the European Union Emissions Trading Scheme (EU ETS). We discuss how this can be justified on the basis of the substantial uncertainties in the carbon markets. We also argue that this link could be due to trading strategies followed by electricity producers who attempt to exploit their initial allocation of free allowances. Analysis of data from three major markets, the EEX, Nord Pool and Powernext, offers empirical support to our conjecture. These findings have significant policy implications since they imply that efforts should be made in order to reduce the uncertainty in the carbon markets by clearly defining the EU ETS regulative framework and design over the next years. Moreover, our results suggest that the allocation of free allowances and their unrestricted trading enable electricity producers to accomplish windfall profits in the derivatives market at the expense of other market participants. (author)

  3. A joint estimation of price-cost margins and sunk capital. Theory and evidence from the European electricity industry

    International Nuclear Information System (INIS)

    Roeger, W.; Warzynski, F.

    2004-01-01

    In this paper, we propose a new methodology to jointly estimate market power and the importance of sunk capital extending the work of Hall (1988) and Roeger (1995). Wc then apply this new technique to the European electricity industry using firm level data for the period 1994-1999, and analyze the impact of the 1996 European directive to liberalize electricity markets. We find that the average price cost margin has declined from 0.29 in 1994 to 0.22 in 1999. Moreover, the magnitude of the decline is linked to firm size: the largest firms have experienced a larger percentage fall. The variable cost parameter has increased from 0.36 in 1994 to 0.56 in 1999. The main reason of the change is the switch of the relationship between real labor productivity and the share of variable capital. Our results therefore document a more competitive electricity market and a more flexible and more efficient use of capital. (au)

  4. Nonhuman primate positron emission tomography neuroimaging in drug abuse research.

    Science.gov (United States)

    Howell, Leonard Lee; Murnane, Kevin Sean

    2011-05-01

    Positron emission tomography (PET) neuroimaging in nonhuman primates has led to significant advances in our current understanding of the neurobiology and treatment of stimulant addiction in humans. PET neuroimaging has defined the in vivo biodistribution and pharmacokinetics of abused drugs and related these findings to the time course of behavioral effects associated with their addictive properties. With novel radiotracers and enhanced resolution, PET neuroimaging techniques have also characterized in vivo drug interactions with specific protein targets in the brain, including neurotransmitter receptors and transporters. In vivo determinations of cerebral blood flow and metabolism have localized brain circuits implicated in the effects of abused drugs and drug-associated stimuli. Moreover, determinations of the predisposing factors to chronic drug use and long-term neurobiological consequences of chronic drug use, such as potential neurotoxicity, have led to novel insights regarding the pathology and treatment of drug addiction. However, similar approaches clearly need to be extended to drug classes other than stimulants. Although dopaminergic systems have been extensively studied, other neurotransmitter systems known to play a critical role in the pharmacological effects of abused drugs have been largely ignored in nonhuman primate PET neuroimaging. Finally, the study of brain activation with PET neuroimaging has been replaced in humans mostly by functional magnetic resonance imaging (fMRI). There has been some success in implementing pharmacological fMRI in awake nonhuman primates. Nevertheless, the unique versatility of PET imaging will continue to complement the systems-level strengths of fMRI, especially in the context of nonhuman primate drug abuse research.

  5. Diagnostic and therapeutic utility of neuroimaging in depression: an overview

    Directory of Open Access Journals (Sweden)

    Wise T

    2014-08-01

    Full Text Available Toby Wise,1 Anthony J Cleare,1 Andrés Herane,1,2 Allan H Young,1 Danilo Arnone1 1King’s College London, Institute of Psychiatry, Department of Psychological Medicine, Centre for Affective Disorders, London, United Kingdom; 2Clínica Psiquiátrica Universitaria, Universidad de Chile, Santiago, Chile Abstract: A growing number of studies have used neuroimaging to further our understanding of how brain structure and function are altered in major depression. More recently, these techniques have begun to show promise for the diagnosis and treatment of depression, both as aids to conventional methods and as methods in their own right. In this review, we describe recent neuroimaging findings in the field that might aid diagnosis and improve treatment accuracy. Overall, major depression is associated with numerous structural and functional differences in neural systems involved in emotion processing and mood regulation. Furthermore, several studies have shown that the structure and function of these systems is changed by pharmacological and psychological treatments of the condition and that these changes in candidate brain regions might predict clinical response. More recently, “machine learning” methods have used neuroimaging data to categorize individual patients according to their diagnostic status and predict treatment response. Despite being mostly limited to group-level comparisons at present, with the introduction of new methods and more naturalistic studies, neuroimaging has the potential to become part of the clinical armamentarium and may improve diagnostic accuracy and inform treatment choice at the patient level. Keywords: depression, mood disorder, neuroimaging, diagnosis, treatment

  6. Charge trapping and de-trapping in isolated CdSe/ZnS nanocrystals under an external electric field: indirect evidence for a permanent dipole moment.

    Science.gov (United States)

    Zang, Huidong; Cristea, Mihail; Shen, Xuan; Liu, Mingzhao; Camino, Fernando; Cotlet, Mircea

    2015-09-28

    Single nanoparticle studies of charge trapping and de-trapping in core/shell CdSe/ZnS nanocrystals incorporated into an insulating matrix and subjected to an external electric field demonstrate the ability to reversibly modulate the exciton dynamics and photoluminescence blinking while providing indirect evidence for the existence of a permanent ground state dipole moment in such nanocrystals. A model assuming the presence of energetically deep charge traps physically aligned along the direction of the permanent dipole is proposed in order to explain the dynamics of nanocrystal blinking in the presence of a permanent dipole moment.

  7. The Neuro-Image: Alain Resnais's Digital Cinema without the Digits

    NARCIS (Netherlands)

    Pisters, P.

    2011-01-01

    This paper proposes to read cinema in the digital age as a new type of image, the neuroimage. Going back to Gilles Deleuze's cinema books and it is argued that the neuro-image is based in the future. The cinema of Alain Resnais is analyzed as a neuro-image and digital cinema .

  8. Dissociable genetic contributions to error processing: a multimodal neuroimaging study.

    Directory of Open Access Journals (Sweden)

    Yigal Agam

    Full Text Available Neuroimaging studies reliably identify two markers of error commission: the error-related negativity (ERN, an event-related potential, and functional MRI activation of the dorsal anterior cingulate cortex (dACC. While theorized to reflect the same neural process, recent evidence suggests that the ERN arises from the posterior cingulate cortex not the dACC. Here, we tested the hypothesis that these two error markers also have different genetic mediation.We measured both error markers in a sample of 92 comprised of healthy individuals and those with diagnoses of schizophrenia, obsessive-compulsive disorder or autism spectrum disorder. Participants performed the same task during functional MRI and simultaneously acquired magnetoencephalography and electroencephalography. We examined the mediation of the error markers by two single nucleotide polymorphisms: dopamine D4 receptor (DRD4 C-521T (rs1800955, which has been associated with the ERN and methylenetetrahydrofolate reductase (MTHFR C677T (rs1801133, which has been associated with error-related dACC activation. We then compared the effects of each polymorphism on the two error markers modeled as a bivariate response.We replicated our previous report of a posterior cingulate source of the ERN in healthy participants in the schizophrenia and obsessive-compulsive disorder groups. The effect of genotype on error markers did not differ significantly by diagnostic group. DRD4 C-521T allele load had a significant linear effect on ERN amplitude, but not on dACC activation, and this difference was significant. MTHFR C677T allele load had a significant linear effect on dACC activation but not ERN amplitude, but the difference in effects on the two error markers was not significant.DRD4 C-521T, but not MTHFR C677T, had a significant differential effect on two canonical error markers. Together with the anatomical dissociation between the ERN and error-related dACC activation, these findings suggest that

  9. Multiple comparison procedures for neuroimaging genomewide association studies.

    Science.gov (United States)

    Hua, Wen-Yu; Nichols, Thomas E; Ghosh, Debashis

    2015-01-01

    Recent research in neuroimaging has focused on assessing associations between genetic variants that are measured on a genomewide scale and brain imaging phenotypes. A large number of works in the area apply massively univariate analyses on a genomewide basis to find single nucleotide polymorphisms that influence brain structure. In this paper, we propose using various dimensionality reduction methods on both brain structural MRI scans and genomic data, motivated by the Alzheimer's Disease Neuroimaging Initiative (ADNI) study. We also consider a new multiple testing adjustment method and compare it with two existing false discovery rate (FDR) adjustment methods. The simulation results suggest an increase in power for the proposed method. The real-data analysis suggests that the proposed procedure is able to find associations between genetic variants and brain volume differences that offer potentially new biological insights. © The Author 2014. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  10. Pain perception and hypnosis: findings from recent functional neuroimaging studies.

    Science.gov (United States)

    Del Casale, Antonio; Ferracuti, Stefano; Rapinesi, Chiara; Serata, Daniele; Caltagirone, Saverio Simone; Savoja, Valeria; Piacentino, Daria; Callovini, Gemma; Manfredi, Giovanni; Sani, Gabriele; Kotzalidis, Georgios D; Girardi, Paolo

    2015-01-01

    Hypnosis modulates pain perception and tolerance by affecting cortical and subcortical activity in brain regions involved in these processes. By reviewing functional neuroimaging studies focusing on pain perception under hypnosis, the authors aimed to identify brain activation-deactivation patterns occurring in hypnosis-modulated pain conditions. Different changes in brain functionality occurred throughout all components of the pain network and other brain areas. The anterior cingulate cortex appears to be central in modulating pain circuitry activity under hypnosis. Most studies also showed that the neural functions of the prefrontal, insular, and somatosensory cortices are consistently modified during hypnosis-modulated pain conditions. Functional neuroimaging studies support the clinical use of hypnosis in the management of pain conditions.

  11. Incidental Findings in Neuroimaging: Ethical and Medicolegal Considerations

    Directory of Open Access Journals (Sweden)

    Lawrence Leung

    2013-01-01

    Full Text Available With the rapid advances in neurosciences in the last three decades, there has been an exponential increase in the use of neuroimaging both in basic sciences and clinical research involving human subjects. During routine neuroimaging, incidental findings that are not part of the protocol or scope of research agenda can occur and they often pose a challenge as to how they should be handled to abide by the medicolegal principles of research ethics. This paper reviews the issue from various ethical (do no harm, general duty to rescue, and mutual benefits and owing and medicolegal perspectives (legal liability, fiduciary duties, Law of Tort, and Law of Contract with a suggested protocol of approach.

  12. Cognitive and emotional processes during dreaming: a neuroimaging view.

    Science.gov (United States)

    Desseilles, Martin; Dang-Vu, Thien Thanh; Sterpenich, Virginie; Schwartz, Sophie

    2011-12-01

    Dream is a state of consciousness characterized by internally-generated sensory, cognitive and emotional experiences occurring during sleep. Dream reports tend to be particularly abundant, with complex, emotional, and perceptually vivid experiences after awakenings from rapid eye movement (REM) sleep. This is why our current knowledge of the cerebral correlates of dreaming, mainly derives from studies of REM sleep. Neuroimaging results show that REM sleep is characterized by a specific pattern of regional brain activity. We demonstrate that this heterogeneous distribution of brain activity during sleep explains many typical features in dreams. Reciprocally, specific dream characteristics suggest the activation of selective brain regions during sleep. Such an integration of neuroimaging data of human sleep, mental imagery, and the content of dreams is critical for current models of dreaming; it also provides neurobiological support for an implication of sleep and dreaming in some important functions such as emotional regulation. Copyright © 2010 Elsevier Inc. All rights reserved.

  13. The utility of neuroimaging in the management of dementia

    Directory of Open Access Journals (Sweden)

    Uduak E Williams

    2015-01-01

    Full Text Available Dementia is a syndrome of progressive dysfunction of two or more cognitive domains associated with impairment of activities of daily living. An understanding of the pathophysiology of dementia and its early diagnosis is important in the pursuit of possible disease modifying therapy for dementia. Neuroimaging has greatly transformed this field of research as its function has changed from a mere tool for diagnosing treatable causes of dementia to an instrument for pre-symptomatic diagnosis of dementia. This review focuses on the diagnostic utility of neuroimaging in the management of progressive dementias. Structural imaging techniques like computerized tomography scan and magnetic resonance imaging highlights the anatomical, structural and volumetric details of the brain; while functional imaging techniques such as positron emission tomography, arterial spin labeling, single photon emission computerized tomography and blood oxygen level-dependent functional magnetic resonance imaging focuses on chemistry, circulatory status and physiology of the different brain structures and regions.

  14. Nervous System Injury and Neuroimaging of Zika Virus Infection

    Science.gov (United States)

    Wu, Shanshan; Zeng, Yu; Lerner, Alexander; Gao, Bo; Law, Meng

    2018-01-01

    In 2016, World Health Organization announced Zika virus infection and its neurological sequalae are a public health emergency of global scope. Preliminary studies have confirmed a relationship between Zika virus infection and certain neurological disorders, including microcephaly and Guillain–Barre syndrome (GBS). The neuroimaging features of microcephaly secondary to Zika virus infection include calcifications at the junction of gray–white matter and subcortical white matter with associated cortical abnormalities, diminution of white matter, large ventricles with or without hydrocephalus, cortical malformations, hypoplasia of cerebellum and brainstem, and enlargement of cerebellomedullary cistern. Contrast enhancement of the cauda equine nerve roots is the typical neuroimaging finding of GBS associated with Zika virus. This review describes the nervous system disorders and associated imaging findings seen in Zika virus infection, with the aim to improve the understanding of this disease. Imaging plays a key role on accurate diagnosis and prognostic evaluation of this disease. PMID:29740383

  15. Neuroimaging the Effectiveness of Substance Use Disorder Treatments.

    Science.gov (United States)

    Cabrera, Elizabeth A; Wiers, Corinde E; Lindgren, Elsa; Miller, Gregg; Volkow, Nora D; Wang, Gene-Jack

    2016-09-01

    Neuroimaging techniques to measure the function and biochemistry of the human brain such as positron emission tomography (PET), proton magnetic resonance spectroscopy ((1)H MRS), and functional magnetic resonance imaging (fMRI), are powerful tools for assessing neurobiological mechanisms underlying the response to treatments in substance use disorders. Here, we review the neuroimaging literature on pharmacological and behavioral treatment in substance use disorder. We focus on neural effects of medications that reduce craving (e.g., naltrexone, bupropion hydrochloride, baclofen, methadone, varenicline) and that improve cognitive control (e.g., modafinil, N-acetylcysteine), of behavioral treatments for substance use disorders (e.g., cognitive bias modification training, virtual reality, motivational interventions) and neuromodulatory interventions such as neurofeedback and transcranial magnetic stimulation. A consistent finding for the effectiveness of therapeutic interventions identifies the improvement of executive control networks and the dampening of limbic activation, highlighting their values as targets for therapeutic interventions in substance use disorders.

  16. Online Open Neuroimaging Mass Meta-Analysis with a Wiki

    DEFF Research Database (Denmark)

    Nielsen, Finn Arup; Kempton, Matthew J.; Williams, Steven C. R.

    2015-01-01

    We describe a system for meta-analysis where a wiki stores numerical data in a simple comma-separated values format and a web service performs the numerical statistical computation. We initially apply the system on multiple meta-analyses of structural neuroimaging data results. The described system...... allows for mass meta-analysis, e.g., meta-analysis across multiple brain regions and multiple mental disorders providing an overview of important relationships and their uncertainties in a collaborative environment....

  17. Partial Least Squares tutorial for analyzing neuroimaging data

    Directory of Open Access Journals (Sweden)

    Patricia Van Roon

    2014-09-01

    Full Text Available Partial least squares (PLS has become a respected and meaningful soft modeling analysis technique that can be applied to very large datasets where the number of factors or variables is greater than the number of observations. Current biometric studies (e.g., eye movements, EKG, body movements, EEG are often of this nature. PLS eliminates the multiple linear regression issues of over-fitting data by finding a few underlying or latent variables (factors that account for most of the variation in the data. In real-world applications, where linear models do not always apply, PLS can model the non-linear relationship well. This tutorial introduces two PLS methods, PLS Correlation (PLSC and PLS Regression (PLSR and their applications in data analysis which are illustrated with neuroimaging examples. Both methods provide straightforward and comprehensible techniques for determining and modeling relationships between two multivariate data blocks by finding latent variables that best describes the relationships. In the examples, the PLSC will analyze the relationship between neuroimaging data such as Event-Related Potential (ERP amplitude averages from different locations on the scalp with their corresponding behavioural data. Using the same data, the PLSR will be used to model the relationship between neuroimaging and behavioural data. This model will be able to predict future behaviour solely from available neuroimaging data. To find latent variables, Singular Value Decomposition (SVD for PLSC and Non-linear Iterative PArtial Least Squares (NIPALS for PLSR are implemented in this tutorial. SVD decomposes the large data block into three manageable matrices containing a diagonal set of singular values, as well as left and right singular vectors. For PLSR, NIPALS algorithms are used because it provides amore precise estimation of the latent variables. Mathematica notebooks are provided for each PLS method with clearly labeled sections and subsections. The

  18. [Neuroimaging and Blood Biomarkers in Functional Prognosis after Stroke].

    Science.gov (United States)

    Branco, João Paulo; Costa, Joana Santos; Sargento-Freitas, João; Oliveira, Sandra; Mendes, Bruno; Laíns, Jorge; Pinheiro, João

    2016-11-01

    Stroke remains one of the leading causes of morbidity and mortality around the world and it is associated with an important long-term functional disability. Some neuroimaging resources and certain peripheral blood or cerebrospinal fluid proteins can give important information about etiology, therapeutic approach, follow-up and functional prognosis in acute ischemic stroke patients. However, among the scientific community, there is currently more interest in the stroke vital prognosis over the functional prognosis. Predicting the functional prognosis during acute phase would allow more objective rehabilitation programs and better management of the available resources. The aim of this work is to review the potential role of acute phase neuroimaging and blood biomarkers as functional recovery predictors after ischemic stroke. Review of the literature published between 2005 and 2015, in English, using the terms "ischemic stroke", "neuroimaging" e "blood biomarkers". We included nine studies, based on abstract reading. Computerized tomography, transcranial doppler ultrasound and diffuse magnetic resonance imaging show potential predictive value, based on the blood flow study and the evaluation of stroke's volume and localization, especially when combined with the National Institutes of Health Stroke Scale. Several biomarkers have been studied as diagnostic, risk stratification and prognostic tools, namely the S100 calcium binding protein B, C-reactive protein, matrix metalloproteinases and cerebral natriuretic peptide. Although some biomarkers and neuroimaging techniques have potential predictive value, none of the studies were able to support its use, alone or in association, as a clinically useful functionality predictor model. All the evaluated markers were considered insufficient to predict functional prognosis at three months, when applied in the first hours after stroke. Additional studies are necessary to identify reliable predictive markers for functional

  19. Neuroimaging in human MDMA (Ecstasy) users: A cortical model

    Science.gov (United States)

    Cowan, Ronald L; Roberts, Deanne M; Joers, James M

    2009-01-01

    MDMA (3,4 methylenedioxymethamphetamine) has been used by millions of people worldwide as a recreational drug. MDMA and Ecstasy are often used synonymously but it is important to note that the purity of Ecstasy sold as MDMA is not certain. MDMA use is of public health concern, not so much because MDMA produces a common or severe dependence syndrome, but rather because rodent and non-human primate studies have indicated that MDMA (when administered at certain dosages and intervals) can cause long-lasting reductions in markers of brain serotonin (5-HT) that appear specific to fine diameter axons arising largely from the dorsal raphe nucleus (DR). Given the popularity of MDMA, the potential for the drug to produce long-lasting or permanent 5-HT axon damage or loss, and the widespread role of 5-HT function in the brain, there is a great need for a better understanding of brain function in human users of this drug. To this end, neuropsychological, neuroendocrine, and neuroimaging studies have all suggested that human MDMA users may have long-lasting changes in brain function consistent with 5-HT toxicity. Data from animal models leads to testable hypotheses regarding MDMA effects on the human brain. Because neuropsychological and neuroimaging findings have focused on the neocortex, a cortical model is developed to provide context for designing and interpreting neuroimaging studies in MDMA users. Aspects of the model are supported by the available neuroimaging data but there are controversial findings in some areas and most findings have not been replicated across different laboratories and using different modalities. This paper reviews existing findings in the context of a cortical model and suggests directions for future research. PMID:18991874

  20. The utility of neuroimaging in the management of dementia

    OpenAIRE

    Uduak E Williams; Ekanem E Philip Ephraim; Sidney K Oparah

    2015-01-01

    Dementia is a syndrome of progressive dysfunction of two or more cognitive domains associated with impairment of activities of daily living. An understanding of the pathophysiology of dementia and its early diagnosis is important in the pursuit of possible disease modifying therapy for dementia. Neuroimaging has greatly transformed this field of research as its function has changed from a mere tool for diagnosing treatable causes of demen...

  1. The Power of Neuroimaging Biomarkers for Screening Frontotemporal Dementia

    OpenAIRE

    McMillan, Corey T.; Avants, Brian B.; Cook, Philip; Ungar, Lyle; Trojanowski, John Q.; Grossman, Murray

    2014-01-01

    Frontotemporal dementia (FTD) is a clinically and pathologically heterogeneous neurodegenerative disease that can result from either frontotemporal lobar degeneration (FTLD) or Alzheimer’s disease (AD) pathology. It is critical to establish statistically powerful biomarkers that can achieve substantial cost-savings and increase feasibility of clinical trials. We assessed three broad categories of neuroimaging methods to screen underlying FTLD and AD pathology in a clinical FTD series: global ...

  2. Functional neuroimaging of Alzheimer's disease and other dementias

    International Nuclear Information System (INIS)

    Wang Ruimin

    2001-01-01

    Dementing illnesses comprise Alzheimer's disease (AD), Pick's disease, Multi-infarct dementia (MID) and other neurological disorders. These diseases have different clinical characters respectively. Neuropsychological examinations can help to diagnose and differential diagnose dementias. The development of neuroimaging dementias is more and more rapid. 18 F-FDG PET method shows neo-cortical hypometabolism occurring in the biparietal-temporal lobes and left-right asymmetry of AD patients in the early stage. It can also differential diagnose Ad from other dementias

  3. Human fear conditioning and extinction in neuroimaging: a systematic review.

    Directory of Open Access Journals (Sweden)

    Christina Sehlmeyer

    Full Text Available Fear conditioning and extinction are basic forms of associative learning that have gained considerable clinical relevance in enhancing our understanding of anxiety disorders and facilitating their treatment. Modern neuroimaging techniques have significantly aided the identification of anatomical structures and networks involved in fear conditioning. On closer inspection, there is considerable variation in methodology and results between studies. This systematic review provides an overview of the current neuroimaging literature on fear conditioning and extinction on healthy subjects, taking into account methodological issues such as the conditioning paradigm. A Pubmed search, as of December 2008, was performed and supplemented by manual searches of bibliographies of key articles. Two independent reviewers made the final study selection and data extraction. A total of 46 studies on cued fear conditioning and/or extinction on healthy volunteers using positron emission tomography or functional magnetic resonance imaging were reviewed. The influence of specific experimental factors, such as contingency and timing parameters, assessment of conditioned responses, and characteristics of conditioned and unconditioned stimuli, on cerebral activation patterns was examined. Results were summarized descriptively. A network consisting of fear-related brain areas, such as amygdala, insula, and anterior cingulate cortex, is activated independently of design parameters. However, some neuroimaging studies do not report these findings in the presence of methodological heterogeneities. Furthermore, other brain areas are differentially activated, depending on specific design parameters. These include stronger hippocampal activation in trace conditioning and tactile stimulation. Furthermore, tactile unconditioned stimuli enhance activation of pain related, motor, and somatosensory areas. Differences concerning experimental factors may partly explain the variance

  4. Cross-View Neuroimage Pattern Analysis for Alzheimer's Disease Staging

    Directory of Open Access Journals (Sweden)

    Sidong eLiu

    2016-02-01

    Full Text Available The research on staging of pre-symptomatic and prodromal phase of neurological disorders, e.g., Alzheimer's disease (AD, is essential for prevention of dementia. New strategies for AD staging with a focus on early detection, are demanded to optimize potential efficacy of disease-modifying therapies that can halt or slow the disease progression. Recently, neuroimaging are increasingly used as additional research-based markers to detect AD onset and predict conversion of MCI and normal control (NC to AD. Researchers have proposed a variety of neuroimaging biomarkers to characterize the patterns of the pathology of AD and MCI, and suggested that multi-view neuroimaging biomarkers could lead to better performance than single-view biomarkers in AD staging. However, it is still unclear what leads to such synergy and how to preserve or maximize. In an attempt to answer these questions, we proposed a cross-view pattern analysis framework for investigating the synergy between different neuroimaging biomarkers. We quantitatively analyzed 9 types of biomarkers derived from FDG-PET and T1-MRI, and evaluated their performance in a task of classifying AD, MCI and NC subjects obtained from the ADNI baseline cohort. The experiment results showed that these biomarkers could depict the pathology of AD from different perspectives, and output distinct patterns that are significantly associated with the disease progression. Most importantly, we found that these features could be separated into clusters, each depicting a particular aspect; and the inter-cluster features could always achieve better performance than the intra-cluster features in AD staging.

  5. Recent progress of neuroimaging studies on sleeping brain

    International Nuclear Information System (INIS)

    Sasaki, Yuka

    2012-01-01

    Although sleep is a familiar phenomenon, its functions are yet to be elucidated. Understanding these functions of sleep is an important focus area in neuroscience. Electroencephalography (EEG) has been the predominantly used method in human sleep research but does not provide detailed spatial information about brain activation during sleep. To supplement the spatial information provided by this method, researchers have started using a combination of EEG and various advanced neuroimaging techniques that have been recently developed, including positron emission tomography (PET) and magnetic resonance imaging (MRI). In this paper, we will review the recent progress in sleep studies, especially studies that have used such advanced neuroimaging techniques. First, we will briefly introduce several neuroimaging techniques available for use in sleep studies. Next, we will review the spatiotemporal brain activation patterns during non-rapid eye movement (NREM) and rapid eye movement (REM) sleep, the dynamics of functional connectivity during sleep, and the consolidation of learning and memory during sleep; studies on the neural correlates of dreams, which have not yet been identified, will also be discussed. Lastly, possible directions for future research in this area will be discussed. (author)

  6. Neuroimaging Studies Illustrate the Commonalities Between Ageing and Brain Diseases.

    Science.gov (United States)

    Cole, James H

    2018-07-01

    The lack of specificity in neuroimaging studies of neurological and psychiatric diseases suggests that these different diseases have more in common than is generally considered. Potentially, features that are secondary effects of different pathological processes may share common neurobiological underpinnings. Intriguingly, many of these mechanisms are also observed in studies of normal (i.e., non-pathological) brain ageing. Different brain diseases may be causing premature or accelerated ageing to the brain, an idea that is supported by a line of "brain ageing" research that combines neuroimaging data with machine learning analysis. In reviewing this field, I conclude that such observations could have important implications, suggesting that we should shift experimental paradigm: away from characterizing the average case-control brain differences resulting from a disease toward methods that place individuals in their age-appropriate context. This will also lead naturally to clinical applications, whereby neuroimaging can contribute to a personalized-medicine approach to improve brain health. © 2018 WILEY Periodicals, Inc.

  7. Design and rationale for examining neuroimaging genetics in ischemic stroke

    Science.gov (United States)

    Giese, Anne-Katrin; Schirmer, Markus D.; Donahue, Kathleen L.; Cloonan, Lisa; Irie, Robert; Winzeck, Stefan; Bouts, Mark J.R.J.; McIntosh, Elissa C.; Mocking, Steven J.; Dalca, Adrian V.; Sridharan, Ramesh; Xu, Huichun; Frid, Petrea; Giralt-Steinhauer, Eva; Holmegaard, Lukas; Roquer, Jaume; Wasselius, Johan; Cole, John W.; McArdle, Patrick F.; Broderick, Joseph P.; Jimenez-Conde, Jordi; Jern, Christina; Kissela, Brett M.; Kleindorfer, Dawn O.; Lemmens, Robin; Lindgren, Arne; Meschia, James F.; Rundek, Tatjana; Sacco, Ralph L.; Schmidt, Reinhold; Sharma, Pankaj; Slowik, Agnieszka; Thijs, Vincent; Woo, Daniel; Worrall, Bradford B.; Kittner, Steven J.; Mitchell, Braxton D.; Rosand, Jonathan; Golland, Polina; Wu, Ona

    2017-01-01

    Objective: To describe the design and rationale for the genetic analysis of acute and chronic cerebrovascular neuroimaging phenotypes detected on clinical MRI in patients with acute ischemic stroke (AIS) within the scope of the MRI–GENetics Interface Exploration (MRI-GENIE) study. Methods: MRI-GENIE capitalizes on the existing infrastructure of the Stroke Genetics Network (SiGN). In total, 12 international SiGN sites contributed MRIs of 3,301 patients with AIS. Detailed clinical phenotyping with the web-based Causative Classification of Stroke (CCS) system and genome-wide genotyping data were available for all participants. Neuroimaging analyses include the manual and automated assessments of established MRI markers. A high-throughput MRI analysis pipeline for the automated assessment of cerebrovascular lesions on clinical scans will be developed in a subset of scans for both acute and chronic lesions, validated against gold standard, and applied to all available scans. The extracted neuroimaging phenotypes will improve characterization of acute and chronic cerebrovascular lesions in ischemic stroke, including CCS subtypes, and their effect on functional outcomes after stroke. Moreover, genetic testing will uncover variants associated with acute and chronic MRI manifestations of cerebrovascular disease. Conclusions: The MRI-GENIE study aims to develop, validate, and distribute the MRI analysis platform for scans acquired as part of clinical care for patients with AIS, which will lead to (1) novel genetic discoveries in ischemic stroke, (2) strategies for personalized stroke risk assessment, and (3) personalized stroke outcome assessment. PMID:28852707

  8. [Recent progress of neuroimaging studies on sleeping brain].

    Science.gov (United States)

    Sasaki, Yuka

    2012-06-01

    Although sleep is a familiar phenomenon, its functions are yet to be elucidated. Understanding these functions of sleep is an important focus area in neuroscience. Electroencephalography (EEG) has been the predominantly used method in human sleep research but does not provide detailed spatial information about brain activation during sleep. To supplement the spatial information provided by this method, researchers have started using a combination of EEG and various advanced neuroimaging techniques that have been recently developed, including positron emission tomography (PET) and magnetic resonance imaging (MRI). In this paper, we will review the recent progress in sleep studies, especially studies that have used such advanced neuroimaging techniques. First, we will briefly introduce several neuroimaging techniques available for use in sleep studies. Next, we will review the spatiotemporal brain activation patterns during non-rapid eye movement (NREM) and rapid eye movement (REM) sleep, the dynamics of functional connectivity during sleep, and the consolidation of learning and memory during sleep; studies on the neural correlates of dreams, which have not yet been identified, will also be discussed. Lastly, possible directions for future research in this area will be discussed.

  9. Advanced electrical current measurements of microdischarges: evidence of sub-critical pulses and ion currents in barrier discharge in air

    Science.gov (United States)

    Synek, Petr; Zemánek, Miroslav; Kudrle, Vít; Hoder, Tomáš

    2018-04-01

    Electrical current measurements in corona or barrier microdischarges are a challenge as they require both high temporal resolution and a large dynamic range of the current probe used. In this article, we apply a simple self-assembled current probe and compare it to commercial ones. An analysis in the time and frequency domain is carried out. Moreover, an improved methodology is presented, enabling both temporal resolution in sub-nanosecond times and current sensitivity in the order of tens of micro-amperes. Combining this methodology with a high-tech oscilloscope and self-developed software, a unique statistical analysis of currents in volume barrier discharge driven in atmospheric-pressure air is made for over 80 consecutive periods of a 15 kHz applied voltage. We reveal the presence of repetitive sub-critical current pulses and conclude that these can be identified with the discharging of surface charge microdomains. Moreover, extremely low, long-lasting microsecond currents were detected which are caused by ion flow, and are analysed in detail. The statistical behaviour presented gives deeper insight into the discharge physics of these usually undetectable current signals.

  10. Animal minds and neuroimaging--bridging the gap between science and ethics?

    Science.gov (United States)

    Buller, Tom

    2014-04-01

    As Colin Allen has argued, discussions between science and ethics about the mentality and moral status of nonhuman animals often stall on account of the fact that the properties that ethics presents as evidence of animal mentality and moral status, namely consciousness and sentience, are not observable "scientifically respectable" properties. In order to further discussion between science and ethics, it seems, therefore, that we need to identify properties that would satisfy both domains. In this article I examine the mentality and moral status of nonhuman animals from the perspective of neuroethics. By adopting this perspective, we can see how advances in neuroimaging regarding (1) research into the neurobiology of pain, (2) "brain reading," and (3) the minimally conscious state may enable us to identify properties that help bridge the gap between science and ethics, and hence help further the debate about the mentality and moral status of nonhuman animals.

  11. [Seeking the aetiology of autistic spectrum disorder. Part 2: Functional neuroimaging].

    Science.gov (United States)

    Bryńska, Anita

    2012-01-01

    Multiple functional imaging techniques help to a better understanding of the neurobiological basis of autism-spectrum disorders (ASD). The early functional imaging studies on ASD focused on task-specific methods related to core symptom domains and explored patterns of activation in response to face processing, theory of mind tasks, language processing and executive function tasks. On the other hand, fMRI research in ASD focused on the development of functional connectivity methods and has provided evidence of alterations in cortical connectivity in ASD and establish autism as a disorder of under-connectivity among the brain regions participating in cortical networks. This atypical functional connectivity in ASD results in inefficiency and poor integration of processing in network connections to achieve task performance. The goal of this review is to summarise the actual neuroimaging functional data and examine their implication for understanding of the neurobiology of ASD.

  12. Evidence of transcranial direct current stimulation-generated electric fields at subthalamic level in human brain in vivo.

    Science.gov (United States)

    Chhatbar, Pratik Y; Kautz, Steven A; Takacs, Istvan; Rowland, Nathan C; Revuelta, Gonzalo J; George, Mark S; Bikson, Marom; Feng, Wuwei

    2018-03-13

    Transcranial direct current stimulation (tDCS) is a promising brain modulation technique for several disease conditions. With this technique, some portion of the current penetrates through the scalp to the cortex and modulates cortical excitability, but a recent human cadaver study questions the amount. This insufficient intracerebral penetration of currents may partially explain the inconsistent and mixed results in tDCS studies to date. Experimental validation of a transcranial alternating current stimulation-generated electric field (EF) in vivo has been performed on the cortical (using electrocorticography, ECoG, electrodes), subcortical (using stereo electroencephalography, SEEG, electrodes) and deeper thalamic/subthalamic levels (using DBS electrodes). However, tDCS-generated EF measurements have never been attempted. We aimed to demonstrate that tDCS generates biologically relevant EF as deep as the subthalamic level in vivo. Patients with movement disorders who have implanted deep brain stimulation (DBS) electrodes serve as a natural experimental model for thalamic/subthalamic recordings of tDCS-generated EF. We measured voltage changes from DBS electrodes and body resistance from tDCS electrodes in three subjects while applying direct current to the scalp at 2 mA and 4 mA over two tDCS montages. Voltage changes at the level of deep nuclei changed proportionally with the level of applied current and varied with different tDCS montages. Our findings suggest that scalp-applied tDCS generates biologically relevant EF. Incorporation of these experimental results may improve finite element analysis (FEA)-based models. Copyright © 2018 Elsevier Inc. All rights reserved.

  13. Experimental evidence for an optical interference model for vibrational sum frequency generation on multilayer organic thin film systems. I. Electric dipole approximation

    International Nuclear Information System (INIS)

    O’Brien, Daniel B.; Massari, Aaron M.

    2015-01-01

    In the field of vibrational sum frequency generation spectroscopy (VSFG) applied to organic thin film systems, a significant challenge to data analysis is in the accurate description of optical interference effects. Herein, we provide experimental evidence that a model recently developed in our lab provides an accurate description of this phenomenon. We studied the organic small molecule N,N′-dioctyl-3,4,9,10-perylenedicarboximide vapor deposited as a thickness gradient on silicon wafer substrates with two oxide thicknesses and two surface preps. VSFG data were obtained using the ssp and the sps polarization combinations in the imide carbonyl stretching region as a function of organic thickness. In this first of two reports, the data are modeled and interpreted within the ubiquitous electric dipole approximation for VSFG. The intrinsic sample responses are parameterized during the fitting routines while optical interference effects are simply calculated from the model using known refractive indices, thin film thicknesses, and beam angles. The results indicate that the thin film model provides a good description of optical interferences, indicating that interfacial terms are significant. Inconsistencies between the fitting results within the bounds of the electric dipole response motivate deliberation for additional effects to be considered in the second report

  14. Experimental evidence for an optical interference model for vibrational sum frequency generation on multilayer organic thin film systems. I. Electric dipole approximation.

    Science.gov (United States)

    O'Brien, Daniel B; Massari, Aaron M

    2015-01-14

    In the field of vibrational sum frequency generation spectroscopy (VSFG) applied to organic thin film systems, a significant challenge to data analysis is in the accurate description of optical interference effects. Herein, we provide experimental evidence that a model recently developed in our lab provides an accurate description of this phenomenon. We studied the organic small molecule N,N'-dioctyl-3,4,9,10-perylenedicarboximide vapor deposited as a thickness gradient on silicon wafer substrates with two oxide thicknesses and two surface preps. VSFG data were obtained using the ssp and the sps polarization combinations in the imide carbonyl stretching region as a function of organic thickness. In this first of two reports, the data are modeled and interpreted within the ubiquitous electric dipole approximation for VSFG. The intrinsic sample responses are parameterized during the fitting routines while optical interference effects are simply calculated from the model using known refractive indices, thin film thicknesses, and beam angles. The results indicate that the thin film model provides a good description of optical interferences, indicating that interfacial terms are significant. Inconsistencies between the fitting results within the bounds of the electric dipole response motivate deliberation for additional effects to be considered in the second report.

  15. Experimental evidence for an optical interference model for vibrational sum frequency generation on multilayer organic thin film systems. I. Electric dipole approximation

    Energy Technology Data Exchange (ETDEWEB)

    O’Brien, Daniel B.; Massari, Aaron M., E-mail: massari@umn.edu [Department of Chemistry, University of Minnesota—Twin Cities, 207 Pleasant Street SE, Minneapolis, Minnesota 55455 (United States)

    2015-01-14

    In the field of vibrational sum frequency generation spectroscopy (VSFG) applied to organic thin film systems, a significant challenge to data analysis is in the accurate description of optical interference effects. Herein, we provide experimental evidence that a model recently developed in our lab provides an accurate description of this phenomenon. We studied the organic small molecule N,N′-dioctyl-3,4,9,10-perylenedicarboximide vapor deposited as a thickness gradient on silicon wafer substrates with two oxide thicknesses and two surface preps. VSFG data were obtained using the ssp and the sps polarization combinations in the imide carbonyl stretching region as a function of organic thickness. In this first of two reports, the data are modeled and interpreted within the ubiquitous electric dipole approximation for VSFG. The intrinsic sample responses are parameterized during the fitting routines while optical interference effects are simply calculated from the model using known refractive indices, thin film thicknesses, and beam angles. The results indicate that the thin film model provides a good description of optical interferences, indicating that interfacial terms are significant. Inconsistencies between the fitting results within the bounds of the electric dipole response motivate deliberation for additional effects to be considered in the second report.

  16. Neuroimaging and neuromodulation approaches to study eating behavior and prevent and treat eating disorders and obesity

    Directory of Open Access Journals (Sweden)

    D. Val-Laillet

    2015-01-01

    Full Text Available Functional, molecular and genetic neuroimaging has highlighted the existence of brain anomalies and neural vulnerability factors related to obesity and eating disorders such as binge eating or anorexia nervosa. In particular, decreased basal metabolism in the prefrontal cortex and striatum as well as dopaminergic alterations have been described in obese subjects, in parallel with increased activation of reward brain areas in response to palatable food cues. Elevated reward region responsivity may trigger food craving and predict future weight gain. This opens the way to prevention studies using functional and molecular neuroimaging to perform early diagnostics and to phenotype subjects at risk by exploring different neurobehavioral dimensions of the food choices and motivation processes. In the first part of this review, advantages and limitations of neuroimaging techniques, such as functional magnetic resonance imaging (fMRI, positron emission tomography (PET, single photon emission computed tomography (SPECT, pharmacogenetic fMRI and functional near-infrared spectroscopy (fNIRS will be discussed in the context of recent work dealing with eating behavior, with a particular focus on obesity. In the second part of the review, non-invasive strategies to modulate food-related brain processes and functions will be presented. At the leading edge of non-invasive brain-based technologies is real-time fMRI (rtfMRI neurofeedback, which is a powerful tool to better understand the complexity of human brain–behavior relationships. rtfMRI, alone or when combined with other techniques and tools such as EEG and cognitive therapy, could be used to alter neural plasticity and learned behavior to optimize and/or restore healthy cognition and eating behavior. Other promising non-invasive neuromodulation approaches being explored are repetitive transcranial magnetic stimulation (rTMS and transcranial direct-current stimulation (tDCS. Converging evidence points at

  17. Neuroimaging and neuromodulation approaches to study eating behavior and prevent and treat eating disorders and obesity.

    Science.gov (United States)

    Val-Laillet, D; Aarts, E; Weber, B; Ferrari, M; Quaresima, V; Stoeckel, L E; Alonso-Alonso, M; Audette, M; Malbert, C H; Stice, E

    2015-01-01

    Functional, molecular and genetic neuroimaging has highlighted the existence of brain anomalies and neural vulnerability factors related to obesity and eating disorders such as binge eating or anorexia nervosa. In particular, decreased basal metabolism in the prefrontal cortex and striatum as well as dopaminergic alterations have been described in obese subjects, in parallel with increased activation of reward brain areas in response to palatable food cues. Elevated reward region responsivity may trigger food craving and predict future weight gain. This opens the way to prevention studies using functional and molecular neuroimaging to perform early diagnostics and to phenotype subjects at risk by exploring different neurobehavioral dimensions of the food choices and motivation processes. In the first part of this review, advantages and limitations of neuroimaging techniques, such as functional magnetic resonance imaging (fMRI), positron emission tomography (PET), single photon emission computed tomography (SPECT), pharmacogenetic fMRI and functional near-infrared spectroscopy (fNIRS) will be discussed in the context of recent work dealing with eating behavior, with a particular focus on obesity. In the second part of the review, non-invasive strategies to modulate food-related brain processes and functions will be presented. At the leading edge of non-invasive brain-based technologies is real-time fMRI (rtfMRI) neurofeedback, which is a powerful tool to better understand the complexity of human brain-behavior relationships. rtfMRI, alone or when combined with other techniques and tools such as EEG and cognitive therapy, could be used to alter neural plasticity and learned behavior to optimize and/or restore healthy cognition and eating behavior. Other promising non-invasive neuromodulation approaches being explored are repetitive transcranial magnetic stimulation (rTMS) and transcranial direct-current stimulation (tDCS). Converging evidence points at the value of

  18. Neuroimaging and neuromodulation approaches to study eating behavior and prevent and treat eating disorders and obesity

    Science.gov (United States)

    Val-Laillet, D.; Aarts, E.; Weber, B.; Ferrari, M.; Quaresima, V.; Stoeckel, L.E.; Alonso-Alonso, M.; Audette, M.; Malbert, C.H.; Stice, E.

    2015-01-01

    Functional, molecular and genetic neuroimaging has highlighted the existence of brain anomalies and neural vulnerability factors related to obesity and eating disorders such as binge eating or anorexia nervosa. In particular, decreased basal metabolism in the prefrontal cortex and striatum as well as dopaminergic alterations have been described in obese subjects, in parallel with increased activation of reward brain areas in response to palatable food cues. Elevated reward region responsivity may trigger food craving and predict future weight gain. This opens the way to prevention studies using functional and molecular neuroimaging to perform early diagnostics and to phenotype subjects at risk by exploring different neurobehavioral dimensions of the food choices and motivation processes. In the first part of this review, advantages and limitations of neuroimaging techniques, such as functional magnetic resonance imaging (fMRI), positron emission tomography (PET), single photon emission computed tomography (SPECT), pharmacogenetic fMRI and functional near-infrared spectroscopy (fNIRS) will be discussed in the context of recent work dealing with eating behavior, with a particular focus on obesity. In the second part of the review, non-invasive strategies to modulate food-related brain processes and functions will be presented. At the leading edge of non-invasive brain-based technologies is real-time fMRI (rtfMRI) neurofeedback, which is a powerful tool to better understand the complexity of human brain–behavior relationships. rtfMRI, alone or when combined with other techniques and tools such as EEG and cognitive therapy, could be used to alter neural plasticity and learned behavior to optimize and/or restore healthy cognition and eating behavior. Other promising non-invasive neuromodulation approaches being explored are repetitive transcranial magnetic stimulation (rTMS) and transcranial direct-current stimulation (tDCS). Converging evidence points at the value of

  19. Neural correlates of attention and arousal: insights from electrophysiology, functional neuroimaging and psychopharmacology.

    Science.gov (United States)

    Coull, J T

    1998-07-01

    Attention and arousal are multi-dimensional psychological processes, which interact closely with one another. The neural substrates of attention, as well as the interaction between arousal and attention, are discussed in this review. After a brief discussion of psychological and neuropsychological theories of attention, event-related potential correlates of attention are discussed. Essentially, attention acts to modulate stimulus-induced electrical potentials (N100/P100, P300, N400), rather than generating any unique potentials of its own. Functional neuroimaging studies of attentional orienting, selective attention, divided attention and sustained attention (and its inter-dependence on underlying levels of arousal) are then reviewed. A distinction is drawn between the brain areas which are crucially involved in the top-down modulation of attention (the 'sources' of attention) and those sensory-association areas whose activity is modulated by attention (the 'sites' of attentional expression). Frontal and parietal (usually right-lateralised) cortices and thalamus are most often associated with the source of attentional modulation. Also, the use of functional neuroimaging to test explicit hypotheses about psychological theories of attention is emphasised. These experimental paradigms form the basis for a 'new generation' of functional imaging studies which exploit the dynamic aspect of imaging and demonstrate how it can be used as more than just a 'brain mapping' device. Finally, a review of psychopharmacological studies in healthy human volunteers outlines the contributions of the noradrenergic, cholinergic and dopaminergic neurotransmitter systems to the neurochemical modulation of human attention and arousal. While, noradrenergic and cholinergic systems are involved in 'low-level' aspects of attention (e.g. attentional orienting), the dopaminergic system is associated with more 'executive' aspects of attention such as attentional set-shifting or working memory.

  20. What do people with dementia and their carers want to know about neuroimaging for dementia?

    Science.gov (United States)

    Featherstone, Hannah; Butler, Marie-Louise; Ciblis, Aurelia; Bokde, Arun L; Mullins, Paul G; McNulty, Jonathan P

    2017-05-01

    Neuroimaging forms an important part of dementia diagnosis. Provision of information on neuroimaging to people with dementia and their carers may aid understanding of the pathological, physiological and psychosocial changes of the disease, and increase understanding of symptoms. This qualitative study aimed to investigate participants' knowledge of the dementia diagnosis pathway, their understanding of neuroimaging and its use in diagnosis, and to determine content requirements for a website providing neuroimaging information. Structured interviews and a focus group were conducted with carers and people with dementia. The findings demonstrate an unmet need for information on neuroimaging both before and after the examination. Carers were keen to know about neuroimaging at a practical and technical level to help avoid diagnosis denial. People with dementia requested greater information, but with a caveat to avoid overwhelming detail, and were less likely to favour an Internet resource.

  1. Neuroimaging: do we really need new contrast agents for MRI?

    International Nuclear Information System (INIS)

    Roberts, T.P.L.; Chuang, N.; Roberts, H.C.

    2000-01-01

    The use of exogenous contrast media in magnetic resonance imaging of the brain has brought dramatic improvement in the sensitivity of detection and delineation of pathological structures, such as primary and metastatic brain tumors, inflammation and ischemia. Disruption of the blood brain barrier leads to accumulation of the intravenously injected contrast material in the extravascular space, leading to signal enhancement. Magnetic resonance angiography benefits from T 1 -shortening effects of contrast agent, improving small vessel depiction and providing vascular visualization even in situations of slow flow. High speed dynamic MRI after bolus injection of contrast media allows tracer kinetic modeling of cerebral perfusion. Progressive enhancement over serial post-contrast imaging allows modeling of vascular permeability and thus quantitative estimation of the severity of blood brain barrier disruption. With such an array of capabilities and ever improving technical abilities, it seems that the role of contrast agents in MR neuroimaging is established and the development of new agents may be superfluous. However, new agents are being developed with prolonged intravascular residence times, and with in-vivo binding of ever-increasing specificity. Intravascular, or blood pool, agents are likely to benefit magnetic resonance angiography of the carotid and cerebral vessels; future agents may allow the visualization of therapeutic drug delivery, the monitoring of, for example, gene expression, and the imaging evaluation of treatment efficacy. So while there is a substantial body of work that can be performed with currently available contrast agents, especially in conjunction with optimized image acquisition strategies, post processing, and mathematical analysis, there are still unrealized opportunities for novel contrast agent introduction, particularly those exploiting biological specificity. This article reviews the current use of contrast media in magnetic resonance

  2. Multiple brain atlas database and atlas-based neuroimaging system.

    Science.gov (United States)

    Nowinski, W L; Fang, A; Nguyen, B T; Raphel, J K; Jagannathan, L; Raghavan, R; Bryan, R N; Miller, G A

    1997-01-01

    For the purpose of developing multiple, complementary, fully labeled electronic brain atlases and an atlas-based neuroimaging system for analysis, quantification, and real-time manipulation of cerebral structures in two and three dimensions, we have digitized, enhanced, segmented, and labeled the following print brain atlases: Co-Planar Stereotaxic Atlas of the Human Brain by Talairach and Tournoux, Atlas for Stereotaxy of the Human Brain by Schaltenbrand and Wahren, Referentially Oriented Cerebral MRI Anatomy by Talairach and Tournoux, and Atlas of the Cerebral Sulci by Ono, Kubik, and Abernathey. Three-dimensional extensions of these atlases have been developed as well. All two- and three-dimensional atlases are mutually preregistered and may be interactively registered with an actual patient's data. An atlas-based neuroimaging system has been developed that provides support for reformatting, registration, visualization, navigation, image processing, and quantification of clinical data. The anatomical index contains about 1,000 structures and over 400 sulcal patterns. Several new applications of the brain atlas database also have been developed, supported by various technologies such as virtual reality, the Internet, and electronic publishing. Fusion of information from multiple atlases assists the user in comprehensively understanding brain structures and identifying and quantifying anatomical regions in clinical data. The multiple brain atlas database and atlas-based neuroimaging system have substantial potential impact in stereotactic neurosurgery and radiotherapy by assisting in visualization and real-time manipulation in three dimensions of anatomical structures, in quantitative neuroradiology by allowing interactive analysis of clinical data, in three-dimensional neuroeducation, and in brain function studies.

  3. Frequency Constrained ShiftCP Modeling of Neuroimaging Data

    DEFF Research Database (Denmark)

    Mørup, Morten; Hansen, Lars Kai; Madsen, Kristoffer H.

    2011-01-01

    The shift invariant multi-linear model based on the CandeComp/PARAFAC (CP) model denoted ShiftCP has proven useful for the modeling of latency changes in trial based neuroimaging data[17]. In order to facilitate component interpretation we presently extend the shiftCP model such that the extracted...... components can be constrained to pertain to predefined frequency ranges such as alpha, beta and gamma activity. To infer the number of components in the model we propose to apply automatic relevance determination by imposing priors that define the range of variation of each component of the shiftCP model...

  4. Visualization of nonlinear kernel models in neuroimaging by sensitivity maps

    DEFF Research Database (Denmark)

    Rasmussen, Peter Mondrup; Hansen, Lars Kai; Madsen, Kristoffer Hougaard

    There is significant current interest in decoding mental states from neuroimages. In this context kernel methods, e.g., support vector machines (SVM) are frequently adopted to learn statistical relations between patterns of brain activation and experimental conditions. In this paper we focus...... on visualization of such nonlinear kernel models. Specifically, we investigate the sensitivity map as a technique for generation of global summary maps of kernel classification methods. We illustrate the performance of the sensitivity map on functional magnetic resonance (fMRI) data based on visual stimuli. We...

  5. Functional neuroimaging in the assessment of cerebral ischaemia

    International Nuclear Information System (INIS)

    Sartor, K.; Heiland, S.

    1997-01-01

    Cerebral infarct causes over 170, 000 deaths per year in the United States. Recent developments in neuroimaging are providing an insight into focal cerebral ischaemia, including its pathophysiology and the area of brain at risk. Perfusion-weighted magnetic resonance (MR) allows evaluation of the blood supply to the ischaemic area, and diffusion-weighted MR permits assessment of tissue damage. Although both functional imaging techniques require some refinement, it is likely that they will soon become part of the normal clinical routine and allow accurate characterisation of pathology. It is expected that this may eventually lead to the development of new treatments. (orig.)

  6. Neuroimaging of Narcolepsy and Kleine-Levin Syndrome.

    Science.gov (United States)

    Hong, Seung Bong

    2017-09-01

    Narcolepsy is a chronic neurologic disorder with the abnormal regulation of the sleep-wake cycle, resulting in excessive daytime sleepiness, disturbed nocturnal sleep, and manifestations related to rapid eye movement sleep, such as cataplexy, sleep paralysis, and hypnagogic hallucination. Over the past decade, numerous neuroimaging studies have been performed to characterize the pathophysiology and various clinical features of narcolepsy. This article reviews structural and functional brain imaging findings in narcolepsy and Kleine-Levin syndrome. Based on the current state of research, brain imaging is a useful tool to investigate and understand the neuroanatomic correlates and brain abnormalities of narcolepsy and other hypersomnia. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Accelerating Neuroimage Registration through Parallel Computation of Similarity Metric.

    Directory of Open Access Journals (Sweden)

    Yun-Gang Luo

    Full Text Available Neuroimage registration is crucial for brain morphometric analysis and treatment efficacy evaluation. However, existing advanced registration algorithms such as FLIRT and ANTs are not efficient enough for clinical use. In this paper, a GPU implementation of FLIRT with the correlation ratio (CR as the similarity metric and a GPU accelerated correlation coefficient (CC calculation for the symmetric diffeomorphic registration of ANTs have been developed. The comparison with their corresponding original tools shows that our accelerated algorithms can greatly outperform the original algorithm in terms of computational efficiency. This paper demonstrates the great potential of applying these registration tools in clinical applications.

  8. Visualization of Nonlinear Classification Models in Neuroimaging - Signed Sensitivity Maps

    DEFF Research Database (Denmark)

    Rasmussen, Peter Mondrup; Schmah, Tanya; Madsen, Kristoffer Hougaard

    2012-01-01

    Classification models are becoming increasing popular tools in the analysis of neuroimaging data sets. Besides obtaining good prediction accuracy, a competing goal is to interpret how the classifier works. From a neuroscientific perspective, we are interested in the brain pattern reflecting...... the underlying neural encoding of an experiment defining multiple brain states. In this relation there is a great desire for the researcher to generate brain maps, that highlight brain locations of importance to the classifiers decisions. Based on sensitivity analysis, we develop further procedures for model...... direction the individual locations influence the classification. We illustrate the visualization procedure on a real data from a simple functional magnetic resonance imaging experiment....

  9. Internet and Gaming Addiction: A Systematic Literature Review of Neuroimaging Studies

    Science.gov (United States)

    Kuss, Daria J.; Griffiths, Mark D.

    2012-01-01

    In the past decade, research has accumulated suggesting that excessive Internet use can lead to the development of a behavioral addiction. Internet addiction has been considered as a serious threat to mental health and the excessive use of the Internet has been linked to a variety of negative psychosocial consequences. The aim of this review is to identify all empirical studies to date that used neuroimaging techniques to shed light upon the emerging mental health problem of Internet and gaming addiction from a neuroscientific perspective. Neuroimaging studies offer an advantage over traditional survey and behavioral research because with this method, it is possible to distinguish particular brain areas that are involved in the development and maintenance of addiction. A systematic literature search was conducted, identifying 18 studies. These studies provide compelling evidence for the similarities between different types of addictions, notably substance-related addictions and Internet and gaming addiction, on a variety of levels. On the molecular level, Internet addiction is characterized by an overall reward deficiency that entails decreased dopaminergic activity. On the level of neural circuitry, Internet and gaming addiction led to neuroadaptation and structural changes that occur as a consequence of prolonged increased activity in brain areas associated with addiction. On a behavioral level, Internet and gaming addicts appear to be constricted with regards to their cognitive functioning in various domains. The paper shows that understanding the neuronal correlates associated with the development of Internet and gaming addiction will promote future research and will pave the way for the development of addiction treatment approaches. PMID:24961198

  10. Internet and Gaming Addiction: A Systematic Literature Review of Neuroimaging Studies

    Directory of Open Access Journals (Sweden)

    Daria J. Kuss

    2012-09-01

    Full Text Available In the past decade, research has accumulated suggesting that excessive Internet use can lead to the development of a behavioral addiction. Internet addiction has been considered as a serious threat to mental health and the excessive use of the Internet has been linked to a variety of negative psychosocial consequences. The aim of this review is to identify all empirical studies to date that used neuroimaging techniques to shed light upon the emerging mental health problem of Internet and gaming addiction from a neuroscientific perspective. Neuroimaging studies offer an advantage over traditional survey and behavioral research because with this method, it is possible to distinguish particular brain areas that are involved in the development and maintenance of addiction. A systematic literature search was conducted, identifying 18 studies. These studies provide compelling evidence for the similarities between different types of addictions, notably substance-related addictions and Internet and gaming addiction, on a variety of levels. On the molecular level, Internet addiction is characterized by an overall reward deficiency that entails decreased dopaminergic activity. On the level of neural circuitry, Internet and gaming addiction led to neuroadaptation and structural changes that occur as a consequence of prolonged increased activity in brain areas associated with addiction. On a behavioral level, Internet and gaming addicts appear to be constricted with regards to their cognitive functioning in various domains. The paper shows that understanding the neuronal correlates associated with the development of Internet and gaming addiction will promote future research and will pave the way for the development of addiction treatment approaches.

  11. Effects of computerized cognitive training on neuroimaging outcomes in older adults: a systematic review.

    Science.gov (United States)

    Ten Brinke, Lisanne F; Davis, Jennifer C; Barha, Cindy K; Liu-Ambrose, Teresa

    2017-07-10

    Worldwide, the population is aging and the number of individuals diagnosed with dementia is rising rapidly. Currently, there are no effective pharmaceutical cures. Hence, identifying lifestyle approaches that may prevent, delay, or treat cognitive impairment and dementia in older adults is becoming increasingly important. Computerized Cognitive Training (CCT) is a promising strategy to combat cognitive decline. Yet, the underlying mechanisms of the effect of CCT on cognition remain poorly understood. Hence, the primary objective of this systematic review was to examine peer-reviewed literature ascertaining the effect of CCT on both structural and functional neuroimaging measures among older adults to gain insight into the underlying mechanisms by which CCT may benefit cognitive function. In accordance with PRISMA guidelines, we used the following databases: MEDLINE, EMBASE, and CINAHL. Two independent reviewers abstracted data using pre-defined terms. These included: main study characteristics such as the type of training (i.e., single- versus multi-domain), participant demographics (age ≥ 50 years; no psychiatric conditions), and the inclusion of neuroimaging outcomes. The Physiotherapy Evidence Database (PEDro) scale was used to assess quality of all studies included in this systematic review. Nine studies were included in this systematic review, with four studies including multiple MRI sequences. Results of this systematic review are mixed: CCT was found to increase and decrease both brain structure and function in older adults. In addition, depending on region of interest, both increases and decreases in structure and function were associated with behavioural performance. Of all studies included in this systematic review, results from the highest quality studies, which were two randomized controlled trials, demonstrated that multi-domain CCT could lead to increases in hippocampal functional connectivity. Further high quality studies that include an active

  12. Internet and gaming addiction: a systematic literature review of neuroimaging studies.

    Science.gov (United States)

    Kuss, Daria J; Griffiths, Mark D

    2012-09-05

    In the past decade, research has accumulated suggesting that excessive Internet use can lead to the development of a behavioral addiction. Internet addiction has been considered as a serious threat to mental health and the excessive use of the Internet has been linked to a variety of negative psychosocial consequences. The aim of this review is to identify all empirical studies to date that used neuroimaging techniques to shed light upon the emerging mental health problem of Internet and gaming addiction from a neuroscientific perspective. Neuroimaging studies offer an advantage over traditional survey and behavioral research because with this method, it is possible to distinguish particular brain areas that are involved in the development and maintenance of addiction. A systematic literature search was conducted, identifying 18 studies. These studies provide compelling evidence for the similarities between different types of addictions, notably substance-related addictions and Internet and gaming addiction, on a variety of levels. On the molecular level, Internet addiction is characterized by an overall reward deficiency that entails decreased dopaminergic activity. On the level of neural circuitry, Internet and gaming addiction led to neuroadaptation and structural changes that occur as a consequence of prolonged increased activity in brain areas associated with addiction. On a behavioral level, Internet and gaming addicts appear to be constricted with regards to their cognitive functioning in various domains. The paper shows that understanding the neuronal correlates associated with the development of Internet and gaming addiction will promote future research and will pave the way for the development of addiction treatment approaches.

  13. Behavioural, computational, and neuroimaging studies of acquired apraxia of speech

    Directory of Open Access Journals (Sweden)

    Kirrie J Ballard

    2014-11-01

    Full Text Available A critical examination of speech motor control depends on an in-depth understanding of network connectivity associated with Brodmann areas 44 and 45 and surrounding cortices. Damage to these areas has been associated with two conditions - the speech motor programming disorder apraxia of speech (AOS and the linguistic / grammatical disorder of Broca’s aphasia. Here we focus on AOS, which is most commonly associated with damage to posterior Broca's area and adjacent cortex. We provide an overview of our own studies into the nature of AOS, including behavioral and neuroimaging methods, to explore components of the speech motor network that are associated with normal and disordered speech motor programming in AOS. Behavioral, neuroimaging, and computational modeling studies are indicating that AOS is associated with impairment in learning feedforward models and/or implementing feedback mechanisms and with the functional contribution of BA6. While functional connectivity methods are not yet routinely applied to the study of AOS, we highlight the need for focusing on the functional impact of localised lesions throughout the speech network, as well as larger scale comparative studies to distinguish the unique behavioral and neurological signature of AOS. By coupling these methods with neural network models, we have a powerful set of tools to improve our understanding of the neural mechanisms that underlie AOS, and speech production generally.

  14. Neuroimaging of nonaccidental head trauma: pitfalls and controversies

    Energy Technology Data Exchange (ETDEWEB)

    Fernando, Sujan [University of Missouri-Kansas School of Medicine, Department of Medicine, Kansas City, MO (United States); Obaldo, Ruby E. [The University of Kansas Medical Center, Department of Radiology, Kansas City, MO (United States); Walsh, Irene R. [The University of Missouri-Kansas City, Children' s Mercy Hospitals and Clinics, Department of Emergency Medicine, Kansas City, MO (United States); Lowe, Lisa H. [The University of Missouri-Kansas City, Children' s Mercy Hospitals and Clinics, Department of Radiology, Kansas City, MO (United States)

    2008-08-15

    Although certain neuroimaging appearances are highly suggestive of abuse, radiological findings are often nonspecific. The objective of this review is to discuss pitfalls, controversies, and mimics occurring in neuroimaging of nonaccidental head trauma in order to allow the reader to establish an increased level of comfort in distinguishing between nonaccidental and accidental head trauma. Specific topics discussed include risk factors, general biomechanics and imaging strategies in nonaccidental head trauma, followed by the characteristics of skull fractures, normal prominent tentorium and falx versus subdural hematoma, birth trauma versus nonaccidental head trauma, hyperacute versus acute on chronic subdural hematomas, expanded subarachnoid space versus subdural hemorrhage, controversy regarding subdural hematomas associated with benign enlarged subarachnoid spaces, controversy regarding hypoxia as a cause of subdural hematoma and/or retinal hemorrhages without trauma, controversy regarding the significance of retinal hemorrhages related to nonaccidental head trauma, controversy regarding the significance of subdural hematomas in general, and pitfalls of glutaric aciduria type 1 and hemophagocytic lymphohistiocytosis mimicking nonaccidental head trauma. (orig.)

  15. Neuroimaging in the Diagnostic Evaluation of Eye Pain.

    Science.gov (United States)

    Szatmáry, Gabriella

    2016-09-01

    Ocular or eye pain is a frequent complaint encountered not only by eye care providers but neurologists. Isolated eye pain is non-specific and non-localizing; therefore, it poses significant differential diagnostic problems. A wide range of neurologic and ophthalmic disorders may cause pain in, around, or behind the eye. These include ocular and orbital diseases and primary and secondary headaches. In patients presenting with an isolated and chronic eye pain, neuroimaging is usually normal. However, at the beginning of a disease process or in low-grade disease, the eye may appear "quiet," misleading a provider lacking familiarity with underlying disorders and high index of clinical suspicion. Delayed diagnosis of some neuro-ophthalmic causes of eye pain could result in significant neurologic and ophthalmic morbidity, conceivably even mortality. This article reviews some recent advances in imaging of the eye, the orbit, and the brain, as well as research in which neuroimaging has advanced the discovery of the underlying pathophysiology and the complex differential diagnosis of eye pain.

  16. DFBIdb: a software package for neuroimaging data management.

    Science.gov (United States)

    Adamson, Christopher L; Wood, Amanda G

    2010-12-01

    We present DFBIdb: a suite of tools for efficient management of neuroimaging project data. Specifically, DFBIdb was designed to allow users to quickly perform routine management tasks of sorting, archiving, exploring, exporting and organising raw data. DFBIdb was implemented as a collection of Python scripts that maintain a project-based, centralised database that is based on the XCEDE 2 data model. Project data is imported from a filesystem hierarchy of raw files, which is an often-used convention of imaging devices, using a single script that catalogues meta-data into a modified XCEDE 2 data model. During the import process data are reversibly anonymised, archived and compressed. The import script was designed to support multiple file formats and features an extensible framework that can be adapted to novel file formats. An ACL-based security model, with accompanying graphical management tools, was implemented to provide a straightforward method to restrict access to raw and meta-data. Graphical user interfaces are provided for data exploration. DFBIdb includes facilities to export, convert and organise customisable subsets of project data according to user-specified criteria. The command-line interface was implemented to allow users to incorporate database commands into more complex scripts that may be utilised to automate data management tasks. By using DFBIdb, neuroimaging laboratories will be able to perform routine data management tasks in an efficient manner.

  17. Publication trends in neuroimaging of minimally conscious states

    Directory of Open Access Journals (Sweden)

    Alex Garnett

    2013-09-01

    Full Text Available We used existing and customized bibliometric and scientometric methods to analyze publication trends in neuroimaging research of minimally conscious states and describe the domain in terms of its geographic, contributor, and content features. We considered publication rates for the years 2002–2011, author interconnections, the rate at which new authors are added, and the domains that inform the work of author contributors. We also provided a content analysis of clinical and ethical themes within the relevant literature. We found a 27% growth in the number of papers over the period of study, professional diversity among a wide range of peripheral author contributors but only few authors who dominate the field, and few new technical paradigms and clinical themes that would fundamentally expand the landscape. The results inform both the science of consciousness as well as parallel ethics and policy studies of the potential for translational challenges of neuroimaging in research and health care of people with disordered states of consciousness.

  18. [Neuropsychology of Tourette's disorder: cognition, neuroimaging and creativity].

    Science.gov (United States)

    Espert, R; Gadea, M; Alino, M; Oltra-Cucarella, J

    2017-02-24

    Tourette's disorder is the result of fronto-striatal brain dysfunction affecting people of all ages, with a debut in early childhood and continuing into adolescence and adulthood. This article reviews the main cognitive, functional neuroimaging and creativity-related studies in a disorder characterized by an excess of dopamine in the brain. Given the special cerebral configuration of these patients, neuropsychological alterations, especially in executive functions, should be expected. However, the findings are inconclusive and are conditioned by factors such as comorbidity with attention deficit hyperactivity disorder and obsessive-compulsive disorder, age or methodological variables. On the other hand, the neuroimaging studies carried out over the last decade have been able to explain the clinical symptoms of Tourette's disorder patients, with special relevance for the supplementary motor area and the anterior cingulate gyrus. Finally, although there is no linear relationship between excess of dopamine and creativity, the scientific literature emphasizes an association between Tourette's disorder and musical creativity, which could be translated into intervention programs based on music.

  19. Self-development: integrating cognitive, socioemotional, and neuroimaging perspectives.

    Science.gov (United States)

    Pfeifer, Jennifer H; Peake, Shannon J

    2012-01-01

    This review integrates cognitive, socioemotional, and neuroimaging perspectives on self-development. Neural correlates of key processes implicated in personal and social identity are reported from studies of children, adolescents, and adults, including autobiographical memory, direct and reflected self-appraisals, and social exclusion. While cortical midline structures of medial prefrontal cortex and medial posterior parietal cortex are consistently identified in neuroimaging studies considering personal identity from a primarily cognitive perspective ("who am I?"), additional regions are implicated by studies considering personal and social identity from a more socioemotional perspective ("what do others think about me, where do I fit in?"), especially in child or adolescent samples. The involvement of these additional regions (including tempo-parietal junction and posterior superior temporal sulcus, temporal poles, anterior insula, ventral striatum, anterior cingulate cortex, middle cingulate cortex, and ventrolateral prefrontal cortex) suggests mentalizing, emotion, and emotion regulation are central to self-development. In addition, these regions appear to function atypically during personal and social identity tasks in autism and depression, exhibiting a broad pattern of hypoactivation and hyperactivation, respectively. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Investigating the pathogenesis of posttraumatic stress disorder with neuroimaging.

    Science.gov (United States)

    Pitman, R K; Shin, L M; Rauch, S L

    2001-01-01

    Rapidly evolving brain neuroimaging techniques such as magnetic resonance imaging (MRI) and positron emission tomography (PET) are proving fruitful in exploring the pathogenesis and pathophysiology of posttraumatic stress disorder (PTSD). Structural abnormalities in PTSD found with MRI include nonspecific white matter lesions and decreased hippocampal volume. These abnormalities may reflect pretrauma vulnerability to develop PTSD, or they may be a consequence of traumatic exposure, PTSD, and/or PTSD sequelae. Functional neuroimaging symptom provocation and cognitive activation paradigms using PET measurement of regional cerebral blood flow have revealed greater activation of the amygdala and anterior paralimbic structures (which are known to be involved in processing negative emotions such as fear), greater deactivation of Broca's region (motor speech) and other nonlimbic cortical regions, and failure of activation of the cingulate cortex (which possibly plays an inhibitory role) in response to trauma-related stimuli in individuals with PTSD. Functional MRI research has shown the amygdala to be hyperresponsive to fear-related stimuli in this disorder. Research with PET suggests that cortical, notably hippocampal, metabolism is suppressed to a greater extent by pharmacologic stimulation of the noradrenergic system in persons with PTSD. The growth of knowledge concerning the anatomical and neurochemical basis of this important mental disorder will hopefully eventually lead to rational psychological and pharmacologic treatments.

  1. Neuroimaging of nonaccidental head trauma: pitfalls and controversies

    International Nuclear Information System (INIS)

    Fernando, Sujan; Obaldo, Ruby E.; Walsh, Irene R.; Lowe, Lisa H.

    2008-01-01

    Although certain neuroimaging appearances are highly suggestive of abuse, radiological findings are often nonspecific. The objective of this review is to discuss pitfalls, controversies, and mimics occurring in neuroimaging of nonaccidental head trauma in order to allow the reader to establish an increased level of comfort in distinguishing between nonaccidental and accidental head trauma. Specific topics discussed include risk factors, general biomechanics and imaging strategies in nonaccidental head trauma, followed by the characteristics of skull fractures, normal prominent tentorium and falx versus subdural hematoma, birth trauma versus nonaccidental head trauma, hyperacute versus acute on chronic subdural hematomas, expanded subarachnoid space versus subdural hemorrhage, controversy regarding subdural hematomas associated with benign enlarged subarachnoid spaces, controversy regarding hypoxia as a cause of subdural hematoma and/or retinal hemorrhages without trauma, controversy regarding the significance of retinal hemorrhages related to nonaccidental head trauma, controversy regarding the significance of subdural hematomas in general, and pitfalls of glutaric aciduria type 1 and hemophagocytic lymphohistiocytosis mimicking nonaccidental head trauma. (orig.)

  2. The search for the number form area: A functional neuroimaging meta-analysis.

    Science.gov (United States)

    Yeo, Darren J; Wilkey, Eric D; Price, Gavin R

    2017-07-01

    Recent studies report a putative "number form area" (NFA) in the inferior temporal gyrus (ITG) suggested to be specialized for Arabic numeral processing. However, a number of earlier studies report no such NFA. The reasons for such discrepancies across studies are unclear. To examine evidence for a convergent NFA across studies, we conducted two activation likelihood estimation meta-analyses on 31 and a subset of 20 neuroimaging studies that have contrasted digits with other meaningful symbols. Results suggest the potential existence of an NFA in the right ITG, in addition to a 'symbolic number processing network' comprising bilateral parietal regions, and right-lateralized superior and inferior frontal regions. Critically, convergent localization for the NFA was only evident when contrasts were appropriately controlled for task demands, and does not appear to depend on employing methods designed to overcome fMRI signal dropout in the ITG. Importantly, only five studies had foci within the identified ITG NFA cluster boundary, indicating that more empirical evidence is necessary to determine the true functional specialization and regional specificity of the putative NFA. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Response of Weeping Lantana (Lantana montevidensis to Compost-Based Growing Media and Electrical Conductivity Level in Soilless Culture: First Evidence

    Directory of Open Access Journals (Sweden)

    Giuseppe Cristiano

    2018-03-01

    Full Text Available The most common substrate for potted ornamental plants is prepared with Sphagnum peat; however, the cost and declining availability of high-quality peat, due to environmental constraints, make it necessary to investigate for alternative organic materials. The present study aimed to determine the effects of partial compost replacement with peat and the optimum electrical conductivity (EC level of the nutrient solution in potted weeping lantana [L. montevidensis (Spreng. Briq.] under a recirculating soilless system. Three compost-based substrates were prepared by mixing peat (Pe with sewage sludge-based compost (Co. at a rate of 0% (Pe90Co0Pu10, control, 30% (Pe60Co30Pu10, or 60% (Pe30Co60Pu10, respectively. The soilless recirculated closed system was equipped with two different EC levels (high and low of nutrient solution. Growing media main characteristics and plant bio-morphometric parameters were evaluated. Our first evidence clearly demonstrates that the replacement of peat with compost at doses of 30% and 60% gave the poorest results for plant diameter, shoots, leaves, flowers, and fresh and dry mass, probably indicating that the physical characteristics of the compost based substrates may be the major factor governing plant growth rate. Compost media pH and EC values, too, showed negative effects on plant growth. Considering the effect of EC level, all morphological traits were significantly improved by high EC compared to low EC in weeping lantana. Thus, based on first evidence, further research is needed on organic materials for the establishment of ecological substrates with optimal physicochemical characteristics for the growth of weeping lantana.

  4. Electric transport of a single-crystal iron chalcogenide FeSe superconductor: Evidence of symmetry-breakdown nematicity and additional ultrafast Dirac cone-like carriers

    Science.gov (United States)

    Huynh, K. K.; Tanabe, Y.; Urata, T.; Oguro, H.; Heguri, S.; Watanabe, K.; Tanigaki, K.

    2014-10-01

    An SDW antiferromagnetic (SDW-AF) low-temperature phase transition is generally observed and the AF spin fluctuations are considered to play an important role for the superconductivity pairing mechanism in FeAs superconductors. However, a similar magnetic phase transition is not observed in FeSe superconductors, which has caused considerable discussion. We report on the intrinsic electronic states of FeSe as elucidated by electric transport measurements under magnetic fields using a high quality single crystal. A mobility spectrum analysis, an ab initio method that does not make assumptions on the transport parameters in a multicarrier system, provides very important and clear evidence that another hidden order, most likely the symmetry broken from the tetragonal C4 symmetry to the C2 symmetry nematicity associated with the selective d -orbital splitting, exists in the case of superconducting FeSe other than the AF magnetic order spin fluctuations. The intrinsic low-temperature phase in FeSe is in the almost compensated semimetallic states but is additionally accompanied by Dirac cone-like ultrafast electrons ˜104cm2(VS) -1 as minority carriers.

  5. Model sparsity and brain pattern interpretation of classification models in neuroimaging

    DEFF Research Database (Denmark)

    Rasmussen, Peter Mondrup; Madsen, Kristoffer Hougaard; Churchill, Nathan W

    2012-01-01

    Interest is increasing in applying discriminative multivariate analysis techniques to the analysis of functional neuroimaging data. Model interpretation is of great importance in the neuroimaging context, and is conventionally based on a ‘brain map’ derived from the classification model. In this ...

  6. Predictive modelling using neuroimaging data in the presence of confounds.

    Science.gov (United States)

    Rao, Anil; Monteiro, Joao M; Mourao-Miranda, Janaina

    2017-04-15

    When training predictive models from neuroimaging data, we typically have available non-imaging variables such as age and gender that affect the imaging data but which we may be uninterested in from a clinical perspective. Such variables are commonly referred to as 'confounds'. In this work, we firstly give a working definition for confound in the context of training predictive models from samples of neuroimaging data. We define a confound as a variable which affects the imaging data and has an association with the target variable in the sample that differs from that in the population-of-interest, i.e., the population over which we intend to apply the estimated predictive model. The focus of this paper is the scenario in which the confound and target variable are independent in the population-of-interest, but the training sample is biased due to a sample association between the target and confound. We then discuss standard approaches for dealing with confounds in predictive modelling such as image adjustment and including the confound as a predictor, before deriving and motivating an Instance Weighting scheme that attempts to account for confounds by focusing model training so that it is optimal for the population-of-interest. We evaluate the standard approaches and Instance Weighting in two regression problems with neuroimaging data in which we train models in the presence of confounding, and predict samples that are representative of the population-of-interest. For comparison, these models are also evaluated when there is no confounding present. In the first experiment we predict the MMSE score using structural MRI from the ADNI database with gender as the confound, while in the second we predict age using structural MRI from the IXI database with acquisition site as the confound. Considered over both datasets we find that none of the methods for dealing with confounding gives more accurate predictions than a baseline model which ignores confounding, although

  7. Right brain, left brain in depressive disorders: Clinical and theoretical implications of behavioral, electrophysiological and neuroimaging findings.

    Science.gov (United States)

    Bruder, Gerard E; Stewart, Jonathan W; McGrath, Patrick J

    2017-07-01

    The right and left side of the brain are asymmetric in anatomy and function. We review electrophysiological (EEG and event-related potential), behavioral (dichotic and visual perceptual asymmetry), and neuroimaging (PET, MRI, NIRS) evidence of right-left asymmetry in depressive disorders. Recent electrophysiological and fMRI studies of emotional processing have provided new evidence of altered laterality in depressive disorders. EEG alpha asymmetry and neuroimaging findings at rest and during cognitive or emotional tasks are consistent with reduced left prefrontal activity in depressed patients, which may impair downregulation of amygdala response to negative emotional information. Dichotic listening and visual hemifield findings for non-verbal or emotional processing have revealed abnormal perceptual asymmetry in depressive disorders, and electrophysiological findings have shown reduced right-lateralized responsivity to emotional stimuli in occipitotemporal or parietotemporal cortex. We discuss models of neural networks underlying these alterations. Of clinical relevance, individual differences among depressed patients on measures of right-left brain function are related to diagnostic subtype of depression, comorbidity with anxiety disorders, and clinical response to antidepressants or cognitive behavioral therapy. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. NeuroDebian Virtual Machine Deployment Facilitates Trainee-Driven Bedside Neuroimaging Research.

    Science.gov (United States)

    Cohen, Alexander; Kenney-Jung, Daniel; Botha, Hugo; Tillema, Jan-Mendelt

    2017-01-01

    Freely available software, derived from the past 2 decades of neuroimaging research, is significantly more flexible for research purposes than presently available clinical tools. Here, we describe and demonstrate the utility of rapidly deployable analysis software to facilitate trainee-driven translational neuroimaging research. A recipe and video tutorial were created to guide the creation of a NeuroDebian-based virtual computer that conforms to current neuroimaging research standards and can exist within a HIPAA-compliant system. This allows for retrieval of clinical imaging data, conversion to standard file formats, and rapid visualization and quantification of individual patients' cortical and subcortical anatomy. As an example, we apply this pipeline to a pediatric patient's data to illustrate the advantages of research-derived neuroimaging tools in asking quantitative questions "at the bedside." Our goal is to provide a path of entry for trainees to become familiar with common neuroimaging tools and foster an increased interest in translational research.

  9. Neuroimaging in refractory epilepsy. Current practice and evolving trends

    International Nuclear Information System (INIS)

    Ramli, N.; Rahmat, K.; Lim, K.S.; Tan, C.T.

    2015-01-01

    Highlights: • Neuroimaging is imperative in diagnostic work up and therapeutic assessment of refractory epilepsy. • Identification of epileptogenic zone on EEG, MRI and functional imaging improves the success of surgery. • High performance MRI greatly enhanced metabolic information and elucidate brain functions. • Optimisation of epilepsy protocols in structural and functional MRI are presented in this article. - Abstract: Identification of the epileptogenic zone is of paramount importance in refractory epilepsy as the success of surgical treatment depends on complete resection of the epileptogenic zone. Imaging plays an important role in the locating and defining anatomic epileptogenic abnormalities in patients with medically refractory epilepsy. The aim of this article is to present an overview of the current MRI sequences used in epilepsy imaging with special emphasis of lesion seen in our practices. Optimisation of epilepsy imaging protocols are addressed and current trends in functional MRI sequences including MR spectroscopy, diffusion tensor imaging and fusion MR with PET and SPECT are discussed

  10. Neuroimaging of psychopathy and antisocial behavior: a targeted review.

    Science.gov (United States)

    Blair, R J R

    2010-02-01

    The goal of this article is to provide a selective and targeted review of the neuroimaging literature on psychopathic tendencies and antisocial behavior and to explore the extent to which this literature supports recent cognitive neuroscientific models of psychopathy and antisocial behavior. The literature reveals that individuals who present with an increased risk for reactive, but not instrumental, aggression show increased amygdala responses to emotionally evocative stimuli. This is consistent with suggestions that such individuals are primed to respond strongly to an inappropriate extent to threatening or frustrating events. In contrast, individuals with psychopathic tendencies show decreased amygdala and orbitofrontal cortex responses to emotionally provocative stimuli or during emotional learning paradigms. This is consistent with suggestions that such individuals face difficulties with basic forms of emotional learning and decision making.

  11. Neuroimaging in refractory epilepsy. Current practice and evolving trends

    Energy Technology Data Exchange (ETDEWEB)

    Ramli, N. [Department of Biomedical Imaging, University Malaya Research Imaging Centre (Malaysia); Rahmat, K., E-mail: katt_xr2000@yahoo.com [Department of Biomedical Imaging, University Malaya Research Imaging Centre (Malaysia); Lim, K.S.; Tan, C.T. [Neurology Unit, Department of Medicine, University Malaya, Kuala Lumpur (Malaysia)

    2015-09-15

    Highlights: • Neuroimaging is imperative in diagnostic work up and therapeutic assessment of refractory epilepsy. • Identification of epileptogenic zone on EEG, MRI and functional imaging improves the success of surgery. • High performance MRI greatly enhanced metabolic information and elucidate brain functions. • Optimisation of epilepsy protocols in structural and functional MRI are presented in this article. - Abstract: Identification of the epileptogenic zone is of paramount importance in refractory epilepsy as the success of surgical treatment depends on complete resection of the epileptogenic zone. Imaging plays an important role in the locating and defining anatomic epileptogenic abnormalities in patients with medically refractory epilepsy. The aim of this article is to present an overview of the current MRI sequences used in epilepsy imaging with special emphasis of lesion seen in our practices. Optimisation of epilepsy imaging protocols are addressed and current trends in functional MRI sequences including MR spectroscopy, diffusion tensor imaging and fusion MR with PET and SPECT are discussed.

  12. Motivating forces of human actions. Neuroimaging reward and social interaction.

    Science.gov (United States)

    Walter, Henrik; Abler, Birgit; Ciaramidaro, Angela; Erk, Susanne

    2005-11-15

    In neuroeconomics, reward and social interaction are central concepts to understand what motivates human behaviour. Both concepts are investigated in humans using neuroimaging methods. In this paper, we provide an overview about these results and discuss their relevance for economic behaviour. For reward it has been shown that a system exists in humans that is involved in predicting rewards and thus guides behaviour, involving a circuit including the striatum, the orbitofrontal cortex and the amygdala. Recent studies on social interaction revealed a mentalizing system representing the mental states of others. A central part of this system is the medial prefrontal cortex, in particular the anterior paracingulate cortex. The reward as well as the mentalizing system is engaged in economic decision-making. We will discuss implications of this study for neuromarketing as well as general implications of these results that may help to provide deeper insights into the motivating forces of human behaviour.

  13. Cranial neuroimaging in pregnancy and the post-partum period

    International Nuclear Information System (INIS)

    Mortimer, A.M.; Bradley, M.D.; Likeman, M.; Stoodley, N.G.; Renowden, S.A.

    2013-01-01

    Several diverse neurological conditions may be seen during pregnancy and the post partum period. These usually require neuroimaging for definitive diagnosis and range from a predisposition to neurovascular abnormalities, such as acute ischaemic stroke and cerebral venous sinus thrombosis, through to more specific pregnancy-related conditions, such as eclampsia/posterior reversible leukoencephalopathy and post-partum angiopathy. Additionally, the pregnant patient is predisposed to pituitary disease. It is necessary that the radiologist has an awareness of these conditions to allow swift specific diagnoses or suggest the most appropriate diagnosis when imaging findings are non-specific. We describe epidemiological and radiological features to allow the radiologist to guide the clinician in management, and review guidelines for safe cranial imaging of the pregnant patient

  14. Functional and molecular neuroimaging of menopause and hormone replacement therapy

    DEFF Research Database (Denmark)

    Comasco, Erika; Frøkjær, Vibe; Sundström-Poromaa, Inger

    2014-01-01

    The level of gonadal hormones to which the female brain is exposed considerably changes across the menopausal transition, which in turn, is likely to be of great relevance for neurodegenerative diseases and psychiatric disorders. However, the neurobiological consequences of these hormone fluctuat......The level of gonadal hormones to which the female brain is exposed considerably changes across the menopausal transition, which in turn, is likely to be of great relevance for neurodegenerative diseases and psychiatric disorders. However, the neurobiological consequences of these hormone...... fluctuations and of hormone replacement therapy in the menopause have only begun to be understood. The present review summarizes the findings of thirty-five studies of human brain function, including functional magnetic resonance imaging, positron and single-photon computed emission tomography studies, in peri......-controlled multi-modal prospective neuroimaging studies as well as investigation on the related molecular mechanisms of effects of menopausal hormonal variations on the brain....

  15. Clinical functional MRI. Persurgical functional neuroimaging. 2. ed.

    International Nuclear Information System (INIS)

    Stippich, Christoph

    2015-01-01

    The second, revised edition of this successful textbook provides an up-to-date description of the use of preoperative fMRI in patients with brain tumors and epilepsies. State of the art fMRI procedures are presented, with detailed consideration of practical aspects, imaging and data processing, normal and pathological findings, and diagnostic possibilities and limitations. Relevant information on brain physiology, functional neuroanatomy, imaging technique, and methodology is provided by recognized experts in these fields. Compared with the first edition, chapters have been updated to reflect the latest developments and in particular the current use of diffusion tensor imaging (DTI) and resting-state fMRI. Entirely new chapters are included on resting-state presurgical fMRI and the role of DTI and tractography in brain tumor surgery. Further chapters address multimodality functional neuroimaging, brain plasticity, and pitfalls, tips, and tricks.

  16. Clinical functional MRI. Persurgical functional neuroimaging. 2. ed.

    Energy Technology Data Exchange (ETDEWEB)

    Stippich, Christoph (ed.) [Univ. Hospitals Basel (Switzerland). Division of Diagnostic and Inventional Neuroradiology

    2015-06-01

    The second, revised edition of this successful textbook provides an up-to-date description of the use of preoperative fMRI in patients with brain tumors and epilepsies. State of the art fMRI procedures are presented, with detailed consideration of practical aspects, imaging and data processing, normal and pathological findings, and diagnostic possibilities and limitations. Relevant information on brain physiology, functional neuroanatomy, imaging technique, and methodology is provided by recognized experts in these fields. Compared with the first edition, chapters have been updated to reflect the latest developments and in particular the current use of diffusion tensor imaging (DTI) and resting-state fMRI. Entirely new chapters are included on resting-state presurgical fMRI and the role of DTI and tractography in brain tumor surgery. Further chapters address multimodality functional neuroimaging, brain plasticity, and pitfalls, tips, and tricks.

  17. Multimodal Neuroimaging Differences in Nicotine Abstinent vs. Satiated Smokers.

    Science.gov (United States)

    Chaarani, Bader; Spechler, Philip A; Ivanciu, Alexandra; Snowe, Mitchell; Nickerson, Joshua P; Higgins, Stephen T; Garavan, Hugh

    2018-04-06

    Research on cigarette smokers suggests cognitive and behavioral impairments. However, much remains unclear how the functional neurobiology of smokers is influenced by nicotine state. Therefore, we sought to determine which state, be it acute nicotine abstinence or satiety, would yield the most robust differences compared to non-smokers when assessing neurobiological markers of nicotine dependence. Smokers(N=15) and sociodemographically matched non-smokers(N=15) were scanned twice using a repeated-measures design. Smokers were scanned after a 24-hour nicotine abstinence, and immediately after smoking their usual brand cigarette. The neuroimaging battery included a stop-signal task of response inhibition and pseudo-continuous arterial spin labeling to measure cerebral blood flow (CBF). Whole brain voxel-wise ANCOVAs were carried out on stop success and stop fail SST contrasts and CBF maps to assess differences among non-, abstinent and satiated smokers. Cluster-correction was performed using AFNI's 3dClustSim to achieve a significance of pSmokers exhibited higher brain activation in bilateral inferior frontal gyrus (IFG), a brain region known to be involved in inhibitory control, during successful response inhibitions relative to non-smokers. This effect was significantly higher during nicotine abstinence relative to satiety. Smokers also exhibited lower CBF in the bilateral IFG than non-smokers. These hypo-perfusions were not different between abstinence and satiety. These findings converge on alterations in smokers in prefrontal circuits known to be critical for inhibitory control. These effects are present, even when smokers are satiated, but the neural activity required to achieve performance equal to controls is increased when smokers are in acute abstinence. Our multi-modal neuroimaging study gives neurobiological insights into the cognitive demands of maintaining abstinence and suggest targets for assessing the efficacy of therapeutic interventions.

  18. Neural correlates of the LSD experience revealed by multimodal neuroimaging.

    Science.gov (United States)

    Carhart-Harris, Robin L; Muthukumaraswamy, Suresh; Roseman, Leor; Kaelen, Mendel; Droog, Wouter; Murphy, Kevin; Tagliazucchi, Enzo; Schenberg, Eduardo E; Nest, Timothy; Orban, Csaba; Leech, Robert; Williams, Luke T; Williams, Tim M; Bolstridge, Mark; Sessa, Ben; McGonigle, John; Sereno, Martin I; Nichols, David; Hellyer, Peter J; Hobden, Peter; Evans, John; Singh, Krish D; Wise, Richard G; Curran, H Valerie; Feilding, Amanda; Nutt, David J

    2016-04-26

    Lysergic acid diethylamide (LSD) is the prototypical psychedelic drug, but its effects on the human brain have never been studied before with modern neuroimaging. Here, three complementary neuroimaging techniques: arterial spin labeling (ASL), blood oxygen level-dependent (BOLD) measures, and magnetoencephalography (MEG), implemented during resting state conditions, revealed marked changes in brain activity after LSD that correlated strongly with its characteristic psychological effects. Increased visual cortex cerebral blood flow (CBF), decreased visual cortex alpha power, and a greatly expanded primary visual cortex (V1) functional connectivity profile correlated strongly with ratings of visual hallucinations, implying that intrinsic brain activity exerts greater influence on visual processing in the psychedelic state, thereby defining its hallucinatory quality. LSD's marked effects on the visual cortex did not significantly correlate with the drug's other characteristic effects on consciousness, however. Rather, decreased connectivity between the parahippocampus and retrosplenial cortex (RSC) correlated strongly with ratings of "ego-dissolution" and "altered meaning," implying the importance of this particular circuit for the maintenance of "self" or "ego" and its processing of "meaning." Strong relationships were also found between the different imaging metrics, enabling firmer inferences to be made about their functional significance. This uniquely comprehensive examination of the LSD state represents an important advance in scientific research with psychedelic drugs at a time of growing interest in their scientific and therapeutic value. The present results contribute important new insights into the characteristic hallucinatory and consciousness-altering properties of psychedelics that inform on how they can model certain pathological states and potentially treat others.

  19. Ethical concepts and future challenges of neuroimaging: an Islamic perspective.

    Science.gov (United States)

    Al-Delaimy, Wael K

    2012-09-01

    Neuroscience is advancing at a rapid pace, with new technologies and approaches that are creating ethical challenges not easily addressed by current ethical frameworks and guidelines. One fascinating technology is neuroimaging, especially functional Magnetic Resonance Imaging (fMRI). Although still in its infancy, fMRI is breaking new ground in neuroscience, potentially offering increased understanding of brain function. Different populations and faith traditions will likely have different reactions to these new technologies and the ethical challenges they bring with them. Muslims are approximately one-fifth of world population and they have a specific and highly regulated ethical and moral code, which helps them deal with scientific advances and decision making processes in an Islamically ethical manner. From this ethical perspective, in light of the relevant tenets of Islam, neuroimaging poses various challenges. The privacy of spirituality and the thought process, the requirement to put community interest before individual interest, and emphasis on conscious confession in legal situations are Islamic concepts that can pose a challenge for the use of something intrusive such as an fMRI. Muslim moral concepts such as There shall be no harm inflicted or reciprocated in Islam and Necessities overrule prohibitions are some of the criteria that might appropriately be used to guide advancing neuroscience. Neuroscientists should be particularly prudent and well prepared in implementing neuroscience advances that are breaking new scientific and ethical ground. Neuroscientists should also be prepared to assist in setting the ethical frameworks in place in advance of what might be perceived as runaway applications of technology.

  20. Porcupine: A visual pipeline tool for neuroimaging analysis.

    Directory of Open Access Journals (Sweden)

    Tim van Mourik

    2018-05-01

    Full Text Available The field of neuroimaging is rapidly adopting a more reproducible approach to data acquisition and analysis. Data structures and formats are being standardised and data analyses are getting more automated. However, as data analysis becomes more complicated, researchers often have to write longer analysis scripts, spanning different tools across multiple programming languages. This makes it more difficult to share or recreate code, reducing the reproducibility of the analysis. We present a tool, Porcupine, that constructs one's analysis visually and automatically produces analysis code. The graphical representation improves understanding of the performed analysis, while retaining the flexibility of modifying the produced code manually to custom needs. Not only does Porcupine produce the analysis code, it also creates a shareable environment for running the code in the form of a Docker image. Together, this forms a reproducible way of constructing, visualising and sharing one's analysis. Currently, Porcupine links to Nipype functionalities, which in turn accesses most standard neuroimaging analysis tools. Our goal is to release researchers from the constraints of specific implementation details, thereby freeing them to think about novel and creative ways to solve a given problem. Porcupine improves the overview researchers have of their processing pipelines, and facilitates both the development and communication of their work. This will reduce the threshold at which less expert users can generate reusable pipelines. With Porcupine, we bridge the gap between a conceptual and an implementational level of analysis and make it easier for researchers to create reproducible and shareable science. We provide a wide range of examples and documentation, as well as installer files for all platforms on our website: https://timvanmourik.github.io/Porcupine. Porcupine is free, open source, and released under the GNU General Public License v3.0.

  1. Outcome of oligodendroglioma treatment in the era of modern neuroimaging

    International Nuclear Information System (INIS)

    Kleinberg, Lawrence R.; Silverman, Edward; Brem, Henry; Wharam, Moody D.

    1997-01-01

    Purpose/Objective: The benefit of routine postoperative radiotherapy for low grade oligodendroglioma remains controversial. Most published series include many patients treated before the availability of CT or MRI scans which allow early diagnosis, guide surgery, detect residual disease, improve radiotherapy, and detect asymptomatic recurrences. The purpose of this analysis is to determine whether observation rather than radiation continues to be an appropriate option for selected patients with the availability of modern neuroimaging. Materials and Methods: 58 patients (age 2-67 years, 6 pts. =2 poor prognostic factor (p=.04). Results: Two and five year actuarial freedom from local progression was 93 +/- 4% and 75% +/- 8% whereas 2 and 5 year overall survival was 94% +/- 3% and 80% +/- 7%. Despite the imbalance of prognostic factors, there was no significant difference whether or not postoperative RT was given. With RT, 2 and 4 year actuarial freedom from progression was 94% +/- 4% and 78% +/- 8%, whereas without RT it was 94% +/- 6% at 2 and 4 years. Similarly, 2 and 4 year actuarial survival was 94% +/- 4% and 78% +/- 8% with RT and was 91% +/- 8% without RT. (5(10)) recurrences were detected radiologically without new or progressive clinical symptoms. Conclusion: These data support the hypothesis that, in the era of modern neuroimaging, the initial observation of good risk patients and immediate irradiation of poor risk patients is an appropriate treatment approach which results in good medium term control and survival for low grade oligodendroglioma patients. A policy of treatment vs. observation based on selected prognostic factors will be tested prospectively in an intergroup trial for low grade glioma histologies

  2. Neuroimaging classification of progression patterns in glioblastoma: a systematic review.

    Science.gov (United States)

    Piper, Rory J; Senthil, Keerthi K; Yan, Jiun-Lin; Price, Stephen J

    2018-03-30

    Our primary objective was to report the current neuroimaging classification systems of spatial patterns of progression in glioblastoma. In addition, we aimed to report the terminology used to describe 'progression' and to assess the compliance with the Response Assessment in Neuro-Oncology (RANO) Criteria. We conducted a systematic review to identify all neuroimaging studies of glioblastoma that have employed a categorical classification system of spatial progression patterns. Our review was registered with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) registry. From the included 157 results, we identified 129 studies that used labels of spatial progression patterns that were not based on radiation volumes (Group 1) and 50 studies that used labels that were based on radiation volumes (Group 2). In Group 1, we found 113 individual labels and the most frequent were: local/localised (58%), distant/distal (51%), diffuse (20%), multifocal (15%) and subependymal/subventricular zone (15%). We identified 13 different labels used to refer to 'progression', of which the most frequent were 'recurrence' (99%) and 'progression' (92%). We identified that 37% (n = 33/90) of the studies published following the release of the RANO classification were adherent compliant with the RANO criteria. Our review reports significant heterogeneity in the published systems used to classify glioblastoma spatial progression patterns. Standardization of terminology and classification systems used in studying progression would increase the efficiency of our research in our attempts to more successfully treat glioblastoma.

  3. Application of neuroanatomical ontologies for neuroimaging data annotation

    Directory of Open Access Journals (Sweden)

    Jessica A Turner

    2010-06-01

    Full Text Available The annotation of functional neuroimaging results for data sharing and reuse is particularly challenging, due to the diversity of terminologies of neuroanatomical structures and cortical parcellation schemes. To address this challenge, we extended the Foundational Model of Anatomy Ontology (FMA to include cytoarchitectural, Brodmann area labels, and a morphological cortical labeling scheme (e.g., the part of Brodmann area 6 in the left precentral gyrus. This representation was also used to augment the neuroanatomical axis of RadLex, the ontology for clinical imaging. The resulting neuroanatomical ontology contains explicit relationships indicating which brain regions are “part of” which other regions, across cytoarchitectural and morphological labeling schemas. We annotated a large functional neuroimaging dataset with terms from the ontology and applied a reasoning engine to analyze this dataset in conjunction with the ontology, and achieved successful inferences from the most specific level (e.g., how many subjects showed activation in a sub-part of the middle frontal gyrus to more general (how many activations were found in areas connected via a known white matter tract?. In summary, we have produced a neuroanatomical ontology that harmonizes several different terminologies of neuroanatomical structures and cortical parcellation schemes. This neuranatomical ontology is publicly available as a view of FMA at the Bioportal website at http://rest.bioontology.org/bioportal/ontologies/download/10005. The ontological encoding of anatomic knowledge can be exploited by computer reasoning engines to make inferences about neuroanatomical relationships described in imaging datasets using different terminologies. This approach could ultimately enable knowledge discovery from large, distributed fMRI studies or medical record mining.

  4. Clinical and neuroimaging profile of congenital brain malformations in children with spastic cerebral palsy

    International Nuclear Information System (INIS)

    Kulak, W.; Okurowska-Zawada, B.; Sobaniec, W.; Goscik, M.; Olenski, J.

    2008-01-01

    Purpose: Analysis of the incidence of congenital brain malformations in children with spastic cerebral palsy (CP) in a hospital based study. Material and Methods: The present study included 74 boys and 56 girls with spastic tetraplegia, diplegia, and hemiplegia CP. Magnetic resonance imaging MRI findings were analyzed in children with CP. Results: Significant abnormalities relevant to the CP were evident on MRI in 124 (95.3%) subjects. Periventicular leukomalacia (PVL) was detected more frequently in children with spastic diplegia than in patients with tetraplegia or hemiplegia. Cerebral atrophy was found more often in the tetraplegic group compared to the diplegic patients. Porencephalic cysts were detected more often in children with spastic hemiplegia. Congenital brain anomalies were evident in 15 (10.7%) children with spastic CP. Brain malformations included: schizencephaly (5), agenesis corpus callosum (4), polymicrogyria (2), holoprosencephaly (2) and lissencephaly (2). Intractable epilepsy and mental retardation were observed more often in children with brain anomalies. Twelve patients with congenital brain malformations were born at term and three born at preterm. Conclusions: Neuroimaging results in children with CP may help determine the etiology and make better prognosis of CP. (authors)

  5. Running Neuroimaging Applications on Amazon Web Services: How, When, and at What Cost?

    Directory of Open Access Journals (Sweden)

    Tara M. Madhyastha

    2017-11-01

    Full Text Available The contribution of this paper is to identify and describe current best practices for using Amazon Web Services (AWS to execute neuroimaging workflows “in the cloud.” Neuroimaging offers a vast set of techniques by which to interrogate the structure and function of the living brain. However, many of the scientists for whom neuroimaging is an extremely important tool have limited training in parallel computation. At the same time, the field is experiencing a surge in computational demands, driven by a combination of data-sharing efforts, improvements in scanner technology that allow acquisition of images with higher image resolution, and by the desire to use statistical techniques that stress processing requirements. Most neuroimaging workflows can be executed as independent parallel jobs and are therefore excellent candidates for running on AWS, but the overhead of learning to do so and determining whether it is worth the cost can be prohibitive. In this paper we describe how to identify neuroimaging workloads that are appropriate for running on AWS, how to benchmark execution time, and how to estimate cost of running on AWS. By benchmarking common neuroimaging applications, we show that cloud computing can be a viable alternative to on-premises hardware. We present guidelines that neuroimaging labs can use to provide a cluster-on-demand type of service that should be familiar to users, and scripts to estimate cost and create such a cluster.

  6. The Impact of Disappointment in Decision Making: Inter-Individual Differences and Electrical Neuroimaging

    Science.gov (United States)

    Tzieropoulos, Hélène; de Peralta, Rolando Grave; Bossaerts, Peter; Andino, Sara L. Gonzalez

    2011-01-01

    Disappointment, the emotion experienced when faced to reward prediction errors (RPEs), considerably impacts decision making (DM). Individuals tend to modify their behavior in an often unpredictable way just to avoid experiencing negative emotions. Despite its importance, disappointment remains much less studied than regret and its impact on upcoming decisions largely unexplored. Here, we adapted the Trust Game to effectively elicit, quantify, and isolate disappointment by relying on the formal definition provided by Bell's in economics. We evaluated the effects of experienced disappointment and elation on future cooperation and trust as well as the rationality and utility of the different behavioral and neural mechanisms used to cope with disappointment. All participants in our game trusted less and particularly expected less from unknown opponents as a result of disappointing outcomes in the previous trial but not necessarily after elation indicating that behavioral consequences of positive and negative RPEs are not the same. A large variance in the tolerance to disappointment was observed across subjects, with some participants needing only a small disappointment to impulsively bias their subsequent decisions. As revealed by high-density EEG recordings the most tolerant individuals – who thought twice before making a decision and earned more money – relied on different neural generators to contend with neutral and unexpected outcomes. This study thus provides some support to the idea that different neural systems underlie reflexive and reflective decisions within the same individuals as predicted by the dual-system theory of social judgment and DM. PMID:21258645

  7. The impact of disappointment in decision making: Inter-individual differences and electrical neuroimaging

    Directory of Open Access Journals (Sweden)

    Helène eTzieropoulos

    2011-01-01

    Full Text Available Disappointment, the emotion experienced when faced to reward prediction errors, considerably impact decision making. Individuals tend to modify their behavior in an often unpredictable way just to avoid experiencing negative emotions. Despite its importance, disappointment remains much less studied than regret and its impact on upcoming decisions largely unexplored. Here, we adapted the Trust Game to effectively elicit, quantify and isolate disappointment by relying on the formal definition provided by Bell’s in economics. We evaluated the effects of experienced disappointment and elation on future cooperation and trust as well as the rationality and utility of the different behavioral and neural mechanisms used to cope with disappointment. All participants in our game trusted less and particularly expected less from unknown opponents as a result of disappointing outcomes in the previous trial but not necessarily after elation indicating that behavioral consequences of positive and negative reward prediction errors are not the same. A large variance in the tolerance to disappointment was observed across subjects, with some participants needing only a small disappointment to impulsively bias their subsequent decisions. As revealed by high-density EEG recordings the most tolerant individuals - who thought twice before making a decision and earned more money – relied on different neural generators to contend with neutral and unexpected outcomes. This study thus provide some support to the idea that different neural systems underlie reflexive and reflective decisions within the same individuals as predicted by the dual-system theory of social judgment and decision making.

  8. The impact of disappointment in decision making: inter-individual differences and electrical neuroimaging.

    Science.gov (United States)

    Tzieropoulos, Hélène; de Peralta, Rolando Grave; Bossaerts, Peter; Gonzalez Andino, Sara L

    2011-01-01

    Disappointment, the emotion experienced when faced to reward prediction errors (RPEs), considerably impacts decision making (DM). Individuals tend to modify their behavior in an often unpredictable way just to avoid experiencing negative emotions. Despite its importance, disappointment remains much less studied than regret and its impact on upcoming decisions largely unexplored. Here, we adapted the Trust Game to effectively elicit, quantify, and isolate disappointment by relying on the formal definition provided by Bell's in economics. We evaluated the effects of experienced disappointment and elation on future cooperation and trust as well as the rationality and utility of the different behavioral and neural mechanisms used to cope with disappointment. All participants in our game trusted less and particularly expected less from unknown opponents as a result of disappointing outcomes in the previous trial but not necessarily after elation indicating that behavioral consequences of positive and negative RPEs are not the same. A large variance in the tolerance to disappointment was observed across subjects, with some participants needing only a small disappointment to impulsively bias their subsequent decisions. As revealed by high-density EEG recordings the most tolerant individuals - who thought twice before making a decision and earned more money - relied on different neural generators to contend with neutral and unexpected outcomes. This study thus provides some support to the idea that different neural systems underlie reflexive and reflective decisions within the same individuals as predicted by the dual-system theory of social judgment and DM.

  9. Semantic brain areas are involved in gesture comprehension: An electrical neuroimaging study.

    Science.gov (United States)

    Proverbio, Alice Mado; Gabaro, Veronica; Orlandi, Andrea; Zani, Alberto

    2015-08-01

    While the mechanism of sign language comprehension in deaf people has been widely investigated, little is known about the neural underpinnings of spontaneous gesture comprehension in healthy speakers. Bioelectrical responses to 800 pictures of actors showing common Italian gestures (e.g., emblems, deictic or iconic gestures) were recorded in 14 persons. Stimuli were selected from a wider corpus of 1122 gestures. Half of the pictures were preceded by an incongruent description. ERPs were recorded from 128 sites while participants decided whether the stimulus was congruent. Congruent pictures elicited a posterior P300 followed by late positivity, while incongruent gestures elicited an anterior N400 response. N400 generators were investigated with swLORETA reconstruction. Processing of congruent gestures activated face- and body-related visual areas (e.g., BA19, BA37, BA22), the left angular gyrus, mirror fronto/parietal areas. The incongruent-congruent contrast particularly stimulated linguistic and semantic brain areas, such as the left medial and the superior temporal lobe. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Neurobiological narratives: Experiences of mood disorder through the lens of neuroimaging

    DEFF Research Database (Denmark)

    Buchman, Daniel Z; Borgelt, Emily L; Whiteley, Louise Emma

    2013-01-01

    of receiving neuroimaging for prediction, diagnosis and planning treatment. The participants discussed the potential role of neuroimages in (i) mitigating stigma; (ii) supporting morally loaded explanations of mental illness due to an imbalance of brain chemistry; (iii) legitimising psychiatric symptoms, which...... illness view functional neuroimaging, or of the potential psychological impacts of its clinical use. We conducted 12 semi-structured interviews with adults diagnosed with major depression or bipolar disorder, probing their experiences with mental health care and their perspectives on the prospect...... to biologisation of mental illness, and argue for bringing these voices into upstream ethics discussion....

  11. Effects of cannabis on impulsivity: a systematic review of neuroimaging findings.

    Science.gov (United States)

    Wrege, Johannes; Schmidt, Andre; Walter, Anna; Smieskova, Renata; Bendfeldt, Kerstin; Radue, Ernst-Wilhelm; Lang, Undine E; Borgwardt, Stefan

    2014-01-01

    We conducted a systematic review to assess the evidence for specific effects of cannabis on impulsivity, disinhibition and motor control. The review had a specific focus on neuroimaging findings associated with acute and chronic use of the drug and covers literature published up until May 2012. Seventeen studies were identified, of which 13 met the inclusion criteria; three studies investigated acute effects of cannabis (1 fMRI, 2 PET), while six studies investigated non-acute functional effects (4 fMRI, 2 PET), and four studies investigated structural alterations. Functional imaging studies of impulsivity studies suggest that prefrontal blood flow is lower in chronic cannabis users than in controls. Studies of acute administration of THC or marijuana report increased brain metabolism in several brain regions during impulsivity tasks. Structural imaging studies of cannabis users found differences in reduced prefrontal volumes and white matter integrity that might mediate the abnormal impulsivity and mood observed in marijuana users. To address the question whether impulsivity as a trait precedes cannabis consumption or whether cannabis aggravates impulsivity and discontinuation of usage more longitudinal study designs are warranted.

  12. Mapping vulnerability to bipolar disorder: a systematic review and meta-analysis of neuroimaging studies

    Science.gov (United States)

    Fusar-Poli, Paolo; Howes, Oliver; Bechdolf, Andreas; Borgwardt, Stefan

    2012-01-01

    Background Although early interventions in individuals with bipolar disorder may reduce the associated personal and economic burden, the neurobiologic markers of enhanced risk are unknown. Methods Neuroimaging studies involving individuals at enhanced genetic risk for bipolar disorder (HR) were included in a systematic review. We then performed a region of interest (ROI) analysis and a whole-brain meta-analysis combined with a formal effect-sizes meta-analysis in a subset of studies. Results There were 37 studies included in our systematic review. The overall sample for the systematic review included 1258 controls and 996 HR individuals. No significant differences were detected between HR individuals and controls in the selected ROIs: striatum, amygdala, hippocampus, pituitary and frontal lobe. The HR group showed increased grey matter volume compared with patients with established bipolar disorder. The HR individuals showed increased neural response in the left superior frontal gyrus, medial frontal gyrus and left insula compared with controls, independent from the functional magnetic resonance imaging task used. There were no publication biases. Sensitivity analysis confirmed the robustness of these results. Limitations As the included studies were cross-sectional, it remains to be determined whether the observed neurofunctional and structural alterations represent risk factors that can be clinically used in preventive interventions for prodromal bipolar disorder. Conclusion Accumulating structural and functional imaging evidence supports the existence of neurobiologic trait abnormalities in individuals at genetic risk for bipolar disorder at various scales of investigation. PMID:22297067

  13. The role of rostral Brodmann area 6 in mental-operation tasks: an integrative neuroimaging approach.

    Science.gov (United States)

    Hanakawa, Takashi; Honda, Manabu; Sawamoto, Nobukatsu; Okada, Tomohisa; Yonekura, Yoshiharu; Fukuyama, Hidena; Shibasaki, Hiroshi

    2002-11-01

    Recent evidence indicates that classical 'motor' areas may also have cognitive functions. We performed three neuroimaging experiments to investigate the functional neuroanatomy underlying three types of nonmotor mental-operation tasks: numerical, verbal, and spatial. (i) Positron emission tomography showed that parts of the posterior frontal cortex, which are consistent with the pre-supplementary motor area (pre-SMA) and the rostral part of the dorsolateral premotor cortex (PMdr), were active during all three tasks. We also observed activity in the posterior parietal cortex and cerebellar hemispheres during all three tasks. Electrophysiological monitoring confirmed that there were no skeletomotor, oculomotor or articulatory movements during task performance. (ii) Functional magnetic resonance imaging (fMRI) showed that PMdr activity during the mental-operation tasks was localized in the depths of the superior precentral sulcus, which substantially overlapped the region active during complex finger movements and was located dorsomedial to the presumptive frontal eye fields. (iii) Single-trial fMRI showed a transient increase in activity time-locked to the performance of mental operations in the pre-SMA and PMdr. The results of the present study suggest that the PMdr is important in the rule-based association of symbolic cues and responses in both motor and nonmotor behaviors.

  14. Applications of Neuroimaging to Disease-Modification Trials in Alzheimer’s Disease

    Directory of Open Access Journals (Sweden)

    Adam S. Fleisher

    2009-01-01

    Full Text Available Critical to development of new therapies for Alzheimer’s disease (AD is the ability to detect clinical or pathological change over time. Clinical outcome measures typically used in therapeutic trials have unfortunately proven to be relatively variable and somewhat insensitive to change in this slowly progressive disease. For this reason, development of surrogate biomarkers that identify significant disease-associated brain changes are necessary to expedite treatment development in AD. Since AD pathology is present in the brain many years prior to clinical manifestation, ideally we want to develop biomarkers of disease that identify abnormal brain structure or function even prior to cognitive decline. Magnetic resonance imaging, fluorodeoxyglucose positron emission tomography, new amyloid imaging techniques, and spinal fluid markers of AD all have great potential to provide surrogate endpoint measures for AD pathology. The Alzheimer’s disease neuroimaging initiative (ADNI was developed for the distinct purpose of evaluating surrogate biomarkers for drug development in AD. Recent evidence from ADNI demonstrates that imaging may provide more sensitive, and earlier, measures of disease progression than traditional clinical measures for powering clinical drug trials in Alzheimer's disease. This review discusses recently presented data from the ADNI dataset, and the importance of imaging in the future of drug development in AD.

  15. Emotion and Cognition Interactions in PTSD: A Review of Neurocognitive and Neuroimaging Studies

    Directory of Open Access Journals (Sweden)

    Jasmeet P Hayes

    2012-10-01

    Full Text Available Posttraumatic stress disorder (PTSD is a psychiatric syndrome that develops after exposure to terrifying and life-threatening events including warfare, motor-vehicle accidents, and physical and sexual assault. The emotional experience of psychological trauma can have long-term cognitive effects. The hallmark symptoms of PTSD involve alterations to cognitive processes such as memory, attention, planning and problem solving, underscoring the detrimental impact that negative emotionality has on cognitive functioning. As such, an important challenge for PTSD researchers and treatment providers is to understand the dynamic interplay between emotion and cognition. Contemporary cognitive models of PTSD theorize that a preponderance of information processing resources are allocated towards threat detection and interpretation of innocuous stimuli as threatening, narrowing one’s attentional focus at the expense of other cognitive operations. Decades of research have shown support for these cognitive models of PTSD using a variety of tasks and methodological approaches. The primary goal of this review is to summarize the latest neurocognitive and neuroimaging research of emotion-cognition interactions in PTSD. To directly assess the influence of emotion on cognition and vice versa, the studies reviewed employed challenge tasks that included both cognitive and emotional components. The findings provide evidence for memory and attention deficits in PTSD that are often associated with changes in functional brain activity. The results are reviewed to provide future directions for research that may direct better and more effective treatments for PTSD.

  16. Neuroimaging of the Dopamine/Reward System in Adolescent Drug Use

    Science.gov (United States)

    Ernst, Monique; Luciana, Monica

    2015-01-01

    Adolescence is characterized by heightened risk-taking, including substance misuse. These behavioral patterns are influenced by ontogenic changes in neurotransmitter systems, particularly the dopamine system, which is fundamentally involved in the neural coding of reward and motivated approach behavior. During adolescence, this system evidences a peak in activity. At the same time, the dopamine system is neuroplastically altered by substance abuse, impacting subsequent function. Here, we describe properties of the dopamine system that change with typical adolescent development and that are altered with substance abuse. Much of this work has been gleaned from animal models due to limitations in measuring dopamine in pediatric samples. Structural and functional neuroimaging techniques have been used to examine structures that are heavily DA-innervated; they measure morphological and functional changes with age and with drug exposure. Presenting marijuana abuse as an exemplar, we consider recent findings that support an adolescent peak in DA-driven reward-seeking behavior and related deviations in motivational systems that are associated with marijuana abuse/dependence. Clinicians are advised that (1) chronic adolescent marijuana use may lead to deficiencies in incentive motivation, (2) that this state is due to marijuana’s interactions with the developing DA system, and (3) that treatment strategies should be directed to remediating resultant deficiencies in goal-directed activity. PMID:26095977

  17. The application of neuroimaging to social inequity and language disparity: A cautionary examination.

    Science.gov (United States)

    Ellwood-Lowe, Monica E; Sacchet, Matthew D; Gotlib, Ian H

    2016-12-01

    In the nascent field of the cognitive neuroscience of socioeconomic status (SES), researchers are using neuroimaging to examine how growing up in poverty affects children's neurocognitive development, particularly their language abilities. In this review we highlight difficulties inherent in the frequent use of reverse inference to interpret SES-related abnormalities in brain regions that support language. While there is growing evidence suggesting that SES moderates children's developing brain structure and function, no studies to date have elucidated explicitly how these neural findings are related to variations in children's language abilities, or precisely what it is about SES that underlies or contributes to these differences. This issue is complicated by the fact that SES is confounded with such linguistic factors as cultural language use, first language, and bilingualism. Thus, SES-associated differences in brain regions that support language may not necessarily indicate differences in neurocognitive abilities. In this review we consider the multidimensionality of SES, discuss studies that have found SES-related differences in structure and function in brain regions that support language, and suggest future directions for studies in the area of cognitive neuroscience of SES that are less reliant on reverse inference. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  18. Effects of Cannabis on Impulsivity: A Systematic Review of Neuroimaging Findings

    Science.gov (United States)

    Wrege, Johannes; Schmidt, André; Walter, Anna; Smieskova, Renata; Bendfeldt, Kerstin; Radue, Ernst-Wilhelm; Lang, Undine E.; Borgwardt, Stefan

    2014-01-01

    We conducted a systematic review to assess the evidence for specific effects of cannabis on impulsivity, disinhibition and motor control. The review had a specific focus on neuroimaging findings associated with acute and chronic use of the drug and covers literature published up until May 2012. Seventeen studies were identified, of which 13 met the inclusion criteria; three studies investigated acute effects of cannabis (1 fMRI, 2 PET), while six studies investigated non-acute functional effects (4 fMRI, 2 PET), and four studies investigated structural alterations. Functional imaging studies of impulsivity studies suggest that prefrontal blood flow is lower in chronic cannabis users than in controls. Studies of acute administration of THC or marijuana report increased brain metabolism in several brain regions during impulsivity tasks. Structural imaging studies of cannabis users found differences in reduced prefrontal volumes and white matter integrity that might mediate the abnormal impulsivity and mood observed in marijuana users. To address the question whether impulsivity as a trait precedes cannabis consumption or whether cannabis aggravates impulsivity and discontinuation of usage more longitudinal study designs are warranted. PMID:23829358

  19. The application of neuroimaging to social inequity and language disparity: A cautionary examination

    Directory of Open Access Journals (Sweden)

    Monica E. Ellwood-Lowe

    2016-12-01

    Full Text Available In the nascent field of the cognitive neuroscience of socioeconomic status (SES, researchers are using neuroimaging to examine how growing up in poverty affects children’s neurocognitive development, particularly their language abilities. In this review we highlight difficulties inherent in the frequent use of reverse inference to interpret SES-related abnormalities in brain regions that support language. While there is growing evidence suggesting that SES moderates children’s developing brain structure and function, no studies to date have elucidated explicitly how these neural findings are related to variations in children’s language abilities, or precisely what it is about SES that underlies or contributes to these differences. This issue is complicated by the fact that SES is confounded with such linguistic factors as cultural language use, first language, and bilingualism. Thus, SES-associated differences in brain regions that support language may not necessarily indicate differences in neurocognitive abilities. In this review we consider the multidimensionality of SES, discuss studies that have found SES-related differences in structure and function in brain regions that support language, and suggest future directions for studies in the area of cognitive neuroscience of SES that are less reliant on reverse inference.

  20. The neuropsychiatry of hyperkinetic movement disorders: insights from neuroimaging into the neural circuit bases of dysfunction.

    Science.gov (United States)

    Hayhow, Bradleigh D; Hassan, Islam; Looi, Jeffrey C L; Gaillard, Francesco; Velakoulis, Dennis; Walterfang, Mark

    2013-01-01

    Movement disorders, particularly those associated with basal ganglia disease, have a high rate of comorbid neuropsychiatric illness. We consider the pathophysiological basis of the comorbidity between movement disorders and neuropsychiatric illness by 1) reviewing the epidemiology of neuropsychiatric illness in a range of hyperkinetic movement disorders, and 2) correlating findings to evidence from studies that have utilized modern neuroimaging techniques to investigate these disorders. In addition to diseases classically associated with basal ganglia pathology, such as Huntington disease, Wilson disease, the neuroacanthocytoses, and diseases of brain iron accumulation, we include diseases associated with pathology of subcortical white matter tracts, brain stem nuclei, and the cerebellum, such as metachromatic leukodystrophy, dentatorubropallidoluysian atrophy, and the spinocerebellar ataxias. Neuropsychiatric symptoms are integral to a thorough phenomenological account of hyperkinetic movement disorders. Drawing on modern theories of cortico-subcortical circuits, we argue that these disorders can be conceptualized as disorders of complex subcortical networks with distinct functional architectures. Damage to any component of these complex information-processing networks can have variable and often profound consequences for the function of more remote neural structures, creating a diverse but nonetheless rational pattern of clinical symptomatology.

  1. Functional neuroimaging of psychotherapeutic processes in anxiety and depression: from mechanisms to predictions.

    Science.gov (United States)

    Lueken, Ulrike; Hahn, Tim

    2016-01-01

    The review provides an update of functional neuroimaging studies that identify neural processes underlying psychotherapy and predict outcomes following psychotherapeutic treatment in anxiety and depressive disorders. Following current developments in this field, studies were classified as 'mechanistic' or 'predictor' studies (i.e., informing neurobiological models about putative mechanisms versus aiming to provide predictive information). Mechanistic evidence points toward a dual-process model of psychotherapy in anxiety disorders with abnormally increased limbic activation being decreased, while prefrontal activity is increased. Partly overlapping findings are reported for depression, albeit with a stronger focus on prefrontal activation following treatment. No studies directly comparing neural pathways of psychotherapy between anxiety and depression were detected. Consensus is accumulating for an overarching role of the anterior cingulate cortex in modulating treatment response across disorders. When aiming to quantify clinical utility, the need for single-subject predictions is increasingly recognized and predictions based on machine learning approaches show high translational potential. Present findings encourage the search for predictors providing clinically meaningful information for single patients. However, independent validation as a crucial prerequisite for clinical use is still needed. Identifying nonresponders a priori creates the need for alternative treatment options that can be developed based on an improved understanding of those neural mechanisms underlying effective interventions.

  2. Neuroimaging findings of congenital Zika virus infection: a pictorial essay.

    Science.gov (United States)

    Zare Mehrjardi, Mohammad; Poretti, Andrea; Huisman, Thierry A G M; Werner, Heron; Keshavarz, Elham; Araujo Júnior, Edward

    2017-03-01

    Zika virus (ZIKV) is a mosquito-borne arbovirus from the Flaviviridae family. It had caused several epidemics since its discovery in 1947, but there was no significant attention to this virus until the recent outbreak in Brazil in 2015. The main concern is the causal relationship between prenatal ZIKV infection and congenital microcephaly, which has been confirmed recently. Moreover, ZIKV may cause other central nervous system abnormalities such as brain parenchymal atrophy with secondary ventriculomegaly, intracranial calcification, malformations of cortical development (such as polymicrogyria, and lissencephaly-pachygyria), agenesis/hypoplasia of the corpus callosum, cerebellar and brainstem hypoplasia, sensorineural hearing-loss, and ocular abnormalities as well as arthrogryposis in the infected fetuses. Postnatal (acquired) ZIKV infection usually has an asymptomatic or mildly symptomatic course, while prenatal (congenital) ZIKV infection has a more severe course and may cause severe brain anomalies that are described as congenital Zika syndrome. In this pictorial essay, we aim to illustrate the prenatal and postnatal neuroimaging findings that may be seen in fetuses and neonates with congenital Zika syndrome, and will discuss possible radiological differential diagnoses. A detailed knowledge of these findings is paramount for an early correct diagnosis, prognosis determination, and counseling of the affected children and families.

  3. Neuroimaging in CMV congenital infected neonates: how and when.

    Science.gov (United States)

    Lanari, M; Capretti, M G; Lazzarotto, T; Gabrielli, L; Rizzollo, S; Mostert, M; Manzoni, P

    2012-05-01

    Neonatal congenital infections are an important cause of mortality, morbidity and long-term neurodevelopmental and sensorineural sequelae. Many pathogens can cause in utero infection, and among them, cytomegalovirus (CMV) plays a prominent role. In developed countries, CMV poses major health problems as it is the most common pathogen leading to congenital infection, and the leading cause of nonhereditary deafness in children. Evaluation of central nervous system (CNS) involvement in congenital CMV infected newborns is mandatory to better assess the severity of the disease, to guide adequate treatment, to define prognosis, and to tailor follow-up observations and parents' counselling. Cerebral ultrasonography (cUS), Computed Tomography (CT), and Magnetic Resonance Imaging (MRI) are the currently available techniques to evaluate infants with suspected or proven congenital CMV infection. In congenital CMV infection, their role in early detection and confirmation of cerebral involvement within the first month of life is crucial to initiate specific treatment with antivirals. Neonatologists, paediatricians and radiologists should be aware of the role, the limitations and the inherent risks related to the use of these specific neuroimaging diagnostic tools in these infants. In this article we will discuss from a neonatological perspective the advantages, disadvantages, risks and limitations of each imaging technique. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  4. Chronic Methamphetamine Abuse and Corticostriatal Deficits Revealed by Neuroimaging

    Science.gov (United States)

    London, Edythe D.; Kohno, Milky; Morales, Angelica; Ballard, Michael E.

    2014-01-01

    Despite aggressive efforts to contain it, methamphetamine use disorder continues to be major public health problem; and with generic behavioral therapies still the mainstay of treatment for methamphetamine abuse, rates of attrition and relapse remain high. This review summarizes the findings of structural, molecular, and functional neuroimaging studies of methamphetamine abusers, focusing on cortical and striatal abnormalities and their potential contributions to cognitive and behavioral phenotypes that can serve to promote compulsive drug use. These studies indicate that individuals with a history of chronic methamphetamine abuse often display several signs of corticostriatal dysfunction, including abnormal gray- and white-matter integrity, monoamine neurotransmitter system deficiencies, neuroinflammation, poor neuronal integrity, and aberrant patterns of brain connectivity and function, both when engaged in cognitive tasks and at rest. More importantly, many of these neural abnormalities were found to be linked with certain addiction-related phenotypes that may influence treatment response (e.g., poor self-control, cognitive inflexibility, maladaptive decision-making), raising the possibility that they may represent novel therapeutic targets. PMID:25451127

  5. On the role of general system theory for functional neuroimaging.

    Science.gov (United States)

    Stephan, Klaas Enno

    2004-12-01

    One of the most important goals of neuroscience is to establish precise structure-function relationships in the brain. Since the 19th century, a major scientific endeavour has been to associate structurally distinct cortical regions with specific cognitive functions. This was traditionally accomplished by correlating microstructurally defined areas with lesion sites found in patients with specific neuropsychological symptoms. Modern neuroimaging techniques with high spatial resolution have promised an alternative approach, enabling non-invasive measurements of regionally specific changes of brain activity that are correlated with certain components of a cognitive process. Reviewing classic approaches towards brain structure-function relationships that are based on correlational approaches, this article argues that these approaches are not sufficient to provide an understanding of the operational principles of a dynamic system such as the brain but must be complemented by models based on general system theory. These models reflect the connectional structure of the system under investigation and emphasize context-dependent couplings between the system elements in terms of effective connectivity. The usefulness of system models whose parameters are fitted to measured functional imaging data for testing hypotheses about structure-function relationships in the brain and their potential for clinical applications is demonstrated by several empirical examples.

  6. Neuroimaging in adult penetrating brain injury: a guide for radiographers

    Energy Technology Data Exchange (ETDEWEB)

    Temple, Nikki; Donald, Cortny; Skora, Amanda [Discipline of Medical Radiation Sciences, The University of Sydney, Lidcombe, New South Wales (Australia); Reed, Warren, E-mail: warren.reed@sydney.edu.au [Medical Image Optimisation and Perception Group, Discipline of Medical Radiation Sciences, The University of Sydney, Lidcombe, New South Wales (Australia)

    2015-06-15

    Penetrating brain injuries (PBI) are a medical emergency, often resulting in complex damage and high mortality rates. Neuroimaging is essential to evaluate the location and extent of injuries, and to manage them accordingly. Currently, a myriad of imaging modalities are included in the diagnostic workup for adult PBI, including skull radiography, computed tomography (CT), magnetic resonance imaging (MRI) and angiography, with each modality providing their own particular benefits. This literature review explores the current modalities available for investigating PBI and aims to assist in decision making for the appropriate use of diagnostic imaging when presented with an adult PBI. Based on the current literature, the authors have developed an imaging pathway for adult penetrating brain injury that functions as both a learning tool and reference guide for radiographers and other health professionals. Currently, CT is recommended as the imaging modality of choice for the initial assessment of PBI patients, while MRI is important in the sub-acute setting where it aids prognosis prediction and rehabilitation planning, Additional follow-up imaging, such as angiography, should be dependent upon clinical findings.

  7. The Virtual Brain Integrates Computational Modeling and Multimodal Neuroimaging

    Science.gov (United States)

    Schirner, Michael; McIntosh, Anthony R.; Jirsa, Viktor K.

    2013-01-01

    Abstract Brain function is thought to emerge from the interactions among neuronal populations. Apart from traditional efforts to reproduce brain dynamics from the micro- to macroscopic scales, complementary approaches develop phenomenological models of lower complexity. Such macroscopic models typically generate only a few selected—ideally functionally relevant—aspects of the brain dynamics. Importantly, they often allow an understanding of the underlying mechanisms beyond computational reproduction. Adding detail to these models will widen their ability to reproduce a broader range of dynamic features of the brain. For instance, such models allow for the exploration of consequences of focal and distributed pathological changes in the system, enabling us to identify and develop approaches to counteract those unfavorable processes. Toward this end, The Virtual Brain (TVB) (www.thevirtualbrain.org), a neuroinformatics platform with a brain simulator that incorporates a range of neuronal models and dynamics at its core, has been developed. This integrated framework allows the model-based simulation, analysis, and inference of neurophysiological mechanisms over several brain scales that underlie the generation of macroscopic neuroimaging signals. In this article, we describe how TVB works, and we present the first proof of concept. PMID:23442172

  8. Clinical and neuroimage findings of dementia with lewy bodies

    International Nuclear Information System (INIS)

    Kang, Do Young; Park, Kyung Won; Kim, Jae Woo

    2002-01-01

    Dementia with lewy bodies (DLB) is the second common degenerative dementia and has several characteristics including fluctuating cognition, visual hallucination and Parkinsonism. We investigated clinical manifestations and neuroimaging findings in DLB patients. Ten probable DLB patients were included in this study. Brain MRI, Tc-99m HMPAO brain perfusion SPECT and I-123 IPT SPECT were performed. All patients were men and mean age of onset was 64.2 years (range from 54 to 80). All had fluctuating cognition and Parkinsonism, and 8 had visual hallucination. Dementia preceded Parkinsonism in 3 patients. Fluctuation of K-MMSE ranges from 3 to 8 points. Rest tremor was seen in 5 patients. Brain MRI showed cortical atrophy in all patients. Tc-99m brain perfusion SPECT showed hypoperfusion in occipital area as well as fronto-temporo-parietal areas. I-123 IPT SPECT revealed reduced uptake comparable to Parkinson's disease in the striatum. DLB should be first considered as one of possible diagnosis in patients showing dementia in the early stage of Parkinsonism. Hypoperfusion in the occipital area was thought to be a characteristic finding in DLB and to be helpful in differentiating DLB from other degenerative dementias

  9. Neuroimaging in adult penetrating brain injury: a guide for radiographers

    International Nuclear Information System (INIS)

    Temple, Nikki; Donald, Cortny; Skora, Amanda; Reed, Warren

    2015-01-01

    Penetrating brain injuries (PBI) are a medical emergency, often resulting in complex damage and high mortality rates. Neuroimaging is essential to evaluate the location and extent of injuries, and to manage them accordingly. Currently, a myriad of imaging modalities are included in the diagnostic workup for adult PBI, including skull radiography, computed tomography (CT), magnetic resonance imaging (MRI) and angiography, with each modality providing their own particular benefits. This literature review explores the current modalities available for investigating PBI and aims to assist in decision making for the appropriate use of diagnostic imaging when presented with an adult PBI. Based on the current literature, the authors have developed an imaging pathway for adult penetrating brain injury that functions as both a learning tool and reference guide for radiographers and other health professionals. Currently, CT is recommended as the imaging modality of choice for the initial assessment of PBI patients, while MRI is important in the sub-acute setting where it aids prognosis prediction and rehabilitation planning, Additional follow-up imaging, such as angiography, should be dependent upon clinical findings

  10. Functional neuroimaging of normal aging: Declining brain, adapting brain.

    Science.gov (United States)

    Sugiura, Motoaki

    2016-09-01

    Early functional neuroimaging research on normal aging brain has been dominated by the interest in cognitive decline. In this framework the age-related compensatory recruitment of prefrontal cortex, in terms of executive system or reduced lateralization, has been established. Further details on these compensatory mechanisms and the findings reflecting cognitive decline, however, remain the matter of intensive investigations. Studies in another framework where age-related neural alteration is considered adaptation to the environmental change are recently burgeoning and appear largely categorized into three domains. The age-related increase in activation of the sensorimotor network may reflect the alteration of the peripheral sensorimotor systems. The increased susceptibility of the network for the mental-state inference to the socioemotional significance may be explained by the age-related motivational shift due to the altered social perception. The age-related change in activation of the self-referential network may be relevant to the focused positive self-concept of elderly driven by a similar motivational shift. Across the domains, the concept of the self and internal model may provide the theoretical bases of this adaptation framework. These two frameworks complement each other to provide a comprehensive view of the normal aging brain. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. The Power of Neuroimaging Biomarkers for Screening Frontotemporal Dementia

    Science.gov (United States)

    McMillan, Corey T.; Avants, Brian B.; Cook, Philip; Ungar, Lyle; Trojanowski, John Q.; Grossman, Murray

    2014-01-01

    Frontotemporal dementia (FTD) is a clinically and pathologically heterogeneous neurodegenerative disease that can result from either frontotemporal lobar degeneration (FTLD) or Alzheimer’s disease (AD) pathology. It is critical to establish statistically powerful biomarkers that can achieve substantial cost-savings and increase feasibility of clinical trials. We assessed three broad categories of neuroimaging methods to screen underlying FTLD and AD pathology in a clinical FTD series: global measures (e.g., ventricular volume), anatomical volumes of interest (VOIs) (e.g., hippocampus) using a standard atlas, and data-driven VOIs using Eigenanatomy. We evaluated clinical FTD patients (N=93) with cerebrospinal fluid, gray matter (GM) MRI, and diffusion tensor imaging (DTI) to assess whether they had underlying FTLD or AD pathology. Linear regression was performed to identify the optimal VOIs for each method in a training dataset and then we evaluated classification sensitivity and specificity in an independent test cohort. Power was evaluated by calculating minimum sample sizes (mSS) required in the test classification analyses for each model. The data-driven VOI analysis using a multimodal combination of GM MRI and DTI achieved the greatest classification accuracy (89% SENSITIVE; 89% SPECIFIC) and required a lower minimum sample size (N=26) relative to anatomical VOI and global measures. We conclude that a data-driven VOI approach employing Eigenanatomy provides more accurate classification, benefits from increased statistical power in unseen datasets, and therefore provides a robust method for screening underlying pathology in FTD patients for entry into clinical trials. PMID:24687814

  12. Neuroimaging of the Injured Pediatric Brain: Methods and New Lessons.

    Science.gov (United States)

    Dennis, Emily L; Babikian, Talin; Giza, Christopher C; Thompson, Paul M; Asarnow, Robert F

    2018-02-01

    Traumatic brain injury (TBI) is a significant public health problem in the United States, especially for children and adolescents. Current epidemiological data estimate over 600,000 patients younger than 20 years are treated for TBI in emergency rooms annually. While many patients experience a full recovery, for others there can be long-lasting cognitive, neurological, psychological, and behavioral disruptions. TBI in youth can disrupt ongoing brain development and create added family stress during a formative period. The neuroimaging methods used to assess brain injury improve each year, providing researchers a more detailed characterization of the injury and recovery process. In this review, we cover current imaging methods used to quantify brain disruption post-injury, including structural magnetic resonance imaging (MRI), diffusion MRI, functional MRI, resting state fMRI, and magnetic resonance spectroscopy (MRS), with brief coverage of other methods, including electroencephalography (EEG), single-photon emission computed tomography (SPECT), and positron emission tomography (PET). We include studies focusing on pediatric moderate-severe TBI from 2 months post-injury and beyond. While the morbidity of pediatric TBI is considerable, continuing advances in imaging methods have the potential to identify new treatment targets that can lead to significant improvements in outcome.

  13. Functional neuroimaging of semantic and episodic musical memory.

    Science.gov (United States)

    Platel, Hervé

    2005-12-01

    The distinction between episodic and semantic memory has become very popular since it was first proposed by Tulving in 1972. So far, very few neuropsychological, psychophysical, and imaging studies have related to the mnemonic aspects of music, notably on the long-term memory features, and practically nothing is known about the functional anatomy of long-term memory for music. Numerous functional imaging studies have shown that retrieval from semantic and episodic memory is subserved by distinct neural networks. For instance, the HERA model (hemispheric encoding/retrieval asymmetry) ascribes to the left prefrontal cortex a preferential role in the encoding process of episodic material and the recall of semantic information, while the right prefrontal cortex would preferentially operate in the recall of episodic information. However, these results were essentially obtained with verbal and visuo-spatial material. We have done a study to determine the neural substrates underlying the semantic and episodic components of music using familiar and nonfamiliar melodic tunes. Two distinct patterns of activations were found: bilateral activation of the middle and superior frontal areas and precuneus for episodic memory, and activation of the medial and orbital frontal cortex bilaterally, left angular gyrus, and the anterior part of the left middle and superior temporal gyri for semantic memory. We discuss these findings in light of the available neuropsychological data obtained in brain-damaged subjects and functional neuroimaging studies.

  14. [Neuroimaging and the neurobiology of obsessive-compulsive disorder].

    Science.gov (United States)

    Schiepek, Günter; Tominschek, Igor; Karch, Susanne; Mulert, Christoph; Pogarell, Oliver

    2007-01-01

    The following review is focusing on results of functional neuroimaging. After some introductory remarks on the phenomenology, epidemiology, and psychotherapy approaches of obsessive-compulsive disorders (OCD) the most important OCD-related brain regions are presented. Obviously, not only the prominent cortico-striato-thalamo-cortical feedback loops are involved, as functional brain imaging studies tell us, but also other regions as the inferior parietal lobe, the anterior and posterior cingulate gyrus, insula, amygdala, cerebellum, and others. Subclassifications using factor-analysis methods support the hypothesis, that most important subtypes ("washing/contamination fear", "obsessions/checking", "symmetry/ordering", "hoarding") involve different, but partially overlapping brain areas. Stimulation paradigms in fMRI-research are commonly based on symptom provocation by visual or tactile stimuli, or on action-monitoring and error-monitoring tasks. Deficits in action-monitoring and planning are discussed to be one of the basic dysfunctions of OCD. Finally, results of psychotherapeutic induced variations of brain activations in OCD are presented.

  15. Neuroimaging and obesity: current knowledge and future directions

    Science.gov (United States)

    Carnell, S.; Gibson, C.; Benson, L.; Ochner, C. N.; Geliebter, A.

    2011-01-01

    Summary Neuroimaging is becoming increasingly common in obesity research as investigators try to understand the neurological underpinnings of appetite and body weight in humans. Positron emission tomography (PET), functional magnetic resonance imaging (fMRI) and magnetic resonance imaging (MRI) studies examining responses to food intake and food cues, dopamine function and brain volume in lean vs. obese individuals are now beginning to coalesce in identifying irregularities in a range of regions implicated in reward (e.g. striatum, orbitofrontal cortex, insula), emotion and memory (e.g. amygdala, hippocampus), homeostatic regulation of intake (e.g. hypothalamus), sensory and motor processing (e.g. insula, precentral gyrus), and cognitive control and attention (e.g. prefrontal cortex, cingulate). Studies of weight change in children and adolescents, and those at high genetic risk for obesity, promise to illuminate causal processes. Studies examining specific eating behaviours (e.g. external eating, emotional eating, dietary restraint) are teaching us about the distinct neural networks that drive components of appetite, and contribute to the phenotype of body weight. Finally, innovative investigations of appetite-related hormones, including studies of abnormalities (e.g. leptin deficiency) and interventions (e.g. leptin replacement, bariatric surgery), are shedding light on the interactive relationship between gut and brain. The dynamic distributed vulnerability model of eating behaviour in obesity that we propose has scientific and practical implications. PMID:21902800

  16. Functional neuroimaging of conversion disorder: the role of ancillary activation.

    Science.gov (United States)

    Burke, Matthew J; Ghaffar, Omar; Staines, W Richard; Downar, Jonathan; Feinstein, Anthony

    2014-01-01

    Previous functional neuroimaging studies investigating the neuroanatomy of conversion disorder have yielded inconsistent results that may be attributed to small sample sizes and disparate methodologies. The objective of this study was to better define the functional neuroanatomical correlates of conversion disorder. Ten subjects meeting clinical criteria for unilateral sensory conversion disorder underwent fMRI during which a vibrotactile stimulus was applied to anesthetic and sensate areas. A block design was used with 4 s of stimulation followed by 26 s of rest, the pattern repeated 10 times. Event-related group averages of the BOLD response were compared between conditions. All subjects were right-handed females, with a mean age of 41. Group analyses revealed 10 areas that had significantly greater activation (p conversion symptoms are associated with a pattern of abnormal cerebral activation comprising neural networks implicated in emotional processing and sensory integration. Further study of the roles and potential interplay of these networks may provide a basis for an underlying psychobiological mechanism of conversion disorder.

  17. Functional neuroimaging studies of prospective memory: what have we learnt so far?

    Science.gov (United States)

    Burgess, Paul W; Gonen-Yaacovi, Gil; Volle, Emmanuelle

    2011-07-01

    The complexity of the behaviour described by the term "prospective memory" meant that it was not at all clear, when the earliest studies were conducted, that this would prove a fruitful area for neuroimaging study. However, a consistent relation rapidly emerged between activation in rostral prefrontal cortex (approximating Brodmann Area 10) and performance of prospective memory paradigms. This consistency has greatly increased the accumulation of findings, since each study has offered perspectives on the previous ones. Considerable help too has come from broad agreement between functional neuroimaging findings and those from other methods (e.g. human lesion studies, electrophysiology). The result has been a quite startling degree of advance given the relatively few studies that have been conducted. These findings are summarised, along with those from other brain regions, and new directions suggested. Key points are that there is a medial-lateral dissociation within rostral PFC. Some (but not all) regions of medial rostral PFC are typically more active during performance of the ongoing task only, and lateral aspects are relatively more active during conditions involving delayed intentions. Some of these rostral PFC activations seem remarkably insensitive to the form of stimulus material presented, the nature of the ongoing task, the specifics of the intention, how easy or hard the PM cue is to detect, or the intended action is to recall. However there are other regions within rostral PFC where haemodynamic changes vary with alterations in these, and other, aspects of prospective memory paradigms. It is concluded that rostral PFC most likely plays a super-ordinate role during many stages of creating, maintaining and enacting delayed intentions, which in some cases may be linked to recent evidence showing that this brain region is involved in the control of stimulus-oriented vs. stimulus-independent attending. Other key brain regions activated during prospective

  18. Substrates of neuropsychological functioning in stimulant dependence: a review of functional neuroimaging research

    NARCIS (Netherlands)

    Crunelle, C.L.; Veltman, D.J.; Booij, J.; van Emmerik-van Oortmerssen, K.; van den Brink, W.

    2012-01-01

    Stimulant dependence is associated with neuropsychological impairments. Here, we summarize and integrate the existing neuroimaging literature on the neural substrates of neuropsychological (dys)function in stimulant dependence, including cocaine, (meth-)amphetamine, ecstasy and nicotine dependence,

  19. Substrates of neuropsychological functioning in stimulant dependence: a review of functional neuroimaging research

    NARCIS (Netherlands)

    Crunelle, Cleo L.; Veltman, Dick J.; Booij, Jan; Emmerik-van Oortmerssen, Katelijne; den Brink, Wim

    2012-01-01

    Stimulant dependence is associated with neuropsychological impairments. Here, we summarize and integrate the existing neuroimaging literature on the neural substrates of neuropsychological (dys) function in stimulant dependence, including cocaine, (meth-) amphetamine, ecstasy and nicotine

  20. Responsible Reporting : Neuroimaging News in the Age of Responsible Research and Innovation

    NARCIS (Netherlands)

    de Jong, Irja Marije; Arentshorst, Marlous; Broerse, Jacqueline; Kupper, J.F.H.

    Besides offering opportunities in both clinical and non-clinical domains, the application of novel neuroimaging technologies raises pressing dilemmas. 'Responsible Research and Innovation' (RRI) aims to stimulate research and innovation activities that take ethical and social considerations into

  1. NeuroVault and the vision for data sharing in neuroimaging

    OpenAIRE

    Gorgolewski, Chris

    2017-01-01

    Talk from the 14 January 2014 "GlaxoSmithKline - Neurophysics Workshop on Skeptical Neuroimaging", an activity hosted at Imperial College and coordinated with the Neurophysics Marie Curie Initial Training Network of which GSK is a participant.

  2. Conceptual and methodological challenges for neuroimaging studies of autistic spectrum disorders

    OpenAIRE

    Mazzone, Luigi; Curatolo, Paolo

    2010-01-01

    Abstract Autistic Spectrum Disorders (ASDs) are a set of complex developmental disabilities defined by impairment in social interaction and communication, as well as by restricted interests or repetitive behaviors. Neuroimaging studies have substantially advanced our understanding of the neural mechanisms that underlie the core symptoms of ASDs. Nevertheless, a number of challenges still remain in the application of neuroimaging techniques to the study of ASDs. We review three major conceptua...

  3. A systematic review of temporal discounting in eating disorders and obesity:behavioural and neuroimaging findings

    OpenAIRE

    McClelland, Jessica; Dalton, Bethan; Kekic, Maria; Bartholdy, Savani; Campbell, Iain C; Schmidt, Ulrike

    2016-01-01

    OBJECTIVE: Eating Disorders (ED) and obesity are suggested to involve a spectrum of self-regulatory control difficulties. Temporal discounting (TD) tasks have been used to explore this idea. This systematic review examines behavioural and neuroimaging TD data in ED and obesity.METHOD: Using PRISMA guidelines, we reviewed relevant articles in MEDLINE, PsycINFO and Embase from inception until 17th August 2016. Studies that reported behavioural differences in TD and/or TD neuroimaging data in ED...

  4. Constructive interference in steady-state/FIESTA-C clinical applications in neuroimaging

    International Nuclear Information System (INIS)

    Kulkami, Makarand

    2011-01-01

    Full text: High spatial resolution is one of the major problems in neuroimaging, par ticularly in cranial and spinal nerve imaging. Constructive interference in steady-state/fast imaging employing steady-state acquisition with phase cycling is a robust sequence in imaging the cranial and spinal nerve patholo gies. This pictorial review is a concise article about the applications of this sequence in neuroimaging with clinical examples.

  5. Sensation Seeking Predicts Brain Responses in the Old-New Task: Converging Multimodal Neuroimaging Evidence

    OpenAIRE

    Lawson, Adam L.; Liu, Xun; Joseph, Jane; Vagnini, Victoria L.; Kelly, Thomas H.; Jiang, Yang

    2012-01-01

    Novel images and message content enhance visual attention and memory for high sensation seekers, but the neural mechanisms associated with this effect are unclear. To investigate the individual differences in brain responses to new and old (studied) visual stimuli, we utilized Event-related Potentials (ERP) and functional Magnetic Resonance Imaging (fMRI) measures to examine brain reactivity among high and low sensation seekers during a classic old-new memory recognition task. Twenty low and ...

  6. Sensation seeking predicts brain responses in the old-new task: converging multimodal neuroimaging evidence.

    Science.gov (United States)

    Lawson, Adam L; Liu, Xun; Joseph, Jane; Vagnini, Victoria L; Kelly, Thomas H; Jiang, Yang

    2012-06-01

    Novel images and message content enhance visual attention and memory for high sensation seekers, but the neural mechanisms associated with this effect are unclear. To investigate the individual differences in brain responses to new and old (studied) visual stimuli, we utilized event-related potentials (ERP) and functional Magnetic Resonance Imaging (fMRI) measures to examine brain reactivity among high and low sensation seekers during a classic old-new memory recognition task. Twenty low and 20 high sensation seekers completed separate, but parallel, ERP and fMRI sessions. For each session, participants initially studied drawings of common images, and then performed an old-new recognition task during scanning. High sensation seekers showed greater ERP responses to new objects at the frontal N2 ERP component, compared to low sensation seekers. The ERP Novelty-N2 responses were correlated with fMRI responses in the orbitofrontal gyrus. Sensation seeking status also modulated the FN400 ERP component indexing familiarity and conceptual learning, along with fMRI responses in the caudate nucleus, which correlated with FN400 activity. No group differences were found in the late ERP positive components indexing classic old-new amplitude effects. Our combined ERP and fMRI results suggest that sensation-seeking personality affects the early brain responses to visual processing, but not the later stage of memory recognition. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. Remembering the Specific Visual Details of Presented Objects: Neuroimaging Evidence for Effects of Emotion

    Science.gov (United States)

    Kensinger, Elizabeth A.; Schacter, Daniel L.

    2007-01-01

    Memories can be retrieved with varied amounts of visual detail, and the emotional content of information can influence the likelihood that visual detail is remembered. In the present fMRI experiment (conducted with 19 adults scanned using a 3T magnet), we examined the neural processes that correspond with recognition of the visual details of…

  8. Reward mechanisms in the brain and their role in dependence : evidence from neurophysiological and neuroimaging studies

    NARCIS (Netherlands)

    Martin-Soelch, C; Leenders, KL; Chevalley, AF; Missimer, J; Kunig, G; Magyar, S; Mino, A; Schultz, W

    2001-01-01

    This article reviews neuronal activity related to reward processing in primate and human brains. In the primate brain, neurophysiological methods provide a differentiated view of reward processing in a limited number of brain structures. Dopamine neurons respond to unpredictable rewards and produce

  9. Experimental Evidence for Improved Neuroimaging Interpretation Using Three-Dimensional Graphic Models

    Science.gov (United States)

    Ruisoto, Pablo; Juanes, Juan Antonio; Contador, Israel; Mayoral, Paula; Prats-Galino, Alberto

    2012-01-01

    Three-dimensional (3D) or volumetric visualization is a useful resource for learning about the anatomy of the human brain. However, the effectiveness of 3D spatial visualization has not yet been assessed systematically. This report analyzes whether 3D volumetric visualization helps learners to identify and locate subcortical structures more…

  10. Behavioral and neuroimaging evidence for overreliance on habit learning in alcohol-dependent patients

    NARCIS (Netherlands)

    Sjoerds, Z.; de Wit, S.; van den Brink, W.; Robbins, T.W.; Beekman, A.T.F.; Penninx, B.W.J.H.; Veltman, D.J.

    2013-01-01

    Substance dependence is characterized by compulsive drug-taking despite negative consequences. Animal research suggests an underlying imbalance between goal-directed and habitual action control with chronic drug use. However, this imbalance, and its associated neurophysiological mechanisms, has not

  11. [Neural correlates of priming in vision: evidence from neuropsychology and neuroimaging].

    Science.gov (United States)

    Kristjánsson, Arni

    2005-04-01

    When we look around us, we are overall more likely to notice objects that we have recently looked at; an effect known as priming. For example, when the color or shape of a visual search target is repeated, observers find the target faster than otherwise. Here I summarize recent research undertaken to uncover the temporary changes in brain activity that accompany these priming effects. In light of the fact that priming seems to have a large effect on how attention is allocated, we investigated priming effects in a visual search task on patients suffering from the neurological disorder "hemispatial neglect" in which patients typically fail to notice display items in one of their visual hemifields. Priming of target color was relatively normal for these patients, while priming of target location seemed to require awareness of the briefly presented visual search target. An experiment with functional magnetic resonance imaging of normal observers revealed that both color and location priming had a strong modulatory influence on attentional mechanisms of the frontal and parietal cortex. Color priming was also correlated with changes in activity in visual cortex as well as color processing areas in the temporal lobe. Location priming was correlated with changes in activity near the temporo- parietal junction and lateral inferior frontal cortex, areas that have been connected with attentional capture; which ties well with our finding of deficits of location priming for the neglect patients who indeed have lesions in the temporo-parietal junction. Overall, the results confirm the tight coupling of visual attention and priming in vision, and also that the visual areas of the brain show some modulation of activity as priming develops.

  12. Cognitive rehabilitation in Parkinson´s disease: evidences from neuroimaging.

    Directory of Open Access Journals (Sweden)

    Cristina eNombela

    2011-12-01

    Full Text Available Cognitive impairment in Parkinson’s disease (PD has received little attention and as such, there are currently very few treatment options available. The aim of the present study was to evaluate the attention impairment in PD patients and to determine whether cognitive training might alleviate any such symptoms. The study, which included a pilot and experimental phase, involved assessing performance in a modified version of the Stroop task during functional magnetic resonance imaging (fMRI. The study was carried out in ten PD patients and ten paired healthy controls, half of the PD patients undergoing 6 months of cognitive training based on Sudoku exercises. The brain training programme improved the cognitive performance of the Parkinson’s patients in attention tasks and it provoked comparable patterns of cortical activation to those observed in controls. Based on these findings, we propose that cognitive training can contribute significantly to save brain resources in PD patients, maybe by readdressing the imbalance caused by the alterations to inhibitory circuitry.

  13. Gene, Brain, and Behavior Relationships in Fragile X Syndrome: Evidence from Neuroimaging Studies

    Science.gov (United States)

    Lightbody, Amy A.; Reiss, Allan L.

    2009-01-01

    Fragile X syndrome (FraX) remains the most common inherited cause of intellectual disability and provides a valuable model for studying gene-brain-behavior relationships. Over the past 15 years, structural and functional magnetic resonance imaging studies have emerged with the goal of better understanding the neural pathways contributing to the…

  14. Responsible Reporting: Neuroimaging News in the Age of Responsible Research and Innovation.

    Science.gov (United States)

    de Jong, Irja Marije; Kupper, Frank; Arentshorst, Marlous; Broerse, Jacqueline

    2016-08-01

    Besides offering opportunities in both clinical and non-clinical domains, the application of novel neuroimaging technologies raises pressing dilemmas. 'Responsible Research and Innovation' (RRI) aims to stimulate research and innovation activities that take ethical and social considerations into account from the outset. We previously identified that Dutch neuroscientists interpret "responsible innovation" as educating the public on neuroimaging technologies via the popular press. Their aim is to mitigate (neuro)hype, an aim shared with the wider emerging RRI community. Here, we present results of a media-analysis undertaken to establish whether the body of articles in the Dutch popular press presents balanced conversations on neuroimaging research to the public. We found that reporting was mostly positive and framed in terms of (healthcare) progress. There was rarely a balance between technology opportunities and limitations, and even fewer articles addressed societal or ethical aspects of neuroimaging research. Furthermore, neuroimaging metaphors seem to favour oversimplification. Current reporting is therefore more likely to enable hype than to mitigate it. How can neuroscientists, given their self-ascribed social responsibility, address this conundrum? We make a case for a collective and shared responsibility among neuroscientists, journalists and other stakeholders, including funders, committed to responsible reporting on neuroimaging research.

  15. Heads in the Cloud: A Primer on Neuroimaging Applications of High Performance Computing

    Directory of Open Access Journals (Sweden)

    Anwar S. Shatil

    2015-01-01

    Full Text Available With larger data sets and more sophisticated analyses, it is becoming increasingly common for neuroimaging researchers to push (or exceed the limitations of standalone computer workstations. Nonetheless, although high-performance computing platforms such as clusters, grids and clouds are already in routine use by a small handful of neuroimaging researchers to increase their storage and/or computational power, the adoption of such resources by the broader neuroimaging community remains relatively uncommon. Therefore, the goal of the current manuscript is to: 1 inform prospective users about the similarities and differences between computing clusters, grids and clouds; 2 highlight their main advantages; 3 discuss when it may (and may not be advisable to use them; 4 review some of their potential problems and barriers to access; and finally 5 give a few practical suggestions for how interested new users can start analyzing their neuroimaging data using cloud resources. Although the aim of cloud computing is to hide most of the complexity of the infrastructure management from end-users, we recognize that this can still be an intimidating area for cognitive neuroscientists, psychologists, neurologists, radiologists, and other neuroimaging researchers lacking a strong computational background. Therefore, with this in mind, we have aimed to provide a basic introduction to cloud computing in general (including some of the basic terminology, computer architectures, infrastructure and service models, etc., a practical overview of the benefits and drawbacks, and a specific focus on how cloud resources can be used for various neuroimaging applications.

  16. Heads in the Cloud: A Primer on Neuroimaging Applications of High Performance Computing.

    Science.gov (United States)

    Shatil, Anwar S; Younas, Sohail; Pourreza, Hossein; Figley, Chase R

    2015-01-01

    With larger data sets and more sophisticated analyses, it is becoming increasingly common for neuroimaging researchers to push (or exceed) the limitations of standalone computer workstations. Nonetheless, although high-performance computing platforms such as clusters, grids and clouds are already in routine use by a small handful of neuroimaging researchers to increase their storage and/or computational power, the adoption of such resources by the broader neuroimaging community remains relatively uncommon. Therefore, the goal of the current manuscript is to: 1) inform prospective users about the similarities and differences between computing clusters, grids and clouds; 2) highlight their main advantages; 3) discuss when it may (and may not) be advisable to use them; 4) review some of their potential problems and barriers to access; and finally 5) give a few practical suggestions for how interested new users can start analyzing their neuroimaging data using cloud resources. Although the aim of cloud computing is to hide most of the complexity of the infrastructure management from end-users, we recognize that this can still be an intimidating area for cognitive neuroscientists, psychologists, neurologists, radiologists, and other neuroimaging researchers lacking a strong computational background. Therefore, with this in mind, we have aimed to provide a basic introduction to cloud computing in general (including some of the basic terminology, computer architectures, infrastructure and service models, etc.), a practical overview of the benefits and drawbacks, and a specific focus on how cloud resources can be used for various neuroimaging applications.

  17. Heads in the Cloud: A Primer on Neuroimaging Applications of High Performance Computing

    Science.gov (United States)

    Shatil, Anwar S.; Younas, Sohail; Pourreza, Hossein; Figley, Chase R.

    2015-01-01

    With larger data sets and more sophisticated analyses, it is becoming increasingly common for neuroimaging researchers to push (or exceed) the limitations of standalone computer workstations. Nonetheless, although high-performance computing platforms such as clusters, grids and clouds are already in routine use by a small handful of neuroimaging researchers to increase their storage and/or computational power, the adoption of such resources by the broader neuroimaging community remains relatively uncommon. Therefore, the goal of the current manuscript is to: 1) inform prospective users about the similarities and differences between computing clusters, grids and clouds; 2) highlight their main advantages; 3) discuss when it may (and may not) be advisable to use them; 4) review some of their potential problems and barriers to access; and finally 5) give a few practical suggestions for how interested new users can start analyzing their neuroimaging data using cloud resources. Although the aim of cloud computing is to hide most of the complexity of the infrastructure management from end-users, we recognize that this can still be an intimidating area for cognitive neuroscientists, psychologists, neurologists, radiologists, and other neuroimaging researchers lacking a strong computational background. Therefore, with this in mind, we have aimed to provide a basic introduction to cloud computing in general (including some of the basic terminology, computer architectures, infrastructure and service models, etc.), a practical overview of the benefits and drawbacks, and a specific focus on how cloud resources can be used for various neuroimaging applications. PMID:27279746

  18. Atmospheric Electricity

    Science.gov (United States)

    Aplin, Karen; Fischer, Georg

    2018-02-01

    Electricity occurs in atmospheres across the Solar System planets and beyond, spanning spectacular lightning displays in clouds of water or dust, to more subtle effects of charge and electric fields. On Earth, lightning is likely to have existed for a long time, based on evidence from fossilized lightning strikes in ancient rocks, but observations of planetary lightning are necessarily much more recent. The generation and observations of lightning and other atmospheric electrical processes, both from within-atmosphere measurements, and spacecraft remote sensing, can be readily studied using a comparative planetology approach, with Earth as a model. All atmospheres contain charged molecules, electrons, and/or molecular clusters created by ionization from cosmic rays and other processes, which may affect an atmosphere's energy balance both through aerosol and cloud formation, and direct absorption of radiation. Several planets are anticipated to host a "global electric circuit" by analogy with the circuit occurring on Earth, where thunderstorms drive current of ions or electrons through weakly conductive parts of the atmosphere. This current flow may further modulate an atmosphere's radiative properties through cloud and aerosol effects. Lightning could potentially have implications for life through its effects on atmospheric chemistry and particle transport. It has been observed on many of the Solar System planets (Earth, Jupiter, Saturn, Uranus, and Neptune) and it may also be present on Venus and Mars. On Earth, Jupiter, and Saturn, lightning is thought to be generated in deep water and ice clouds, but discharges can be generated in dust, as for terrestrial volcanic lightning, and on Mars. Other, less well-understood mechanisms causing discharges in non-water clouds also seem likely. The discovery of thousands of exoplanets has recently led to a range of further exotic possibilities for atmospheric electricity, though lightning detection beyond our Solar System

  19. Neuroimaging studies of the striatum in cognition Part I: healthy individuals.

    Science.gov (United States)

    Provost, Jean-Sebastien; Hanganu, Alexandru; Monchi, Oury

    2015-01-01

    The striatum has traditionally mainly been associated with playing a key role in the modulation of motor functions. Indeed, lesion studies in animals and studies of some neurological conditions in humans have brought further evidence to this idea. However, better methods of investigation have raised concerns about this notion, and it was proposed that the striatum could also be involved in different types of functions including cognitive ones. Although the notion was originally a matter of debate, it is now well-accepted that the caudate nucleus contributes to cognition, while the putamen could be involved in motor functions, and to some extent in cognitive functions as well. With the arrival of modern neuroimaging techniques in the early 1990, knowledge supporting the cognitive aspect of the striatum has greatly increased, and a substantial number of scientific papers were published studying the role of the striatum in healthy individuals. For the first time, it was possible to assess the contribution of specific areas of the brain during the execution of a cognitive task. Neuroanatomical studies have described functional loops involving the striatum and the prefrontal cortex suggesting a specific interaction between these two structures. This review examines the data up to date and provides strong evidence for a specific contribution of the fronto-striatal regions in different cognitive processes, such as set-shifting, self-initiated responses, rule learning, action-contingency, and planning. Finally, a new two-level functional model involving the prefrontal cortex and the dorsal striatum is proposed suggesting an essential role of the dorsal striatum in selecting between competing potential responses or actions, and in resolving a high level of ambiguity.

  20. [Functional Neuroimaging Pilot Study of Borderline Personality Disorder in Adolescents].

    Science.gov (United States)

    LeBoeuf, Amélie; Guilé, Jean-Marc; Labelle, Réal; Luck, David

    Borderline personality disorder (BPD) is being increasingly recognized by clinicians working with adolescents, and the reliability and validity of the diagnosis have been established in the adolescent population. Adolescence is known to be a period of high risk for BPD development as most patients identify the onset of their symptoms to be in the adolescent period. As with other mental health disorders, personality disorder, are thought to result from the interaction between biological and environmental factors. Functional neuroimaging studies are reporting an increasing amount of data on abnormal neuronal functions in BPD adult patients. However, no functional neuroimaging studies have been conducted in adolescents with BPD.Objectives This pilot project aims to evaluate the feasibility of a functional magnetic resonance imaging (fMRI) study coupled with clinical and psychological measures in adolescent girls with a diagnosis of BPD. It also aims to identify neuronal regions of interest (ROI) for the study of BPD in adolescent girls.Method Six female adolescents meeting DSM-IV criteria for BPD and 6 female adolescents without psychiatric disorder were recruited. Both groups were evaluated for BPD symptoms, depressive symptoms, impulsivity, affective lability, and other potential psychiatric comorbidities. We used fMRI to compare patterns of regional brain activation between these two groups as they viewed 20 positive, 20 negative and 20 neutral emotion-inducing pictures, which were presented in random order.Results Participants were recruited over a period of 22 months. The protocol was well tolerated by participants. Mean age of the BPD group and control group was 15.8 ± 0.9 years-old and 15.5 ± 1.2 years-old respectively. Psychiatric comorbidity and use of medication was common among participants in the BPD group. This group showed higher impulsivity and affective lability scores. For the fMRI task, BPD patients demonstrated greater differences in activation

  1. On the electricity shortage, price and electricity theft nexus

    International Nuclear Information System (INIS)

    Jamil, Faisal

    2013-01-01

    Pakistan is facing severe electricity shortfall of its history since 2006. Several measures have been implemented in order to mitigate electricity shortage. The focus has been on raising the installed capacity of electricity generation and transmission. The present policy results in expensive thermal electricity generation mostly using expensive and environmentally hazardous furnace oil and inability of utilities to recover their cost of supply although there is unprecedented rise in electricity tariffs. This study concentrates on the electricity demand and traces the relationship between electricity shortfalls, tariff rate and electricity theft in the background of recent electricity crisis using the data for the period 1985–2010. We employed the Granger causality test through error correction model and out-of-sample causality through variance decomposition method. Empirical evidence shows that electricity theft greatly influences electricity shortfalls through lowering investment and inefficient use of electricity. The study concludes that electricity crisis cannot be handled without combating rampant electricity theft in the country. - Highlights: ► The study investigates relationship among electricity outages, price and electricity theft. ► It employed Johansen approach, ECM and variance decomposition analysis. ► Empirical evidence shows that electricity theft causes outages and rising tariff rates. ► Variance decomposition analysis results are slightly different from ECM

  2. Geriatric medicine, Japanese Alzheimer's disease neuroimaging initiative and biomarker development

    International Nuclear Information System (INIS)

    Arai, Hiroyuki; Furukawa, Katsutoshi; Okamura, Nobuyuki; Kudo, Yukitsuka

    2010-01-01

    Due to a change in disease spectrum in aged countries, the primary role of geriatricians should be directed to an appropriate management and prevention of cognitive decline and dementia, swallowing and aspiration pneumonia and falls and fractures. Management of dementia constitutes a central part in the practice of geriatric medicine in order to support independence of life in elderly people. The current paradigm of cognitive function-based testing for the diagnosis and treatment of Alzheimer's disease (AD) is going to drastically shift to a biomarker-based test approach, a shift that will correspond to the emergence of disease-modifying drugs. In addition, a new molecular imaging technique that visualizes neuronal protein deposits or pathological features has been developed in Japan and the U.S.A. Based on these achievements, the Alzheimer's Disease Neuroimaging Initiative (ADNI) was proposed and initiated in 2005. The ADNI is a long-term observational study being conducted in the U.S.A., Europe, Australia, and Japan using identical protocols. The objectives of ADNI are: to establish methodology which will allow standard values related to long-term changes in imaging data, such as MRI and positron emission tomography (PET), in patients with AD and mild cognitive impairment and normal elderly persons; to obtain clinical indices, psychological test data, and blood/cerebrospinal fluid biomarkers to demonstrate the validity of image-based surrogate markers; and to establish optimum methods to monitor the therapeutic effects of disease-modifying drugs for AD. Patient enrollment in the Japanese ADNI has begun in July 2008. Imaging of AD pathology not only acts as a reliable biomarker with which to assay curative drug development by novel pharmaceutical companies, but it also helps health promotion toward AD prevention. (author)

  3. Multiple Sclerosis in Malaysia: Demographics, Clinical Features, and Neuroimaging Characteristics

    Directory of Open Access Journals (Sweden)

    S. Viswanathan

    2013-01-01

    Full Text Available Background. Multiple sclerosis (MS is an uncommon disease in multiracial Malaysia. Diagnosing patients with idiopathic inflammatory demyelinating diseases has been greatly aided by the evolution in diagnostic criterion, the identification of new biomarkers, and improved accessibility to neuroimaging in the country. Objectives. To investigate the spectrum of multiple sclerosis in Malaysia. Methods. Retrospective analysis with longitudinal follow-up of patients referred to a single tertiary medical center with neurology services in Malaysia. Results. Out of 245 patients with idiopathic inflammatory demyelinating disease, 104 patients had multiple sclerosis. Female to male ratio was 5 : 1. Mean age at onset was 28.6 ± 9.9 years. The Malays were the predominant racial group affected followed by the Chinese, Indians, and other indigenous groups. Subgroup analysis revealed more Chinese having neuromyelitis optica and its spectrum disorders rather than multiple sclerosis. Positive family history was reported in 5%. Optic neuritis and myelitis were the commonest presentations at onset of disease, and relapsing remitting course was the commonest disease pattern observed. Oligoclonal band positivity was 57.6%. At disease onset, 61.5% and 66.4% fulfilled the 2005 and 2010 McDonald’s criteria for dissemination in space. Mean cord lesion length was 1.86 ± 1.65 vertebral segments in the relapsing remitting group as opposed to 6.25 ± 5.18 vertebral segments in patients with neuromyelitis optica and its spectrum disorders. Conclusion. The spectrum of multiple sclerosis in Malaysia has changed over the years. Further advancement in diagnostic criteria will no doubt continue to contribute to the evolution of this disease here.

  4. Multiple Sclerosis in Malaysia: Demographics, Clinical Features, and Neuroimaging Characteristics

    Science.gov (United States)

    Viswanathan, S.; Rose, N.; Masita, A.; Dhaliwal, J. S.; Puvanarajah, S. D.; Rafia, M. H.; Muda, S.

    2013-01-01

    Background. Multiple sclerosis (MS) is an uncommon disease in multiracial Malaysia. Diagnosing patients with idiopathic inflammatory demyelinating diseases has been greatly aided by the evolution in diagnostic criterion, the identification of new biomarkers, and improved accessibility to neuroimaging in the country. Objectives. To investigate the spectrum of multiple sclerosis in Malaysia. Methods. Retrospective analysis with longitudinal follow-up of patients referred to a single tertiary medical center with neurology services in Malaysia. Results. Out of 245 patients with idiopathic inflammatory demyelinating disease, 104 patients had multiple sclerosis. Female to male ratio was 5 : 1. Mean age at onset was 28.6 ± 9.9 years. The Malays were the predominant racial group affected followed by the Chinese, Indians, and other indigenous groups. Subgroup analysis revealed more Chinese having neuromyelitis optica and its spectrum disorders rather than multiple sclerosis. Positive family history was reported in 5%. Optic neuritis and myelitis were the commonest presentations at onset of disease, and relapsing remitting course was the commonest disease pattern observed. Oligoclonal band positivity was 57.6%. At disease onset, 61.5% and 66.4% fulfilled the 2005 and 2010 McDonald's criteria for dissemination in space. Mean cord lesion length was 1.86 ± 1.65 vertebral segments in the relapsing remitting group as opposed to 6.25 ± 5.18 vertebral segments in patients with neuromyelitis optica and its spectrum disorders. Conclusion. The spectrum of multiple sclerosis in Malaysia has changed over the years. Further advancement in diagnostic criteria will no doubt continue to contribute to the evolution of this disease here. PMID:24455266

  5. Neuroimaging and the search for a cure for Alzheimer disease.

    Science.gov (United States)

    Petrella, Jeffrey R

    2013-12-01

    As radiologists, our role in the workup of the dementia patient has long been limited by the sensitivity of our imaging tools and lack of effective treatment options. Over the past 30 years, we have made tremendous strides in understanding the genetic, molecular, and cellular basis of Alzheimer disease (AD). We now know that the pathologic features of AD are present 1 to 2 decades prior to development of symptoms, though currently approved symptomatic therapies are administered much later in the disease course. The search for true disease-modifying therapy continues and many clinical trials are underway. Current outcome measures, based on cognitive tests, are relatively insensitive to pathologic disease progression, requiring long, expensive trials with large numbers of participants. Biomarkers, including neuroimaging, have great potential to increase the power of trials by matching imaging methodology with therapeutic mechanism. One of the most important advances over the past decade has been the development of in vivo imaging probes targeted to amyloid beta protein, and one agent is already available for clinical use. Additional advances include automated volumetric imaging methods to quantitate cerebral volume loss. Use of such techniques in small, early phase trials are expected to significantly increase the number and quality of candidate drugs for testing in larger trials. In addition to a critical role in trials, structural, molecular, and functional imaging techniques can give us a window on the etiology of AD and other neurodegenerative diseases. This combination of developments has potential to bring diagnostic radiology to the forefront in AD research, therapeutic trials, and patient care. ©RSNA, 2013.

  6. 'Number-forms' in neuroimaging?;- a PET activation study

    International Nuclear Information System (INIS)

    Cowell, S.F.; Code, C.; Harasty, J.; Egan, G.F.; Watson, J.D.G.; University of New South Wales,; Royal Prince Alfred Hospital, Sydney, NSW; University of Melbourne, VIC; University of Exeter,

    2000-01-01

    Full text: In 1880 Francis Galton reported a mental imagery study in which imagers were able to describe and draw arithmetic operations called 'number-forms' (NF). While many studies have reported NFs, little is known about their neural basis. We report a PET case study of a normal volunteer who invoked NFs during mental arithmetic tasks. This PET study used two conditions, repetition and calculation, presented bi-aurally while the subject was blindfolded. The calculation condition required the subject to say out loud the answers to arithmetic tasks, eg. 'nineteen minus seven'. A post-test protocol for vividness of visual imagery during calculation (PVVIC), based on the interviews of Galton (1880) and Seron and colleagues (1992), identified AF, a 43year-old women, as the highest imager (PVVIC - 95%) from a group of 12 normal volunteers. She was able to accurately describe and draw a well-used imagery strategy for mental arithmetic. Her results were contrasted with non-imager, FM (PVVIC - 10%). AF's MRI guided PET results showed significant rCBF activations during the calculation tasks including the right precuneus, right superior frontal gyrus (BA8), left superior parietal lobe (BA7), left visual cortex, medial thalamus and cerebellum. Except for the activation in the right BA8, common to both subjects, AF's areas were not activated by FM. These data confirm previous PET findings that the precuneus plays a major role in mental imagery and point to a neural network for mental imagery during simple calculation. AF's imagery strategies could be the first number-forms reported in a neuroimaging study. Copyright (2000) The Australian and New Zealand Society of Nuclear Medicine Inc

  7. Neuroimaging study of Fukuyama type congenital muscular dystrophy

    International Nuclear Information System (INIS)

    Murasugi, Hiroko

    1992-01-01

    Fukuyama type congenital muscular dystrophy (FCMD) has been attracting attention in recent years because of its brain malformation and progressive muscular dystrophy. The intravitam recognition of brain malformation has been remarkably enhanced by the advent of noninvasive neuroimaging techniques such as CT and MRI. In this study, 87 cranial CT scans and 22 MRIs of the brain, carried out on 60 patients with FCMD, were systematically surveyed, and the correlation between neuroradiological findings and clinical disabilities, and, in two autopsy cases, neuropathological findings was evaluated. Four cases of lissencephalic, 29 of pachygyric, and one of polymicrogyric (suspected) brain surface, and 2 normal brain surfaces were recognized. The patients with lissencephalic brain surface were compared using Dobyns' criteria. Grading of pachygyria was judged as bilateral II in 52% of cases and bilateral I in 48%. The surface of the occipital lobe could not be confirmed with either CT or MRI. Polymicrogyria was suspected using MRI but could not confirmed with CT. Five caces of lissencephaly had never learned any meaningful words and all but one were bedridden because of poor head control. The abilities of patients were better when the grading of pachygyria was milder. Mental disability and peak motor function correlate more closely with the degree and extent of brain malformation than with muscle degeneration. The decrease in radiodensity in the white matter was remarkable in 12 out of 19 cases (63%), and was usually bilaterally symmetrical. An increase in radiodensity in the white matter with age was observed in 3 patients. The rate of myelination was slower than normal in 3 out of the 6 cases. (author)

  8. Neuroimaging study of Fukuyama type congenital muscular dystrophy

    Energy Technology Data Exchange (ETDEWEB)

    Murasugi, Hiroko (Tokyo Women' s Medical Coll. (Japan))

    1992-11-01

    Fukuyama type congenital muscular dystrophy (FCMD) has been attracting attention in recent years because of its brain malformation and progressive muscular dystrophy. The intravitam recognition of brain malformation has been remarkably enhanced by the advent of noninvasive neuroimaging techniques such as CT and MRI. In this study, 87 cranial CT scans and 22 MRIs of the brain, carried out on 60 patients with FCMD, were systematically surveyed, and the correlation between neuroradiological findings and clinical disabilities, and, in two autopsy cases, neuropathological findings was evaluated. Four cases of lissencephalic, 29 of pachygyric, and one of polymicrogyric (suspected) brain surface, and 2 normal brain surfaces were recognized. The patients with lissencephalic brain surface were compared using Dobyns' criteria. Grading of pachygyria was judged as bilateral II in 52% of cases and bilateral I in 48%. The surface of the occipital lobe could not be confirmed with either CT or MRI. Polymicrogyria was suspected using MRI but could not confirmed with CT. Five caces of lissencephaly had never learned any meaningful words and all but one were bedridden because of poor head control. The abilities of patients were better when the grading of pachygyria was milder. Mental disability and peak motor function correlate more closely with the degree and extent of brain malformation than with muscle degeneration. The decrease in radiodensity in the white matter was remarkable in 12 out of 19 cases (63%), and was usually bilaterally symmetrical. An increase in radiodensity in the white matter with age was observed in 3 patients. The rate of myelination was slower than normal in 3 out of the 6 cases. (author).

  9. Functional and molecular neuroimaging of menopause and hormone replacement therapy

    Directory of Open Access Journals (Sweden)

    Erika eComasco

    2014-12-01

    Full Text Available The level of gonadal hormones to which the female brain is exposed considerably changes across the menopausal transition, which in turn, is likely to be of great relevance for neurodegenerative diseases and psychiatric disorders. However, the neurobiological consequences of these hormone fluctuations and of hormone replacement therapy in the menopause have only begun to be understood. This review summarizes the findings of thirty-four studies of human brain function, including functional magnetic resonance imaging, positron and single-photon computed emission tomography studies, in peri- and postmenopausal women treated with estrogen, or estrogen-progestagen replacement therapy. Seven studies using gonadotropin-releasing hormone agonist intervention as a model of hormonal withdrawal are also included. Cognitive paradigms are employed by the majority of studies evaluating the effect of unopposed estrogen or estrogen-progestagen treatment on peri- and postmenopausal women’s brain. In randomized-controlled trials, estrogen treatment enhances activation of fronto-cingulate regions during cognitive functioning, though in many cases no difference in cognitive performance was present. Progestagens seems to counteract the effects of estrogens. Findings on cognitive functioning during acute ovarian hormone withdrawal suggest a decrease in activation of the inferior frontal gyrus, thus essentially corroborating the findings in postmenopausal women. Studies of the cholinergic and serotonergic systems indicate these systems as biological mediators of hormonal influences on the brain. More, hormonal replacement appears to increase cerebral blood flow in cortical regions. On the other hand, studies on emotion processing in postmenopausal women are lacking. These results call for well-powered randomized-controlled multi-modal prospective neuroimaging studies as well as investigation on the related molecular mechanisms of effects of menopausal hormonal

  10. Functional neuroimaging insights into the physiology of human sleep.

    Science.gov (United States)

    Dang-Vu, Thien Thanh; Schabus, Manuel; Desseilles, Martin; Sterpenich, Virginie; Bonjean, Maxime; Maquet, Pierre

    2010-12-01

    Functional brain imaging has been used in humans to noninvasively investigate the neural mechanisms underlying the generation of sleep stages. On the one hand, REM sleep has been associated with the activation of the pons, thalamus, limbic areas, and temporo-occipital cortices, and the deactivation of prefrontal areas, in line with theories of REM sleep generation and dreaming properties. On the other hand, during non-REM (NREM) sleep, decreases in brain activity have been consistently found in the brainstem, thalamus, and in several cortical areas including the medial prefrontal cortex (MPFC), in agreement with a homeostatic need for brain energy recovery. Benefiting from a better temporal resolution, more recent studies have characterized the brain activations related to phasic events within specific sleep stages. In particular, they have demonstrated that NREM sleep oscillations (spindles and slow waves) are indeed associated with increases in brain activity in specific subcortical and cortical areas involved in the generation or modulation of these waves. These data highlight that, even during NREM sleep, brain activity is increased, yet regionally specific and transient. Besides refining the understanding of sleep mechanisms, functional brain imaging has also advanced the description of the functional properties of sleep. For instance, it has been shown that the sleeping brain is still able to process external information and even detect the pertinence of its content. The relationship between sleep and memory has also been refined using neuroimaging, demonstrating post-learning reactivation during sleep, as well as the reorganization of memory representation on the systems level, sometimes with long-lasting effects on subsequent memory performance. Further imaging studies should focus on clarifying the role of specific sleep patterns for the processing of external stimuli, as well as the consolidation of freshly encoded information during sleep.

  11. The Extended Fronto-Striatal Model of Obsessive Compulsive Disorder: Convergence from Event-Related Potentials, Neuropsychology and Neuroimaging

    Directory of Open Access Journals (Sweden)

    Margherita eMelloni

    2012-09-01

    Full Text Available In this work, we explored convergent evidence supporting the fronto-striatal model of obsessive-compulsive disorder (FSMOCD and the contribution of event-related potential (ERP studies to this model. First, we considered minor modifications to the FSMOCD model based on neuroimaging and neuropsychological data. We noted the brain areas most affected in this disorder -anterior cingulate cortex (ACC, basal ganglia (BG and orbito-frontal cortex (OFC- and their related cognitive functions, such as monitoring and inhibition. Then, we assessed the ERPs that are directly related to the FSMOCD, including the error-related negativity (ERN, N200 and P600. Several OCD studies present enhanced ERN and N2 responses during conflict tasks as well as an enhanced P600 during working memory tasks. Evidence from ERP studies (especially regarding ERN and N200 amplitude enhancement, neuroimaging and neuropsychological findings suggests abnormal activity in the OFC, ACC and BG in OCD patients. Moreover, additional findings from these analyses suggest dorsolateral prefrontal and parietal cortex involvement, which might be related to executive function deficits. Thus, these convergent results suggest the existence of a self-monitoring imbalance involving inhibitory deficits and executive dysfunctions. OCD patients present an impaired ability to monitor, control, and inhibit intrusive thoughts, urges, feelings and behaviors. In the current model, this imbalance is triggered by an excitatory role of the BG (associated with cognitive or motor actions without volitional control and inhibitory activity of the OFC as well as excessive monitoring of the ACC to block excitatory impulses. This imbalance would interact with the reduced activation of the parietal-DLPC network, leading to executive dysfunction. ERP research may provide further insight regarding the temporal dynamics of action monitoring and executive functioning in OCD.

  12. Metabolic determinants of electrical failure in ex-vivo canine model of cardiac arrest: evidence for the protective role of inorganic pyrophosphate.

    Directory of Open Access Journals (Sweden)

    Junko Shibayama

    Full Text Available Deterioration of ventricular fibrillation (VF into asystole or severe bradycardia (electrical failure heralds a fatal outcome of cardiac arrest. The role of metabolism in the timing of electrical failure remains unknown.To determine metabolic factors of early electrical failure in an ex-vivo canine model of cardiac arrest (VF+global ischemia.Metabolomic screening was performed in left ventricular biopsies collected before and after 0.3, 2, 5, 10 and 20 min of VF and global ischemia. Electrical activity was monitored via plunge needle electrodes and pseudo-ECG. Four out of nine hearts exhibited electrical failure at 10.1±0.9 min (early-asys, while 5/9 hearts maintained VF for at least 19.7 min (late-asys. As compared to late-asys, early-asys hearts had more ADP, less phosphocreatine, and higher levels of lactate at some time points during VF/ischemia (all comparisons p<0.05. Pre-ischemic samples from late-asys hearts contained ∼25 times more inorganic pyrophosphate (PPi than early-asys hearts. A mechanistic role of PPi in cardioprotection was then tested by monitoring mitochondrial membrane potential (ΔΨ during 20 min of simulated-demand ischemia using potentiometric probe TMRM in rabbit adult ventricular myocytes incubated with PPi versus control group. Untreated myocytes experienced significant loss of ΔΨ while in the PPi-treated myocytes ΔΨ was relatively maintained throughout 20 min of simulated-demand ischemia as compared to control (p<0.05.High tissue level of PPi may prevent ΔΨm loss and electrical failure at the early phase of ischemic stress. The link between the two protective effects may involve decreased rates of mitochondrial ATP hydrolysis and lactate accumulation.

  13. The Appropriate Use of Neuroimaging in the Diagnostic Work-Up of Dementia

    Science.gov (United States)

    2014-01-01

    Background Diagnosis of dementia is challenging and requires both ruling out potentially treatable underlying causes and ruling in a diagnosis of dementia subtype to manage patients and suitably plan for the future. Objectives This analysis sought to determine the appropriate use of neuroimaging during the diagnostic work-up of dementia, including indications for neuroimaging and comparative accuracy of alternative technologies. Data Sources A literature search was performed using Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid Embase, the Wiley Cochrane Library, and the Centre for Reviews and Dissemination database, for studies published between 2000 and 2013. Review Methods Data on diagnostic accuracy and impact on clinical decision making were abstracted from included studies. Quality of evidence was assessed using GRADE. Results The search yielded 5,374 citations and 15 studies were included. Approximately 10% of dementia cases are potentially treatable, though less than 1% reverse partially or fully. Neither prediction rules nor clinical indications reliably select the subset of patients who will likely benefit from neuroimaging. Clinical utility is highest in ambiguous cases or where dementia may be mixed, and lowest for clinically diagnosed Alzheimer disease or clinically excluded vascular dementia. There is a lack of evidence that MRI is superior to CT in detecting a vascular component to dementia. Accuracy of structural imaging is moderate to high for discriminating different types of dementia. Limitations There was significant heterogeneity in estimates of diagnostic accuracy, which often prohibited a statistical summary of findings. The quality of data reported by studies prohibited calculation of likelihood ratios in the present analysis. No studies from primary care were found; thus, generalizability beyond tertiary care settings may be limited. Conclusions A diagnosis of reversible dementia is rare. Imaging has the most

  14. Understanding Actions of Others: The Electrodynamics of the Left and Right Hemispheres. A High-Density EEG Neuroimaging Study

    Science.gov (United States)

    Ortigue, Stephanie; Sinigaglia, Corrado; Rizzolatti, Giacomo; Grafton, Scott T.

    2010-01-01

    Background When we observe an individual performing a motor act (e.g. grasping a cup) we get two types of information on the basis of how the motor act is done and the context: what the agent is doing (i.e. grasping) and the intention underlying it (i.e. grasping for drinking). Here we examined the temporal dynamics of the brain activations that follow the observation of a motor act and underlie the observer's capacity to understand what the agent is doing and why. Methodology/Principal Findings Volunteers were presented with two-frame video-clips. The first frame (T0) showed an object with or without context; the second frame (T1) showed a hand interacting with the object. The volunteers were instructed to understand the intention of the observed actions while their brain activity was recorded with a high-density 128-channel EEG system. Visual event-related potentials (VEPs) were recorded time-locked with the frame showing the hand-object interaction (T1). The data were analyzed by using electrical neuroimaging, which combines a cluster analysis performed on the group-averaged VEPs with the localization of the cortical sources that give rise to different spatio-temporal states of the global electrical field. Electrical neuroimaging results revealed four major steps: 1) bilateral posterior cortical activations; 2) a strong activation of the left posterior temporal and inferior parietal cortices with almost a complete disappearance of activations in the right hemisphere; 3) a significant increase of the activations of the right temporo-parietal region with simultaneously co-active left hemispheric sources, and 4) a significant global decrease of cortical activity accompanied by the appearance of activation of the orbito-frontal cortex. Conclusions/Significance We conclude that the early striking left hemisphere involvement is due to the activation of a lateralized action-observation/action execution network. The activation of this lateralized network mediates the

  15. Understanding actions of others: the electrodynamics of the left and right hemispheres. A high-density EEG neuroimaging study.

    Directory of Open Access Journals (Sweden)

    Stephanie Ortigue

    Full Text Available BACKGROUND: When we observe an individual performing a motor act (e.g. grasping a cup we get two types of information on the basis of how the motor act is done and the context: what the agent is doing (i.e. grasping and the intention underlying it (i.e. grasping for drinking. Here we examined the temporal dynamics of the brain activations that follow the observation of a motor act and underlie the observer's capacity to understand what the agent is doing and why. METHODOLOGY/PRINCIPAL FINDINGS: Volunteers were presented with two-frame video-clips. The first frame (T0 showed an object with or without context; the second frame (T1 showed a hand interacting with the object. The volunteers were instructed to understand the intention of the observed actions while their brain activity was recorded with a high-density 128-channel EEG system. Visual event-related potentials (VEPs were recorded time-locked with the frame showing the hand-object interaction (T1. The data were analyzed by using electrical neuroimaging, which combines a cluster analysis performed on the group-averaged VEPs with the localization of the cortical sources that give rise to different spatio-temporal states of the global electrical field. Electrical neuroimaging results revealed four major steps: 1 bilateral posterior cortical activations; 2 a strong activation of the left posterior temporal and inferior parietal cortices with almost a complete disappearance of activations in the right hemisphere; 3 a significant increase of the activations of the right temporo-parietal region with simultaneously co-active left hemispheric sources, and 4 a significant global decrease of cortical activity accompanied by the appearance of activation of the orbito-frontal cortex. CONCLUSIONS/SIGNIFICANCE: We conclude that the early striking left hemisphere involvement is due to the activation of a lateralized action-observation/action execution network. The activation of this lateralized network

  16. Neurofunctional systems. 3D reconstructions with correlated neuroimaging

    International Nuclear Information System (INIS)

    Kretschmann, H.J.; Fiekert, W.; Gerke, M.; Vogt, H.; Weirich, D.; Wesemann, M.; Weinrich, W.

    1998-01-01

    This book introduces, for the first time, computer-generated images of the neurofunctional systems of the human brain. These images are more accurate than drawings. The main views presented are of the medial lemniscus system, auditory system, visual system, basal ganglia, corticospinal system, and the limbic system. The arteries and sulci of the cerebral hemispheres are also illustrated by computer. These images provide a three-dimensional orientation of the intracranial space and help, for example, to assess vascular functional disturbance of the brain. Clinicians will find these images valuable for the spatial interpretation of magnetic resonance (MR), computed tomography (CT), and positron emission tomography (PET) images since many neurofunctional systems cannot be visualized as isolated structures in neuroimaging. Computer-assisted surface reconstructions of the neurofunctional systems and the cerebral arteries serve as a basis for constructing these computer-generated images. The surface reconstructions are anatomically realistic having been created from brain sections with minimal deformations. The method of computer graphics, known as ray tracing, produces digital images form these reconstructions. The computer-generated methods are explained. The computer-generated images are accompanied by illustrations and texts on neuroanatomy and clinical practice. The neurofunctional systems of the human brain are also shown in sections so that the reader can mentally reconstruct the neurofunctional systems, thus facilitating the transformation of information into textbooks and atlantes of MR and CT imaging. The aim of this book is acquaint the reader with the three-dimensional aspects of the neurofunctional systems and the cerebral arteries of the human brain using methods of computer graphics. Computer scientists and those interested in this technique are provided with basic neuroanatomic and neurofunctional information. Physicians will have a clearer understanding

  17. Neurofunctional systems. 3D reconstructions with correlated neuroimaging

    Energy Technology Data Exchange (ETDEWEB)

    Kretschmann, H.J.; Fiekert, W.; Gerke, M.; Vogt, H.; Weirich, D.; Wesemann, M. [Medizinische Hochschule Hannover (Germany). Abt. Neuroanatomie; Weinrich, W. [Staedtisches Krankenhaus Nordstadt, Hannover (Germany). Abt. fuer Neurologie

    1998-12-31

    This book introduces, for the first time, computer-generated images of the neurofunctional systems of the human brain. These images are more accurate than drawings. The main views presented are of the medial lemniscus system, auditory system, visual system, basal ganglia, corticospinal system, and the limbic system. The arteries and sulci of the cerebral hemispheres are also illustrated by computer. These images provide a three-dimensional orientation of the intracranial space and help, for example, to assess vascular functional disturbance of the brain. Clinicians will find these images valuable for the spatial interpretation of magnetic resonance (MR), computed tomography (CT), and positron emission tomography (PET) images since many neurofunctional systems cannot be visualized as isolated structures in neuroimaging. Computer-assisted surface reconstructions of the neurofunctional systems and the cerebral arteries serve as a basis for constructing these computer-generated images. The surface reconstructions are anatomically realistic having been created from brain sections with minimal deformations. The method of computer graphics, known as ray tracing, produces digital images form these reconstructions. The computer-generated methods are explained. The computer-generated images are accompanied by illustrations and texts on neuroanatomy and clinical practice. The neurofunctional systems of the human brain are also shown in sections so that the reader can mentally reconstruct the neurofunctional systems, thus facilitating the transformation of information into textbooks and atlantes of MR and CT imaging. The aim of this book is acquaint the reader with the three-dimensional aspects of the neurofunctional systems and the cerebral arteries of the human brain using methods of computer graphics. Computer scientists and those interested in this technique are provided with basic neuroanatomic and neurofunctional information. Physicians will have a clearer understanding

  18. Assessment: efficacy of transcutaneous electric nerve stimulation in the treatment of pain in neurologic disorders (an evidence-based review): report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology.

    Science.gov (United States)

    Dubinsky, Richard M; Miyasaki, Janis

    2010-01-12

    To determine if transcutaneous electric nerve stimulation (TENS) is efficacious in the treatment of pain in neurologic disorders. We performed a systematic literature search of Medline and the Cochrane Library from inception to April 2009. There are conflicting reports of TENS compared to sham TENS in the treatment of chronic low back pain, with 2 Class II studies showing benefit, but 2 Class I studies and another Class II study not showing benefit. Because the Class I studies are stronger evidence, TENS is established as ineffective for the treatment of chronic low back pain (2 Class I studies). TENS is probably effective in treating painful diabetic neuropathy (2 Class II studies). Transcutaneous electric nerve stimulation (TENS) is not recommended for the treatment of chronic low back pain (Level A). TENS should be considered in the treatment of painful diabetic neuropathy (Level B). Further research into the mechanism of action of TENS is needed, as well as more rigorous studies for determination of efficacy.

  19. The Shepherd's Crook Sign: A New Neuroimaging Pareidolia in Joubert Syndrome.

    Science.gov (United States)

    Manley, Andrew T; Maertens, Paul M

    2015-01-01

    By pareidolically recognizing specific patterns indicative of particular diseases, neuroimagers reinforce their mnemonic strategies and improve their neuroimaging diagnostic skills. Joubert Syndrome (JS) is an autosomal recessive disorder characterized clinically by mental retardation, episodes of abnormal deep and rapid breathing, abnormal eye movements, and ataxia. Many neuroimaging signs characteristic of JS have been reported. In retrospective case study, two consanguineous neonates diagnosed with JS were evaluated with brain magnetic resonance imaging (MRI), computed tomography (CT), and neurosonography. Both cranial ultrasound and MRI of the brain showed the characteristic molar tooth sign. There was a shepherd's crook in the sagittal views of the posterior fossa where the shaft of the crook is made by the brainstem and the pons. The arc of the crook is made by the abnormal superior cerebellar peduncle and cerebellar hemisphere. By ultrasound, the shepherd's crook sign was seen through the posterior fontanelle only. CT imaging also showed the shepherd's crook sign. Neuroimaging diagnosis of JS, which already involves the pareidolical recognition of specific patterns indicative of the disease, can be improved by recognition of the shepherd's crook sign on MRI, CT, and cranial ultrasound. Copyright © 2014 by the American Society of Neuroimaging.

  20. Integration of a neuroimaging processing pipeline into a pan-canadian computing grid

    International Nuclear Information System (INIS)

    Lavoie-Courchesne, S; Chouinard-Decorte, F; Doyon, J; Bellec, P; Rioux, P; Sherif, T; Rousseau, M-E; Das, S; Adalat, R; Evans, A C; Craddock, C; Margulies, D; Chu, C; Lyttelton, O

    2012-01-01

    The ethos of the neuroimaging field is quickly moving towards the open sharing of resources, including both imaging databases and processing tools. As a neuroimaging database represents a large volume of datasets and as neuroimaging processing pipelines are composed of heterogeneous, computationally intensive tools, such open sharing raises specific computational challenges. This motivates the design of novel dedicated computing infrastructures. This paper describes an interface between PSOM, a code-oriented pipeline development framework, and CBRAIN, a web-oriented platform for grid computing. This interface was used to integrate a PSOM-compliant pipeline for preprocessing of structural and functional magnetic resonance imaging into CBRAIN. We further tested the capacity of our infrastructure to handle a real large-scale project. A neuroimaging database including close to 1000 subjects was preprocessed using our interface and publicly released to help the participants of the ADHD-200 international competition. This successful experiment demonstrated that our integrated grid-computing platform is a powerful solution for high-throughput pipeline analysis in the field of neuroimaging.

  1. ABrIL - Advanced Brain Imaging Lab : a cloud based computation environment for cooperative neuroimaging projects.

    Science.gov (United States)

    Neves Tafula, Sérgio M; Moreira da Silva, Nádia; Rozanski, Verena E; Silva Cunha, João Paulo

    2014-01-01

    Neuroscience is an increasingly multidisciplinary and highly cooperative field where neuroimaging plays an important role. Neuroimaging rapid evolution is demanding for a growing number of computing resources and skills that need to be put in place at every lab. Typically each group tries to setup their own servers and workstations to support their neuroimaging needs, having to learn from Operating System management to specific neuroscience software tools details before any results can be obtained from each setup. This setup and learning process is replicated in every lab, even if a strong collaboration among several groups is going on. In this paper we present a new cloud service model - Brain Imaging Application as a Service (BiAaaS) - and one of its implementation - Advanced Brain Imaging Lab (ABrIL) - in the form of an ubiquitous virtual desktop remote infrastructure that offers a set of neuroimaging computational services in an interactive neuroscientist-friendly graphical user interface (GUI). This remote desktop has been used for several multi-institution cooperative projects with different neuroscience objectives that already achieved important results, such as the contribution to a high impact paper published in the January issue of the Neuroimage journal. The ABrIL system has shown its applicability in several neuroscience projects with a relatively low-cost, promoting truly collaborative actions and speeding up project results and their clinical applicability.

  2. Lin4Neuro: a customized Linux distribution ready for neuroimaging analysis.

    Science.gov (United States)

    Nemoto, Kiyotaka; Dan, Ippeita; Rorden, Christopher; Ohnishi, Takashi; Tsuzuki, Daisuke; Okamoto, Masako; Yamashita, Fumio; Asada, Takashi

    2011-01-25

    A variety of neuroimaging software packages have been released from various laboratories worldwide, and many researchers use these packages in combination. Though most of these software packages are freely available, some people find them difficult to install and configure because they are mostly based on UNIX-like operating systems. We developed a live USB-bootable Linux package named "Lin4Neuro." This system includes popular neuroimaging analysis tools. The user interface is customized so that even Windows users can use it intuitively. The boot time of this system was only around 40 seconds. We performed a benchmark test of inhomogeneity correction on 10 subjects of three-dimensional T1-weighted MRI scans. The processing speed of USB-booted Lin4Neuro was as fast as that of the package installed on the hard disk drive. We also installed Lin4Neuro on a virtualization software package that emulates the Linux environment on a Windows-based operation system. Although the processing speed was slower than that under other conditions, it remained comparable. With Lin4Neuro in one's hand, one can access neuroimaging software packages easily, and immediately focus on analyzing data. Lin4Neuro can be a good primer for beginners of neuroimaging analysis or students who are interested in neuroimaging analysis. It also provides a practical means of sharing analysis environments across sites.

  3. Sex Differences in Trauma-Related Psychopathology: a Critical Review of Neuroimaging Literature (2014-2017).

    Science.gov (United States)

    Helpman, Liat; Zhu, Xi; Suarez-Jimenez, Benjamin; Lazarov, Amit; Monk, Catherine; Neria, Yuval

    2017-11-08

    Sex differences in the epidemiology and clinical presentation of trauma-related psychopathology have long been documented. Multiple underlying mechanisms have been examined, both psychosocial and biological. Among the most promising biological mechanisms are neural substrates of trauma-related psychopathology that have been uncovered in recent years. Neuroimaging studies of sex-related heterogeneity published over the past 3 years (2014-2017) demonstrate an interaction between sex and type, timing, and load of trauma exposure. These studies suggest that, for males, early trauma exposure may involve a loss of gray matter in the limbic system, including the prefrontal cortex (PFC), amygdala, and hippocampus, and an over-activity and increased connectivity of salience hubs, and particularly dorsal anterior cingulate cortex (dACC). For females, however, early trauma exposure may involve overactive and possibly an enlarged amygdala, as well as decreased connectivity of salience hubs such as the dACC. Underlying mechanisms may include interaction with several endocrine systems and result in differential neural response to naturally occurring and added endocrine ligands, as well as sex-specific genetic and epigenetic risk and resilience factors. This complex interaction between multiple biological systems may be associated with sex-specific behavioral patterns, in turn associated with trauma-related psychopathology. While substantial number of published studies present preliminary evidence for neural mechanisms of sex-specific posttraumatic responses, there is a paucity of research directly designed to examine sex as a biological factor in trauma-related psychopathology. Specific foci for future studies aiming to bridge current gaps in the literature are discussed.

  4. A general XML schema and SPM toolbox for storage of neuro-imaging results and anatomical labels.

    Science.gov (United States)

    Keator, David Bryant; Gadde, Syam; Grethe, Jeffrey S; Taylor, Derek V; Potkin, Steven G

    2006-01-01

    With the increased frequency of multisite, large-scale collaborative neuro-imaging studies, the need for a general, self-documenting framework for the storage and retrieval of activation maps and anatomical labels becomes evident. To address this need, we have developed and extensible markup language (XML) schema and associated tools for the storage of neuro-imaging activation maps and anatomical labels. This schema, as part of the XML-based Clinical Experiment Data Exchange (XCEDE) schema, provides storage capabilities for analysis annotations, activation threshold parameters, and cluster and voxel-level statistics. Activation parameters contain information describing the threshold, degrees of freedom, FWHM smoothness, search volumes, voxel sizes, expected voxels per cluster, and expected number of clusters in the statistical map. Cluster and voxel statistics can be stored along with the coordinates, threshold, and anatomical label information. Multiple threshold types can be documented for a given cluster or voxel along with the uncorrected and corrected probability values. Multiple atlases can be used to generate anatomical labels and stored for each significant voxel or cluter. Additionally, a toolbox for Statistical Parametric Mapping software (http://www. fil. ion.ucl.ac.uk/spm/) was created to capture the results from activation maps using the XML schema that supports both SPM99 and SPM2 versions (http://nbirn.net/Resources/Users/ Applications/xcede/SPM_XMLTools.htm). Support for anatomical labeling is available via the Talairach Daemon (http://ric.uthscsa. edu/projects/talairachdaemon.html) and Automated Anatomical Labeling (http://www. cyceron.fr/freeware/).

  5. Mind-Body Practices and the Adolescent Brain: Clinical Neuroimaging Studies.

    Science.gov (United States)

    Sharma, Anup; Newberg, Andrew B

    Mind-Body practices constitute a large and diverse group of practices that can substantially affect neurophysiology in both healthy individuals and those with various psychiatric disorders. In spite of the growing literature on the clinical and physiological effects of mind-body practices, very little is known about their impact on central nervous system (CNS) structure and function in adolescents with psychiatric disorders. This overview highlights findings in a select group of mind-body practices including yoga postures, yoga breathing techniques and meditation practices. Mind-body practices offer novel therapeutic approaches for adolescents with psychiatric disorders. Findings from these studies provide insights into the design and implementation of neuroimaging studies for adolescents with psychiatric disorders. Clinical neuroimaging studies will be critical in understanding how different practices affect disease pathogenesis and symptomatology in adolescents. Neuroimaging of mind-body practices on adolescents with psychiatric disorders will certainly be an open and exciting area of investigation.

  6. Electrical stimulation of the dorsolateral prefrontal cortex improves memory monitoring.

    Science.gov (United States)

    Chua, Elizabeth F; Ahmed, Rifat

    2016-05-01

    The ability to accurately monitor one's own memory is an important feature of normal memory function. Converging evidence from neuroimaging and lesion studies have implicated the dorsolateral prefrontal cortex (DLPFC) in memory monitoring. Here we used high definition transcranial direct stimulation (HD-tDCS), a non-invasive form of brain stimulation, to test whether the DLPFC has a causal role in memory monitoring, and the nature of that role. We used a metamemory monitoring task, in which participants first attempted to recall the answer to a general knowledge question, then gave a feeling-of-knowing (FOK) judgment, followed by a forced choice recognition task. When participants received DLPFC stimulation, their feeling-of-knowing judgments were better predictors of memory performance, i.e., they had better memory monitoring accuracy, compared to stimulation of a control site, the anterior temporal lobe (ATL). Effects of DLPFC stimulation were specific to monitoring accuracy, as there was no significant increase in memory performance, and if anything, there was poorer memory performance with DLPFC stimulation. Thus we have demonstrated a causal role for the DLPFC in memory monitoring, and showed that electrically stimulating the left DLPFC led people to more accurately monitor and judge their own memory. Copyright © 2016 Elsevier Ltd. All rights reserved.

  7. Neuroimaging in pediatric traumatic head injury: diagnostic considerations and relationships to neurobehavioral outcome.

    Science.gov (United States)

    Bigler, E D

    1999-08-01

    Contemporary neuorimaging techniques in child traumatic brain injury are reviewed, with an emphasis on computerized tomography (CT) and magnetic resonance (MR) imaging. A brief overview of MR spectroscopy (MRS), functional MR imaging (fMRI), single-photon emission computed tomography (SPECT), and magnetoencephalography (MEG) is also provided because these techniques will likely constitute important neuroimaging techniques of the future. Numerous figures are provided to illustrate the multifaceted manner in which traumatic deficits can be imaged and the role of neuroimaging information as it relates to TBI outcome.

  8. Neuroimaging studies of aggressive and violent behavior: current findings and implications for criminology and criminal justice.

    Science.gov (United States)

    Bufkin, Jana L; Luttrell, Vickie R

    2005-04-01

    With the availability of new functional and structural neuroimaging techniques, researchers have begun to localize brain areas that may be dysfunctional in offenders who are aggressive and violent. Our review of 17 neuroimaging studies reveals that the areas associated with aggressive and/or violent behavioral histories, particularly impulsive acts, are located in the prefrontal cortex and the medial temporal regions. These findings are explained in the context of negative emotion regulation, and suggestions are provided concerning how such findings may affect future theoretical frameworks in criminology, crime prevention efforts, and the functioning of the criminal justice system.

  9. Sex differences in brain activation to emotional stimuli: a meta-analysis of neuroimaging studies.

    Science.gov (United States)

    Stevens, Jennifer S; Hamann, Stephan

    2012-06-01

    Substantial sex differences in emotional responses and perception have been reported in previous psychological and psychophysiological studies. For example, women have been found to respond more strongly to negative emotional stimuli, a sex difference that has been linked to an increased risk of depression and anxiety disorders. The extent to which such sex differences are reflected in corresponding differences in regional brain activation remains a largely unresolved issue, however, in part because relatively few neuroimaging studies have addressed this issue. Here, by conducting a quantitative meta-analysis of neuroimaging studies, we were able to substantially increase statistical power to detect sex differences relative to prior studies, by combining emotion studies which explicitly examined sex differences with the much larger number of studies that examined only women or men. We used an activation likelihood estimation approach to characterize sex differences in the likelihood of regional brain activation elicited by emotional stimuli relative to non-emotional stimuli. We examined sex differences separately for negative and positive emotions, in addition to examining all emotions combined. Sex differences varied markedly between negative and positive emotion studies. The majority of sex differences favoring women were observed for negative emotion, whereas the majority of the sex differences favoring men were observed for positive emotion. This valence-specificity was particularly evident for the amygdala. For negative emotion, women exhibited greater activation than men in the left amygdala, as well as in other regions including the left thalamus, hypothalamus, mammillary bodies, left caudate, and medial prefrontal cortex. In contrast, for positive emotion, men exhibited greater activation than women in the left amygdala, as well as greater activation in other regions including the bilateral inferior frontal gyrus and right fusiform gyrus. These meta

  10. Evolutionary conservativeness of electric field in the Cu,Zn superoxide dismutase active site. Evidence for co-ordinated mutation of charged amino acid residues.

    Science.gov (United States)

    Desideri, A; Falconi, M; Polticelli, F; Bolognesi, M; Djinovic, K; Rotilio, G

    1992-01-05

    Equipotential lines were calculated, using the Poisson-Boltzmann equation, for six Cu,Zn superoxide dismutases with different protein electric charge and various degrees of sequence homology, namely those from ox, pig, sheep, yeast, and the isoenzymes A and B from the amphibian Xenopus laevis. The three-dimensional structures of the porcine and ovine superoxide dismutases were obtained by molecular modelling reconstruction using the structure of the highly homologous bovine enzyme as a template. The three-dimensional structure of the evolutionary distant yeast Cu,Zn superoxide dismutase was recently resolved by us, while computer-modelled structures are available for X. laevis isoenzymes. The six proteins display large differences in the net protein charge and distribution of electrically charged surface residues but the trend of the equipotential lines in the proximity of the active sites was found to be constant in all cases. These results are in line with the very similar catlytic rate constants experimentally measured for the corresponding enzyme activities. This analysis shows that electrostatic guidance for the enzyme-substrate interaction in Cu,Zn superoxide dismutases is related to a spatial distribution of charges, arranged so as to maintain, in the area surrounding the active sites, an identical electrostatic potential distribution, which is conserved in the evolution of this protein family.

  11. EFNS Task Force on Teaching of Neuroimaging in Neurology Curricula in Europe : present status and recommendations for the future

    NARCIS (Netherlands)

    Pantano, P; Chollet, F; Paulson, O; von Kummer, R; Laihinen, A; Leenders, K; Yancheva, S

    A Task Force on 'Teaching of Neuroimaging in Neurology Curricula in Europe' was appointed in September 1998 by the education committee of the European Federation of Neurological Societies (EFNS) in order to: (1) examine the present status of teaching of neuroimaging in the training of neurology in

  12. EFNS Task Force on Teaching of Neuroimaging in Neurology Curricula in Europe : present status and recommendations for the future

    NARCIS (Netherlands)

    Pantano, P; Chollet, F; Paulson, O; von Kummer, R; Laihinen, A; Leenders, K; Yancheva, S

    2001-01-01

    A Task Force on 'Teaching of Neuroimaging in Neurology Curricula in Europe' was appointed in September 1998 by the education committee of the European Federation of Neurological Societies (EFNS) in order to: (1) examine the present status of teaching of neuroimaging in the training of neurology in

  13. Brain morphometry and the neurobiology of levodopa-induced dyskinesias: current knowledge and future potential for translational pre-clinical neuroimaging studies.

    Directory of Open Access Journals (Sweden)

    Clare eFinlay

    2014-06-01

    Full Text Available Dopamine replacement therapy in the form of levodopa results in a significant proportion of patients with Parkinson's disease (PD developing debilitating dyskinesia. This significantly complicates further treatment and negatively impacts patient quality of life. A greater understanding of the neurobiological mechanisms underlying levodopa-induced dyskinesia (LID is therefore crucial to develop new treatments to prevent or mitigate LID. Such investigations in humans are largely confined to assessment of neurochemical and cerebrovascular blood flow changes using positron emission tomography (PET and functional magnetic resonance imaging (fMRI. However, recent evidence suggests that LID is associated with specific morphological changes in the frontal cortex and midbrain, detectable by structural MRI and voxel-based morphometry (VBM. Current human neuroimaging methods however lack sufficient resolution to reveal the biological mechanism driving these morphological changes at the cellular level. In contrast, there is a wealth of literature from well-established rodent models of LID documenting detailed post-mortem cellular and molecular measurements. The combination therefore of advanced neuroimaging methods and rodent LID models offers an exciting opportunity to bridge these currently disparate areas of research. To highlight this opportunity, in this mini-review, we provide an overview of the current clinical evidence for morphological changes in the brain associated with LID and identify potential cellular mechanisms as suggested from human and animal studies. We then suggest a framework for combining small animal MRI imaging with rodent models of LID, which may provide important mechanistic insights into the neurobiology of LID.

  14. Correlation analysis of findings from neuroimaging and histopathology in focal cortical dysplasia

    International Nuclear Information System (INIS)

    Ma Mingping; Fan Jianzhong; Jiang Zirong; Bao Qiang; Du Ruibin; Ritter, J.L.

    2009-01-01

    Objective: To characterize neuroimaging features of focal cortical dysplasia (FCD) retrospectively and correlate those with pathological findings, which may improve our understanding of neuroimaging characteristics of FCD. Methods: Clinical information and neuroimaging findings of 28 cases with FCD proved by pathology were retrospectively reviewed, and neuroimaging features of FCD were correlated with the pathological changes. Results: MRI revealed abnormal changes in 24 of 28 patients (85.7%) and no abnormalities were observed in 4 cases. Focal cortical thickening and blurring of the gray- white matter junction were the major features of FCD on MRI. Accompanied abnormal MR signals can also be observed in cortical or subcortical white matter in FCD. The radial band of hyperintensity in subcortical white matter tapering to the ventricle is one of the characteristic features of FCD on MRI. On FDG-PET examination, focal hypometabolism were revealed in 9 of 14 cases (64.3%). Histologically, cortical dyslamination was accompanied by various degrees of dysmorphic neurons and balloon cells in cortical and subcortical areas. Subcortical white matter dysmyelination and spongiotic necrotic changes were found in some cases with FCD. Conclusion: High resolution MRI can reveal most of the lesions in FCD, including abnormal changes of cortical and subcortical white matter, which makes MRI the best pre-operation examination for FCD. (authors)

  15. Adolescent Schizophrenia: A Methodologic Review of the Current Neuroimaging and Neuropsychologic Literature.

    Science.gov (United States)

    Findling, Robert L.; And Others

    1995-01-01

    This paper reviews the methodology in articles that have reported structural neuroimaging or neuropsychological data in adolescent patients with schizophrenia. Identification of methodological issues led to the finding that, at present, no conclusions can be made regarding the presence or absence of neuropsychologic dysfunction or structural…

  16. Reading the Freudian theory of sexual drives from a functional neuroimaging perspective

    Directory of Open Access Journals (Sweden)

    Serge eStoléru

    2014-03-01

    Full Text Available One of the essential tasks of neuropsychoanalysis is to investigate the neural correlates of sexual drives. Here, we consider the four defining characteristics of sexual drives as delineated by Freud: their pressure, aim, object, and source. We systematically examine the relations between these characteristics and the four-component neurophenomenological model that we have proposed based on functional neuroimaging studies, which comprises a cognitive, a motivational, an emotional and an autonomic/neuroendocrine component. Functional neuroimaging studies of sexual arousal have thrown a new light on the four fundamental characteristics of sexual drives by identifying their potential neural correlates. While these studies are essentally consistent with the Freudian model of drives, the main difference emerging between the functional neuroimaging perspective on sexual drives and the Freudian theory relates to the source of drives. From a functional neuroimaging perspective sources of sexual drives, conceived by psychoanalysis as processes of excitation occurring in a peripheral organ, do not seem, at least in adult subjects, to be an essential part of the determinants of sexual arousal. It is rather the central processing of visual or genital stimuli that gives to these stimuli their sexually arousing and sexually pleasurable character.

  17. Data mining a functional neuroimaging database for functional segregation in brain regions

    DEFF Research Database (Denmark)

    Nielsen, Finn Årup; Balslev, Daniela; Hansen, Lars Kai

    2006-01-01

    We describe a specialized neuroinformatic data mining technique in connection with a meta-analytic functional neuroimaging database: We mine for functional segregation within brain regions by identifying journal articles that report brain activations within the regions and clustering the abstract...

  18. Exploring responsible innovation : Dutch public perceptions of the future of medical neuroimaging technology

    NARCIS (Netherlands)

    Arentshorst, Marlous E.; Broerse, Jacqueline E W; de Cock Buning, J.T.

    2016-01-01

    Insight into public perceptions provides opportunities to take public desires and concerns into account in an early phase of innovation development in order to maximise the potential benefits for users of the future. Public perceptions of neuroimaging in health care are presented in this article,

  19. Attention to pain! A neurocognitive perspective on attentional modulation of pain in neuroimaging studies.

    Science.gov (United States)

    Torta, D M; Legrain, V; Mouraux, A; Valentini, E

    2017-04-01

    Several studies have used neuroimaging techniques to investigate brain correlates of the attentional modulation of pain. Although these studies have advanced the knowledge in the field, important confounding factors such as imprecise theoretical definitions of attention, incomplete operationalization of the construct under exam, and limitations of techniques relying on measuring regional changes in cerebral blood flow have hampered the potential relevance of the conclusions. Here, we first provide an overview of the major theories of attention and of attention in the study of pain to bridge theory and experimental results. We conclude that load and motivational/affective theories are particularly relevant to study the attentional modulation of pain and should be carefully integrated in functional neuroimaging studies. Then, we summarize previous findings and discuss the possible neural correlates of the attentional modulation of pain. We discuss whether classical functional neuroimaging techniques are suitable to measure the effect of a fluctuating process like attention, and in which circumstances functional neuroimaging can be reliably used to measure the attentional modulation of pain. Finally, we argue that the analysis of brain networks and spontaneous oscillations may be a crucial future development in the study of attentional modulation of pain, and why the interplay between attention and pain, as examined so far, may rely on neural mechanisms shared with other sensory modalities. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. An empirical comparison of different approaches for combining multimodal neuroimaging data with support vector machine

    NARCIS (Netherlands)

    Pettersson-Yeo, W.; Benetti, S.; Marquand, A.F.; Joules, R.; Catani, M.; Williams, S.C.; Allen, P.; McGuire, P.; Mechelli, A.

    2014-01-01

    In the pursuit of clinical utility, neuroimaging researchers of psychiatric and neurological illness are increasingly using analyses, such as support vector machine, that allow inference at the single-subject level. Recent studies employing single-modality data, however, suggest that classification

  1. Identifying predictors, moderators, and mediators of antidepressant response in major depressive disorder: neuroimaging approaches.

    Science.gov (United States)

    Phillips, Mary L; Chase, Henry W; Sheline, Yvette I; Etkin, Amit; Almeida, Jorge R C; Deckersbach, Thilo; Trivedi, Madhukar H

    2015-02-01

    Despite significant advances in neuroscience and treatment development, no widely accepted biomarkers are available to inform diagnostics or identify preferred treatments for individuals with major depressive disorder. In this critical review, the authors examine the extent to which multimodal neuroimaging techniques can identify biomarkers reflecting key pathophysiologic processes in depression and whether such biomarkers may act as predictors, moderators, and mediators of treatment response that might facilitate development of personalized treatments based on a better understanding of these processes. The authors first highlight the most consistent findings from neuroimaging studies using different techniques in depression, including structural and functional abnormalities in two parallel neural circuits: serotonergically modulated implicit emotion regulation circuitry, centered on the amygdala and different regions in the medial prefrontal cortex; and dopaminergically modulated reward neural circuitry, centered on the ventral striatum and medial prefrontal cortex. They then describe key findings from the relatively small number of studies indicating that specific measures of regional function and, to a lesser extent, structure in these neural circuits predict treatment response in depression. Limitations of existing studies include small sample sizes, use of only one neuroimaging modality, and a focus on identifying predictors rather than moderators and mediators of differential treatment response. By addressing these limitations and, most importantly, capitalizing on the benefits of multimodal neuroimaging, future studies can yield moderators and mediators of treatment response in depression to facilitate significant improvements in shorter- and longer-term clinical and functional outcomes.

  2. Integrating Functional Brain Neuroimaging and Developmental Cognitive Neuroscience in Child Psychiatry Research

    Science.gov (United States)

    Pavuluri, Mani N.; Sweeney, John A.

    2008-01-01

    The use of cognitive neuroscience and functional brain neuroimaging to understand brain dysfunction in pediatric psychiatric disorders is discussed. Results show that bipolar youths demonstrate impairment in affective and cognitive neural systems and in these two circuits' interface. Implications for the diagnosis and treatment of psychiatric…

  3. The ENIGMA Consortium : large-scale collaborative analyses of neuroimaging and genetic data

    NARCIS (Netherlands)

    Thompson, Paul M.; Stein, Jason L.; Medland, Sarah E.; Hibar, Derrek P.; Vasquez, Alejandro Arias; Renteria, Miguel E.; Toro, Roberto; Jahanshad, Neda; Schumann, Gunter; Franke, Barbara; Wright, Margaret J.; Martin, Nicholas G.; Agartz, Ingrid; Alda, Martin; Alhusaini, Saud; Almasy, Laura; Almeida, Jorge; Alpert, Kathryn; Andreasen, Nancy C.; Andreassen, Ole A.; Apostolova, Liana G.; Appel, Katja; Armstrong, Nicola J.; Aribisala, Benjamin; Bastin, Mark E.; Bauer, Michael; Bearden, Carrie E.; Bergmann, Orjan; Binder, Elisabeth B.; Blangero, John; Bockholt, Henry J.; Boen, Erlend; Bois, Catherine; Boomsma, Dorret I.; Booth, Tom; Bowman, Ian J.; Bralten, Janita; Brouwer, Rachel M.; Brunner, Han G.; Brohawn, David G.; Buckner, Randy L.; Buitelaar, Jan; Bulayeva, Kazima; Bustillo, Juan R.; Calhoun, Vince D.; Hartman, Catharina A.; Hoekstra, Pieter J.; Penninx, Brenda W.; Schmaal, Lianne; van Tol, Marie-Jose

    The Enhancing NeuroImaging Genetics through Meta-Analysis (ENIGMA) Consortium is a collaborative network of researchers working together on a range of large-scale studies that integrate data from 70 institutions worldwide. Organized into Working Groups that tackle questions in neuroscience,

  4. The ENIGMA Consortium: large-scale collaborative analyses of neuroimaging and genetic data

    NARCIS (Netherlands)

    Thompson, Paul M.; Stein, Jason L.; Medland, Sarah E.; Hibar, Derrek P.; Vasquez, Alejandro Arias; Renteria, Miguel E.; Toro, Roberto; Jahanshad, Neda; Schumann, Gunter; Franke, Barbara; Wright, Margaret J.; Martin, Nicholas G.; Agartz, Ingrid; Alda, Martin; Alhusaini, Saud; Almasy, Laura; Almeida, Jorge; Alpert, Kathryn; Andreasen, Nancy C.; Andreassen, Ole A.; Apostolova, Liana G.; Appel, Katja; Armstrong, Nicola J.; Aribisala, Benjamin; Bastin, Mark E.; Bauer, Michael; Bearden, Carrie E.; Bergmann, Orjan; Binder, Elisabeth B.; Blangero, John; Bockholt, Henry J.; Bøen, Erlend; Bois, Catherine; Boomsma, Dorret I.; Booth, Tom; Bowman, Ian J.; Bralten, Janita; Brouwer, Rachel M.; Brunner, Han G.; Brohawn, David G.; Buckner, Randy L.; Buitelaar, Jan; Bulayeva, Kazima; Bustillo, Juan R.; Calhoun, Vince D.; Cannon, Dara M.; Cantor, Rita M.; Carless, Melanie A.; Caseras, Xavier; Cavalleri, Gianpiero L.; Chakravarty, M. Mallar; Chang, Kiki D.; Ching, Christopher R. K.; Christoforou, Andrea; Cichon, Sven; Clark, Vincent P.; Conrod, Patricia; Coppola, Giovanni; Crespo-Facorro, Benedicto; Curran, Joanne E.; Czisch, Michael; Deary, Ian J.; de Geus, Eco J. C.; den Braber, Anouk; Delvecchio, Giuseppe; Depondt, Chantal; de Haan, Lieuwe; de Zubicaray, Greig I.; Dima, Danai; Dimitrova, Rali; Djurovic, Srdjan; Dong, Hongwei; Donohoe, Gary; Duggirala, Ravindranath; Dyer, Thomas D.; Ehrlich, Stefan; Ekman, Carl Johan; Elvsåshagen, Torbjørn; Emsell, Louise; Erk, Susanne; Espeseth, Thomas; Fagerness, Jesen; Fears, Scott; Fedko, Iryna; Fernández, Guillén; Fisher, Simon E.; Foroud, Tatiana; Fox, Peter T.; Francks, Clyde; Frangou, Sophia; Frey, Eva Maria; Frodl, Thomas; Frouin, Vincent; Garavan, Hugh; Giddaluru, Sudheer; Glahn, David C.; Godlewska, Beata; Goldstein, Rita Z.; Gollub, Randy L.; Grabe, Hans J.; Grimm, Oliver; Gruber, Oliver; Guadalupe, Tulio; Gur, Raquel E.; Gur, Ruben C.; Göring, Harald H. H.; Hagenaars, Saskia; Hajek, Tomas; Hall, Geoffrey B.; Hall, Jeremy; Hardy, John; Hartman, Catharina A.; Hass, Johanna; Hatton, Sean N.; Haukvik, Unn K.; Hegenscheid, Katrin; Heinz, Andreas; Hickie, Ian B.; Ho, Beng-Choon; Hoehn, David; Hoekstra, Pieter J.; Hollinshead, Marisa; Holmes, Avram J.; Homuth, Georg; Hoogman, Martine; Hong, L. Elliot; Hosten, Norbert; Hottenga, Jouke-Jan; Hulshoff Pol, Hilleke E.; Hwang, Kristy S.; Jack, Clifford R.; Jenkinson, Mark; Johnston, Caroline; Jönsson, Erik G.; Kahn, René S.; Kasperaviciute, Dalia; Kelly, Sinead; Kim, Sungeun; Kochunov, Peter; Koenders, Laura; Krämer, Bernd; Kwok, John B. J.; Lagopoulos, Jim; Laje, Gonzalo; Landen, Mikael; Landman, Bennett A.; Lauriello, John; Lawrie, Stephen M.; Lee, Phil H.; Le Hellard, Stephanie; Lemaître, Herve; Leonardo, Cassandra D.; Li, Chiang-Shan; Liberg, Benny; Liewald, David C.; Liu, Xinmin; Lopez, Lorna M.; Loth, Eva; Lourdusamy, Anbarasu; Luciano, Michelle; Macciardi, Fabio; Machielsen, Marise W. J.; Macqueen, Glenda M.; Malt, Ulrik F.; Mandl, René; Manoach, Dara S.; Martinot, Jean-Luc; Matarin, Mar; Mather, Karen A.; Mattheisen, Manuel; Mattingsdal, Morten; Meyer-Lindenberg, Andreas; McDonald, Colm; McIntosh, Andrew M.; McMahon, Francis J.; McMahon, Katie L.; Meisenzahl, Eva; Melle, Ingrid; Milaneschi, Yuri; Mohnke, Sebastian; Montgomery, Grant W.; Morris, Derek W.; Moses, Eric K.; Mueller, Bryon A.; Muñoz Maniega, Susana; Mühleisen, Thomas W.; Müller-Myhsok, Bertram; Mwangi, Benson; Nauck, Matthias; Nho, Kwangsik; Nichols, Thomas E.; Nilsson, Lars-Göran; Nugent, Allison C.; Nyberg, Lars; Olvera, Rene L.; Oosterlaan, Jaap; Ophoff, Roel A.; Pandolfo, Massimo; Papalampropoulou-Tsiridou, Melina; Papmeyer, Martina; Paus, Tomas; Pausova, Zdenka; Pearlson, Godfrey D.; Penninx, Brenda W.; Peterson, Charles P.; Pfennig, Andrea; Phillips, Mary; Pike, G. Bruce; Poline, Jean-Baptiste; Potkin, Steven G.; Pütz, Benno; Ramasamy, Adaikalavan; Rasmussen, Jerod; Rietschel, Marcella; Rijpkema, Mark; Risacher, Shannon L.; Roffman, Joshua L.; Roiz-Santiañez, Roberto; Romanczuk-Seiferth, Nina; Rose, Emma J.; Royle, Natalie A.; Rujescu, Dan; Ryten, Mina; Sachdev, Perminder S.; Salami, Alireza; Satterthwaite, Theodore D.; Savitz, Jonathan; Saykin, Andrew J.; Scanlon, Cathy; Schmaal, Lianne; Schnack, Hugo G.; Schork, Andrew J.; Schulz, S. Charles; Schür, Remmelt; Seidman, Larry; Shen, Li; Shoemaker, Jody M.; Simmons, Andrew; Sisodiya, Sanjay M.; Smith, Colin; Smoller, Jordan W.; Soares, Jair C.; Sponheim, Scott R.; Sprooten, Emma; Starr, John M.; Steen, Vidar M.; Strakowski, Stephen; Strike, Lachlan; Sussmann, Jessika; Sämann, Philipp G.; Teumer, Alexander; Toga, Arthur W.; Tordesillas-Gutierrez, Diana; Trabzuni, Daniah; Trost, Sarah; Turner, Jessica; van den Heuvel, Martijn; van der Wee, Nic J.; van Eijk, Kristel; van Erp, Theo G. M.; van Haren, Neeltje E. M.; van 't Ent, Dennis; van Tol, Marie-Jose; Valdés Hernández, Maria C.; Veltman, Dick J.; Versace, Amelia; Völzke, Henry; Walker, Robert; Walter, Henrik; Wang, Lei; Wardlaw, Joanna M.; Weale, Michael E.; Weiner, Michael W.; Wen, Wei; Westlye, Lars T.; Whalley, Heather C.; Whelan, Christopher D.; White, Tonya; Winkler, Anderson M.; Wittfeld, Katharina; Woldehawariat, Girma; Wolf, Christiane; Zilles, David; Zwiers, Marcel P.; Thalamuthu, Anbupalam; Schofield, Peter R.; Freimer, Nelson B.; Lawrence, Natalia S.; Drevets, Wayne

    2014-01-01

    The Enhancing NeuroImaging Genetics through Meta-Analysis (ENIGMA) Consortium is a collaborative network of researchers working together on a range of large-scale studies that integrate data from 70 institutions worldwide. Organized into Working Groups that tackle questions in neuroscience,

  5. The ENIGMA Consortium: Large-scale collaborative analyses of neuroimaging and genetic data

    NARCIS (Netherlands)

    P.M. Thompson (Paul); J.L. Stein; S.E. Medland (Sarah Elizabeth); D.P. Hibar (Derrek); A.A. Vásquez (Arias); M.E. Rentería (Miguel); R. Toro (Roberto); N. Jahanshad (Neda); G. Schumann (Gunter); B. Franke (Barbara); M.J. Wright (Margaret); N.G. Martin (Nicholas); I. Agartz (Ingrid); M. Alda (Martin); S. Alhusaini (Saud); L. Almasy (Laura); K. Alpert (Kathryn); N.C. Andreasen; O.A. Andreassen (Ole); L.G. Apostolova (Liana); K. Appel (Katja); N.J. Armstrong (Nicola); B. Aribisala (Benjamin); M.E. Bastin (Mark); M. Bauer (Michael); C.E. Bearden (Carrie); Ø. Bergmann (Ørjan); E.B. Binder (Elisabeth); J. Blangero (John); H.J. Bockholt; E. Bøen (Erlend); M. Bois (Monique); D.I. Boomsma (Dorret); T. Booth (Tom); I.J. Bowman (Ian); L.B.C. Bralten (Linda); R.M. Brouwer (Rachel); H.G. Brunner; D.G. Brohawn (David); M. Buckner; J.K. Buitelaar (Jan); K. Bulayeva (Kazima); J. Bustillo; V.D. Calhoun (Vince); D.M. Cannon (Dara); R.M. Cantor; M.A. Carless (Melanie); X. Caseras (Xavier); G. Cavalleri (Gianpiero); M.M. Chakravarty (M. Mallar); K.D. Chang (Kiki); C.R.K. Ching (Christopher); A. Christoforou (Andrea); S. Cichon (Sven); V.P. Clark; P. Conrod (Patricia); D. Coppola (Domenico); B. Crespo-Facorro (Benedicto); J.E. Curran (Joanne); M. Czisch (Michael); I.J. Deary (Ian); E.J.C. de Geus (Eco); A. den Braber (Anouk); G. Delvecchio (Giuseppe); C. Depondt (Chantal); L. de Haan (Lieuwe); G.I. de Zubicaray (Greig); D. Dima (Danai); R. Dimitrova (Rali); S. Djurovic (Srdjan); H. Dong (Hongwei); D.J. Donohoe (Dennis); A. Duggirala (Aparna); M.D. Dyer (Matthew); S.M. Ehrlich (Stefan); C.J. Ekman (Carl Johan); T. Elvsåshagen (Torbjørn); L. Emsell (Louise); S. Erk; T. Espeseth (Thomas); J. Fagerness (Jesen); S. Fears (Scott); I. Fedko (Iryna); G. Fernandez (Guillén); S.E. Fisher (Simon); T. Foroud (Tatiana); P.T. Fox (Peter); C. Francks (Clyde); S. Frangou (Sophia); E.M. Frey (Eva Maria); T. Frodl (Thomas); V. Frouin (Vincent); H. Garavan (Hugh); S. Giddaluru (Sudheer); D.C. Glahn (David); B. Godlewska (Beata); R.Z. Goldstein (Rita); R.L. Gollub (Randy); H.J. Grabe (Hans Jörgen); O. Grimm (Oliver); O. Gruber (Oliver); T. Guadalupe (Tulio); R.E. Gur (Raquel); R.C. Gur (Ruben); H.H.H. Göring (Harald); S. Hagenaars (Saskia); T. Hajek (Tomas); G.B. Hall (Garry); J. Hall (Jeremy); J. Hardy (John); C.A. Hartman (Catharina); J. Hass (Johanna); W. Hatton; U.K. Haukvik (Unn); K. Hegenscheid (Katrin); J. Heinz (Judith); I.B. Hickie (Ian); B.C. Ho (Beng ); D. Hoehn (David); P.J. Hoekstra (Pieter); M. Hollinshead (Marisa); A.J. Holmes (Avram); G. Homuth (Georg); M. Hoogman (Martine); L.E. Hong (L.Elliot); N. Hosten (Norbert); J.J. Hottenga (Jouke Jan); H.E. Hulshoff Pol (Hilleke); K.S. Hwang (Kristy); C.R. Jack Jr. (Clifford); S. Jenkinson (Sarah); C. Johnston; E.G. Jönsson (Erik); R.S. Kahn (René); D. Kasperaviciute (Dalia); S. Kelly (Steve); S. Kim (Shinseog); P. Kochunov (Peter); L. Koenders (Laura); B. Krämer (Bernd); J.B.J. Kwok (John); J. Lagopoulos (Jim); G. Laje (Gonzalo); M. Landén (Mikael); B.A. Landman (Bennett); J. Lauriello; S. Lawrie (Stephen); P.H. Lee (Phil); S. Le Hellard (Stephanie); H. Lemaître (Herve); C.D. Leonardo (Cassandra); C.-S. Li (Chiang-shan); B. Liberg (Benny); D.C. Liewald (David C.); X. Liu (Xinmin); L.M. Lopez (Lorna); E. Loth (Eva); A. Lourdusamy (Anbarasu); M. Luciano (Michelle); F. MacCiardi (Fabio); M.W.J. Machielsen (Marise); G.M. MacQueen (Glenda); U.F. Malt (Ulrik); R. Mandl (René); D.S. Manoach (Dara); J.-L. Martinot (Jean-Luc); M. Matarin (Mar); R. Mather; M. Mattheisen (Manuel); M. Mattingsdal (Morten); A. Meyer-Lindenberg; C. McDonald (Colm); A.M. McIntosh (Andrew); F.J. Mcmahon (Francis J); K.L. Mcmahon (Katie); E. Meisenzahl (Eva); I. Melle (Ingrid); Y. Milaneschi (Yuri); S. Mohnke (Sebastian); G.W. Montgomery (Grant); D.W. Morris (Derek W); E.K. Moses (Eric); B.A. Mueller (Bryon ); S. Muñoz Maniega (Susana); T.W. Mühleisen (Thomas); B. Müller-Myhsok (Bertram); B. Mwangi (Benson); M. Nauck (Matthias); K. Nho (Kwangsik); T.E. Nichols (Thomas); L.G. Nilsson; A.C. Nugent (Allison); L. Nyberg (Lisa); R.L. Olvera (Rene); J. Oosterlaan (Jaap); R.A. Ophoff (Roel); M. Pandolfo (Massimo); M. Papalampropoulou-Tsiridou (Melina); M. Papmeyer (Martina); T. Paus (Tomas); Z. Pausova (Zdenka); G. Pearlson (Godfrey); B.W.J.H. Penninx (Brenda); C.P. Peterson (Charles); A. Pfennig (Andrea); M. Phillips (Mary); G.B. Pike (G Bruce); J.B. Poline (Jean Baptiste); S.G. Potkin (Steven); B. Pütz (Benno); A. Ramasamy (Adaikalavan); J. Rasmussen (Jerod); M. Rietschel (Marcella); M. Rijpkema (Mark); S.L. Risacher (Shannon); J.L. Roffman (Joshua); R. Roiz-Santiañez (Roberto); N. Romanczuk-Seiferth (Nina); E.J. Rose (Emma); N.A. Royle (Natalie); D. Rujescu (Dan); M. Ryten (Mina); P.S. Sachdev (Perminder); A. Salami (Alireza); T.D. Satterthwaite (Theodore); J. Savitz (Jonathan); A.J. Saykin (Andrew); C. Scanlon (Cathy); L. Schmaal (Lianne); H. Schnack (Hugo); N.J. Schork (Nicholas); S.C. Schulz (S.Charles); R. Schür (Remmelt); L.J. Seidman (Larry); L. Shen (Li); L. Shoemaker (Lawrence); A. Simmons (Andrew); S.M. Sisodiya (Sanjay); C. Smith (Colin); J.W. Smoller; J.C. Soares (Jair); S.R. Sponheim (Scott); R. Sprooten (Roy); J.M. Starr (John); V.M. Steen (Vidar); S. Strakowski (Stephen); L.T. Strike (Lachlan); J. Sussmann (Jessika); P.G. Sämann (Philipp); A. Teumer (Alexander); A.W. Toga (Arthur); D. Tordesillas-Gutierrez (Diana); D. Trabzuni (Danyah); S. Trost (Sarah); J. Turner (Jessica); M. van den Heuvel (Martijn); N.J. van der Wee (Nic); K.R. van Eijk (Kristel); T.G.M. van Erp (Theo G.); N.E.M. van Haren (Neeltje E.); D. van 't Ent (Dennis); M.J.D. van Tol (Marie-José); M.C. Valdés Hernández (Maria); D.J. Veltman (Dick); A. Versace (Amelia); H. Völzke (Henry); R. Walker (Robert); H.J. Walter (Henrik); L. Wang (Lei); J.M. Wardlaw (J.); M.E. Weale (Michael); M.W. Weiner (Michael); W. Wen (Wei); L.T. Westlye (Lars); H.C. Whalley (Heather); C.D. Whelan (Christopher); T.J.H. White (Tonya); A.M. Winkler (Anderson); K. Wittfeld (Katharina); G. Woldehawariat (Girma); A. Björnsson (Asgeir); D. Zilles (David); M.P. Zwiers (Marcel); A. Thalamuthu (Anbupalam); J.R. Almeida (Jorge); C.J. Schofield (Christopher); N.B. Freimer (Nelson); N.S. Lawrence (Natalia); D.A. Drevets (Douglas)

    2014-01-01

    textabstractThe Enhancing NeuroImaging Genetics through Meta-Analysis (ENIGMA) Consortium is a collaborative network of researchers working together on a range of large-scale studies that integrate data from 70 institutions worldwide. Organized into Working Groups that tackle questions in

  6. Neuroimaging standards for research into small vessel disease and its contribution to ageing and neurodegeneration

    NARCIS (Netherlands)

    Wardlaw, J.M.; Smith, E.E.; Biessels, G.J.; Cordonnier, C.; Fazekas, F.; Frayne, R.; Lindley, R.I.; O'Brien, J. T.; Barkhof, F.; Benavente, O.R.; Black, S.E.; Brayne, C.; Breteler, M.; Chabriat, H.; deCarli, C.; de Leeuw, F.E.; Doubal, F.; Duering, M.; Fox, N.C.; Greenberg, S.; Hachinski, V.; Kilimann, I.; Mok, V.; van Oostenbrugge, R.; Pantoni, L.; Speck, O.; Stephan, B.C.M.; Teipel, S.; Viswanathan, A.; Werring, D.; Chen, C.; Smith, C.; van Buchem, M.; Norrving, B.; Gorelick, P.B.; Dichgans, M.

    2013-01-01

    Cerebral small vessel disease (SVD) is a common accompaniment of ageing. Features seen on neuroimaging include recent small subcortical infarcts, lacunes, white matter hyperintensities, perivascular spaces, microbleeds, and brain atrophy. SVD can present as a stroke or cognitive decline, or can have

  7. Combining non-invasive transcranial brain stimulation with neuroimaging and electrophysiology: Current approaches and future perspectives.

    Science.gov (United States)

    Bergmann, Til Ole; Karabanov, Anke; Hartwigsen, Gesa; Thielscher, Axel; Siebner, Hartwig Roman

    2016-10-15

    Non-invasive transcranial brain stimulation (NTBS) techniques such as transcranial magnetic stimulation (TMS) and transcranial current stimulation (TCS) are important tools in human systems and cognitive neuroscience because they are able to reveal the relevance of certain brain structures or neuronal activity patterns for a given brain function. It is nowadays feasible to combine NTBS, either consecutively or concurrently, with a variety of neuroimaging and electrophysiological techniques. Here we discuss what kind of information can be gained from combined approaches, which often are technically demanding. We argue that the benefit from this combination is twofold. Firstly, neuroimaging and electrophysiology can inform subsequent NTBS, providing the required information to optimize where, when, and how to stimulate the brain. Information can be achieved both before and during the NTBS experiment, requiring consecutive and concurrent applications, respectively. Secondly, neuroimaging and electrophysiology can provide the readout for neural changes induced by NTBS. Again, using either concurrent or consecutive applications, both "online" NTBS effects immediately following the stimulation and "offline" NTBS effects outlasting plasticity-inducing NTBS protocols can be assessed. Finally, both strategies can be combined to close the loop between measuring and modulating brain activity by means of closed-loop brain state-dependent NTBS. In this paper, we will provide a conceptual framework, emphasizing principal strategies and highlighting promising future directions to exploit the benefits of combining NTBS with neuroimaging or electrophysiology. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  8. Data mining a functional neuroimaging database for functional|segregation in brain regions

    DEFF Research Database (Denmark)

    Nielsen, Finn Årup

    2006-01-01

    We describe a specialized neuroinformatic data mining technique in connection with a meta-analytic functional neuroimaging database: We mine for functional segregation within brain regions by identifying journal articles that report brain activations within the regions and clustering the abstract...

  9. Mining for associations between text and brain activation in a functional neuroimaging database

    DEFF Research Database (Denmark)

    Nielsen, Finn Årup; Hansen, Lars Kai; Balslev, D.

    2004-01-01

    We describe a method for mining a neuroimaging database for associations between text and brain locations. The objective is to discover association rules between words indicative of cognitive function as described in abstracts of neuroscience papers and sets of reported stereotactic Talairach...

  10. Identifying Predictors, Moderators, and Mediators of Antidepressant Response in Major Depressive Disorder: Neuroimaging Approaches

    Science.gov (United States)

    Phillips, Mary L.; Chase, Henry W.; Sheline, Yvette I.; Etkin, Amit; Almeida, Jorge R.C.; Deckersbach, Thilo; Trivedi, Madhukar H.

    2015-01-01

    Objective Despite significant advances in neuroscience and treatment development, no widely accepted biomarkers are available to inform diagnostics or identify preferred treatments for individuals with major depressive disorder. Method In this critical review, the authors examine the extent to which multimodal neuroimaging techniques can identify biomarkers reflecting key pathophysiologic processes in depression and whether such biomarkers may act as predictors, moderators, and mediators of treatment response that might facilitate development of personalized treatments based on a better understanding of these processes. Results The authors first highlight the most consistent findings from neuroimaging studies using different techniques in depression, including structural and functional abnormalities in two parallel neural circuits: serotonergically modulated implicit emotion regulation circuitry, centered on the amygdala and different regions in the medial prefrontal cortex; and dopaminergically modulated reward neural circuitry, centered on the ventral striatum and medial prefrontal cortex. They then describe key findings from the relatively small number of studies indicating that specific measures of regional function and, to a lesser extent, structure in these neural circuits predict treatment response in depression. Conclusions Limitations of existing studies include small sample sizes, use of only one neuroimaging modality, and a focus on identifying predictors rather than moderators and mediators of differential treatment response. By addressing these limitations and, most importantly, capitalizing on the benefits of multimodal neuroimaging, future studies can yield moderators and mediators of treatment response in depression to facilitate significant improvements in shorter- and longer-term clinical and functional outcomes. PMID:25640931

  11. Neonatal Cerebral Sinovenous Thrombosis : Neuroimaging and Long-term Follow-up

    NARCIS (Netherlands)

    Kersbergen, Karina J.; Groenendaal, Floris; Benders, Manon J. N. L.; de Vries, Linda S.

    Neonates are known to have a higher risk of cerebral sinovenous thrombosis than children of other age groups. The exact incidence in neonates remains unknown and is likely to be underestimated, as clinical presentation is nonspecific and diagnosis can only be made when dedicated neuroimaging

  12. Restoring the Generalizability of SVM Based Decoding in High Dimensional Neuroimage Data

    DEFF Research Database (Denmark)

    Abrahamsen, Trine Julie; Hansen, Lars Kai

    2011-01-01

    Variance inflation is caused by a mismatch between linear projections of test and training data when projections are estimated on training sets smaller than the dimensionality of the feature space. We demonstrate that variance inflation can lead to an increased neuroimage decoding error rate...

  13. The role of social stimuli content in neuroimaging studies investigating alcohol cue-reactivity

    NARCIS (Netherlands)

    Groefsema, M.M.; Engels, R.C.M.E.; Luijten, M.

    2016-01-01

    Introduction: Cue-reactivity is thought to play a fundamental role in the maintenance of addiction. The incentive sensitization theory proposes that conditioned responses are related to increased sensitivity of the reward-related dopaminergic pathways in the brain. However, neuroimaging studies on

  14. Hypomyelination and congenital cataract: neuroimaging features of a novel inherited white matter disorder

    NARCIS (Netherlands)

    Rossi, A.; Biancheri, R.; Zara, F.; Bruno, C.; Uziel, G.; van der Knaap, M.S.; Minetti, C.; Tortori-Donati, P.

    2008-01-01

    BACKGROUND AND PURPOSE: Hypomyelination and congenital cataract (HCC) is an autosomal recessive white matter disease caused by deficiency of hyccin, a membrane protein implicated in both central and peripheral myelination. We aimed to describe the neuroimaging features of this novel entity.

  15. Electricity Theory

    International Nuclear Information System (INIS)

    Gong, Ha Soung

    2006-12-01

    The text book composed of five parts, which are summary of this book, arrangement of electricity theory including electricity nad magnetism, a direct current, and alternating current. It has two dictionary electricity terms for a synonym. The last is an appendix. It is for preparing for test of officer, electricity engineer and fire fighting engineer.

  16. Contributions of Neuroimaging to Understanding Sex Differences in Cocaine Abuse

    OpenAIRE

    Andersen, ML; Sawyer, EK; Howell, LL

    2011-01-01

    A consistent observation in drug abuse research is that males and females show differences in their response to drugs of abuse. In order to understand the neurobiology underlying cocaine abuse and effective treatments, it is important to consider the role of sex differences. Sex hormones have been investigated in both behavioral and molecular studies, but further evidence addressing drug abuse and dependence in both sexes would expand our knowledge of sex-differences in response to drugs of a...

  17. Movement and afferent representations in human motor areas: a simultaneous neuroimaging and transcranial magnetic/peripheral nerve-stimulation study

    Directory of Open Access Journals (Sweden)

    Hitoshi eShitara

    2013-09-01

    Full Text Available Neuroimaging combined with transcranial magnetic stimulation (TMS to primary motor cortex (M1 is an emerging technique that can examine motor-system functionality through evoked activity. However, because sensory afferents from twitching muscles are widely represented in motor areas the amount of evoked activity directly resulting from TMS remains unclear. We delivered suprathreshold TMS to left M1 or electrically stimulated the right median nerve (MNS in 18 healthy volunteers while simultaneously conducting functional magnetic resonance imaging and monitoring with electromyography (EMG. We examined in detail the localization of TMS-, muscle afferent- and superficial afferent-induced activity in M1 subdivisions. Muscle afferent- and TMS-evoked activity occurred mainly in rostral M1, while superficial afferents generated a slightly different activation distribution. In 12 participants who yielded quantifiable EMG, differences in brain activity ascribed to differences in movement-size were adjusted using integrated information from the EMGs. Sensory components only explained 10-20% of the suprathreshold TMS-induced activity, indicating that locally and remotely evoked activity in motor areas mostly resulted from the recruitment of neural and synaptic activity. The present study appears to justify the use of fMRI combined with suprathreshold TMS to M1 for evoked motor network imaging.

  18. Pain as a fact and heuristic: how pain neuroimaging illuminates moral dimensions of law.

    Science.gov (United States)

    Pustilnik, Amanda C

    2012-05-01

    In legal domains ranging from tort to torture, pain and its degree do important definitional work by delimiting boundaries of lawfulness and of entitlements. Yet, for all the work done by pain as a term in legal texts and practice, it has a confounding lack of external verifiability. Now, neuroimaging is rendering pain and myriad other subjective states at least partly ascertainable. This emerging ability to ascertain and quantify subjective states is prompting a "hedonic" or a "subjectivist" turn in legal scholarship, which has sparked a vigorous debate as to whether the quantification of subjective states might affect legal theory and practice. Subjectivists contend that much values-talk in law has been a necessary but poor substitute for quantitative determinations of subjective states--determinations that will be possible in the law's "experiential future." This Article argues the converse: that pain discourse in law frequently is a heuristic for values. Drawing on interviews and laboratory visits with neuroimaging researchers, this Article shows current and in-principle limitations of pain quantification through neuroimaging. It then presents case studies on torture-murder, torture, the death penalty, and abortion to show the largely heuristic role of pain discourse in law. Introducing the theory of "embodied morality," the Article describes how moral conceptions of rights and duties are informed by human physicality and constrained by the limits of empathic identification. Pain neuroimaging helps reveal this dual factual and heuristic nature of pain in the law, and thus itself points to the translational work required for neuroimaging to influence, much less transform, legal practice and doctrine.

  19. Did Geomagnetic Activity Challenge Electric Power Reliability During Solar Cycle 23? Evidence from the PJM Regional Transmission Organization in North America

    Science.gov (United States)

    Forbes, Kevin F.; Cyr, Chris St

    2012-01-01

    During solar cycle 22, a very intense geomagnetic storm on 13 March 1989 contributed to the collapse of the Hydro-Quebec power system in Canada. This event clearly demonstrated that geomagnetic storms have the potential to lead to blackouts. This paper addresses whether geomagnetic activity challenged power system reliability during solar cycle 23. Operations by PJM Interconnection, LLC (hereafter PJM), a regional transmission organization in North America, are examined over the period 1 April 2002 through 30 April 2004. During this time PJM coordinated the movement of wholesale electricity in all or parts of Delaware, Maryland, New Jersey, Ohio, Pennsylvania, Virginia, West Virginia, and the District of Columbia in the United States. We examine the relationship between a proxy of geomagnetically induced currents (GICs) and a metric of challenged reliability. In this study, GICs are proxied using magnetometer data from a geomagnetic observatory located just outside the PJM control area. The metric of challenged reliability is the incidence of out-of-economic-merit order dispatching due to adverse reactive power conditions. The statistical methods employed make it possible to disentangle the effects of GICs on power system operations from purely terrestrial factors. The results of the analysis indicate that geomagnetic activity can significantly increase the likelihood that the system operator will dispatch generating units based on system stability considerations rather than economic merit.

  20. FIRST SOUND EVIDENCE OF MUSCLE REGENERATION IN RECOVERY OF FUNCTION OF HUMAN PERMANENT DENERVATED MUSCLES BY A LONG-LASTING FUNCTIONAL ELECTRICAL STIMULATION (FES TRAINING: BIOPSY FINDINGS

    Directory of Open Access Journals (Sweden)

    Helmut Kern

    2004-12-01

    Full Text Available Contrary to general believe, in one case of 18month cauda equina lesion four-month electrical stimulation of thigh muscles (impulse energy 1.92 Joule increased stimulation frequency from 2 to 20 Hz, i. e., up to tetanic contractions. After 2 years o