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

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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.

A convergent functional architecture of the insula emerges across imaging modalities.

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Kelly, Clare; Toro, Roberto; Di Martino, Adriana; Cox, Christine L; Bellec, Pierre; Castellanos, F Xavier; Milham, Michael P

2012-07-16

Empirical evidence increasingly supports the hypothesis that patterns of intrinsic functional connectivity (iFC) are sculpted by a history of evoked coactivation within distinct neuronal networks. This, together with evidence of strong correspondence among the networks defined by iFC and those delineated using a variety of other neuroimaging techniques, suggests a fundamental brain architecture detectable across multiple functional and structural imaging modalities. Here, we leverage this insight to examine the functional organization of the human insula. We parcellated the insula on the basis of three distinct neuroimaging modalities - task-evoked coactivation, intrinsic (i.e., task-independent) functional connectivity, and gray matter structural covariance. Clustering of these three different covariance-based measures revealed a convergent elemental organization of the insula that likely reflects a fundamental brain architecture governing both brain structure and function at multiple spatial scales. While not constrained to be hierarchical, our parcellation revealed a pseudo-hierarchical, multiscale organization that was consistent with previous clustering and meta-analytic studies of the insula. Finally, meta-analytic examination of the cognitive and behavioral domains associated with each of the insular clusters obtained elucidated the broad functional dissociations likely underlying the topography observed. To facilitate future investigations of insula function across healthy and pathological states, the insular parcels have been made freely available for download via http://fcon_1000.projects.nitrc.org, along with the analytic scripts used to perform the parcellations. Copyright © 2012 Elsevier Inc. All rights reserved.

The teen brain: insights from neuroimaging.

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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.

On Multiplicative Linear Logic, Modality and Quantum Circuits

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Ugo Dal Lago

2012-10-01

Full Text Available A logical system derived from linear logic and called QMLL is introduced and shown able to capture all unitary quantum circuits. Conversely, any proof is shown to compute, through a concrete GoI interpretation, some quantum circuits. The system QMLL, which enjoys cut-elimination, is obtained by endowing multiplicative linear logic with a quantum modality.

The Co-evolution of Neuroimaging and Psychiatric Neurosurgery.

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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.

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.

The optimal hormonal replacement modality selection for multiple organ procurement from brain-dead organ donors

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Mi Z

2014-12-01

Full Text Available Zhibao Mi,1 Dimitri Novitzky,2 Joseph F Collins,1 David KC Cooper3 1Cooperative Studies Program Coordinating Center, VA Maryland Health Care Systems, Perry Point, MD, USA; 2Department of Cardiothoracic Surgery, University of South Florida, Tampa, FL, USA; 3Thomas E Starzl Transplantation Institute, University of Pittsburgh, Pittsburgh, PA, USA Abstract: The management of brain-dead organ donors is complex. The use of inotropic agents and replacement of depleted hormones (hormonal replacement therapy is crucial for successful multiple organ procurement, yet the optimal hormonal replacement has not been identified, and the statistical adjustment to determine the best selection is not trivial. Traditional pair-wise comparisons between every pair of treatments, and multiple comparisons to all (MCA, are statistically conservative. Hsu’s multiple comparisons with the best (MCB – adapted from the Dunnett’s multiple comparisons with control (MCC – has been used for selecting the best treatment based on continuous variables. We selected the best hormonal replacement modality for successful multiple organ procurement using a two-step approach. First, we estimated the predicted margins by constructing generalized linear models (GLM or generalized linear mixed models (GLMM, and then we applied the multiple comparison methods to identify the best hormonal replacement modality given that the testing of hormonal replacement modalities is independent. Based on 10-year data from the United Network for Organ Sharing (UNOS, among 16 hormonal replacement modalities, and using the 95% simultaneous confidence intervals, we found that the combination of thyroid hormone, a corticosteroid, antidiuretic hormone, and insulin was the best modality for multiple organ procurement for transplantation. Keywords: best treatment selection, brain-dead organ donors, hormonal replacement, multiple binary endpoints, organ procurement, multiple comparisons

Autonomy of image and use of single or multiple sense modalities in original verbal image production.

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Khatena, J

1978-06-01

The use of a single or of multiple sense modalities in the production of original verbal images as related to autonomy of imagery was explored. 72 college adults were administered Onomatopoeia and Images and the Gordon Test of Visual Imagery Control. A modified scoring procedure for the Gordon scale differentiated imagers who were moderate or low in autonomy. The two groups produced original verbal images using multiple sense modalities more frequently than a single modality.

Multiple Sclerosis in Malaysia: Demographics, Clinical Features, and Neuroimaging Characteristics

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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

Multiple Sclerosis in Malaysia: Demographics, Clinical Features, and Neuroimaging Characteristics

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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.

The Multi-modal Australian ScienceS Imaging and Visualisation Environment (MASSIVE high performance computing infrastructure: applications in neuroscience and neuroinformatics research

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Wojtek James eGoscinski

2014-03-01

Full Text Available The Multi-modal Australian ScienceS Imaging and Visualisation Environment (MASSIVE is a national imaging and visualisation facility established by Monash University, the Australian Synchrotron, the Commonwealth Scientific Industrial Research Organisation (CSIRO, and the Victorian Partnership for Advanced Computing (VPAC, with funding from the National Computational Infrastructure and the Victorian Government. The MASSIVE facility provides hardware, software and expertise to drive research in the biomedical sciences, particularly advanced brain imaging research using synchrotron x-ray and infrared imaging, functional and structural magnetic resonance imaging (MRI, x-ray computer tomography (CT, electron microscopy and optical microscopy. The development of MASSIVE has been based on best practice in system integration methodologies, frameworks, and architectures. The facility has: (i integrated multiple different neuroimaging analysis software components, (ii enabled cross-platform and cross-modality integration of neuroinformatics tools, and (iii brought together neuroimaging databases and analysis workflows. MASSIVE is now operational as a nationally distributed and integrated facility for neuroinfomatics and brain imaging research.

Manifold regularized multi-task feature selection for multi-modality classification in Alzheimer's disease.

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Jie, Biao; Zhang, Daoqiang; Cheng, Bo; Shen, Dinggang

2013-01-01

Accurate diagnosis of Alzheimer's disease (AD), as well as its prodromal stage (i.e., mild cognitive impairment, MCI), is very important for possible delay and early treatment of the disease. Recently, multi-modality methods have been used for fusing information from multiple different and complementary imaging and non-imaging modalities. Although there are a number of existing multi-modality methods, few of them have addressed the problem of joint identification of disease-related brain regions from multi-modality data for classification. In this paper, we proposed a manifold regularized multi-task learning framework to jointly select features from multi-modality data. Specifically, we formulate the multi-modality classification as a multi-task learning framework, where each task focuses on the classification based on each modality. In order to capture the intrinsic relatedness among multiple tasks (i.e., modalities), we adopted a group sparsity regularizer, which ensures only a small number of features to be selected jointly. In addition, we introduced a new manifold based Laplacian regularization term to preserve the geometric distribution of original data from each task, which can lead to the selection of more discriminative features. Furthermore, we extend our method to the semi-supervised setting, which is very important since the acquisition of a large set of labeled data (i.e., diagnosis of disease) is usually expensive and time-consuming, while the collection of unlabeled data is relatively much easier. To validate our method, we have performed extensive evaluations on the baseline Magnetic resonance imaging (MRI) and fluorodeoxyglucose positron emission tomography (FDG-PET) data of Alzheimer's Disease Neuroimaging Initiative (ADNI) database. Our experimental results demonstrate the effectiveness of the proposed method.

Manifold Regularized Multi-Task Feature Selection for Multi-Modality Classification in Alzheimer’s Disease

Science.gov (United States)

Jie, Biao; Cheng, Bo

2014-01-01

Accurate diagnosis of Alzheimer’s disease (AD), as well as its pro-dromal stage (i.e., mild cognitive impairment, MCI), is very important for possible delay and early treatment of the disease. Recently, multi-modality methods have been used for fusing information from multiple different and complementary imaging and non-imaging modalities. Although there are a number of existing multi-modality methods, few of them have addressed the problem of joint identification of disease-related brain regions from multi-modality data for classification. In this paper, we proposed a manifold regularized multi-task learning framework to jointly select features from multi-modality data. Specifically, we formulate the multi-modality classification as a multi-task learning framework, where each task focuses on the classification based on each modality. In order to capture the intrinsic relatedness among multiple tasks (i.e., modalities), we adopted a group sparsity regularizer, which ensures only a small number of features to be selected jointly. In addition, we introduced a new manifold based Laplacian regularization term to preserve the geometric distribution of original data from each task, which can lead to the selection of more discriminative features. Furthermore, we extend our method to the semi-supervised setting, which is very important since the acquisition of a large set of labeled data (i.e., diagnosis of disease) is usually expensive and time-consuming, while the collection of unlabeled data is relatively much easier. To validate our method, we have performed extensive evaluations on the baseline Magnetic resonance imaging (MRI) and fluorodeoxyglucose positron emission tomography (FDG-PET) data of Alzheimer’s Disease Neuroimaging Initiative (ADNI) database. Our experimental results demonstrate the effectiveness of the proposed method. PMID:24505676

The Java Image Science Toolkit (JIST) for Rapid Prototyping and Publishing of Neuroimaging Software

Science.gov (United States)

Lucas, Blake C.; Bogovic, John A.; Carass, Aaron; Bazin, Pierre-Louis; Prince, Jerry L.; Pham, Dzung

2010-01-01

Non-invasive neuroimaging techniques enable extraordinarily sensitive and specific in vivo study of the structure, functional response and connectivity of biological mechanisms. With these advanced methods comes a heavy reliance on computer-based processing, analysis and interpretation. While the neuroimaging community has produced many excellent academic and commercial tool packages, new tools are often required to interpret new modalities and paradigms. Developing custom tools and ensuring interoperability with existing tools is a significant hurdle. To address these limitations, we present a new framework for algorithm development that implicitly ensures tool interoperability, generates graphical user interfaces, provides advanced batch processing tools, and, most importantly, requires minimal additional programming or computational overhead. Java-based rapid prototyping with this system is an efficient and practical approach to evaluate new algorithms since the proposed system ensures that rapidly constructed prototypes are actually fully-functional processing modules with support for multiple GUI's, a broad range of file formats, and distributed computation. Herein, we demonstrate MRI image processing with the proposed system for cortical surface extraction in large cross-sectional cohorts, provide a system for fully automated diffusion tensor image analysis, and illustrate how the system can be used as a simulation framework for the development of a new image analysis method. The system is released as open source under the Lesser GNU Public License (LGPL) through the Neuroimaging Informatics Tools and Resources Clearinghouse (NITRC). PMID:20077162

The Java Image Science Toolkit (JIST) for rapid prototyping and publishing of neuroimaging software.

Science.gov (United States)

Lucas, Blake C; Bogovic, John A; Carass, Aaron; Bazin, Pierre-Louis; Prince, Jerry L; Pham, Dzung L; Landman, Bennett A

2010-03-01

Non-invasive neuroimaging techniques enable extraordinarily sensitive and specific in vivo study of the structure, functional response and connectivity of biological mechanisms. With these advanced methods comes a heavy reliance on computer-based processing, analysis and interpretation. While the neuroimaging community has produced many excellent academic and commercial tool packages, new tools are often required to interpret new modalities and paradigms. Developing custom tools and ensuring interoperability with existing tools is a significant hurdle. To address these limitations, we present a new framework for algorithm development that implicitly ensures tool interoperability, generates graphical user interfaces, provides advanced batch processing tools, and, most importantly, requires minimal additional programming or computational overhead. Java-based rapid prototyping with this system is an efficient and practical approach to evaluate new algorithms since the proposed system ensures that rapidly constructed prototypes are actually fully-functional processing modules with support for multiple GUI's, a broad range of file formats, and distributed computation. Herein, we demonstrate MRI image processing with the proposed system for cortical surface extraction in large cross-sectional cohorts, provide a system for fully automated diffusion tensor image analysis, and illustrate how the system can be used as a simulation framework for the development of a new image analysis method. The system is released as open source under the Lesser GNU Public License (LGPL) through the Neuroimaging Informatics Tools and Resources Clearinghouse (NITRC).

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

Functional neuroimaging studies in addiction: multisensory drug stimuli and neural cue reactivity.

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Yalachkov, Yavor; Kaiser, Jochen; Naumer, Marcus J

2012-02-01

Neuroimaging studies on cue reactivity have substantially contributed to the understanding of addiction. In the majority of studies drug cues were presented in the visual modality. However, exposure to conditioned cues in real life occurs often simultaneously in more than one sensory modality. Therefore, multisensory cues should elicit cue reactivity more consistently than unisensory stimuli and increase the ecological validity and the reliability of brain activation measurements. This review includes the data from 44 whole-brain functional neuroimaging studies with a total of 1168 subjects (812 patients and 356 controls). Correlations between neural cue reactivity and clinical covariates such as craving have been reported significantly more often for multisensory than unisensory cues in the motor cortex, insula and posterior cingulate cortex. Thus, multisensory drug cues are particularly effective in revealing brain-behavior relationships in neurocircuits of addiction responsible for motivation, craving awareness and self-related processing. Copyright © 2011 Elsevier Ltd. All rights reserved.

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)

Priming within and across modalities: exploring the nature of rCBF increases and decreases.

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Badgaiyan, R D; Schacter, D L; Alpert, N M

2001-02-01

Neuroimaging studies suggest that within-modality priming is associated with reduced regional cerebral blood flow (rCBF) in the extrastriate area, whereas cross-modality priming is associated with increased rCBF in prefrontal cortex. To characterize the nature of rCBF changes in within- and cross-modality priming, we conducted two neuroimaging experiments using positron emission tomography (PET). In experiment 1, rCBF changes in within-modality auditory priming on a word stem completion task were observed under same- and different-voice conditions. Both conditions were associated with decreased rCBF in extrastriate cortex. In the different-voice condition there were additional rCBF changes in the middle temporal gyrus and prefrontal cortex. Results suggest that the extrastriate involvement in within-modality priming is sensitive to a change in sensory modality of target stimuli between study and test, but not to a change in the feature of a stimulus within the same modality. In experiment 2, we studied cross-modality priming on a visual stem completion test after encoding under full- and divided-attention conditions. Increased rCBF in the anterior prefrontal cortex was observed in the full- but not in the divided-attention condition. Because explicit retrieval is compromised after encoding under the divided-attention condition, prefrontal involvement in cross-modality priming indicates recruitment of an aspect of explicit retrieval mechanism. The aspect of explicit retrieval that is most likely to be involved in cross-modality priming is the familiarity effect. Copyright 2001 Academic Press.

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

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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

Clinical and neuroimaging correlates of antiphospholipid antibodies in multiple sclerosis: a preliminary study

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Gonzalez-Toledo Eduardo

2007-10-01

Full Text Available Abstract Background The presence of antiphospholipid antibodies (APLA in multiple sclerosis (MS patients has been reported frequently but no clear relationship between APLA and the clinical and neuroimaging features of MS have heretofore been shown. We assessed the clinical and neuroimaging features of MS patients with plasma APLA. Methods A consecutive cohort of 24 subjects with relapsing-remitting (RR MS were studied of whom 7 were in remission (Rem and 17 in exacerbation (Exc. All subjects were examined and underwent MRI of brain. Patients' plasma was tested by standard ELISA for the presence of both IgM and IgG antibodies using a panel of 6 targets: cardiolipin (CL, β2 glycoprotein I (β2GPI, Factor VII/VIIa (FVIIa, phosphatidylcholine (PC, phosphatidylserine (PS and phosphatidylethanolamine (PE. Results In exacerbation up to 80% of MS subjects had elevated titers of IgM antibodies directed against the above antigens. However, in remission, less than half of MS patients had elevated titers of IgM antibodies against one or more of the above antigens. This difference was significant, p Conclusion The findings of this preliminary study show that increased APLA IgM is associated with exacerbations of MS. Currently, the significance of this association in pathogenesis of MS remains unknown. However, systematic longitudinal studies to measure APLA in larger cohorts of patients with relapsing-remitting MS, particularly before and after treatment with immunomodulatory agents, are needed to confirm these preliminary findings.

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

Acute disseminated encephalomyelitis complicating dengue infection with neuroimaging mimicking multiple sclerosis: A report of two cases.

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Viswanathan, S; Botross, N; Rusli, B N; Riad, A

2016-11-01

Acute disseminated encephalomyelitis (ADEM) complicating dengue infection is still exceedingly rare even in endemic countries such as Malaysia. Here we report two such cases, the first in an elderly female patient and the second in a young man. Both presented with encephalopathy, brainstem involvement and worsening upper and lower limb weakness. Initial magnetic resonance imaging (MRI) of the brain was normal in the first case. Serum for dengue Ig M and NS-1 was positive in both cases. Cerebrospinal fluid (CSF) showed pleocytosis in both with Dengue IgM and NS-1 positive in the second case but not done in the first. MRI brain showed changes of perpendicular subcortical palisading white matter, callosal and brainstem disease mimicking multiple sclerosis (MS) in both patients though in the former case there was a lag between the onset of clinical symptoms and MRI changes which was only clarified on reimaging. The temporal evolution and duration of the clinical symptoms, CSF changes and neuroimaging were more suggestive of Dengue ADEM rather than an encephalitis though initially the first case began as dengue encephalitis. Furthermore in dengue encephalitis neuroimaging is usually normal or rarely edema, haemorrhage, brainstem, thalamic or focal lesions are seen. Therefore, early recognition of ADEM as a sequelae of dengue infection with neuroimaging mimicking MS and repeat imaging helped in identifying these two cases. Treatment with intravenous steroids followed by maintenance oral steroids produced good outcome in both patients. Copyright © 2016 Elsevier B.V. All rights reserved.

Three-dimensional registration methods for multi-modal magnetic resonance neuroimages

International Nuclear Information System (INIS)

Triantafyllou, C.

2001-08-01

In this thesis, image alignment techniques are developed and evaluated for applications in neuroimaging. In particular, the problem of combining cross-sequence MRI (Magnetic Resonance Imaging) intra-subject scans is considered. The challenge in this case is to find topographically uniform mappings in order to register (find a mapping between) low resolution echo-planar images and their high resolution structural counterparts. Such an approach enables us to effectually fuse, in a clinically useful way, information across scans. This dissertation devises a new framework by which this may be achieved, involving appropriate optimisation of the required mapping functions, which turn out to be non-linear and high-dimensional in nature. Novel ways to constrain and regularise these functions to enhance the computational speed of the process and the accuracy of the solution are also studied. The algorithms, whose characteristics are demonstrated for this specific application should be fully generalisable to other medical imaging modalities and potentially, other areas of image processing. To begin with, some existing registration methods are reviewed, followed by the introduction of an automated global 3-D registration method. Its performance is investigated on extracted cortical and ventricular surfaces by utilising the principles of the chamfer matching approach. Evaluations on synthetic and real data-sets, are performed to show that removal of global image differences is possible in principle, although the true accuracy of the method depends on the type of geometrical distortions present. These results also reveal that this class of algorithm is unable to solve more localised variations and higher order magnetic field distortions between the images. These facts motivate the development of a high-dimensional 3-D registration method capable of effecting a one-to-one correspondence by capturing the localised differences. This method was seen to account not only for

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...

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

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.

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...

Neuroimaging in dementia and Alzheimer's disease: Current protocols and practice in the Republic of Ireland

International Nuclear Information System (INIS)

Kelly, I.; Butler, M.-L.; Ciblis, A.; McNulty, J.P.

2016-01-01

Introduction: Neuroimaging plays an essential supportive role in the diagnosis of dementia, assisting in establishing the dementia subtype(s). This has significant value in both treatment and care decisions and has important implications for prognosis. This study aims to explore the development and nature of neuroimaging protocols currently used in the assessment of dementia and Alzheimer's disease (AD). Methods: An online questionnaire was designed and distributed to lead radiography personnel working in computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET) departments (n = 94) in both hospital-based and out-patient imaging centres in the Republic of Ireland. Results: Response rates for each modality ranged from 42 to 44%. CT, MRI, and PET were used to specifically diagnose dementia or AD by 43%, 40% and 50% of responding centres respectively. Of these, dementia-specific neuroimaging protocols were utilised in 33%, 50% and 100% of CT, MRI and PET centres respectively, with the remainder using either standard or other non-specific protocols. Both radiologists and clinical specialist radiographers participated in the development of the majority of protocols. The Royal College of Radiologists (RCR) guidelines were most commonly referenced as informing protocol development, however, none of the MRI respondents were able to identify any guidelines used to inform MR protocol development. Conclusion: Currently there is no consensus in Ireland on optimal dementia/AD neuroimaging protocols, particularly for PET and MRI. Similarly the use of validated and published guidelines to inform protocols is not universal. - Highlights: • We examined the nature of neuroimaging protocols for dementia and Alzheimer's disease in Ireland. • Dementia or Alzheimer's disease-specific protocols were used by between 33 and 100% of centres depending on modality. • Stated dementia-specific protocols were identical for CT whereas

Functional-structural reorganisation of the neuronal network for auditory perception in subjects with unilateral hearing loss: Review of neuroimaging studies.

Science.gov (United States)

Heggdal, Peder O Laugen; Brännström, Jonas; Aarstad, Hans Jørgen; Vassbotn, Flemming S; Specht, Karsten

2016-02-01

This paper aims to provide a review of studies using neuroimaging to measure functional-structural reorganisation of the neuronal network for auditory perception after unilateral hearing loss. A literature search was performed in PubMed. Search criterions were peer reviewed original research papers in English completed by the 11th of March 2015. Twelve studies were found to use neuroimaging in subjects with unilateral hearing loss. An additional five papers not identified by the literature search were provided by a reviewer. Thus, a total of 17 studies were included in the review. Four different neuroimaging methods were used in these studies: Functional magnetic resonance imaging (fMRI) (n = 11), diffusion tensor imaging (DTI) (n = 4), T1/T2 volumetric images (n = 2), magnetic resonance spectroscopy (MRS) (n = 1). One study utilized two imaging methods (fMRI and T1 volumetric images). Neuroimaging techniques could provide valuable information regarding the effects of unilateral hearing loss on both auditory and non-auditory performance. fMRI-studies showing a bilateral BOLD-response in patients with unilateral hearing loss have not yet been followed by DTI studies confirming their microstructural correlates. In addition, the review shows that an auditory modality-specific deficit could affect multi-modal brain regions and their connections. Copyright © 2015 Elsevier B.V. All rights reserved.

Meaning Making through Multiple Modalities in a Biology Classroom: A Multimodal Semiotics Discourse Analysis

Science.gov (United States)

Jaipal, Kamini

2010-01-01

The teaching of science is a complex process, involving the use of multiple modalities. This paper illustrates the potential of a multimodal semiotics discourse analysis framework to illuminate meaning-making possibilities during the teaching of a science concept. A multimodal semiotics analytical framework is developed and used to (1) analyze the…

Supervised Cross-Modal Factor Analysis for Multiple Modal Data Classification

KAUST Repository

Wang, Jingbin; Zhou, Yihua; Duan, Kanghong; Wang, Jim Jing-Yan; Bensmail, Halima

2015-01-01

. In this paper, we improve CFA by incorporating the supervision information to represent and classify both image and text modals of documents. We project both image and text data to a shared data space by factor analysis, and then train a class label predictor

Neuroimaging after mild traumatic brain injury: Review and meta-analysis

Directory of Open Access Journals (Sweden)

Cyrus Eierud

2014-01-01

Full Text Available This paper broadly reviews the study of mild traumatic brain injury (mTBI, across the spectrum of neuroimaging modalities. Among the range of imaging methods, however, magnetic resonance imaging (MRI is unique in its applicability to studying both structure and function. Thus we additionally performed meta-analyses of MRI results to examine 1 the issue of anatomical variability and consistency for functional MRI (fMRI findings, 2 the analogous issue of anatomical consistency for white-matter findings, and 3 the importance of accounting for the time post injury in diffusion weighted imaging reports. As we discuss, the human neuroimaging literature consists of both small and large studies spanning acute to chronic time points that have examined both structural and functional changes with mTBI, using virtually every available medical imaging modality. Two key commonalities have been used across the majority of imaging studies. The first is the comparison between mTBI and control populations. The second is the attempt to link imaging results with neuropsychological assessments. Our fMRI meta-analysis demonstrates a frontal vulnerability to mTBI, demonstrated by decreased signal in prefrontal cortex compared to controls. This vulnerability is further highlighted by examining the frequency of reported mTBI white matter anisotropy, in which we show a strong anterior-to-posterior gradient (with anterior regions being more frequently reported in mTBI. Our final DTI meta-analysis examines a debated topic arising from inconsistent anisotropy findings across studies. Our results support the hypothesis that acute mTBI is associated with elevated anisotropy values and chronic mTBI complaints are correlated with depressed anisotropy. Thus, this review and set of meta-analyses demonstrate several important points about the ongoing use of neuroimaging to understand the functional and structural changes that occur throughout the time course of mTBI recovery

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....

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

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.

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

Multiple-modality exercise and mind-motor training to improve cardiovascular health and fitness in older adults at risk for cognitive impairment: A randomized controlled trial.

Science.gov (United States)

Boa Sorte Silva, Narlon C; Gregory, Michael A; Gill, Dawn P; Petrella, Robert J

The effects of multiple-modality exercise on arterial stiffening and cardiovascular fitness has not been fully explored. To explore the influence of a 24-week multiple-modality exercise program associated with a mind-motor training in cardiovascular health and fitness in community-dwelling older adults, compared to multiple-modality exercise (M2) alone. Participants (n=127, aged 67.5 [7.3] years, 71% females) were randomized to either M4 or M2 groups. Both groups received multiple-modality exercise intervention (60min/day, 3days/week for 24-weeks); however, the M4 group underwent additional 15min of mind-motor training, whereas the M2 group received 15min of balance training. Participants were assessed at 24-weeks and after a 28-week non-contact follow-up (52-weeks). at 52-weeks, the M4 group demonstrated a greater VO2max (ml/kg/min) compared to the M2 group (mean difference: 2.39, 95% CI: 0. 61 to 4.16, p=0.009). Within-group analysis indicated that the M4 group demonstrated a positive change in VO2max at 24-weeks (mean change: 1.93, 95% CI: 0.82 to 3.05, p=0.001) and 52-weeks (4.02, 95% CI: 2.71 to 5.32, p=0.001). Similarly, the M2 group increased VO2max at 24-weeks (2.28, 95% CI: 1.23 to 3.32, pMind-motor training associated with multiple-modality exercise can positively impact cardiovascular fitness to the same extent as multiple-modality exercise alone. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Decoding the complex brain: multivariate and multimodal analyses of neuroimaging data

International Nuclear Information System (INIS)

Salami, Alireza

2012-01-01

Functional brain images are extraordinarily rich data sets that reveal distributed brain networks engaged in a wide variety of cognitive operations. It is a substantial challenge both to create models of cognition that mimic behavior and underlying cognitive processes and to choose a suitable analytic method to identify underlying brain networks. Most of the contemporary techniques used in analyses of functional neuroimaging data are based on univariate approaches in which single image elements (i.e. voxels) are considered to be computationally independent measures. Beyond univariate methods (e.g. statistical parametric mapping), multivariate approaches, which identify a network across all regions of the brain rather than a tessellation of regions, are potentially well suited for analyses of brain imaging data. A multivariate method (e.g. partial least squares) is a computational strategy that determines time-varying distributed patterns of the brain (as a function of a cognitive task). Compared to its univariate counterparts, a multivariate approach provides greater levels of sensitivity and reflects cooperative interactions among brain regions. Thus, by considering information across more than one measuring point, additional information on brain function can be revealed. Similarly, by considering information across more than one measuring technique, the nature of underlying cognitive processes become well-understood. Cognitive processes have been investigated in conjunction with multiple neuroimaging modalities (e.g. fMRI, sMRI, EEG, DTI), whereas the typical method has been to analyze each modality separately. Accordingly, little work has been carried out to examine the relation between different modalities. Indeed, due to the interconnected nature of brain processing, it is plausible that changes in one modality locally or distally modulate changes in another modality. This thesis focuses on multivariate and multimodal methods of image analysis applied to

Decoding the complex brain: multivariate and multimodal analyses of neuroimaging data

Energy Technology Data Exchange (ETDEWEB)

Salami, Alireza

2012-07-01

Functional brain images are extraordinarily rich data sets that reveal distributed brain networks engaged in a wide variety of cognitive operations. It is a substantial challenge both to create models of cognition that mimic behavior and underlying cognitive processes and to choose a suitable analytic method to identify underlying brain networks. Most of the contemporary techniques used in analyses of functional neuroimaging data are based on univariate approaches in which single image elements (i.e. voxels) are considered to be computationally independent measures. Beyond univariate methods (e.g. statistical parametric mapping), multivariate approaches, which identify a network across all regions of the brain rather than a tessellation of regions, are potentially well suited for analyses of brain imaging data. A multivariate method (e.g. partial least squares) is a computational strategy that determines time-varying distributed patterns of the brain (as a function of a cognitive task). Compared to its univariate counterparts, a multivariate approach provides greater levels of sensitivity and reflects cooperative interactions among brain regions. Thus, by considering information across more than one measuring point, additional information on brain function can be revealed. Similarly, by considering information across more than one measuring technique, the nature of underlying cognitive processes become well-understood. Cognitive processes have been investigated in conjunction with multiple neuroimaging modalities (e.g. fMRI, sMRI, EEG, DTI), whereas the typical method has been to analyze each modality separately. Accordingly, little work has been carried out to examine the relation between different modalities. Indeed, due to the interconnected nature of brain processing, it is plausible that changes in one modality locally or distally modulate changes in another modality. This thesis focuses on multivariate and multimodal methods of image analysis applied to

Effects of multiple training modalities in patients with Alzheimer’s disease: a pilot study

Directory of Open Access Journals (Sweden)

Tai SY

2016-11-01

Full Text Available Shu-Yu Tai,1–4 Chia-Ling Hsu,5 Shu-Wan Huang,5 Tzu-Chiao Ma,6,7 Wen-Chien Hsieh,8,9 Yuan-Han Yang5,7,10,11 1Department of Family Medicine, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University, 2Department of Family Medicine, Kaohsiung Medical University Hospital, Kaohsiung Medical University, 3Department of Family Medicine, School of Medicine, College of Medicine, Kaohsiung Medical University, 4Research Center for Environmental Medicine, Kaohsiung Medical University, 5Department of Neurology, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University, 6Graduate Institute of Oral Health Sciences, Kaohsiung Medical University, 7Mentality Protection Center, Fo Guang Shan Compassion Foundation, 8Department of Social Work, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung Medical University, 9Department of Sociology and Social Work, Kaohsiung Medical University, 10Department of Neurology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, 11Department of and Master’s Program in Neurology, Faculty of Medicine, Kaohsiung Medical University, Kaohsiung City, Taiwan Objective: This pilot study investigated the effects of multiple training modalities on cognition, neuropsychiatric symptoms, caregivers’ burden, and quality of life in patients with Alzheimer’s disease (AD.Patients and methods: This intervention study was conducted in 24 patients with AD aged ≥65 years with a Clinical Dementia Rating (CDR score of 0.5–1. The patients were assigned to receive multiple training modalities (1 hour for each training: Tai Chi, calligraphy, and drawing over a 6-week period in either the experimental group (n=14 or the comparison group (n=10. A series of neuropsychological tests – namely the Traditional Chinese version Mini-Mental Status Examination, Cognitive Assessment Screening Instrument (CASI, Neuropsychiatric Inventory and the Neuropsychiatric Inventory Caregiver Distress Scale, and the Clinical Dementia

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

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.

A Comparison of Neuroimaging Abnormalities in Multiple Sclerosis, Major Depression and Chronic Fatigue Syndrome (Myalgic Encephalomyelitis): is There a Common Cause?

Science.gov (United States)

Morris, Gerwyn; Berk, Michael; Puri, Basant K

2018-04-01

There is copious evidence of abnormalities in resting-state functional network connectivity states, grey and white matter pathology and impaired cerebral perfusion in patients afforded a diagnosis of multiple sclerosis, major depression or chronic fatigue syndrome (CFS) (myalgic encephalomyelitis). Systemic inflammation may well be a major element explaining such findings. Inter-patient and inter-illness variations in neuroimaging findings may arise at least in part from regional genetic, epigenetic and environmental variations in the functions of microglia and astrocytes. Regional differences in neuronal resistance to oxidative and inflammatory insults and in the performance of antioxidant defences in the central nervous system may also play a role. Importantly, replicated experimental findings suggest that the use of high-resolution SPECT imaging may have the capacity to differentiate patients afforded a diagnosis of CFS from those with a diagnosis of depression. Further research involving this form of neuroimaging appears warranted in an attempt to overcome the problem of aetiologically heterogeneous cohorts which probably explain conflicting findings produced by investigative teams active in this field. However, the ionising radiation and relative lack of sensitivity involved probably preclude its use as a routine diagnostic tool.

Scientific and industrial challenges of developing nanoparticle-based theranostics and multiple-modality contrast agents for clinical application

Science.gov (United States)

Wáng, Yì Xiáng J.; Idée, Jean-Marc; Corot, Claire

2015-10-01

Designing of theranostics and dual or multi-modality contrast agents are currently two of the hottest topics in biotechnology and biomaterials science. However, for single entity theranostics, a right ratio of their diagnostic component and their therapeutic component may not always be realized in a composite suitable for clinical application. For dual/multiple modality molecular imaging agents, after in vivo administration, there is an optimal time window for imaging, when an agent is imaged by one modality, the pharmacokinetics of this agent may not allow imaging by another modality. Due to reticuloendothelial system clearance, efficient in vivo delivery of nanoparticles to the lesion site is sometimes difficult. The toxicity of these entities also remains poorly understood. While the medical need of theranostics is admitted, the business model remains to be established. There is an urgent need for a global and internationally harmonized re-evaluation of the approval and marketing processes of theranostics. However, a reasonable expectation exists that, in the near future, the current obstacles will be removed, thus allowing the wide use of these very promising agents.

VoxelStats: A MATLAB Package for Multi-Modal Voxel-Wise Brain Image Analysis.

Science.gov (United States)

Mathotaarachchi, Sulantha; Wang, Seqian; Shin, Monica; Pascoal, Tharick A; Benedet, Andrea L; Kang, Min Su; Beaudry, Thomas; Fonov, Vladimir S; Gauthier, Serge; Labbe, Aurélie; Rosa-Neto, Pedro

2016-01-01

In healthy individuals, behavioral outcomes are highly associated with the variability on brain regional structure or neurochemical phenotypes. Similarly, in the context of neurodegenerative conditions, neuroimaging reveals that cognitive decline is linked to the magnitude of atrophy, neurochemical declines, or concentrations of abnormal protein aggregates across brain regions. However, modeling the effects of multiple regional abnormalities as determinants of cognitive decline at the voxel level remains largely unexplored by multimodal imaging research, given the high computational cost of estimating regression models for every single voxel from various imaging modalities. VoxelStats is a voxel-wise computational framework to overcome these computational limitations and to perform statistical operations on multiple scalar variables and imaging modalities at the voxel level. VoxelStats package has been developed in Matlab(®) and supports imaging formats such as Nifti-1, ANALYZE, and MINC v2. Prebuilt functions in VoxelStats enable the user to perform voxel-wise general and generalized linear models and mixed effect models with multiple volumetric covariates. Importantly, VoxelStats can recognize scalar values or image volumes as response variables and can accommodate volumetric statistical covariates as well as their interaction effects with other variables. Furthermore, this package includes built-in functionality to perform voxel-wise receiver operating characteristic analysis and paired and unpaired group contrast analysis. Validation of VoxelStats was conducted by comparing the linear regression functionality with existing toolboxes such as glim_image and RMINC. The validation results were identical to existing methods and the additional functionality was demonstrated by generating feature case assessments (t-statistics, odds ratio, and true positive rate maps). In summary, VoxelStats expands the current methods for multimodal imaging analysis by allowing the

A review of transcranial magnetic stimulation and multimodal neuroimaging to characterize post-stroke neuroplasticity

Directory of Open Access Journals (Sweden)

Angela Michelle Auriat

2015-10-01

Full Text Available Following stroke, the brain undergoes various stages of recovery where the central nervous system can reorganize neural circuitry (neuroplasticity both spontaneously and with the aid of behavioural rehabilitation and non-invasive brain stimulation. Multiple neuroimaging techniques can characterize common structural and functional stroke-related deficits, and importantly, help predict recovery of function. Diffusion tensor imaging (DTI typically reveals increased overall diffusivity throughout the brain following stroke, and is capable of indexing the extent of white matter damage. Magnetic resonance spectroscopy (MRS provides an index of metabolic changes in surviving neural tissue after stroke, serving as a marker of brain function. The neural correlates of altered brain activity after stroke have been demonstrated by abnormal activation of sensorimotor cortices during task performance, and at rest, using functional magnetic resonance imaging (fMRI. Electroencephalography (EEG has been used to characterize motor dysfunction in terms of increased cortical amplitude in the sensorimotor regions when performing upper-limb movement, indicating abnormally increased cognitive effort and planning in individuals with stroke. Transcranial magnetic stimulation (TMS work reveals changes in ipsilesional and contralesional cortical excitability in the sensorimotor cortices. The severity of motor deficits indexed using TMS has been linked to the magnitude of activity imbalance between the sensorimotor cortices. In this paper we will provide a narrative review of data from studies utilizing DTI, MRS, fMRI, EEG and brain stimulation techniques focusing on TMS and its combination with uni and multi-modal neuroimaging methods to assess recovery after stroke. Approaches that delineate the best measures with which to predict or positively alter outcomes will be highlighted.

Dizziness in a community hospital: central neurological causes, clinical predictors, and diagnostic yield and cost of neuroimaging studies.

Science.gov (United States)

Ammar, Hussam; Govindu, Rukma; Fouda, Ragai; Zohdy, Wael; Supsupin, Emilio

2017-03-01

Objectives : Neuroimaging is contributing to the rising costs of dizziness evaluation. This study examined the rate of central neurological causes of dizziness, relevant clinical predictors, and the costs and diagnostic yields of neuroimaging in dizziness assessment. Methods : We retrospectively reviewed the records of 521 adult patients who visited the hospital during a 12-month period with dizziness as the chief complaint. Clinical findings were analyzed using Fisher's exact test to determine how they correlated with central neurological causes of dizziness identified by neuroimaging. Costs and diagnostic yields of neuroimaging were calculated. Results : Of the 521 patients, 1.5% had dizziness produced by central neurological causes. Gait abnormalities, limb ataxia, diabetes mellitus, and the existence of multiple neurological findings predicted central causes. Cases were associated with gait abnormalities, limb ataxia, diabetes mellitus, and the existence of multiple neurological findings . Brain computed tomography (CT) and magnetic resonance imaging (MRI) were performed in 42% and 9.5% of the examined cases, respectively, with diagnostic yields of 3.6% and 12%, respectively. Nine cases of dizziness were diagnosed from 269 brain scans, costing $607 914. Conclusion : Clinical evaluation can predict the presence of central neurological causes of dizziness, whereas neuroimaging is a costly and low-yield approach. Guidelines are needed for physicians, regarding the appropriateness of ordering neuroimaging studies. Abbreviations : OR: odds ratio; CI: confidence interval; ED: emergency department; CT: computed tomography; MRI: magnetic resonance imaging; HINTS: Head impulse, Nystagmus, Test of skew.

Convergent functional architecture of the superior parietal lobule unraveled with multimodal neuroimaging approaches.

Science.gov (United States)

Wang, Jiaojian; Yang, Yong; Fan, Lingzhong; Xu, Jinping; Li, Changhai; Liu, Yong; Fox, Peter T; Eickhoff, Simon B; Yu, Chunshui; Jiang, Tianzi

2015-01-01

The superior parietal lobule (SPL) plays a pivotal role in many cognitive, perceptive, and motor-related processes. This implies that a mosaic of distinct functional and structural subregions may exist in this area. Recent studies have demonstrated that the ongoing spontaneous fluctuations in the brain at rest are highly structured and, like coactivation patterns, reflect the integration of cortical locations into long-distance networks. This suggests that the internal differentiation of a complex brain region may be revealed by interaction patterns that are reflected in different neuroimaging modalities. On the basis of this perspective, we aimed to identify a convergent functional organization of the SPL using multimodal neuroimaging approaches. The SPL was first parcellated based on its structural connections as well as on its resting-state connectivity and coactivation patterns. Then, post hoc functional characterizations and connectivity analyses were performed for each subregion. The three types of connectivity-based parcellations consistently identified five subregions in the SPL of each hemisphere. The two anterior subregions were found to be primarily involved in action processes and in visually guided visuomotor functions, whereas the three posterior subregions were primarily associated with visual perception, spatial cognition, reasoning, working memory, and attention. This parcellation scheme for the SPL was further supported by revealing distinct connectivity patterns for each subregion in all the used modalities. These results thus indicate a convergent functional architecture of the SPL that can be revealed based on different types of connectivity and is reflected by different functions and interactions. © 2014 Wiley Periodicals, Inc.

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...

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

Imaging by multiple modalities of patients with a carotidynia syndrome

Energy Technology Data Exchange (ETDEWEB)

Kosaka, Nobuyuki; Uematsu, Hidemasa; Kimura, Hirohiko; Itoh, Harumi [University of Fukui, Department of Radiology, Faculty of Medical Sciences, Fukui (Japan); Sagoh, Tadashi; Noguchi, Masato [Fukui Red Cross Hospital, Department of Radiology, Fukui (Japan); Miyayama, Shiro [Fukuiken Saiseikai Hospital, Department of Diagnostic Radiology, Fukui (Japan)

2007-09-15

The purpose of this article is to familiarize readers with the clinical syndrome of carotidynia. In the past, the International Headache Society (IHS) described idiopathic carotidynia as a diagnostic entity consisting of a self-limiting neck pain syndrome and tenderness over the carotid bifurcation without structural abnormality and then recently removed it from its classification. Although the clinical criteria of carotidynia in the former classification of the IHS included the absence of structural abnormality, several publications have demonstrated associated radiological findings and have described the usefulness of radiological investigations in diagnosing this syndrome. In this paper, we report four additional cases with a carotidynia clinical syndrome (according to the former classification) and the presence of abnormal soft tissue infiltration surrounding the symptomatic carotid artery as demonstrated by multiple imaging modalities, without any other underlying cause for the carotid pain syndrome. Our findings support the hypothesis that carotidynia could be a distinct disease entity, possibly caused by inflammation. (orig.)

Imaging by multiple modalities of patients with a carotidynia syndrome

International Nuclear Information System (INIS)

Kosaka, Nobuyuki; Uematsu, Hidemasa; Kimura, Hirohiko; Itoh, Harumi; Sagoh, Tadashi; Noguchi, Masato; Miyayama, Shiro

2007-01-01

The purpose of this article is to familiarize readers with the clinical syndrome of carotidynia. In the past, the International Headache Society (IHS) described idiopathic carotidynia as a diagnostic entity consisting of a self-limiting neck pain syndrome and tenderness over the carotid bifurcation without structural abnormality and then recently removed it from its classification. Although the clinical criteria of carotidynia in the former classification of the IHS included the absence of structural abnormality, several publications have demonstrated associated radiological findings and have described the usefulness of radiological investigations in diagnosing this syndrome. In this paper, we report four additional cases with a carotidynia clinical syndrome (according to the former classification) and the presence of abnormal soft tissue infiltration surrounding the symptomatic carotid artery as demonstrated by multiple imaging modalities, without any other underlying cause for the carotid pain syndrome. Our findings support the hypothesis that carotidynia could be a distinct disease entity, possibly caused by inflammation. (orig.)

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.

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.

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.

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.

Research progress of functional magnetic resonance imaging in cross-modal activation of visual cortex during tactile perception

International Nuclear Information System (INIS)

Zhan Jie; Gong Honghan

2013-01-01

An increasing amount of neuroimaging studies recently demonstrated activation of visual cortex in both blind and sighted participants when performing a variety of tactile tasks such as Braille reading and tactile object recognition, which indicates that visual cortex not only receives visual information, but may participate in tactile perception. To address these cross-modal changes of visual cortex and the neurophysiological mechanisms, many researchers conducted explosive studies using functional magnetic resonance imaging (fMRI) and have made some achievements. This review focuses on cross-modal activation of visual cortex and the underlying mechanisms during tactile perception in both blind and sighted individuals. (authors)

Cross-modal processing in auditory and visual working memory.

Science.gov (United States)

Suchan, Boris; Linnewerth, Britta; Köster, Odo; Daum, Irene; Schmid, Gebhard

2006-02-01

This study aimed to further explore processing of auditory and visual stimuli in working memory. Smith and Jonides (1997) [Smith, E.E., Jonides, J., 1997. Working memory: A view from neuroimaging. Cogn. Psychol. 33, 5-42] described a modified working memory model in which visual input is automatically transformed into a phonological code. To study this process, auditory and the corresponding visual stimuli were presented in a variant of the 2-back task which involved changes from the auditory to the visual modality and vice versa. Brain activation patterns underlying visual and auditory processing as well as transformation mechanisms were analyzed. Results yielded a significant activation in the left primary auditory cortex associated with transformation of visual into auditory information which reflects the matching and recoding of a stored item and its modality. This finding yields empirical evidence for a transformation of visual input into a phonological code, with the auditory cortex as the neural correlate of the recoding process in working memory.

40 CFR 1033.520 - Alternative ramped modal cycles.

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2010-07-01

... 40 Protection of Environment 32 2010-07-01 2010-07-01 false Alternative ramped modal cycles. 1033... cycles. (a) Locomotive testing over a ramped modal cycle is intended to improve measurement accuracy at... locomotive notch settings. Ramped modal cycles combine multiple test modes of a discrete-mode steady-state...

Neuroimaging of consciousness

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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

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

Effects of auditory and visual modalities in recall of words.

Science.gov (United States)

Gadzella, B M; Whitehead, D A

1975-02-01

Ten experimental conditions were used to study the effects of auditory and visual (printed words, uncolored and colored pictures) modalities and their various combinations with college students. A recall paradigm was employed in which subjects responded in a written test. Analysis of data showed the auditory modality was superior to visual (pictures) ones but was not significantly different from visual (printed words) modality. In visual modalities, printed words were superior to colored pictures. Generally, conditions with multiple modes of representation of stimuli were significantly higher than for conditions with single modes. Multiple modalities, consisting of two or three modes, did not differ significantly from each other. It was concluded that any two modalities of the stimuli presented simultaneously were just as effective as three in recall of stimulus words.

MindSeer: a portable and extensible tool for visualization of structural and functional neuroimaging data

Directory of Open Access Journals (Sweden)

Brinkley James F

2007-10-01

Full Text Available Abstract Background Three-dimensional (3-D visualization of multimodality neuroimaging data provides a powerful technique for viewing the relationship between structure and function. A number of applications are available that include some aspect of 3-D visualization, including both free and commercial products. These applications range from highly specific programs for a single modality, to general purpose toolkits that include many image processing functions in addition to visualization. However, few if any of these combine both stand-alone and remote multi-modality visualization in an open source, portable and extensible tool that is easy to install and use, yet can be included as a component of a larger information system. Results We have developed a new open source multimodality 3-D visualization application, called MindSeer, that has these features: integrated and interactive 3-D volume and surface visualization, Java and Java3D for true cross-platform portability, one-click installation and startup, integrated data management to help organize large studies, extensibility through plugins, transparent remote visualization, and the ability to be integrated into larger information management systems. We describe the design and implementation of the system, as well as several case studies that demonstrate its utility. These case studies are available as tutorials or demos on the associated website: http://sig.biostr.washington.edu/projects/MindSeer. Conclusion MindSeer provides a powerful visualization tool for multimodality neuroimaging data. Its architecture and unique features also allow it to be extended into other visualization domains within biomedicine.

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.

Naturalizing aesthetics: brain areas for aesthetic appraisal across sensory modalities.

Science.gov (United States)

Brown, Steven; Gao, Xiaoqing; Tisdelle, Loren; Eickhoff, Simon B; Liotti, Mario

2011-09-01

We present here the most comprehensive analysis to date of neuroaesthetic processing by reporting the results of voxel-based meta-analyses of 93 neuroimaging studies of positive-valence aesthetic appraisal across four sensory modalities. The results demonstrate that the most concordant area of activation across all four modalities is the right anterior insula, an area typically associated with visceral perception, especially of negative valence (disgust, pain, etc.). We argue that aesthetic processing is, at its core, the appraisal of the valence of perceived objects. This appraisal is in no way limited to artworks but is instead applicable to all types of perceived objects. Therefore, one way to naturalize aesthetics is to argue that such a system evolved first for the appraisal of objects of survival advantage, such as food sources, and was later co-opted in humans for the experience of artworks for the satisfaction of social needs. Copyright © 2011 Elsevier Inc. All rights reserved.

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.

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

Neuroimaging to Investigate Multisystem Involvement and Provide Biomarkers in Amyotrophic Lateral Sclerosis

Science.gov (United States)

Pradat, Pierre-François; El Mendili, Mohamed-Mounir

2014-01-01

Neuroimaging allows investigating the extent of neurological systems degeneration in amyotrophic lateral sclerosis (ALS). Advanced MRI methods can detect changes related to the degeneration of upper motor neurons but have also demonstrated the participation of other systems such as the sensory system or basal ganglia, demonstrating in vivo that ALS is a multisystem disorder. Structural and functional imaging also allows studying dysfunction of brain areas associated with cognitive signs. From a biomarker perspective, numerous studies using diffusion tensor imaging showed a decrease of fractional anisotropy in the intracranial portion of the corticospinal tract but its diagnostic value at the individual level remains limited. A multiparametric approach will be required to use MRI in the diagnostic workup of ALS. A promising avenue is the new methodological developments of spinal cord imaging that has the advantage to investigate the two motor system components that are involved in ALS, that is, the lower and upper motor neuron. For all neuroimaging modalities, due to the intrinsic heterogeneity of ALS, larger pooled banks of images with standardized image acquisition and analysis procedures are needed. In this paper, we will review the main findings obtained with MRI, PET, SPECT, and nuclear magnetic resonance spectroscopy in ALS. PMID:24949452

The effect of repetitive subconcussive collisions on brain integrity in collegiate football players over a single football season: A multi-modal neuroimaging study.

Science.gov (United States)

Slobounov, Semyon M; Walter, Alexa; Breiter, Hans C; Zhu, David C; Bai, Xiaoxiao; Bream, Tim; Seidenberg, Peter; Mao, Xianglun; Johnson, Brian; Talavage, Thomas M

2017-01-01

The cumulative effect of repetitive subconcussive collisions on the structural and functional integrity of the brain remains largely unknown. Athletes in collision sports, like football, experience a large number of impacts across a single season of play. The majority of these impacts, however, are generally overlooked, and their long-term consequences remain poorly understood. This study sought to examine the effects of repetitive collisions across a single competitive season in NCAA Football Bowl Subdivision athletes using advanced neuroimaging approaches. Players were evaluated before and after the season using multiple MRI sequences, including T 1 -weighted imaging, diffusion tensor imaging (DTI), arterial spin labeling (ASL), resting-state functional MRI (rs-fMRI), and susceptibility weighted imaging (SWI). While no significant differences were found between pre- and post-season for DTI metrics or cortical volumes, seed-based analysis of rs-fMRI revealed significant ( p  Football Bowl Subdivision, even in the absence of clinical symptoms or a diagnosis of concussion. Whether these changes reflect compensatory adaptation to cumulative head impacts or more lasting alteration of brain integrity remains to be further explored.

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

Near-infrared neuroimaging with NinPy

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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.

Neuroimaging in pre-motor Parkinson's disease

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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.

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.

Patient-tailored multimodal neuroimaging, visualization and quantification of human intra-cerebral hemorrhage

Science.gov (United States)

Goh, Sheng-Yang M.; Irimia, Andrei; Vespa, Paul M.; Van Horn, John D.

2016-03-01

In traumatic brain injury (TBI) and intracerebral hemorrhage (ICH), the heterogeneity of lesion sizes and types necessitates a variety of imaging modalities to acquire a comprehensive perspective on injury extent. Although it is advantageous to combine imaging modalities and to leverage their complementary benefits, there are difficulties in integrating information across imaging types. Thus, it is important that efforts be dedicated to the creation and sustained refinement of resources for multimodal data integration. Here, we propose a novel approach to the integration of neuroimaging data acquired from human patients with TBI/ICH using various modalities; we also demonstrate the integrated use of multimodal magnetic resonance imaging (MRI) and diffusion tensor imaging (DTI) data for TBI analysis based on both visual observations and quantitative metrics. 3D models of healthy-appearing tissues and TBIrelated pathology are generated, both of which are derived from multimodal imaging data. MRI volumes acquired using FLAIR, SWI, and T2 GRE are used to segment pathology. Healthy tissues are segmented using user-supervised tools, and results are visualized using a novel graphical approach called a `connectogram', where brain connectivity information is depicted within a circle of radially aligned elements. Inter-region connectivity and its strength are represented by links of variable opacities drawn between regions, where opacity reflects the percentage longitudinal change in brain connectivity density. Our method for integrating, analyzing and visualizing structural brain changes due to TBI and ICH can promote knowledge extraction and enhance the understanding of mechanisms underlying recovery.

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.

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 ...

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....

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...

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.

Complementarity of Sex Differences in Brain and Behavior: From Laterality to Multi-Modal Neuroimaging

Science.gov (United States)

Gur, Ruben C.; Gur, Raquel E.

2016-01-01

While overwhelmingly behavior is similar in males and females, and correspondingly the brains are similar, sex differences permeate both brain and behavioral measures and these differences have been the focus of increasing scrutiny by neuroscientists. Here we describe milestones of over three decades of research in brain and behavior. This research was necessarily bound by available methodology, and we began by indirect behavioral indicators of brain function such as handedness. We proceeded to using neuropsychological batteries and then to structural and functional neuroimaging that provided the foundations of a cognitive neuroscience based computerized neurocognitive battery. Sex differences were apparent and consistent in neurocognitive measures, with females performing better on memory and social cognition tasks and males on spatial processing and motor speed. Sex differences were also prominent on all major brain parameters, including higher rates of cerebral blood flow, higher percent of gray matter tissue and higher inter-hemispheric connectivity in females compared to higher percent of white matter and greater intra-hemispheric connectivity, as well as higher glucose metabolism in limbic regions in males. Many of these differences are present in childhood but they become more prominent with adolescence, perhaps linked to puberty. Together they indicate complementarity between the sexes that would result in higher adaptive diversity. PMID:27870413

The "handwriting brain": a meta-analysis of neuroimaging studies of motor versus orthographic processes.

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Planton, Samuel; Jucla, Mélanie; Roux, Franck-Emmanuel; Démonet, Jean-François

2013-01-01

Handwriting is a modality of language production whose cerebral substrates remain poorly known although the existence of specific regions is postulated. The description of brain damaged patients with agraphia and, more recently, several neuroimaging studies suggest the involvement of different brain regions. However, results vary with the methodological choices made and may not always discriminate between "writing-specific" and motor or linguistic processes shared with other abilities. We used the "Activation Likelihood Estimate" (ALE) meta-analytical method to identify the cerebral network of areas commonly activated during handwriting in 18 neuroimaging studies published in the literature. Included contrasts were also classified according to the control tasks used, whether non-specific motor/output-control or linguistic/input-control. These data were included in two secondary meta-analyses in order to reveal the functional role of the different areas of this network. An extensive, mainly left-hemisphere network of 12 cortical and sub-cortical areas was obtained; three of which were considered as primarily writing-specific (left superior frontal sulcus/middle frontal gyrus area, left intraparietal sulcus/superior parietal area, right cerebellum) while others related rather to non-specific motor (primary motor and sensorimotor cortex, supplementary motor area, thalamus and putamen) or linguistic processes (ventral premotor cortex, posterior/inferior temporal cortex). This meta-analysis provides a description of the cerebral network of handwriting as revealed by various types of neuroimaging experiments and confirms the crucial involvement of the left frontal and superior parietal regions. These findings provide new insights into cognitive processes involved in handwriting and their cerebral substrates. Copyright © 2013 Elsevier Ltd. All rights reserved.

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.)

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.)

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.

Turner Syndrome: Neuroimaging Findings--Structural and Functional

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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…

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

Multiple Kernel Learning with Random Effects for Predicting Longitudinal Outcomes and Data Integration

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Chen, Tianle; Zeng, Donglin

2015-01-01

Summary Predicting disease risk and progression is one of the main goals in many clinical research studies. Cohort studies on the natural history and etiology of chronic diseases span years and data are collected at multiple visits. Although kernel-based statistical learning methods are proven to be powerful for a wide range of disease prediction problems, these methods are only well studied for independent data but not for longitudinal data. It is thus important to develop time-sensitive prediction rules that make use of the longitudinal nature of the data. In this paper, we develop a novel statistical learning method for longitudinal data by introducing subject-specific short-term and long-term latent effects through a designed kernel to account for within-subject correlation of longitudinal measurements. Since the presence of multiple sources of data is increasingly common, we embed our method in a multiple kernel learning framework and propose a regularized multiple kernel statistical learning with random effects to construct effective nonparametric prediction rules. Our method allows easy integration of various heterogeneous data sources and takes advantage of correlation among longitudinal measures to increase prediction power. We use different kernels for each data source taking advantage of the distinctive feature of each data modality, and then optimally combine data across modalities. We apply the developed methods to two large epidemiological studies, one on Huntington's disease and the other on Alzheimer's Disease (Alzheimer's Disease Neuroimaging Initiative, ADNI) where we explore a unique opportunity to combine imaging and genetic data to study prediction of mild cognitive impairment, and show a substantial gain in performance while accounting for the longitudinal aspect of the data. PMID:26177419

Seven-Tesla Magnetization Transfer Imaging to Detect Multiple Sclerosis White Matter Lesions.

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Chou, I-Jun; Lim, Su-Yin; Tanasescu, Radu; Al-Radaideh, Ali; Mougin, Olivier E; Tench, Christopher R; Whitehouse, William P; Gowland, Penny A; Constantinescu, Cris S

2018-03-01

Fluid-attenuated inversion recovery (FLAIR) imaging at 3 Tesla (T) field strength is the most sensitive modality for detecting white matter lesions in multiple sclerosis. While 7T FLAIR is effective in detecting cortical lesions, it has not been fully optimized for visualization of white matter lesions and thus has not been used for delineating lesions in quantitative magnetic resonance imaging (MRI) studies of the normal appearing white matter in multiple sclerosis. Therefore, we aimed to evaluate the sensitivity of 7T magnetization-transfer-weighted (MT w ) images in the detection of white matter lesions compared with 3T-FLAIR. Fifteen patients with clinically isolated syndrome, 6 with multiple sclerosis, and 10 healthy participants were scanned with 7T 3-dimensional (D) MT w and 3T-2D-FLAIR sequences on the same day. White matter lesions visible on either sequence were delineated. Of 662 lesions identified on 3T-2D-FLAIR images, 652 were detected on 7T-3D-MT w images (sensitivity, 98%; 95% confidence interval, 97% to 99%). The Spearman correlation coefficient between lesion loads estimated by the two sequences was .910. The intrarater and interrater reliability for 7T-3D-MT w images was good with an intraclass correlation coefficient (ICC) of 98.4% and 81.8%, which is similar to that for 3T-2D-FLAIR images (ICC 96.1% and 96.7%). Seven-Tesla MT w sequences detected most of the white matter lesions identified by FLAIR at 3T. This suggests that 7T-MT w imaging is a robust alternative for detecting demyelinating lesions in addition to 3T-FLAIR. Future studies need to compare the roles of optimized 7T-FLAIR and of 7T-MT w imaging. © 2017 The Authors. Journal of Neuroimaging published by Wiley Periodicals, Inc. on behalf of American Society of Neuroimaging.

Integration of Multi-Modal Biomedical Data to Predict Cancer Grade and Patient Survival.

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Phan, John H; Hoffman, Ryan; Kothari, Sonal; Wu, Po-Yen; Wang, May D

2016-02-01

The Big Data era in Biomedical research has resulted in large-cohort data repositories such as The Cancer Genome Atlas (TCGA). These repositories routinely contain hundreds of matched patient samples for genomic, proteomic, imaging, and clinical data modalities, enabling holistic and multi-modal integrative analysis of human disease. Using TCGA renal and ovarian cancer data, we conducted a novel investigation of multi-modal data integration by combining histopathological image and RNA-seq data. We compared the performances of two integrative prediction methods: majority vote and stacked generalization. Results indicate that integration of multiple data modalities improves prediction of cancer grade and outcome. Specifically, stacked generalization, a method that integrates multiple data modalities to produce a single prediction result, outperforms both single-data-modality prediction and majority vote. Moreover, stacked generalization reveals the contribution of each data modality (and specific features within each data modality) to the final prediction result and may provide biological insights to explain prediction performance.

Detection ability of FDG-PET/CT comparing with other imaging modalities in multiple myeloma patients

International Nuclear Information System (INIS)

Chae, Min Jeong; Lee, Tae Hyun; Pai, Moon Sun; Cheon, Gi Jeong; Choi, Chang Woon; Lim, Sang Moo

2007-01-01

Multiple myeloma (MM) is characterized by bone marrow infiltration with malignant plasma cells. It is important to detect involving bone for diagnosis and management of MM. The aim of this study was to evaluate the diagnostic ability and limitation of 18F-FDG-PET/CT (PET/CT) comparing other imaging modalities (separated PET and CT, whole body plain X-ray (XR), bone scintigraphy (BS), and MRI) in MM. Twenty PET/CT scans were performed in 16 patients (M: F=6: 10, median age=59 y). PET/CT findings were compared with available other images (n of CT=21, XR=21, BS=8, and MRI=5). Concordance with more than 2 image modalities, laboratory data, symptom, and biopsies were used for diagnosis of detected lesions. PET/CT revealed 256 of total 287 sites (sensitivity, 89.2%; accuracy, 84.8%). The sensitivity and accuracy of separating PET, CT, and XR were 86.3%, 70.4%; 47.4%, 50.3%; and 72.8%, 72.4%, respectively. Available BS identified 67 of 202 sites (sensitivity, 33.2%; accuracy, 44.0%). MRI detected 20 of 24 sites (sensitivity, 83.3%; accuracy, 36.3%). False positive rate (FP) of PET, XR, and MRI was as high as 87.8%, 95.1%, and 100%. PET for rib lesion identified 9 of 10 patients (90.0%) but for skull lesion only 4 of 7 patients (57.2%) with underestimation. 5 patients in MRI showed diffuse marrow signal change but only 3 had marrow involvement. But PET/CT showed higher accuracy than MRI. PET/CT was the most useful tool for detecting involving bone of MM comparing with other imaging modalities. Moreover, PET/CT is expected to overcome the limitations for the small osteolytic bone lesions with diffuse FDG uptake on PET

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…

Modal Testing of Seven Shuttle Cargo Elements for Space Station

Science.gov (United States)

Kappus, Kathy O.; Driskill, Timothy C.; Parks, Russel A.; Patterson, Alan (Technical Monitor)

2001-01-01

From December 1996 to May 2001, the Modal and Control Dynamics Team at NASA's Marshall Space Flight Center (MSFC) conducted modal tests on seven large elements of the International Space Station. Each of these elements has been or will be launched as a Space Shuttle payload for transport to the International Space Station (ISS). Like other Shuttle payloads, modal testing of these elements was required for verification of the finite element models used in coupled loads analyses for launch and landing. The seven modal tests included three modules - Node, Laboratory, and Airlock, and four truss segments - P6, P3/P4, S1/P1, and P5. Each element was installed and tested in the Shuttle Payload Modal Test Bed at MSFC. This unique facility can accommodate any Shuttle cargo element for modal test qualification. Flexure assemblies were utilized at each Shuttle-to-payload interface to simulate a constrained boundary in the load carrying degrees of freedom. For each element, multiple-input, multiple-output burst random modal testing was the primary approach with controlled input sine sweeps for linearity assessments. The accelerometer channel counts ranged from 252 channels to 1251 channels. An overview of these tests, as well as some lessons learned, will be provided in this paper.

Big Data and Neuroimaging.

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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.

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...

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.

A digital 3D atlas of the marmoset brain based on multi-modal MRI.

Science.gov (United States)

Liu, Cirong; Ye, Frank Q; Yen, Cecil Chern-Chyi; Newman, John D; Glen, Daniel; Leopold, David A; Silva, Afonso C

2018-04-01

The common marmoset (Callithrix jacchus) is a New-World monkey of growing interest in neuroscience. Magnetic resonance imaging (MRI) is an essential tool to unveil the anatomical and functional organization of the marmoset brain. To facilitate identification of regions of interest, it is desirable to register MR images to an atlas of the brain. However, currently available atlases of the marmoset brain are mainly based on 2D histological data, which are difficult to apply to 3D imaging techniques. Here, we constructed a 3D digital atlas based on high-resolution ex-vivo MRI images, including magnetization transfer ratio (a T1-like contrast), T2w images, and multi-shell diffusion MRI. Based on the multi-modal MRI images, we manually delineated 54 cortical areas and 16 subcortical regions on one hemisphere of the brain (the core version). The 54 cortical areas were merged into 13 larger cortical regions according to their locations to yield a coarse version of the atlas, and also parcellated into 106 sub-regions using a connectivity-based parcellation method to produce a refined atlas. Finally, we compared the new atlas set with existing histology atlases and demonstrated its applications in connectome studies, and in resting state and stimulus-based fMRI. The atlas set has been integrated into the widely-distributed neuroimaging data analysis software AFNI and SUMA, providing a readily usable multi-modal template space with multi-level anatomical labels (including labels from the Paxinos atlas) that can facilitate various neuroimaging studies of marmosets. Published by Elsevier Inc.

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 .

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.

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).

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...

Wilson's disease: two treatment modalities. Correlations to pretreatment and posttreatment brain MRI

International Nuclear Information System (INIS)

Leiros da Costa, Maria do Desterro; Spitz, Mariana; Bacheschi, Luiz Alberto; Barbosa, Egberto Reis; Leite, Claudia Costa; Lucato, Leandro Tavares

2009-01-01

Brain magnetic resonance imaging (MRI) studies on Wilson's disease (WD) show lack of correlations between neurological and neuroimaging features. Long-term follow-up reports with sequential brain MRI in patients with neurological WD comparing different modalities of treatment are scarce. Eighteen patients with neurological WD underwent pretreatment and posttreatment brain MRI scans to evaluate the range of abnormalities and the evolution along these different periods. All patients underwent at least two MRI scans at different intervals, up to 11 years after the beginning of treatment. MRI findings were correlated with clinical picture, clinical severity, duration of neurological symptoms, and treatment with two different drugs. Patients were divided into two groups according to treatment: d-penicillamine (D-P), zinc (Zn), and Zn after the onset of severe intolerance to D-P. MRI scans before treatment showed, in all patients, hypersignal intensity lesions on T2- and proton-density-weighted images bilaterally and symmetrically at basal nuclei, thalamus, brain stem, cerebellum, brain cortex, and brain white matter. The most common neurological symptoms were: dysarthria, parkinsonism, dystonia, tremor, psychiatric disturbances, dysphagia, risus sardonicus, ataxia, chorea, and athetosis. From the neurological point of view, there was no difference on the evolution between the group treated exclusively with D-P and the one treated with Zn. Analysis of MRI scans with longer intervals after the beginning of treatment depicted a trend for neuroimaging worsening, without neurological correspondence, among patients treated with Zn. Neuroimaging pattern of evolution was more favorable for the group that received exclusively D-P. (orig.)

A Neuroimaging Web Services Interface as a Cyber Physical System for Medical Imaging and Data Management in Brain Research: Design Study.

Science.gov (United States)

Lizarraga, Gabriel; Li, Chunfei; Cabrerizo, Mercedes; Barker, Warren; Loewenstein, David A; Duara, Ranjan; Adjouadi, Malek

2018-04-26

Structural and functional brain images are essential imaging modalities for medical experts to study brain anatomy. These images are typically visually inspected by experts. To analyze images without any bias, they must be first converted to numeric values. Many software packages are available to process the images, but they are complex and difficult to use. The software packages are also hardware intensive. The results obtained after processing vary depending on the native operating system used and its associated software libraries; data processed in one system cannot typically be combined with data on another system. The aim of this study was to fulfill the neuroimaging community’s need for a common platform to store, process, explore, and visualize their neuroimaging data and results using Neuroimaging Web Services Interface: a series of processing pipelines designed as a cyber physical system for neuroimaging and clinical data in brain research. Neuroimaging Web Services Interface accepts magnetic resonance imaging, positron emission tomography, diffusion tensor imaging, and functional magnetic resonance imaging. These images are processed using existing and custom software packages. The output is then stored as image files, tabulated files, and MySQL tables. The system, made up of a series of interconnected servers, is password-protected and is securely accessible through a Web interface and allows (1) visualization of results and (2) downloading of tabulated data. All results were obtained using our processing servers in order to maintain data validity and consistency. The design is responsive and scalable. The processing pipeline started from a FreeSurfer reconstruction of Structural magnetic resonance imaging images. The FreeSurfer and regional standardized uptake value ratio calculations were validated using Alzheimer’s Disease Neuroimaging Initiative input images, and the results were posted at the Laboratory of Neuro Imaging data archive. Notable

Online multi-modal robust non-negative dictionary learning for visual tracking.

Science.gov (United States)

Zhang, Xiang; Guan, Naiyang; Tao, Dacheng; Qiu, Xiaogang; Luo, Zhigang

2015-01-01

Dictionary learning is a method of acquiring a collection of atoms for subsequent signal representation. Due to its excellent representation ability, dictionary learning has been widely applied in multimedia and computer vision. However, conventional dictionary learning algorithms fail to deal with multi-modal datasets. In this paper, we propose an online multi-modal robust non-negative dictionary learning (OMRNDL) algorithm to overcome this deficiency. Notably, OMRNDL casts visual tracking as a dictionary learning problem under the particle filter framework and captures the intrinsic knowledge about the target from multiple visual modalities, e.g., pixel intensity and texture information. To this end, OMRNDL adaptively learns an individual dictionary, i.e., template, for each modality from available frames, and then represents new particles over all the learned dictionaries by minimizing the fitting loss of data based on M-estimation. The resultant representation coefficient can be viewed as the common semantic representation of particles across multiple modalities, and can be utilized to track the target. OMRNDL incrementally learns the dictionary and the coefficient of each particle by using multiplicative update rules to respectively guarantee their non-negativity constraints. Experimental results on a popular challenging video benchmark validate the effectiveness of OMRNDL for visual tracking in both quantity and quality.

A new algebraic white-noise modal combination rule - GAC(A)

International Nuclear Information System (INIS)

Mertens, P.G.

1994-01-01

It is a well known fact that above the rigid frequency the maximum dynamic modal responses even with different multiple supports can be combined algebraically. Below the rigid frequency, and more specifically in the white-noise (amplified) region of the response spectrum, algebraic modal combination is still a matter of controversy, demonstrated e.g. by the NRC R.G. 1.92 requirement to take the absolute values of the modal responses in heuristic modal combination rules; whereas algebraic support combination is only allowed in conjunction with the envelope support response spectrum (ERS). Such regulatory requirements can lead to unrealistically high calculated responses e.g. in the coupled analysis of light secondary systems attached to heavy primary structures and in the decoupled analysis of systems when the centres of mass and stiffness do not coincide, or when the ERS is used. A new Generalised Algebraic Combination (GAC) methodology has been theoretically developed which allows practical algebraic modal and support combination over the whole frequency range of multiple support spectra. The present paper deals with the GAC-(A) i.e. the modal combination version in the white noise region of a single response spectrum and more specifically its time history integration validation, which shows that this new modal combination rule can satisfy any realistic conservatism that may be required by regulatory institutions. (orig.)

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.

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)

The Cerefy Neuroradiology Atlas: a Talairach-Tournoux atlas-based tool for analysis of neuroimages available over the internet.

Science.gov (United States)

Nowinski, Wieslaw L; Belov, Dmitry

2003-09-01

The article introduces an atlas-assisted method and a tool called the Cerefy Neuroradiology Atlas (CNA), available over the Internet for neuroradiology and human brain mapping. The CNA contains an enhanced, extended, and fully segmented and labeled electronic version of the Talairach-Tournoux brain atlas, including parcelated gyri and Brodmann's areas. To our best knowledge, this is the first online, publicly available application with the Talairach-Tournoux atlas. The process of atlas-assisted neuroimage analysis is done in five steps: image data loading, Talairach landmark setting, atlas normalization, image data exploration and analysis, and result saving. Neuroimage analysis is supported by a near-real-time, atlas-to-data warping based on the Talairach transformation. The CNA runs on multiple platforms; is able to process simultaneously multiple anatomical and functional data sets; and provides functions for a rapid atlas-to-data registration, interactive structure labeling and annotating, and mensuration. It is also empowered with several unique features, including interactive atlas warping facilitating fine tuning of atlas-to-data fit, navigation on the triplanar formed by the image data and the atlas, multiple-images-in-one display with interactive atlas-anatomy-function blending, multiple label display, and saving of labeled and annotated image data. The CNA is useful for fast atlas-assisted analysis of neuroimage data sets. It increases accuracy and reduces time in localization analysis of activation regions; facilitates to communicate the information on the interpreted scans from the neuroradiologist to other clinicians and medical students; increases the neuroradiologist's confidence in terms of anatomy and spatial relationships; and serves as a user-friendly, public domain tool for neuroeducation. At present, more than 700 users from five continents have subscribed to the CNA.

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...

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.

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.

Conceptual structure within and between modalities

Directory of Open Access Journals (Sweden)

Katia eDilkina

2013-01-01

Full Text Available Current views of semantic memory share the assumption that conceptual representations are based on multi-modal experience, which activates distinct modality-specific brain regions. This proposition is widely accepted, yet little is known about how each modality contributes to conceptual knowledge and how the structure of this contribution varies across these multiple information sources. We used verbal feature lists, features from drawings and verbal co-occurrence statistics from latent semantic analysis to examine the informational structure in four domains of knowledge: perceptual, functional, encyclopedic and verbal. The goals of the analysis were three-fold: (1 to assess the structure within individual modalities; (2 to compare structures between modalities; and (3 to assess the degree to which concepts organize categorically or randomly.Our results indicated significant and unique structure in all four modalities: perceptually, concepts organize based on prominent features such as shape, size, color and parts; functionally, they group based on use and interaction; encyclopedically, they arrange based on commonality in location or behavior; and verbally, they group associatively or relationally. Visual/perceptual knowledge gives rise to the strongest hierarchical organization and is closest to classic taxonomic structure. Information is organized somewhat similarly in the perceptual and encyclopedic domains, which differs significantly from the structure in the functional and verbal domains. Notably, the verbal modality has the most unique organization, which is not at all categorical but also not random. The idiosyncrasy and complexity of conceptual structure across modalities begs the question of how all of these modality-specific experiences are fused together into coherent, multi-faceted yet unified concepts. Accordingly, both methodological and theoretical implications of the present findings are discussed.

Task-related component analysis for functional neuroimaging and application to near-infrared spectroscopy data.

Science.gov (United States)

Tanaka, Hirokazu; Katura, Takusige; Sato, Hiroki

2013-01-01

Reproducibility of experimental results lies at the heart of scientific disciplines. Here we propose a signal processing method that extracts task-related components by maximizing the reproducibility during task periods from neuroimaging data. Unlike hypothesis-driven methods such as general linear models, no specific time courses are presumed, and unlike data-driven approaches such as independent component analysis, no arbitrary interpretation of components is needed. Task-related components are constructed by a linear, weighted sum of multiple time courses, and its weights are optimized so as to maximize inter-block correlations (CorrMax) or covariances (CovMax). Our analysis method is referred to as task-related component analysis (TRCA). The covariance maximization is formulated as a Rayleigh-Ritz eigenvalue problem, and corresponding eigenvectors give candidates of task-related components. In addition, a systematic statistical test based on eigenvalues is proposed, so task-related and -unrelated components are classified objectively and automatically. The proposed test of statistical significance is found to be independent of the degree of autocorrelation in data if the task duration is sufficiently longer than the temporal scale of autocorrelation, so TRCA can be applied to data with autocorrelation without any modification. We demonstrate that simple extensions of TRCA can provide most distinctive signals for two tasks and can integrate multiple modalities of information to remove task-unrelated artifacts. TRCA was successfully applied to synthetic data as well as near-infrared spectroscopy (NIRS) data of finger tapping. There were two statistically significant task-related components; one was a hemodynamic response, and another was a piece-wise linear time course. In summary, we conclude that TRCA has a wide range of applications in multi-channel biophysical and behavioral measurements. Copyright © 2012 Elsevier Inc. All rights reserved.

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)

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.

Aeroelastic modal dynamics of wind turbines including anisotropic effects

DEFF Research Database (Denmark)

Skjoldan, Peter Fisker

frequency is thus identified as the dominant frequency in the response of a pure excitation of the mode observed in the inertial frame. A modal analysis tool based directly on the complex aeroelastic wind turbine code BHawC is presented. It uses the Coleman approach in isotropic conditions......Several methods for aeroelastic modal analysis of a rotating wind turbine are developed and used to analyse the modal dynamics of two simplified models and a complex model in isotropic and anisotropic conditions. The Coleman transformation is used to enable extraction of the modal frequencies...... of Floquet analysis or Hill's method which do not provide a unique reference frame for observing the modal frequency, to which any multiple of the rotor speed can be added. This indeterminacy is resolved by requiring that the periodic mode shape be as constant as possible in the inertial frame. The modal...

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

Stokes-space analysis of modal dispersion in fibers with multiple mode transmission.

Science.gov (United States)

Antonelli, Cristian; Mecozzi, Antonio; Shtaif, Mark; Winzer, Peter J

2012-05-21

Modal dispersion (MD) in a multimode fiber may be considered as a generalized form of polarization mode dispersion (PMD) in single mode fibers. Using this analogy, we extend the formalism developed for PMD to characterize MD in fibers with multiple spatial modes. We introduce a MD vector defined in a D-dimensional extended Stokes space whose square length is the sum of the square group delays of the generalized principal states. For strong mode coupling, the MD vector undertakes a D-dimensional isotropic random walk, so that the distribution of its length is a chi distribution with D degrees of freedom. We also characterize the largest differential group delay, that is the difference between the delays of the fastest and the slowest principal states, and show that it too is very well approximated by a chi distribution, although in general with a smaller number of degrees of freedom. Finally, we study the spectral properties of MD in terms of the frequency autocorrelation functions of the MD vector, of the square modulus of the MD vector, and of the largest differential group delay. The analytical results are supported by extensive numerical simulations.

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.

Automatic classification of early Parkinson's disease with multi-modal MR imaging.

Directory of Open Access Journals (Sweden)

Dan Long

Full Text Available BACKGROUND: In recent years, neuroimaging has been increasingly used as an objective method for the diagnosis of Parkinson's disease (PD. Most previous studies were based on invasive imaging modalities or on a single modality which was not an ideal diagnostic tool. In this study, we developed a non-invasive technology intended for use in the diagnosis of early PD by integrating the advantages of various modals. MATERIALS AND METHODS: Nineteen early PD patients and twenty-seven normal volunteers participated in this study. For each subject, we collected resting-state functional magnetic resonance imaging (rsfMRI and structural images. For the rsfMRI images, we extracted the characteristics at three different levels: ALFF (amplitude of low-frequency fluctuations, ReHo (regional homogeneity and RFCS (regional functional connectivity strength. For the structural images, we extracted the volume characteristics from the gray matter (GM, the white matter (WM and the cerebrospinal fluid (CSF. A two-sample t-test was used for the feature selection, and then the remaining features were fused for classification. Finally a classifier for early PD patients and normal control subjects was identified from support vector machine training. The performance of the classifier was evaluated using the leave-one-out cross-validation method. RESULTS: Using the proposed methods to classify the data set, good results (accuracy  = 86.96%, sensitivity  = 78.95%, specificity  = 92.59% were obtained. CONCLUSIONS: This method demonstrates a promising diagnosis performance by the integration of information from a variety of imaging modalities, and it shows potential for improving the clinical diagnosis and treatment of PD.

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.

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.)

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.

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....

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.

Localisation of epileptic foci using novel imaging modalities

Science.gov (United States)

De Ciantis, Alessio; Lemieux, Louis

2013-01-01

Purpose of review This review examines recent reports on the use of advanced techniques to map the regions and networks involved during focal epileptic seizure generation in humans. Recent findings A number of imaging techniques are capable of providing new localizing information on the ictal processes and epileptogenic zone. Evaluating the clinical utility of these findings has been mainly performed through post-hoc comparison with the findings of invasive EEG and ictal single-photon emission computed tomography, using postsurgical seizure reduction as the main outcome measure. Added value has been demonstrated in MRI-negative cases. Improved understanding of the human ictiogenic processes and the focus vs. network hypothesis is likely to result from the application of multimodal techniques that combine electrophysiological, semiological, and whole-brain coverage of brain activity changes. Summary On the basis of recent research in the field of neuroimaging, several novel imaging modalities have been improved and developed to provide information about the localization of epileptic foci. PMID:23823464

Wilson's disease: two treatment modalities. Correlations to pretreatment and posttreatment brain MRI

Energy Technology Data Exchange (ETDEWEB)

Leiros da Costa, Maria do Desterro [Federal University of Paraiba, Movement Disorders Unit, Paraiba (Brazil); Spitz, Mariana; Bacheschi, Luiz Alberto; Barbosa, Egberto Reis [University of Sao Paulo, Movement Disorders Unit, Sao Paulo (Brazil); Leite, Claudia Costa; Lucato, Leandro Tavares [University of Sao Paulo, Department of Radiology, Sao Paulo (Brazil)

2009-10-15

Brain magnetic resonance imaging (MRI) studies on Wilson's disease (WD) show lack of correlations between neurological and neuroimaging features. Long-term follow-up reports with sequential brain MRI in patients with neurological WD comparing different modalities of treatment are scarce. Eighteen patients with neurological WD underwent pretreatment and posttreatment brain MRI scans to evaluate the range of abnormalities and the evolution along these different periods. All patients underwent at least two MRI scans at different intervals, up to 11 years after the beginning of treatment. MRI findings were correlated with clinical picture, clinical severity, duration of neurological symptoms, and treatment with two different drugs. Patients were divided into two groups according to treatment: d-penicillamine (D-P), zinc (Zn), and Zn after the onset of severe intolerance to D-P. MRI scans before treatment showed, in all patients, hypersignal intensity lesions on T2- and proton-density-weighted images bilaterally and symmetrically at basal nuclei, thalamus, brain stem, cerebellum, brain cortex, and brain white matter. The most common neurological symptoms were: dysarthria, parkinsonism, dystonia, tremor, psychiatric disturbances, dysphagia, risus sardonicus, ataxia, chorea, and athetosis. From the neurological point of view, there was no difference on the evolution between the group treated exclusively with D-P and the one treated with Zn. Analysis of MRI scans with longer intervals after the beginning of treatment depicted a trend for neuroimaging worsening, without neurological correspondence, among patients treated with Zn. Neuroimaging pattern of evolution was more favorable for the group that received exclusively D-P. (orig.)

NEUROIMAGING AND PATTERN RECOGNITION TECHNIQUES FOR AUTOMATIC DETECTION OF ALZHEIMER’S DISEASE: A REVIEW

Directory of Open Access Journals (Sweden)

Rupali Kamathe

2017-08-01

Full Text Available Alzheimer’s disease (AD is the most common form of dementia with currently unavailable firm treatments that can stop or reverse the disease progression. A combination of brain imaging and clinical tests for checking the signs of memory impairment is used to identify patients with AD. In recent years, Neuroimaging techniques combined with machine learning algorithms have received lot of attention in this field. There is a need for development of automated techniques to detect the disease well before patient suffers from irreversible loss. This paper is about the review of such semi or fully automatic techniques with detail comparison of methods implemented, class labels considered, data base used and the results obtained for related study. This review provides detailed comparison of different Neuroimaging techniques and reveals potential application of machine learning algorithms in medical image analysis; particularly in AD enabling even the early detection of the disease- the class labelled as Multiple Cognitive Impairment.

Detecting Pedestrian Flocks by Fusion of Multi-Modal Sensors in Mobile Phones

DEFF Research Database (Denmark)

Kjærgaard, Mikkel Baun; Wirz, Martin; Roggen, Daniel

2012-01-01

derived from multiple sensor modalities of modern smartphones. Automatic detection of flocks has several important applications, including evacuation management and socially aware computing. The novelty of this paper is, firstly, to use data fusion techniques to combine several sensor modalities (WiFi...

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.

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.)

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.)

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.

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.

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.

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.

Assessment of rigid multi-modality image registration consistency using the multiple sub-volume registration (MSR) method

International Nuclear Information System (INIS)

Ceylan, C; Heide, U A van der; Bol, G H; Lagendijk, J J W; Kotte, A N T J

2005-01-01

Registration of different imaging modalities such as CT, MRI, functional MRI (fMRI), positron (PET) and single photon (SPECT) emission tomography is used in many clinical applications. Determining the quality of any automatic registration procedure has been a challenging part because no gold standard is available to evaluate the registration. In this note we present a method, called the 'multiple sub-volume registration' (MSR) method, for assessing the consistency of a rigid registration. This is done by registering sub-images of one data set on the other data set, performing a crude non-rigid registration. By analysing the deviations (local deformations) of the sub-volume registrations from the full registration we get a measure of the consistency of the rigid registration. Registration of 15 data sets which include CT, MR and PET images for brain, head and neck, cervix, prostate and lung was performed utilizing a rigid body registration with normalized mutual information as the similarity measure. The resulting registrations were classified as good or bad by visual inspection. The resulting registrations were also classified using our MSR method. The results of our MSR method agree with the classification obtained from visual inspection for all cases (p < 0.02 based on ANOVA of the good and bad groups). The proposed method is independent of the registration algorithm and similarity measure. It can be used for multi-modality image data sets and different anatomic sites of the patient. (note)

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...

On modal cross-coupling in the asymptotic modal limit

Science.gov (United States)

Culver, Dean; Dowell, Earl

2018-03-01

The conditions under which significant modal cross-coupling occurs in dynamical systems responding to high-frequency, broadband forcing that excites many modes is studied. The modal overlap factor plays a key role in the analysis of these systems as the modal density (the ratio of number of modes to the frequency bandwidth) becomes large. The modal overlap factor is effectively the ratio of the width of a resonant peak (the damping ratio times the resonant frequency) to the average frequency interval between resonant peaks (or rather, the inverse of the modal density). It is shown that this parameter largely determines whether substantial modal cross-coupling occurs in a given system's response. Here, two prototypical systems are considered. The first is a simple rectangular plate whose significant modal cross-coupling is the exception rather than the norm. The second is a pair of rectangular plates attached at a point where significant modal cross-coupling is more likely to occur. We show that, for certain cases of modal density and damping, non-negligible cross coupling occurs in both systems. Under similar circumstances, the constraint force between the two plates in the latter system becomes broadband. The implications of this for using Asymptotic Modal Analysis (AMA) in multi-component systems are discussed.

Modality dependency of familiarity ratings of Japanese words.

Science.gov (United States)

Amano, S; Kondo, T; Kakehi, K

1995-07-01

Familiarity ratings for a large number of aurally and visually presented Japanese words wer measured for 11 subjects, in order to investigate the modality dependency of familiarity. The correlation coefficient between auditory and visual ratings was .808, which is lower than that observed for English words, suggesting that a substantial portion of the mental lexicon is modality dependent. It was shown that the modality dependency is greater for low-familiarity words than it is for medium- or high-familiarity words. This difference between the low- and the medium- or high-familiarity words has a relationship to orthography. That is, the dependency is larger in words consisting only of kanji, which may have multiple pronunciations and usually represent meaning, than it is in words consisting only of hiragana or katakana, which have a single pronunciation and usually do not represent meaning. These results indicate that the idiosyncratic characteristics of Japanese orthography contribute to the modality dependency.

[Cost-effectiveness of multiple screening modalities on breast cancer in Chinese women from Shanghai].

Science.gov (United States)

Wu, F; Mo, M; Qin, X X; Fang, H; Zhao, G M; Liu, G Y; Chen, Y Y; Cao, Z G; Yan, Y J; Lyu, L L; Xu, W H; Shao, Z M

2017-12-10

Objective: To determine the most cost-effective modality for breast cancer screening in women living in Shanghai. Methods: A Markov model for breast cancer was redeveloped based on true effect which was derived from a project for detection of women at high risk of breast cancer and an organized breast cancer screening program conducted simultaneously in Minhang district, Shanghai, during 2008 to 2012. Parameters of the model were derived from literatures. General principles related to cost-effectiveness analysis were used to compare the costs and effects of 12 different screening modalities in a simulated cohort involving 100 000 women aged 45 years. Incremental cost-effectiveness ratio (ICER) was used to determine the most cost-effective modality. Sensitivity analysis was conducted to evaluate how these factors affected the estimated cost-effectiveness. Results: The modality of biennial CBE followed by ultrasonic and mammography among those with positive CBE was observed as the most cost-effective one. The costs appeared as 182 526 Yuan RMB per life year gained and 144 386 Yuan RMB per quality adjusted life-year (QALY) saved, which were within the threshold of 2-3 times of local per capita Gross Domestic Product. Results from sensitivity analysis showed that, due to higher incidence rate of breast cancer in Shanghai, the cost per QALY would be 64 836 Yuan RMB lower in Shanghai than the average level in China. Conclusion: Our research findings showed that the biennial CBE program followed by ultrasonic and mammography for those with positive CBE results might serve as the optimal breast cancer screening modality for Chinese women living in Shanghai, and thus be widely promoted in this population elsewhere.

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.

Aeroelastic modal dynamics of wind turbines including anisotropic effects

Energy Technology Data Exchange (ETDEWEB)

Fisker Skjoldan, P.

2011-03-15

Several methods for aeroelastic modal analysis of a rotating wind turbine are developed and used to analyse the modal dynamics of two simplified models and a complex model in isotropic and anisotropic conditions. The Coleman transformation is used to enable extraction of the modal frequencies, damping, and periodic mode shapes of a rotating wind turbine by describing the rotor degrees of freedom in the inertial frame. This approach is valid only for an isotropic system. Anisotropic systems, e.g., with an unbalanced rotor or operating in wind shear, are treated with the general approaches of Floquet analysis or Hill's method which do not provide a unique reference frame for observing the modal frequency, to which any multiple of the rotor speed can be added. This indeterminacy is resolved by requiring that the periodic mode shape be as constant as possible in the inertial frame. The modal frequency is thus identified as the dominant frequency in the response of a pure excitation of the mode observed in the inertial frame. A modal analysis tool based directly on the complex aeroelastic wind turbine code BHawC is presented. It uses the Coleman approach in isotropic conditions and the computationally efficient implicit Floquet analysis in anisotropic conditions. The tool is validated against system identifications with the partial Floquet method on the nonlinear BHawC model of a 2.3 MW wind turbine. System identification results show that nonlinear effects on the 2.3 MW turbine in most cases are small, but indicate that the controller creates nonlinear damping. In isotropic conditions the periodic mode shape contains up to three harmonic components, but in anisotropic conditions it can contain an infinite number of harmonic components with frequencies that are multiples of the rotor speed. These harmonics appear in calculated frequency responses of the turbine. Extreme wind shear changes the modal damping when the flow is separated due to an interaction between

Multi-Modal Curriculum Learning for Semi-Supervised Image Classification.

Science.gov (United States)

Gong, Chen; Tao, Dacheng; Maybank, Stephen J; Liu, Wei; Kang, Guoliang; Yang, Jie

2016-07-01

Semi-supervised image classification aims to classify a large quantity of unlabeled images by typically harnessing scarce labeled images. Existing semi-supervised methods often suffer from inadequate classification accuracy when encountering difficult yet critical images, such as outliers, because they treat all unlabeled images equally and conduct classifications in an imperfectly ordered sequence. In this paper, we employ the curriculum learning methodology by investigating the difficulty of classifying every unlabeled image. The reliability and the discriminability of these unlabeled images are particularly investigated for evaluating their difficulty. As a result, an optimized image sequence is generated during the iterative propagations, and the unlabeled images are logically classified from simple to difficult. Furthermore, since images are usually characterized by multiple visual feature descriptors, we associate each kind of features with a teacher, and design a multi-modal curriculum learning (MMCL) strategy to integrate the information from different feature modalities. In each propagation, each teacher analyzes the difficulties of the currently unlabeled images from its own modality viewpoint. A consensus is subsequently reached among all the teachers, determining the currently simplest images (i.e., a curriculum), which are to be reliably classified by the multi-modal learner. This well-organized propagation process leveraging multiple teachers and one learner enables our MMCL to outperform five state-of-the-art methods on eight popular image data sets.

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...

How Acute Total Sleep Loss Affects the Attending Brain: A Meta-Analysis of Neuroimaging Studies

Science.gov (United States)

Ma, Ning; Dinges, David F.; Basner, Mathias; Rao, Hengyi

2015-01-01

Study Objectives: Attention is a cognitive domain that can be severely affected by sleep deprivation. Previous neuroimaging studies have used different attention paradigms and reported both increased and reduced brain activation after sleep deprivation. However, due to large variability in sleep deprivation protocols, task paradigms, experimental designs, characteristics of subject populations, and imaging techniques, there is no consensus regarding the effects of sleep loss on the attending brain. The aim of this meta-analysis was to identify brain activations that are commonly altered by acute total sleep deprivation across different attention tasks. Design: Coordinate-based meta-analysis of neuroimaging studies of performance on attention tasks during experimental sleep deprivation. Methods: The current version of the activation likelihood estimation (ALE) approach was used for meta-analysis. The authors searched published articles and identified 11 sleep deprivation neuroimaging studies using different attention tasks with a total of 185 participants, equaling 81 foci for ALE analysis. Results: The meta-analysis revealed significantly reduced brain activation in multiple regions following sleep deprivation compared to rested wakefulness, including bilateral intraparietal sulcus, bilateral insula, right prefrontal cortex, medial frontal cortex, and right parahippocampal gyrus. Increased activation was found only in bilateral thalamus after sleep deprivation compared to rested wakefulness. Conclusion: Acute total sleep deprivation decreases brain activation in the fronto-parietal attention network (prefrontal cortex and intraparietal sulcus) and in the salience network (insula and medial frontal cortex). Increased thalamic activation after sleep deprivation may reflect a complex interaction between the de-arousing effects of sleep loss and the arousing effects of task performance on thalamic activity. Citation: Ma N, Dinges DF, Basner M, Rao H. How acute total

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.

Multisite, multimodal neuroimaging of chronic urological pelvic pain: Methodology of the MAPP Research Network

Directory of Open Access Journals (Sweden)

Jeffry R. Alger

2016-01-01

Full Text Available The Multidisciplinary Approach to the Study of Chronic Pelvic Pain (MAPP Research Network is an ongoing multi-center collaborative research group established to conduct integrated studies in participants with urologic chronic pelvic pain syndrome (UCPPS. The goal of these investigations is to provide new insights into the etiology, natural history, clinical, demographic and behavioral characteristics, search for new and evaluate candidate biomarkers, systematically test for contributions of infectious agents to symptoms, and conduct animal studies to understand underlying mechanisms for UCPPS. Study participants were enrolled in a one-year observational study and evaluated through a multisite, collaborative neuroimaging study to evaluate the association between UCPPS and brain structure and function. 3D T1-weighted structural images, resting-state fMRI, and high angular resolution diffusion MRI were acquired in five participating MAPP Network sites using 8 separate MRI hardware and software configurations. We describe the neuroimaging methods and procedures used to scan participants, the challenges encountered in obtaining data from multiple sites with different equipment/software, and our efforts to minimize site-to-site variation.

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.

Heterogeneous Optimization Framework: Reproducible Preprocessing of Multi-Spectral Clinical MRI for Neuro-Oncology Imaging Research

OpenAIRE

Milchenko, Mikhail; Snyder, Abraham Z.; LaMontagne, Pamela; Shimony, Joshua S; Benzinger, Tammie L.; Fouke, Sarah Jost; Marcus, Daniel S.

2016-01-01

Neuroimaging research often relies on clinically acquired magnetic resonance imaging (MRI) datasets that can originate from multiple institutions. Such datasets are characterized by high heterogeneity of modalities and variability of sequence parameters. This heterogeneity complicates the automation of image processing tasks such as spatial co-registration and physiological or functional image analysis.

Multi-modal locomotion: from animal to application

International Nuclear Information System (INIS)

Lock, R J; Burgess, S C; Vaidyanathan, R

2014-01-01

The majority of robotic vehicles that can be found today are bound to operations within a single media (i.e. land, air or water). This is very rarely the case when considering locomotive capabilities in natural systems. Utility for small robots often reflects the exact same problem domain as small animals, hence providing numerous avenues for biological inspiration. This paper begins to investigate the various modes of locomotion adopted by different genus groups in multiple media as an initial attempt to determine the compromise in ability adopted by the animals when achieving multi-modal locomotion. A review of current biologically inspired multi-modal robots is also presented. The primary aim of this research is to lay the foundation for a generation of vehicles capable of multi-modal locomotion, allowing ambulatory abilities in more than one media, surpassing current capabilities. By identifying and understanding when natural systems use specific locomotion mechanisms, when they opt for disparate mechanisms for each mode of locomotion rather than using a synergized singular mechanism, and how this affects their capability in each medium, similar combinations can be used as inspiration for future multi-modal biologically inspired robotic platforms. (topical review)

Linking Essential Tremor to the Cerebellum-Neuroimaging Evidence.

Science.gov (United States)

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.

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 ...

FogBank: a single cell segmentation across multiple cell lines and image modalities.

Science.gov (United States)

Chalfoun, Joe; Majurski, Michael; Dima, Alden; Stuelten, Christina; Peskin, Adele; Brady, Mary

2014-12-30

sheets with high accuracy. It can be applied to microscopy images of multiple cell lines and a variety of imaging modalities. The code for the segmentation method is available as open-source and includes a Graphical User Interface for user friendly execution.

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....

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.

STRUKTUR MODAL DAN MODAL KERJA PT XYZ SERTA PENGARUHNYA TERHADAP KINERJA PERUSAHAAN

Directory of Open Access Journals (Sweden)

Untung Setiono

2017-01-01

Full Text Available n 2012, the electronic payment system transactions reached IDR 104.830 trillion or increase 46,52% from the previous year.  PT. XYZ is the  pioneer in the electronic payment system Indonesia  and still one of the leading companies in electronic payment system interbank, through ATM (Automatic Teller Machine and EDC (Electronic Data Capture in Indonesia.  In 2012 the company spent USD 3,4 million on software tandem from a foreign vendor.  Therefore it is important to study (1 policy on the modal structure of the company, (2 the working capital policy of the company, (3 the monetary performance relationship of the company based on the 2 policies.  The method used to analyze the data is multiple linear regression analysis; this method is used to calculate the relationship between the structure variable of the capital and working capital.  The result is; 1 the structure policy on the capital of the company is in accordance with the Pecking Order theory where the company uses their own capital before applying the long term debt to the others, 2 the inefficient policy on the company’s working capital is because most of the active asset is in monthly deposit bonds and even extended  the active debt, 3 the relationship between short term debt and liquidity ratio is negative while the total debt (short and long term has a positive correlation with the solvability/leverage ratio of the company.  The research recommends the management to decrease the active asset and uses it for long term investment not only for timed deposit.Keywords:  ATM, EDC, capital structure, financial performance     AbstrakVoulme transaksi dalam menggunakan sistem pembayaran elektronis pada tahun 2012 mencapai Rp104.830 triliun atau meningkat sekitar 46,52% dari tahun sebelumnya. PT XYZ adalah salah satu perusahaan pionir dalam sistem bidang pembayaran elektronis di Indonesia dan tetap menjadi pemain utama dalam sistem pembayaran elektronis antar bank, ATM

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....

Modality

DEFF Research Database (Denmark)

Klinge, Alex; Müller, Henrik Høeg

Modality: Studies in Form and Function reflects the diversity of theoretical frameworks and the heterogeneity of linguistic phenomena under the general heading of modality. Researchers in the fields of logic, philosophy and linguistics have for many years been pondering the elusive nature...... of modality and grappled with ways of capturing it. The 11 studies included here cover the span from contributions that seek to clarify controversial theoretical constructs to studies which take an empirical approach to linguistic categories and cross-linguistic typological issues. The key concepts addressed...

A method for experimental modal separation

Science.gov (United States)

Hallauer, W. L., Jr.

1977-01-01

A method is described for the numerical simulation of multiple-shaker modal survey testing using simulated experimental data to optimize the shaker force-amplitude distribution for the purpose of isolating individual modes of vibration. Inertia, damping, stiffness, and model data are stored on magnetic disks, available by direct access to the interactive FORTRAN programs which perform all computations required by this relative force amplitude distribution method.

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.

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.

Validity of the Symbol Digit Modalities Test as a cognition performance outcome measure for multiple sclerosis.

Science.gov (United States)

Benedict, Ralph Hb; DeLuca, John; Phillips, Glenn; LaRocca, Nicholas; Hudson, Lynn D; Rudick, Richard

2017-04-01

Cognitive and motor performance measures are commonly employed in multiple sclerosis (MS) research, particularly when the purpose is to determine the efficacy of treatment. The increasing focus of new therapies on slowing progression or reversing neurological disability makes the utilization of sensitive, reproducible, and valid measures essential. Processing speed is a basic elemental cognitive function that likely influences downstream processes such as memory. The Multiple Sclerosis Outcome Assessments Consortium (MSOAC) includes representatives from advocacy organizations, Food and Drug Administration (FDA), European Medicines Agency (EMA), National Institute of Neurological Disorders and Stroke (NINDS), academic institutions, and industry partners along with persons living with MS. Among the MSOAC goals is acceptance and qualification by regulators of performance outcomes that are highly reliable and valid, practical, cost-effective, and meaningful to persons with MS. A critical step for these neuroperformance metrics is elucidation of clinically relevant benchmarks, well-defined degrees of disability, and gradients of change that are deemed clinically meaningful. This topical review provides an overview of research on one particular cognitive measure, the Symbol Digit Modalities Test (SDMT), recognized as being particularly sensitive to slowed processing of information that is commonly seen in MS. The research in MS clearly supports the reliability and validity of this test and recently has supported a responder definition of SDMT change approximating 4 points or 10% in magnitude.

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.

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.

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

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.

Pediatric neuroimaging using magnetic resonance imaging during non-sedated sleep

Energy Technology Data Exchange (ETDEWEB)

Dean, Douglas C.; Dirks, Holly; Walker, Lindsay; Lehman, Katie; Han, Michelle; Waskiewicz, Nicole; Deoni, Sean C.L. [Brown University, Advanced Baby Imaging Lab, School of Engineering, Providence, RI (United States); O' Muircheartaigh, Jonathan [Brown University, Advanced Baby Imaging Lab, School of Engineering, Providence, RI (United States); King' s College London, Institute of Psychiatry, Department of NeuroImaging Sciences, London (United Kingdom); Jerskey, Beth A. [Brown University, Department of Human Behaviour and Psychiatry, Warren Alpert Medical School, Providence, RI (United States)

2014-01-15

Etiological studies of many neurological and psychiatric disorders are increasingly turning toward longitudinal investigations of infant brain development in order to discern predisposing structural and/or functional differences prior to the onset of overt clinical symptoms. While MRI provides a noninvasive window into the developing brain, MRI of infants and toddlers is challenging due to the modality's extreme motion sensitivity and children's difficulty in remaining still during image acquisition. Here, we outline a broad research protocol for successful MRI of children under 4 years of age during natural, non-sedated sleep. All children were imaged during natural, non-sedated sleep. Active and passive measures to reduce acoustic noise were implemented to reduce the likelihood of the children waking up during acquisition. Foam cushions and vacuum immobilizers were used to limit intra-scan motion artifacts. More than 380 MRI datasets have been successfully acquired from 220 children younger than 4 years of age within the past 39 months. Implemented measures permitted children to remain asleep for the duration of the scan and allowed the data to be acquired with an overall 97% success rate. The proposed method greatly advances current pediatric imaging techniques and may be readily implemented in other research and clinical settings to facilitate and further improve pediatric neuroimaging. (orig.)

Pediatric neuroimaging using magnetic resonance imaging during non-sedated sleep

International Nuclear Information System (INIS)

Dean, Douglas C.; Dirks, Holly; Walker, Lindsay; Lehman, Katie; Han, Michelle; Waskiewicz, Nicole; Deoni, Sean C.L.; O'Muircheartaigh, Jonathan; Jerskey, Beth A.

2014-01-01

Etiological studies of many neurological and psychiatric disorders are increasingly turning toward longitudinal investigations of infant brain development in order to discern predisposing structural and/or functional differences prior to the onset of overt clinical symptoms. While MRI provides a noninvasive window into the developing brain, MRI of infants and toddlers is challenging due to the modality's extreme motion sensitivity and children's difficulty in remaining still during image acquisition. Here, we outline a broad research protocol for successful MRI of children under 4 years of age during natural, non-sedated sleep. All children were imaged during natural, non-sedated sleep. Active and passive measures to reduce acoustic noise were implemented to reduce the likelihood of the children waking up during acquisition. Foam cushions and vacuum immobilizers were used to limit intra-scan motion artifacts. More than 380 MRI datasets have been successfully acquired from 220 children younger than 4 years of age within the past 39 months. Implemented measures permitted children to remain asleep for the duration of the scan and allowed the data to be acquired with an overall 97% success rate. The proposed method greatly advances current pediatric imaging techniques and may be readily implemented in other research and clinical settings to facilitate and further improve pediatric neuroimaging. (orig.)

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.

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

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.

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.

Reusable Client-Side JavaScript Modules for Immersive Web-Based Real-Time Collaborative Neuroimage Visualization.

Science.gov (United States)

Bernal-Rusiel, Jorge L; Rannou, Nicolas; Gollub, Randy L; Pieper, Steve; Murphy, Shawn; Robertson, Richard; Grant, Patricia E; Pienaar, Rudolph

2017-01-01

In this paper we present a web-based software solution to the problem of implementing real-time collaborative neuroimage visualization. In both clinical and research settings, simple and powerful access to imaging technologies across multiple devices is becoming increasingly useful. Prior technical solutions have used a server-side rendering and push-to-client model wherein only the server has the full image dataset. We propose a rich client solution in which each client has all the data and uses the Google Drive Realtime API for state synchronization. We have developed a small set of reusable client-side object-oriented JavaScript modules that make use of the XTK toolkit, a popular open-source JavaScript library also developed by our team, for the in-browser rendering and visualization of brain image volumes. Efficient realtime communication among the remote instances is achieved by using just a small JSON object, comprising a representation of the XTK image renderers' state, as the Google Drive Realtime collaborative data model. The developed open-source JavaScript modules have already been instantiated in a web-app called MedView , a distributed collaborative neuroimage visualization application that is delivered to the users over the web without requiring the installation of any extra software or browser plugin. This responsive application allows multiple physically distant physicians or researchers to cooperate in real time to reach a diagnosis or scientific conclusion. It also serves as a proof of concept for the capabilities of the presented technological solution.

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)

[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.

Effect of Temperature Variation on Modal Frequency of Reinforced Concrete Slab and Beam in Cold Regions

Directory of Open Access Journals (Sweden)

Hanbing Liu

2016-01-01

Full Text Available Changes of modal frequencies induced by temperature variation can be more obvious than those caused by structural damage, which will lead to the false damage identification results. Therefore, quantifying the temperature effect on modal frequencies is a critical step to eliminate its interference in damage detection. Due to the nonuniform and time-dependent characteristics of temperature distribution, it is insufficient to obtain the reliable relationships between temperatures and modal frequencies using temperatures in air or at surface. In this paper, correlations between measured temperatures (air temperature, surface temperature, mean temperature, etc. and modal frequencies for the slab and beam are comparatively analyzed. And the quantitative models are constructed considering nonuniform temperature distribution. Firstly, the reinforced concrete slab and beam were constructed and placed outside the laboratory to be monitored. Secondly, the correlation coefficients between modal frequencies and three kinds of temperatures are calculated, respectively. Thirdly, simple linear regression models between mean temperature and modal frequencies are established for the slab and beam. Finally, five temperature variables are selected to construct the multiple linear regression models. Prediction results reveal that the proposed multiple linear regression models possess favorable accuracy to quantify the temperature effect on modal frequencies considering nonuniform temperature distribution.

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

Directory of Open Access Journals (Sweden)

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.

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.

How acute total sleep loss affects the attending brain: a meta-analysis of neuroimaging studies.

Science.gov (United States)

Ma, Ning; Dinges, David F; Basner, Mathias; Rao, Hengyi

2015-02-01

Attention is a cognitive domain that can be severely affected by sleep deprivation. Previous neuroimaging studies have used different attention paradigms and reported both increased and reduced brain activation after sleep deprivation. However, due to large variability in sleep deprivation protocols, task paradigms, experimental designs, characteristics of subject populations, and imaging techniques, there is no consensus regarding the effects of sleep loss on the attending brain. The aim of this meta-analysis was to identify brain activations that are commonly altered by acute total sleep deprivation across different attention tasks. Coordinate-based meta-analysis of neuroimaging studies of performance on attention tasks during experimental sleep deprivation. The current version of the activation likelihood estimation (ALE) approach was used for meta-analysis. The authors searched published articles and identified 11 sleep deprivation neuroimaging studies using different attention tasks with a total of 185 participants, equaling 81 foci for ALE analysis. The meta-analysis revealed significantly reduced brain activation in multiple regions following sleep deprivation compared to rested wakefulness, including bilateral intraparietal sulcus, bilateral insula, right prefrontal cortex, medial frontal cortex, and right parahippocampal gyrus. Increased activation was found only in bilateral thalamus after sleep deprivation compared to rested wakefulness. Acute total sleep deprivation decreases brain activation in the fronto-parietal attention network (prefrontal cortex and intraparietal sulcus) and in the salience network (insula and medial frontal cortex). Increased thalamic activation after sleep deprivation may reflect a complex interaction between the de-arousing effects of sleep loss and the arousing effects of task performance on thalamic activity. © 2015 Associated Professional Sleep Societies, LLC.

Multi-modal neuroimaging of adolescents with non-suicidal self-injury: Amygdala functional connectivity.

Science.gov (United States)

Westlund Schreiner, Melinda; Klimes-Dougan, Bonnie; Mueller, Bryon A; Eberly, Lynn E; Reigstad, Kristina M; Carstedt, Patricia A; Thomas, Kathleen M; Hunt, Ruskin H; Lim, Kelvin O; Cullen, Kathryn R

2017-10-15

Non-suicidal self-injury (NSSI) is a significant mental health problem among adolescents. Research is needed to clarify the neurobiology of NSSI and identify candidate neurobiological targets for interventions. Based on prior research implicating heightened negative affect and amygdala hyperactivity in NSSI, we pursued a systems approach to characterize amygdala functional connectivity networks during rest (resting-state functional connectivity [RSFC)]) and a task (task functional connectivity [TFC]) in adolescents with NSSI. We examined amygdala networks in female adolescents with NSSI and healthy controls (n = 45) using resting-state fMRI and a negative emotion face-matching fMRI task designed to activate the amygdala. Connectivity analyses included amygdala RSFC, amygdala TFC, and psychophysiological interactions (PPI) between amygdala connectivity and task conditions. Compared to healthy controls, adolescents with NSSI showed atypical amygdala-frontal connectivity during rest and task; greater amygdala RSFC in supplementary motor area (SMA) and dorsal anterior cingulate; and differential amygdala-occipital connectivity between rest and task. After correcting for depression symptoms, amygdala-SMA RSFC abnormalities, among others, remained significant. This study's limitations include its cross-sectional design and its absence of a psychiatric control group. Using a multi-modal approach, we identified widespread amygdala circuitry anomalies in adolescents with NSSI. While deficits in amygdala-frontal connectivity (driven by depression symptoms) replicates prior work in depression, hyperconnectivity between amygdala and SMA (independent of depression symptoms) has not been previously reported. This circuit may represent an important mechanism underlying the link between negative affect and habitual behaviors. These abnormalities may represent intervention targets for adolescents with NSSI. Copyright © 2017 Elsevier B.V. All rights reserved.

Modality and Task Switching Interactions using Bi-Modal and Bivalent Stimuli

Science.gov (United States)

Sandhu, Rajwant; Dyson, Benjamin J.

2013-01-01

Investigations of concurrent task and modality switching effects have to date been studied under conditions of uni-modal stimulus presentation. As such, it is difficult to directly compare resultant task and modality switching effects, as the stimuli afford both tasks on each trial, but only one modality. The current study investigated task and…

Non-ablative fractional resurfacing in combination with topical tretinoin cream as a field treatment modality for multiple actinic keratosis: a pilot study and a review of other field treatment modalities.

Science.gov (United States)

Prens, Sebastiaan P; de Vries, Karin; Neumann, H A Martino; Prens, Errol P

2013-06-01

Actinic keratoses (AK) are premalignant lesions occurring mainly in sun-damaged skin. Current topical treatment options for AK and photo-damaged skin such as liquid nitrogen and electrosurgery are not suitable for field treatment. Otherwise, therapies suitable for field treatment bring along considerable patient discomfort. Non-ablative fractional resurfacing has emerged as a logical treatment option especially for field treatment of AK. To evaluate the clinical efficacy of fractional laser therapy for clearing AK and improving skin quality. To compare patient friendliness of the "fractional" therapy with those reported for other field treatment modalities. Ten patients with Fitzpatrick skin type I to III with multiple AK and extensive sun-damaged skin, received 5-10 sessions with a 4-week interval using a 1550 nm Erbium-Glass Fractionated laser (Sellas, Korea). Four weeks and 24 weeks after the last treatment the clinical results were evaluated by an independent physician. The mean degree of improvement, in terms of reduction in the number of AK and improvement of skin texture, was 54% on a 4 point PGA scale, and persisted for approximately 6 months. The biggest advantage of fractional laser treatment, besides the eradication of AK and a clear rejuvenation effect, is the absence of "downtime". Fractional non-ablative resurfacing induces significant reduction in the number of AK and improves the skin quality. Also all patients preferred fractional laser therapy above other AK treatment modalities.

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...

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

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.

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...

A systemic literature review of neuroimaging studies in women with breast cancer treated with adjuvant chemotherapy

Directory of Open Access Journals (Sweden)

Paulina Andryszak

2017-03-01

Full Text Available Chemotherapy-induced cognitive deficits in patients with breast cancer, predominantly in attention and verbal memory, have been observed in numerous studies. These neuropsychological findings are corroborated by the results of neuroimaging studies. The aim of this paper was to survey the reports on cerebral structural and functional alterations in women with breast cancer treated with chemotherapy (CTx. First, we discuss the host-related and disease-related mechanisms underlying cognitive impairment after CTx. We point out the direct and indirect neurotoxic effect of cytostatics, which may cause: a damage to neurons or glial cells, changes in neurotransmitter levels, deregulation of the immune system and/or cytokine release. Second, we focus on the results of neuroimaging studies on brain structure and function that revealed decreased: density of grey matter, integrity of white matter and volume of multiple brain regions, as well as their lower activation during cognitive task performance. Finally, we concentrate on compensatory mechanisms, which activate additional brain areas or neural connection to reach the premorbid cognitive efficiency.

Congenital syphylitic hepatitis: a case report with multiple imaging modalities (syphilitic hepatitis)

Energy Technology Data Exchange (ETDEWEB)

Heyman, S; Rosenberg, H K; Mandell, G A; Golden, D A

1983-11-14

A case of syphilitic hepatitis is described with no evidence of mass effect on the ultrasonic and computerized tomographic study, but with discrete areas of decreased uptake on liver scan suggestive of space-occupying lesion. This is the second instance in the literature of the incongruence of the liver scan and the other imaging modalities in syphilitic hepatitis.

Congenital syphylitic hepatitis: a case report with multiple imaging modalities (syphilitic hepatitis)

International Nuclear Information System (INIS)

Heyman, S.; Rosenberg, H.K.; Mandell, G.A.; Golden, D.A.

1983-01-01

A case of syphilitic hepatitis is described with no evidence of mass effect on the ultrasonic and computerized tomographic study, but discrete areas of decreased uptake on liver scan suggestive of space-occupying lesion. This is the second instance in the literature of the incongruence of the liver scan and the other imaging modalities in syphilitic hepatitis. (orig.)

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

The Modal Dimension

Directory of Open Access Journals (Sweden)

Giluano Torrengo

2018-05-01

Full Text Available Space and time are two obvious candidates as dimensions of reality. Yet, are they the only two dimensions of reality? Famously, David Lewis maintained the doctrine of ―modal realism‖, the thesis that possible worlds exist and are entities as concrete as the actual world that we live in. In this paper, I will explore the idea that modality can be construed as a dimension along with space and time. However, although Lewis‘ modal realism is the main source of inspiration for this construal of modality, I will argue that something else is required for having a modal dimension.

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

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.

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.

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.

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.

Experimental modal analysis

Energy Technology Data Exchange (ETDEWEB)

Ibsen, Lars Bo; Liingaard, M.

2006-12-15

This technical report concerns the basic theory and principles for experimental modal analysis. The sections within the report are: Output-only modal analysis software, general digital analysis, basics of structural dynamics and modal analysis and system identification. (au)

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.

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/).

Evaluation of registration strategies for multi-modality images of rat brain slices

International Nuclear Information System (INIS)

Palm, Christoph; Vieten, Andrea; Salber, Dagmar; Pietrzyk, Uwe

2009-01-01

In neuroscience, small-animal studies frequently involve dealing with series of images from multiple modalities such as histology and autoradiography. The consistent and bias-free restacking of multi-modality image series is obligatory as a starting point for subsequent non-rigid registration procedures and for quantitative comparisons with positron emission tomography (PET) and other in vivo data. Up to now, consistency between 2D slices without cross validation using an inherent 3D modality is frequently presumed to be close to the true morphology due to the smooth appearance of the contours of anatomical structures. However, in multi-modality stacks consistency is difficult to assess. In this work, consistency is defined in terms of smoothness of neighboring slices within a single modality and between different modalities. Registration bias denotes the distortion of the registered stack in comparison to the true 3D morphology and shape. Based on these metrics, different restacking strategies of multi-modality rat brain slices are experimentally evaluated. Experiments based on MRI-simulated and real dual-tracer autoradiograms reveal a clear bias of the restacked volume despite quantitatively high consistency and qualitatively smooth brain structures. However, different registration strategies yield different inter-consistency metrics. If no genuine 3D modality is available, the use of the so-called SOP (slice-order preferred) or MOSOP (modality-and-slice-order preferred) strategy is recommended.

MOSFET dosimetry on modern radiation oncology modalities

International Nuclear Information System (INIS)

Rosenfeld, A.B.

2002-01-01

The development of MOSFET dosimetry is presented with an emphasis on the development of a scanning MOSFET dosimetry system for modern radiation oncology modalities. Fundamental aspects of MOSFETs in relation to their use as dosemeters are briefly discussed. The performance of MOSFET dosemeters in conformal radiotherapy, hadron therapy, intensity-modulated radiotherapy and microbeam radiation therapy is compared with other dosimetric techniques. In particular the application of MOSFET dosemeters in the characterisation and quality assurance of the steep dose gradients associated with the penumbra of some modern radiation oncology modalities is investigated. A new in vivo, on-line, scanning MOSFET read out system is also presented. The system has the ability to read out multiple MOSFET dosemeters with excellent spatial resolution and temperature stability and minimal slow border trapping effects. (author)

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.

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.

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

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

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.

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.

Action semantics: A unifying conceptual framework for the selective use of multimodal and modality-specific object knowledge.

Science.gov (United States)

van Elk, Michiel; van Schie, Hein; Bekkering, Harold

2014-06-01

Our capacity to use tools and objects is often considered one of the hallmarks of the human species. Many objects greatly extend our bodily capabilities to act in the physical world, such as when using a hammer or a saw. In addition, humans have the remarkable capability to use objects in a flexible fashion and to combine multiple objects in complex actions. We prepare coffee, cook dinner and drive our car. In this review we propose that humans have developed declarative and procedural knowledge, i.e. action semantics that enables us to use objects in a meaningful way. A state-of-the-art review of research on object use is provided, involving behavioral, developmental, neuropsychological and neuroimaging studies. We show that research in each of these domains is characterized by similar discussions regarding (1) the role of object affordances, (2) the relation between goals and means in object use and (3) the functional and neural organization of action semantics. We propose a novel conceptual framework of action semantics to address these issues and to integrate the previous findings. We argue that action semantics entails both multimodal object representations and modality-specific sub-systems, involving manipulation knowledge, functional knowledge and representations of the sensory and proprioceptive consequences of object use. Furthermore, we argue that action semantics are hierarchically organized and selectively activated and used depending on the action intention of the actor and the current task context. Our framework presents an integrative account of multiple findings and perspectives on object use that may guide future studies in this interdisciplinary domain. Copyright © 2013 Elsevier B.V. All rights reserved.

Metaphysical Modality, Modality of Predicate and the Theory of "Decisive Necessity”

Directory of Open Access Journals (Sweden)

L. Nabavi

2010-01-01

Full Text Available Aristotle in the Organon (1949: 9,30 a ,15-19 explicitly states that in a categorical syllogism when the minor premise is absolute (without modality operator and the major is necessary, the conclusion will be necessary too. This Aristotle's view has been the source of many conflicts and disputes in the history of logic. The famous logicians and historians of logic in the twentieth century as "Nicholas Rescher" and "Becker" believe that Aristotle's view is justifiable and defensible (at least compared to the first figure only if, the modality of major premise is considered as the property of predicate (modality de re. Today, we know very well that the modality of predicate is closely linked to Metaphysical and philosophical Modality. “Shihab al-Din al- Suhrawardi” in the theory of "Decisive (Battateh Necessity” by accepting this base, explicitly states that, in the beginning, the modality must be mentioned as a part of the predicate and then the modality of relation or copula is summarized and reduced to necessity. The modern formalization of the most important part of this theory is as follows: ("x (àAx É à Bx º ("x □ (àAx É à BxThis paper discusses the historical overview of the metaphysical modality firstly and then shows that the theory of "Decisive Necessity” is true and justified in a model of modal logic with equivalent accessibility relation and homogeneous possible world view (fixed domain.

Reusable Client-Side JavaScript Modules for Immersive Web-Based Real-Time Collaborative Neuroimage Visualization

Directory of Open Access Journals (Sweden)

Jorge L. Bernal-Rusiel

2017-05-01

Full Text Available In this paper we present a web-based software solution to the problem of implementing real-time collaborative neuroimage visualization. In both clinical and research settings, simple and powerful access to imaging technologies across multiple devices is becoming increasingly useful. Prior technical solutions have used a server-side rendering and push-to-client model wherein only the server has the full image dataset. We propose a rich client solution in which each client has all the data and uses the Google Drive Realtime API for state synchronization. We have developed a small set of reusable client-side object-oriented JavaScript modules that make use of the XTK toolkit, a popular open-source JavaScript library also developed by our team, for the in-browser rendering and visualization of brain image volumes. Efficient realtime communication among the remote instances is achieved by using just a small JSON object, comprising a representation of the XTK image renderers' state, as the Google Drive Realtime collaborative data model. The developed open-source JavaScript modules have already been instantiated in a web-app called MedView, a distributed collaborative neuroimage visualization application that is delivered to the users over the web without requiring the installation of any extra software or browser plugin. This responsive application allows multiple physically distant physicians or researchers to cooperate in real time to reach a diagnosis or scientific conclusion. It also serves as a proof of concept for the capabilities of the presented technological solution.

Cross-modal versus within-modal recall: differences in behavioral and brain responses.

Science.gov (United States)

Butler, Andrew J; James, Karin H

2011-10-31

Although human experience is multisensory in nature, previous research has focused predominantly on memory for unisensory as opposed to multisensory information. In this work, we sought to investigate behavioral and neural differences between the cued recall of cross-modal audiovisual associations versus within-modal visual or auditory associations. Participants were presented with cue-target associations comprised of pairs of nonsense objects, pairs of nonsense sounds, objects paired with sounds, and sounds paired with objects. Subsequently, they were required to recall the modality of the target given the cue while behavioral accuracy, reaction time, and blood oxygenation level dependent (BOLD) activation were measured. Successful within-modal recall was associated with modality-specific reactivation in primary perceptual regions, and was more accurate than cross-modal retrieval. When auditory targets were correctly or incorrectly recalled using a cross-modal visual cue, there was re-activation in auditory association cortex, and recall of information from cross-modal associations activated the hippocampus to a greater degree than within-modal associations. Findings support theories that propose an overlap between regions active during perception and memory, and show that behavioral and neural differences exist between within- and cross-modal associations. Overall the current study highlights the importance of the role of multisensory information in memory. Copyright © 2011 Elsevier B.V. All rights reserved.

A review of structural neuroimaging in schizophrenia: from connectivity to connectomics

Directory of Open Access Journals (Sweden)

Anne L Wheeler

2014-08-01

Full Text Available In patients with schizophrenia neuroimaging studies have revealed global differences with some brain regions showing focal abnormalities. Examining neurocircuitry, diffusion-weighted imaging studies have identified altered structural integrity of white matter in frontal and temporal brain regions and tracts such as the cingulum bundles, uncinate fasciculi and corpus callosum associated with the illness. Furthermore, structural co-variance analyses have revealed altered structural relationships among regional morphology in the thalamus, frontal, temporal and parietal cortices in schizophrenia patients. The distributed nature of these abnormalities in schizophrenia suggests that multiple brain circuits are impaired, a neural feature that may be better addressed with network level analyses. However, even with the advent of these newer analyses, a large amount of variability in findings remains, likely partially due to the considerable heterogeneity of this disorder.

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.

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.

Operational Modal Analysis Tutorial

DEFF Research Database (Denmark)

Brincker, Rune; Andersen, Palle

of modal parameters of practical interest - including the mode shape scaling factor - with a high degree of accuracy. It is also argued that the operational technology offers the user a number of advantages over traditional modal testing. The operational modal technology allows the user to perform a modal......In this paper the basic principles in operational modal testing and analysis are presented and discussed. A brief review of the techniques for operational modal testing and identification is presented, and it is argued, that there is now a wide range of techniques for effective identification...

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...

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

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.

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

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...

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.

Meditations on Metaphysical Modality

OpenAIRE

Willis, Edmund Lindsay James

2011-01-01

Although metaphysical modality has been much discussed and exploited by philosophers, its precise nature is often left unanalysed and obscure. This dissertation marks an attempt to understand it better. After examining modality in general, the specific topic is introduced through consideration of the views of Kripke and Lewis. Comparisons are then made with logical, scientific and conceptual modalities. Finally, it is argued that metaphysical modality is that variety of modality which is alet...

Metaphysical Modality, Modality of Predicate and the Theory of

Directory of Open Access Journals (Sweden)

l nabavi

2010-05-01

This paper discusses the historical overview of the metaphysical modality firstly and then shows that the theory of "Decisive Necessity” is true and justified in a model of modal logic with equivalent accessibility relation and homogeneous possible world view (fixed domain.

Perceptual load interacts with stimulus processing across sensory modalities.

Science.gov (United States)

Klemen, J; Büchel, C; Rose, M

2009-06-01

According to perceptual load theory, processing of task-irrelevant stimuli is limited by the perceptual load of a parallel attended task if both the task and the irrelevant stimuli are presented to the same sensory modality. However, it remains a matter of debate whether the same principles apply to cross-sensory perceptual load and, more generally, what form cross-sensory attentional modulation in early perceptual areas takes in humans. Here we addressed these questions using functional magnetic resonance imaging. Participants undertook an auditory one-back working memory task of low or high perceptual load, while concurrently viewing task-irrelevant images at one of three object visibility levels. The processing of the visual and auditory stimuli was measured in the lateral occipital cortex (LOC) and auditory cortex (AC), respectively. Cross-sensory interference with sensory processing was observed in both the LOC and AC, in accordance with previous results of unisensory perceptual load studies. The present neuroimaging results therefore warrant the extension of perceptual load theory from a unisensory to a cross-sensory context: a validation of this cross-sensory interference effect through behavioural measures would consolidate the findings.

Toward predicate approaches to modality

CERN Document Server

Stern, Johannes

2016-01-01

In this volume, the author investigates and argues for, a particular answer to the question: What is the right way to logically analyze modalities from natural language within formal languages? The answer is: by formalizing modal expressions in terms of predicates. But, as in the case of truth, the most intuitive modal principles lead to paradox once the modal notions are conceived as predicates. The book discusses the philosophical interpretation of these modal paradoxes and argues that any satisfactory approach to modality will have to face the paradoxes independently of the grammatical category of the modal notion. By systematizing modal principles with respect to their joint consistency and inconsistency, Stern provides an overview of the options and limitations of the predicate approach to modality that may serve as a useful starting point for future work on predicate approaches to modality. Stern also develops a general strategy for constructing philosophically attractive theories of modal notions conce...

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.

Reading the Freudian theory of sexual drives from a functional neuroimaging perspective

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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.

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.

[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

Modal testing and analysis of NOVA laser structures

International Nuclear Information System (INIS)

Burdick, R.B.; Weaver, H.J.; Pastrnak, J.W.

1984-09-01

NOVA, currently the world's most powerful laser system, is an ongoing project at the Lawrence Livermore National Laboratory in California. The project seeks to develop a feasible method of achieving controlled fusion reaction, initiated by multiple laser beams targeted on a tiny fuel pellet. The NOVA system consists of several large steel framed structures, the largest of which is the Target Chamber Tower. In conjunction with design engineers, the tower was first modelled and analyzed by sophisticated finite element techniques. A modal test was then conducted on the tower structure to evaluate its vibrational characteristics and seismic integrity as well as for general comparison to the finite element results. This paper will discuss the procedure used in the experimental modal analysis and the results obtained from that test

Multi-Modal Inference in Animacy Perception for Artificial Object

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Kohske Takahashi

2011-10-01

Full Text Available Sometimes we feel animacy for artificial objects and their motion. Animals usually interact with environments through multiple sensory modalities. Here we investigated how the sensory responsiveness of artificial objects to the environment would contribute to animacy judgment for them. In a 90-s trial, observers freely viewed four objects moving in a virtual 3D space. The objects, whose position and motion were determined following Perlin-noise series, kept drifting independently in the space. Visual flashes, auditory bursts, or synchronous flashes and bursts appeared with 1–2 s intervals. The first object abruptly accelerated their motion just after visual flashes, giving an impression of responding to the flash. The second object responded to bursts. The third object responded to synchronous flashes and bursts. The forth object accelerated at a random timing independent of flashes and bursts. The observers rated how strongly they felt animacy for each object. The results showed that the object responding to the auditory bursts was rated as having weaker animacy compared to the other objects. This implies that sensory modality through which an object interacts with the environment may be a factor for animacy perception in the object and may serve as the basis of multi-modal and cross-modal inference of animacy.

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)

Generation of Composite Dose and Biological Effective Dose (BED) Over Multiple Treatment Modalities and Multistage Planning Using Deformable Image Registration

International Nuclear Information System (INIS)

Zhang, Geoffrey; Huang, T-C; Feygelman, Vladimir; Stevens, Craig; Forster, Kenneth

2010-01-01

Currently there are no commercially available tools to generate composite plans across different treatment modalities and/or different planning image sets. Without a composite plan, it may be difficult to perform a meaningful dosimetric evaluation of the overall treatment course. In this paper, we introduce a method to generate composite biological effective dose (BED) plans over multiple radiotherapy treatment modalities and/or multistage plans, using deformable image registration. Two cases were used to demonstrate the method. Case I was prostate cancer treated with intensity-modulated radiation therapy (IMRT) and a permanent seed implant. Case II involved lung cancer treated with two treatment plans generated on two separate computed tomography image sets. Thin-plate spline or optical flow methods were used as appropriate to generate deformation matrices. The deformation matrices were then applied to the dose matrices and the resulting physical doses were converted to BED and added to yield the composite plan. Cell proliferation and sublethal repair were considered in the BED calculations. The difference in BED between normal tissues and tumor volumes was accounted for by using different BED models, α/β values, and cell potential doubling times. The method to generate composite BED plans presented in this paper provides information not available with the traditional simple dose summation or physical dose summation. With the understanding of limitations and uncertainties of the algorithms involved, it may be valuable for the overall treatment plan evaluation.

Deep Multimodal Pain Recognition: A Database and Comparison of Spatio-Temporal Visual Modalities

DEFF Research Database (Denmark)

Haque, Mohammad Ahsanul; Nasrollahi, Kamal; Moeslund, Thomas B.

2018-01-01

, exploiting both spatial and temporal information of the face to assess pain level, and second, incorporating multiple visual modalities to capture complementary face information related to pain. Most works in the literature focus on merely exploiting spatial information on chromatic (RGB) video data......PAIN)' database, for RGBDT pain level recognition in sequences. We provide a first baseline results including 5 pain levels recognition by analyzing independent visual modalities and their fusion with CNN and LSTM models. From the experimental evaluation we observe that fusion of modalities helps to enhance...... recognition performance of pain levels in comparison to isolated ones. In particular, the combination of RGB, D, and T in an early fusion fashion achieved the best recognition rate....

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)

Overview of multi-input frequency domain modal testing methods with an emphasis on sine testing

Science.gov (United States)

Rost, Robert W.; Brown, David L.

1988-01-01

An overview of the current state of the art multiple-input, multiple-output modal testing technology is discussed. A very brief review of the current time domain methods is given. A detailed review of frequency and spatial domain methods is presented with an emphasis on sine testing.

Radiological Evaluation of Ambiguous Genitalia with Various Imaging Modalities

Science.gov (United States)

Ravi, N.; Bindushree, Kadakola

2012-07-01

Disorders of sex development (DSDs) are congenital conditions in which the development of chromosomal, gonadal, or anatomic sex is atypical. These can be classified broadly into four categories on the basis of gonadal histologic features: female pseudohermaphroditism (46,XX with two ovaries); male pseudohermaphroditism (46,XY with two testes); true hermaphroditism (ovotesticular DSD) (both ovarian and testicular tissues); and gonadal dysgenesis, either mixed (a testis and a streak gonad) or pure (bilateral streak gonads). Imaging plays an important role in demonstrating the anatomy and associated anomalies. Ultrasonography is the primary modality for demonstrating internal organs and magnetic resonance imaging is used as an adjunct modality to assess for internal gonads and genitalia. Early and appropriate gender assignment is necessary for healthy physical and psychologic development of children with ambiguous genitalia. Gender assignment can be facilitated with a team approach that involves a pediatric endocrinologist, geneticist, urologist, psychiatrist, social worker, neonatologist, nurse, and radiologist, allowing timely diagnosis and proper management. We describe case series on ambiguous genitalia presented to our department who were evaluated with multiple imaging modalities.

[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.

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.

PENGARUH GOOD CORPORATE GOVERNANCE, KINERJA KEUANGAN, MODAL INTELEKTUAL TERHADAP PENGUNGKAPAN MODAL INTELEKTUAL

Directory of Open Access Journals (Sweden)

Gilang Anies Saendy

2015-10-01

Full Text Available Dampak perkembangan globalisasi membutuhkan informasi lebih lanjut, terutama informasi tentang modal intelektual perusahaan. Tapi, dalam kondisi nyata informasi modal intelektual masih rendah, yakni sekitar 27-35%. Objek penelitian ini adalah perbankan yang terdapat dalam direktori Pasar Modal Indonesia (ICMD 2010-2013. Jumlah populasi adalah 36 perbankan dan 17 sampel dengan menggunakan purposive sampling. Metode yang digunakan adalah analisis jalur. Hasil penelitian ini menunjukkan bahwa tidak pengaruh antara pelaksanaan GCG untuk pengungkapan modal intelektual dan kinerja keuangan. Selain itu, ada pengaruh positif antara kinerja modal intelektual terhadap kinerja keuangan dan kinerja keuangan untuk pengungkapan modal intelektual. Selanjutnya, hasil penelitian menunjukkan bahwa tidak efek mediasi melalui kinerja keuangan perusahaan antara implementasi GCG dalam pengungkapan modal intelektual. Hasilnya juga mengatakan ada efek mediasi antara pelaksanaan GCG untuk pengungkapan modal intelektual pikir kinerja modal intelektual. The development due to the increase of globalization gives impact to the need of having more information. One of them is the need to have information on company’s intellectual capital. But, in real condition, intellectual capital information is still low. It is about 27-35%. The objects of this research are banks organized in Indonesian Capital Market Directory (ICMD from 2010-2013. Total populations were 36 banks, and finally 17 samples were selected by using purposive sampling. The method used is path analysis. The results of this research show that there is no influence between GCG’s implementation on intellectual capital disclosure and financial performance. However, there are  positive influences of intellectual capital performance on the financial performance, and financial performance on the disclosure of intellectual capital. Besides, this research said that there is no effect of mediation through the company

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.)

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.)

[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.

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

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

Polyarteritis nodosa: MDCT as a 'One-Stop Shop' Modality for Whole-Body Arterial Evaluation

International Nuclear Information System (INIS)

Tsai, W.-L.; Tsai, I-C.; Lee Tain; Hsieh, C.-W.

2008-01-01

Polyarteritis nodosa is a rare disease, which is characterized by aneurysm formation and occlusion in the arteries of multiple systems. Due to its extensive involvement, whole-body evaluation is necessary for diagnosis and treatment monitoring. We report a case of polyarteritis nodosa using multidetector-row computed tomography (MDCT) as a 'one-stop shop' modality for whole-body arterial evaluation. With precise protocol design, MDCT can be used as a reliable noninvasive modality providing comprehensive whole-body arterial evaluation.

Advances of operational modal identification

International Nuclear Information System (INIS)

Zhang, L.

2001-01-01

Operational modal analysis has shown many advantages compared to the traditional one. In this paper, the development of ambient modal identification in time domain is summarized. The mathematical models for modal identification have been presented as unified framework for time domain (TD) System realization algorithms, such as polyrefence (PRCE), extended Ibrahim time domain (EITD) and eigensystem realization algorithm (ERA), etc., and recently developed Stochastic subspace technique (SST). The latest technique named as frequency domain decomposition (FDD) is introduced for operational modal identification, which has many advantages as a frequency domain (FD) technique. Applications of the operational modal analysis in civil and mechanical engineering have shown the success and accuracy of the advanced operational modal identification algorithms- FDD and SST techniques. The major issues of TD and FD operational modal identification are also discussed. (author)

Mixed-Modality Stimulation to Evoke Two Modalities Simultaneously in One Channel for Electrocutaneous Sensory Feedback.

Science.gov (United States)

Choi, Kyunghwan; Kim, Pyungkang; Kim, Kyung-Soo; Kim, Soohyun

2017-12-01

One of the long-standing challenges in upper limb prosthetics is restoring the sensory feedback that is missing due to amputation. Two approaches have previously been presented to provide various types of sensory information to users, namely, multi-modality sensory feedback and using an array of single-modality stimulators. However, the feedback systems used in these approaches were too bulky to be embedded in prosthesis sockets. In this paper, we propose an electrocutaneous sensory feedback method that is capable of conveying two modalities simultaneously with only one electrode. The stimulation method, which we call mixed-modality stimulation, utilizes the phenomenon in which the superposition of two electric pulse trains of different frequencies is able to evoke two different modalities (i.e., pressure and tapping) at the same time. We conducted psychophysical experiments in which healthy subjects were required to recognize the intensity of pressure or the frequency of tapping from mixed-modality or two-channel stimulations. The results demonstrated that the subjects were able to discriminate the features of the two modalities in one electrode during mixed-modality stimulation and that the accuracies of successful recognitions (mean ± standard deviation) for the two feedback variables were 84.3 ± 7% for mixed-modality stimulation and 89.5 ± 6% for two-channel dual-modality stimulation, showing no statistically significant difference. Therefore, mixed-modality stimulation is an attractive method for modulating two modalities independently with only one electrode, and it could be used for implementing a compact sensory feedback system that is able to provide two different types of sensory information from prosthetics.

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...

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

Combining motor imagery with selective sensation toward a hybrid-modality BCI.

Science.gov (United States)

Yao, Lin; Meng, Jianjun; Zhang, Dingguo; Sheng, Xinjun; Zhu, Xiangyang

2014-08-01

A hybrid modality brain-computer interface (BCI) is proposed in this paper, which combines motor imagery with selective sensation to enhance the discrimination between left and right mental tasks, e.g., the classification between left/ right stimulation sensation and right/ left motor imagery. In this paradigm, wearable vibrotactile rings are used to stimulate both the skin on both wrists. Subjects are required to perform the mental tasks according to the randomly presented cues (i.e., left hand motor imagery, right hand motor imagery, left stimulation sensation or right stimulation sensation). Two-way ANOVA statistical analysis showed a significant group effect (F (2,20) = 7.17, p = 0.0045), and the Benferroni-corrected multiple comparison test (with α = 0.05) showed that the hybrid modality group is 11.13% higher on average than the motor imagery group, and 10.45% higher than the selective sensation group. The hybrid modality experiment exhibits potentially wider spread usage within ten subjects crossed 70% accuracy, followed by four subjects in motor imagery and five subjects in selective sensation. Six subjects showed statistically significant improvement ( Benferroni-corrected) in hybrid modality in comparison with both motor imagery and selective sensation. Furthermore, among subjects having difficulties in both motor imagery and selective sensation, the hybrid modality improves their performance to 90% accuracy. The proposed hybrid modality BCI has demonstrated clear benefits for those poorly performing BCI users. Not only does the requirement of motor and sensory anticipation in this hybrid modality provide basic function of BCI for communication and control, it also has the potential for enhancing the rehabilitation during motor recovery.

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 ...

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.

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.

Understanding the impact of TV commercials: electrical neuroimaging.

Science.gov (United States)

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.

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.)

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.

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.

[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.

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.)

Temporal Explorations in Cosmic Consciousness: Intra-Agential Entanglements and the Neuro-Image

Directory of Open Access Journals (Sweden)

Patricia Pisters

2015-11-01

Full Text Available When Deleuze in the 1980s argued that ‘the brain is the screen’ he introduced the concepts of movement-image and time-image, two different modes of cinema with particular ontological and aesthetic characteristics. Contemporary cinema, however, has moved into yet another aesthetic mode, which I have proposed to call the neuro-image. One of the characteristics of the neuro-image is that we no longer follow the movements and actions of characters in a certain space (as in the movement-image, nor see the world coloured through their eyes (as in the time-image, but we (often quite literally experience brain worlds more directly, from within mental landscapes. In this essay I will investigate in which ways these brain worlds aesthetically express an embodied and embedded brain, addressing the new materialist dimensions of the neuro-image in a journey of cosmic cinema and, to speak with Barad, ‘meeting the universe halfway.’

Large-Scale Brain Networks Supporting Divided Attention across Spatial Locations and Sensory Modalities.

Science.gov (United States)

Santangelo, Valerio

2018-01-01

Higher-order cognitive processes were shown to rely on the interplay between large-scale neural networks. However, brain networks involved with the capability to split attentional resource over multiple spatial locations and multiple stimuli or sensory modalities have been largely unexplored to date. Here I re-analyzed data from Santangelo et al. (2010) to explore the causal interactions between large-scale brain networks during divided attention. During fMRI scanning, participants monitored streams of visual and/or auditory stimuli in one or two spatial locations for detection of occasional targets. This design allowed comparing a condition in which participants monitored one stimulus/modality (either visual or auditory) in two spatial locations vs. a condition in which participants monitored two stimuli/modalities (both visual and auditory) in one spatial location. The analysis of the independent components (ICs) revealed that dividing attentional resources across two spatial locations necessitated a brain network involving the left ventro- and dorso-lateral prefrontal cortex plus the posterior parietal cortex, including the intraparietal sulcus (IPS) and the angular gyrus, bilaterally. The analysis of Granger causality highlighted that the activity of lateral prefrontal regions were predictive of the activity of all of the posteriors parietal nodes. By contrast, dividing attention across two sensory modalities necessitated a brain network including nodes belonging to the dorsal frontoparietal network, i.e., the bilateral frontal eye-fields (FEF) and IPS, plus nodes belonging to the salience network, i.e., the anterior cingulated cortex and the left and right anterior insular cortex (aIC). The analysis of Granger causality highlights a tight interdependence between the dorsal frontoparietal and salience nodes in trials requiring divided attention between different sensory modalities. The current findings therefore highlighted a dissociation among brain networks

Large-Scale Brain Networks Supporting Divided Attention across Spatial Locations and Sensory Modalities

Directory of Open Access Journals (Sweden)

Valerio Santangelo

2018-02-01

Full Text Available Higher-order cognitive processes were shown to rely on the interplay between large-scale neural networks. However, brain networks involved with the capability to split attentional resource over multiple spatial locations and multiple stimuli or sensory modalities have been largely unexplored to date. Here I re-analyzed data from Santangelo et al. (2010 to explore the causal interactions between large-scale brain networks during divided attention. During fMRI scanning, participants monitored streams of visual and/or auditory stimuli in one or two spatial locations for detection of occasional targets. This design allowed comparing a condition in which participants monitored one stimulus/modality (either visual or auditory in two spatial locations vs. a condition in which participants monitored two stimuli/modalities (both visual and auditory in one spatial location. The analysis of the independent components (ICs revealed that dividing attentional resources across two spatial locations necessitated a brain network involving the left ventro- and dorso-lateral prefrontal cortex plus the posterior parietal cortex, including the intraparietal sulcus (IPS and the angular gyrus, bilaterally. The analysis of Granger causality highlighted that the activity of lateral prefrontal regions were predictive of the activity of all of the posteriors parietal nodes. By contrast, dividing attention across two sensory modalities necessitated a brain network including nodes belonging to the dorsal frontoparietal network, i.e., the bilateral frontal eye-fields (FEF and IPS, plus nodes belonging to the salience network, i.e., the anterior cingulated cortex and the left and right anterior insular cortex (aIC. The analysis of Granger causality highlights a tight interdependence between the dorsal frontoparietal and salience nodes in trials requiring divided attention between different sensory modalities. The current findings therefore highlighted a dissociation among

Modal Logics and Definability

OpenAIRE

Kuusisto, Antti

2013-01-01

In recent years, research into the mathematical foundations of modal logic has become increasingly popular. One of the main reasons for this is the fact that modal logic seems to adapt well to the requirements of a wide range of different fields of application. This paper is a summary of some of the author’s contributions to the understanding of modal definability theory.

Modality Use in Joint Attention between Hearing Parents and Deaf Children

Directory of Open Access Journals (Sweden)

Nicole eDepowski

2015-10-01

Full Text Available The present study examined differences in modality use during episodes of joint attention between hearing parent-hearing child dyads and hearing parent-deaf child dyads. Hearing children were age-matched to deaf children. Dyads were video recorded in a free play session with analyses focused on uni- and multimodality use during joint attention episodes. Results revealed that adults in hearing parent-deaf child dyads spent a significantly greater proportion of time interacting with their children using multiple communicative modalities than adults in hearing parent-hearing child dyads, who tended to use the auditory modality (e.g., oral language most often. While these findings demonstrate that hearing parents accommodate their children's hearing status, we observed greater overall time spent in joint attention in hearing parent-hearing child dyads than hearing parent-deaf child dyads. Our results point to important avenues for future research on how parents can better accommodate their child’s hearing status through the use of multimodal communication strategies.

NIF Periscope Wall Modal Study Comparison of Results for 2 FEA Models with 2 Modal Tests

International Nuclear Information System (INIS)

Eli, M W; Gerhard, M A; Lee, C L; Sommer, S C; Woehrle, T G

2000-01-01

This report summarizes experimentally and numerically determined modal properties for one of the reinforced concrete end walls of the NIF Periscope Support Structure in Laser Bay 1. Two methods were used to determine these modal properties: (1) Computational finite-element analyses (modal extraction process); and (2) Experimental modal analysis based on measured test data. This report also includes experimentally determined modal properties for a prototype LM3/Polarizer line-replaceable unit (LRU) and a prototype PEPC LRU. Two important parameters, used during the design phase, are validated through testing [ref 1]. These parameters are the natural frequencies and modal damping (of the system in question) for the first several global modes of vibration. Experimental modal testing provides these modal values, along with the corresponding mode shapes. Another important parameter, the input excitation (expected during normal operation of the NIF laser system) [ref 1], can be verified by performing a series of ambient vibration measurements in the vicinity of the particular system (or subsystem) of interest. The topic of ambient input excitation will be covered in a separate report. Due to the large mass of the Periscope Pedestal, it is difficult to excite the entire series of Periscope Pedestal Walls all at once. It was decided that the experimental modal tests would be performed on just one Periscope End Wall in Laser Bay 1. Experimental modal properties for the Periscope End Wall have been used to validate and update the FE analyses. Results from the analyses and modal tests support the conclusion that the Periscope Pedestal will not exceed the stability budget, which is described in reference 1. The results of the modal tests for the Periscope End Wall in Laser Bay 1 have provided examples of modal properties that can be derived from future modal tests of the entire Periscope Assembly (excluding the LRU's). This next series of larger modal tests can be performed

The clinical value of brain computerised tomography in a general ...

African Journals Online (AJOL)

Background: The use of neuroimaging modalities in psychiatry has been evaluated in several studies. The vast majority seem to suggest that neuroimaging may be overutilised in psychiatry. There is a significant constraint on availability and cost related to neuroimaging of patients at general state medical facilities.

Advances in Modal Logic

DEFF Research Database (Denmark)

Modal logic is a subject with ancient roots in the western logical tradition. Up until the last few generations, it was pursued mainly as a branch of philosophy. But in recent years, the subject has taken new directions with connections to topics in computer science and mathematics. This volume...... is the proceedings of the conference of record in its fi eld, Advances in Modal Logic. Its contributions are state-of-the-art papers. The topics include decidability and complexity results for specifi c modal logics, proof theory of modal logic, logics for reasoning about time and space, provability logic, dynamic...... epistemic logic, and the logic of evidence....

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.

Cross-modal perceptual load: the impact of modality and individual differences.

Science.gov (United States)

Sandhu, Rajwant; Dyson, Benjamin James

2016-05-01

Visual distractor processing tends to be more pronounced when the perceptual load (PL) of a task is low compared to when it is high [perpetual load theory (PLT); Lavie in J Exp Psychol Hum Percept Perform 21(3):451-468, 1995]. While PLT is well established in the visual domain, application to cross-modal processing has produced mixed results, and the current study was designed in an attempt to improve previous methodologies. First, we assessed PLT using response competition, a typical metric from the uni-modal domain. Second, we looked at the impact of auditory load on visual distractors, and of visual load on auditory distractors, within the same individual. Third, we compared individual uni- and cross-modal selective attention abilities, by correlating performance with the visual Attentional Network Test (ANT). Fourth, we obtained a measure of the relative processing efficiency between vision and audition, to investigate whether processing ease influences the extent of distractor processing. Although distractor processing was evident during both attend auditory and attend visual conditions, we found that PL did not modulate processing of either visual or auditory distractors. We also found support for a correlation between the uni-modal (visual) ANT and our cross-modal task but only when the distractors were visual. Finally, although auditory processing was more impacted by visual distractors, our measure of processing efficiency only accounted for this asymmetry in the auditory high-load condition. The results are discussed with respect to the continued debate regarding the shared or separate nature of processing resources across modalities.

Robust modal curvature features for identifying multiple damage in beams

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Ostachowicz, Wiesław; Xu, Wei; Bai, Runbo; Radzieński, Maciej; Cao, Maosen

2014-03-01

Curvature mode shape is an effective feature for damage detection in beams. However, it is susceptible to measurement noise, easily impairing its advantage of sensitivity to damage. To deal with this deficiency, this study formulates an improved curvature mode shape for multiple damage detection in beams based on integrating a wavelet transform (WT) and a Teager energy operator (TEO). The improved curvature mode shape, termed the WT - TEO curvature mode shape, has inherent capabilities of immunity to noise and sensitivity to damage. The proposed method is experimentally validated by identifying multiple cracks in cantilever steel beams with the mode shapes acquired using a scanning laser vibrometer. The results demonstrate that the improved curvature mode shape can identify multiple damage accurately and reliably, and it is fairly robust to measurement noise.

Evidence for a supra-modal representation of emotion from cross-modal adaptation.

Science.gov (United States)

Pye, Annie; Bestelmeyer, Patricia E G

2015-01-01

Successful social interaction hinges on accurate perception of emotional signals. These signals are typically conveyed multi-modally by the face and voice. Previous research has demonstrated uni-modal contrastive aftereffects for emotionally expressive faces or voices. Here we were interested in whether these aftereffects transfer across modality as theoretical models predict. We show that adaptation to facial expressions elicits significant auditory aftereffects. Adaptation to angry facial expressions caused ambiguous vocal stimuli drawn from an anger-fear morphed continuum to be perceived as less angry and more fearful relative to adaptation to fearful faces. In a second experiment, we demonstrate that these aftereffects are not dependent on learned face-voice congruence, i.e. adaptation to one facial identity transferred to an unmatched voice identity. Taken together, our findings provide support for a supra-modal representation of emotion and suggest further that identity and emotion may be processed independently from one another, at least at the supra-modal level of the processing hierarchy. Copyright © 2014 Elsevier B.V. All rights reserved.

Automated Modal Parameter Estimation for Operational Modal Analysis of Large Systems

DEFF Research Database (Denmark)

Andersen, Palle; Brincker, Rune; Goursat, Maurice

2007-01-01

In this paper the problems of doing automatic modal parameter extraction and how to account for large number of data to process are considered. Two different approaches for obtaining the modal parameters automatically using OMA are presented: The Frequency Domain Decomposition (FDD) technique and...

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.)

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.)

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.

Modality-specific effects on crosstalk in task switching: evidence from modality compatibility using bimodal stimulation.

Science.gov (United States)

Stephan, Denise Nadine; Koch, Iring

2016-11-01

The present study was aimed at examining modality-specific influences in task switching. To this end, participants switched either between modality compatible tasks (auditory-vocal and visual-manual) or incompatible spatial discrimination tasks (auditory-manual and visual-vocal). In addition, auditory and visual stimuli were presented simultaneously (i.e., bimodally) in each trial, so that selective attention was required to process the task-relevant stimulus. The inclusion of bimodal stimuli enabled us to assess congruence effects as a converging measure of increased between-task interference. The tasks followed a pre-instructed sequence of double alternations (AABB), so that no explicit task cues were required. The results show that switching between two modality incompatible tasks increases both switch costs and congruence effects compared to switching between two modality compatible tasks. The finding of increased congruence effects in modality incompatible tasks supports our explanation in terms of ideomotor "backward" linkages between anticipated response effects and the stimuli that called for this response in the first place. According to this generalized ideomotor idea, the modality match between response effects and stimuli would prime selection of a response in the compatible modality. This priming would cause increased difficulties to ignore the competing stimulus and hence increases the congruence effect. Moreover, performance would be hindered when switching between modality incompatible tasks and facilitated when switching between modality compatible tasks.

Neuroimaging in Parkinsonism: a study with magnetic resonance and spectroscopy as tools in the differential diagnosis

International Nuclear Information System (INIS)

Vasconcellos, Luiz Felipe Rocha; Novis, Sergio A. Pereira; Rosso, Ana Lucia Z.; Moreira, Denise Madeira

2009-01-01

The differential diagnosis of Parkinsonism based on clinical features, sometimes may be difficult. Diagnostic tests in these cases might be useful, especially magnetic resonance imaging, a noninvasive exam, not as expensive as positron emission tomography, and provides a good basis for anatomical analysis. The magnetic resonance spectroscopy analyzes cerebral metabolism, yielding inconsistent results in parkinsonian disorders. We selected 40 individuals for magnetic resonance imaging and spectroscopy analysis, 12 with Parkinson's disease, 11 with progressive supranuclear palsy, 7 with multiple system atrophy (parkinsonian type), and 10 individuals without any psychiatric or neurological disorders (controls). Clinical scales included Hoenh and Yahr, unified Parkinson's disease rating scale and mini mental status examination. The results showed that patients with Parkinson's disease and controls presented the same aspects on neuroimaging, with few or absence of abnormalities, and supranuclear progressive palsy and multiple system atrophy showed abnormalities, some of which statistically significant. Thus, magnetic resonance imaging and spectroscopy could be useful as a tool in differential diagnosis of Parkinsonism. (author)

Pain as a fact and heuristic: how pain neuroimaging illuminates moral dimensions of law.

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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.

Neural correlates of fear: insights from neuroimaging

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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

Manifold regularized multitask feature learning for multimodality disease classification.

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Jie, Biao; Zhang, Daoqiang; Cheng, Bo; Shen, Dinggang

2015-02-01

Multimodality based methods have shown great advantages in classification of Alzheimer's disease (AD) and its prodromal stage, that is, mild cognitive impairment (MCI). Recently, multitask feature selection methods are typically used for joint selection of common features across multiple modalities. However, one disadvantage of existing multimodality based methods is that they ignore the useful data distribution information in each modality, which is essential for subsequent classification. Accordingly, in this paper we propose a manifold regularized multitask feature learning method to preserve both the intrinsic relatedness among multiple modalities of data and the data distribution information in each modality. Specifically, we denote the feature learning on each modality as a single task, and use group-sparsity regularizer to capture the intrinsic relatedness among multiple tasks (i.e., modalities) and jointly select the common features from multiple tasks. Furthermore, we introduce a new manifold-based Laplacian regularizer to preserve the data distribution information from each task. Finally, we use the multikernel support vector machine method to fuse multimodality data for eventual classification. Conversely, we also extend our method to the semisupervised setting, where only partial data are labeled. We evaluate our method using the baseline magnetic resonance imaging (MRI), fluorodeoxyglucose positron emission tomography (FDG-PET), and cerebrospinal fluid (CSF) data of subjects from AD neuroimaging initiative database. The experimental results demonstrate that our proposed method can not only achieve improved classification performance, but also help to discover the disease-related brain regions useful for disease diagnosis. © 2014 Wiley Periodicals, Inc.

Determination of a modal interaction correction for narrowband fragility data

International Nuclear Information System (INIS)

Kana, D.D.; Pomerening, D.J.

1987-01-01

Laboratory tests for safety equipment operation under seismic environments in nuclear power plants have typically included various motion simulations based on either successively-applied multiple narrowband waveforms or simultaneous multifrequency broadband random waveforms. However, only broadband excitations are directly applicable when equipment performance is affected by interaction between simultaneously responding modes. Therefore, a modal interaction correction factor is developed so that a narrowed response spectrum can be transformed to an approximately equivalent broadband spectrum which accounts for modal interaction effects. The approach includes study of the fragility response of a simple two-degree-of-freedom oscillator for representative narrowband and broadband excitations, and relating the two resulting fragility response spectra. It is found that multiplication of the narrowband response spectrum by an 0.7 factor produces a conservative equivalent broadband response spectrum. The results are interpreted in terms of a secondary device responding on a primary support structure, or a primary structure having two resonances. The approach is useful for updating existing test results based on narrowband spectra, developing composite spectra for similar equipment, or providing more flexibility in designing new tests, and is applicable to qualification proof test data as well as fragility data. 10 refs., 8 figs

Physical modalities in chronic pain management.

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Rakel, Barbara; Barr, John O

2003-09-01

The following conclusions can be made based on review of the evidence: There is limited but positive evidence that select physical modalities are effective in managing chronic pain associated with specific conditions experienced by adults and older individuals. Overall, studies have provided the most support for the modality of therapeutic exercise. Different physical modalities have similar magnitudes of effects on chronic pain. Therefore, selection of the most appropriate physical modality may depend on the desired functional outcome for the patient, the underlying impairment, and the patient's preference or prior experience with the modality. Certain patient characteristics may decrease the effectiveness of physical modalities, as has been seen with TENS. These characteristics include depression, high trait anxiety, a powerful others locus of control, obesity, narcotic use, and neuroticism. The effect on pain by various modalities is generally strongest in the short-term period immediately after the intervention series, but effects can last as long as 1 year after treatment (e.g., with massage). Most research has tested the effect of physical modalities on chronic low back pain and knee OA. The effectiveness of physical modalities for other chronic pain conditions needs to be evaluated more completely. Older and younger adults often experience similar effects on their perception of pain from treatment with physical modalities. Therefore, use of these modalities for chronic pain in older adults is appropriate, but special precautions need to be taken. Practitioners applying physical modalities need formal training that includes the risks and precautions for these modalities. If practitioners lack formal training in the use of physical modalities, or if modality use is not within their scope of practice, it is important to consult with and refer patients to members of the team who have this specialized training. Use of a multidisciplinary approach to chronic pain

Modeling of Temperature Effect on Modal Frequency of Concrete Beam Based on Field Monitoring Data

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Wenchen Shan

2018-01-01

Full Text Available Temperature variation has been widely demonstrated to produce significant effect on modal frequencies that even exceed the effect of actual damage. In order to eliminate the temperature effect on modal frequency, an effective method is to construct quantitative models which accurately predict the modal frequency corresponding to temperature variation. In this paper, principal component analysis (PCA is conducted on the temperatures taken from all embedded thermocouples for extracting input parameters of regression models. Three regression-based numerical models using multiple linear regression (MLR, back-propagation neural network (BPNN, and support vector regression (SVR techniques are constructed to capture the relationships between modal frequencies and temperature distributions from measurements of a concrete beam during a period of forty days of monitoring. A comparison with respect to the performance of various optimally configured regression models has been performed on measurement data. Results indicate that the SVR exhibits a better reproduction and prediction capability than BPNN and MLR models for predicting the modal frequencies with respect to nonuniformly distributed temperatures. It is succeeded that temperature effects on modal frequencies can be effectively eliminated based on the optimally formulated SVR model.

Attention to spoken word planning: Chronometric and neuroimaging evidence

NARCIS (Netherlands)

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,

The iconography of mourning and its neural correlates: a functional neuroimaging study.

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Labek, Karin; Berger, Samantha; Buchheim, Anna; Bosch, Julia; Spohrs, Jennifer; Dommes, Lisa; Beschoner, Petra; Stingl, Julia C; Viviani, Roberto

2017-08-01

The present functional neuroimaging study focuses on the iconography of mourning. A culture-specific pattern of body postures of mourning individuals, mostly suggesting withdrawal, emerged from a survey of visual material. When used in different combinations in stylized drawings in our neuroimaging study, this material activated cortical areas commonly seen in studies of social cognition (temporo-parietal junction, superior temporal gyrus, and inferior temporal lobe), empathy for pain (somatosensory cortex), and loss (precuneus, middle/posterior cingular gyrus). This pattern of activation developed over time. While in the early phases of exposure lower association areas, such as the extrastriate body area, were active, in the late phases activation in parietal and temporal association areas and the prefrontal cortex was more prominent. These findings are consistent with the conventional and contextual character of iconographic material, and further differentiate it from emotionally negatively valenced and high-arousing stimuli. In future studies, this neuroimaging assay may be useful in characterizing interpretive appraisal of material of negative emotional valence. © The Author (2017). Published by Oxford University Press.

Modal Testing of the NPSAT1 Engineering Development Unit

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2012-07-01

erkläre ich, dass die vorliegende Master Arbeit von mir selbstständig und nur unter Verwendung der angegebenen Quellen und Hilfsmittel angefertigt...logarithmic scale . As 5 Figure 2 shows, natural frequencies are indicated by large values of the first CMIF (peaks), and multiple modes can be detected by...structure’s behavior. Ewins even states, “that no large- scale modal test should be permitted to proceed until some preliminary SDOF analyses have

A reformed surgical treatment modality for children with giant cystic craniopharyngioma.

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Zhu, Wanchun; Li, Xiang; He, Jintao; Sun, Tao; Li, Chunde; Gong, Jian

2017-09-01

Surgical removal plays an important role in treating children's craniopharyngioma. For a safe and minimally invasive craniotomy, a reformed surgical modality was proposed in this paper by combining the insertion of an Ommaya reservoir system (ORS) by stereotactic puncture, aspiration of cystic fluid in 2-day interval for consecutive 7-10 days, and the delayed tumor resection. Eleven patients (aged from 5 to 9 years old) with giant cystic craniopharyngiomas who had undergone the reformed surgical modality during November 2014 and December 2015 were collected as group A. In contrast, seven patients (aged from 5 to 11 years old) who had undergone the traditional directed operation without any prior management from January 2014 to October 2014 were collected into group B. A retrospective analysis was performed for both groups at one institution. The preoperative and postoperative clinical presentations, neuroimaging, early postoperative outcome, and the surgery-related complications of both groups were reviewed. For group A, the mean value of the maximum tumor diameters shank from 52.36 to 23.82 mm after implementing aspiration of the cystic fluid in 1-day interval for consecutive 8.23 days. Eight patients (72.73%) in group A underwent a gross total resection (GTR), while two (28.57%) patients underwent GTR in group B. The postoperative electrolyte disturbance rate and endocrine disorder rate of group B were significantly higher than those of group A (42.86 vs 36.36%; 71.43 vs 45.45%). Postoperative long-term diabetes insipidus only occurred in one patient of group B, and postoperative visual deterioration occurred in two patients of group B. Besides, one patient of group B died of severe postoperative hypothalamus dysfunction. Patients with residual tumors were applied with additional adjuvant radiotherapy, and no recurrence was observed in follow-up examinations. A favorable outcome can be achieved by combining the insertion of an ORS by stereotactic puncture

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

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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.

Structured and Sparse Canonical Correlation Analysis as a Brain-Wide Multi-Modal Data Fusion Approach.

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Mohammadi-Nejad, Ali-Reza; Hossein-Zadeh, Gholam-Ali; Soltanian-Zadeh, Hamid

2017-07-01

Multi-modal data fusion has recently emerged as a comprehensive neuroimaging analysis approach, which usually uses canonical correlation analysis (CCA). However, the current CCA-based fusion approaches face problems like high-dimensionality, multi-collinearity, unimodal feature selection, asymmetry, and loss of spatial information in reshaping the imaging data into vectors. This paper proposes a structured and sparse CCA (ssCCA) technique as a novel CCA method to overcome the above problems. To investigate the performance of the proposed algorithm, we have compared three data fusion techniques: standard CCA, regularized CCA, and ssCCA, and evaluated their ability to detect multi-modal data associations. We have used simulations to compare the performance of these approaches and probe the effects of non-negativity constraint, the dimensionality of features, sample size, and noise power. The results demonstrate that ssCCA outperforms the existing standard and regularized CCA-based fusion approaches. We have also applied the methods to real functional magnetic resonance imaging (fMRI) and structural MRI data of Alzheimer's disease (AD) patients (n = 34) and healthy control (HC) subjects (n = 42) from the ADNI database. The results illustrate that the proposed unsupervised technique differentiates the transition pattern between the subject-course of AD patients and HC subjects with a p-value of less than 1×10 -6 . Furthermore, we have depicted the brain mapping of functional areas that are most correlated with the anatomical changes in AD patients relative to HC subjects.

Modality-Driven Classification and Visualization of Ensemble Variance

Energy Technology Data Exchange (ETDEWEB)

Bensema, Kevin; Gosink, Luke; Obermaier, Harald; Joy, Kenneth I.

2016-10-01

Advances in computational power now enable domain scientists to address conceptual and parametric uncertainty by running simulations multiple times in order to sufficiently sample the uncertain input space. While this approach helps address conceptual and parametric uncertainties, the ensemble datasets produced by this technique present a special challenge to visualization researchers as the ensemble dataset records a distribution of possible values for each location in the domain. Contemporary visualization approaches that rely solely on summary statistics (e.g., mean and variance) cannot convey the detailed information encoded in ensemble distributions that are paramount to ensemble analysis; summary statistics provide no information about modality classification and modality persistence. To address this problem, we propose a novel technique that classifies high-variance locations based on the modality of the distribution of ensemble predictions. Additionally, we develop a set of confidence metrics to inform the end-user of the quality of fit between the distribution at a given location and its assigned class. We apply a similar method to time-varying ensembles to illustrate the relationship between peak variance and bimodal or multimodal behavior. These classification schemes enable a deeper understanding of the behavior of the ensemble members by distinguishing between distributions that can be described by a single tendency and distributions which reflect divergent trends in the ensemble.

Characterization and functional correlation of multiple imaging modalities with focal choroidal excavation

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Yun-Chen Chen

2018-05-01

Full Text Available Background: To investigate the clinical manifestations and imaging features of near-infrared autofluorescence (NIA, infrared reflectance (IR, fundus autofluorescence (FAF, indocyanine green angiography (ICGA and fluorescein angiography (FAG in the detection of patients with focal choroidal excavation (FCE identified by cross-sectional spectral-domain optical coherence tomography (SD-OCT. Methods: This retrospective cross-sectional study included 12 eyes of 10 Taiwanese patients with FCE diagnosed by SD-OCT. The areas and depths of FCE in serial cross-sectional and en-face OCT were compared in different imaging modalities. NIA, IR, FAF, ICGA and FAG images were obtained. Best corrected visual acuity, subjective distortion area in the Amsler grid and history of maculopathies were also recorded. Results: In areas where the choroid started to excavate as shown in SD-OCT, hypo-autofluorescence in NIA was noted. The area of hypo-fluorescence in NIA of all the FCE lesions showed good correlation with the size. The area of FCE was associated with complications such as choroidal neovascularization and central serous chorioretinopathy (p = 0.014, d.f = 1 and the volume (NIA area × Depth measured by SD-OCT × 1/3 was associated with subjective distortion strongly (p = 0.051, Spearman's correlation = 0.600. Conclusion: Among all image modalities, NIA was the most sensitive tool in area measurement of FCE and peripheral lesion detection. Also, the volume of FCE was associated with subjective distortion and the area was related to complications. Recording the area and volume of FCE could play an important role in monitoring complications. Keywords: Choroid-retina disease, Focal choroidal excavation, Near-infrared autofluorescence, Spectral-domain optical coherence tomography

Altered Brain Activity in Unipolar Depression Revisited: Meta-analyses of Neuroimaging Studies.

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Müller, Veronika I; Cieslik, Edna C; Serbanescu, Ilinca; Laird, Angela R; Fox, Peter T; Eickhoff, Simon B

2017-01-01

During the past 20 years, numerous neuroimaging experiments have investigated aberrant brain activation during cognitive and emotional processing in patients with unipolar depression (UD). The results of those investigations, however, vary considerably; moreover, previous meta-analyses also yielded inconsistent findings. To readdress aberrant brain activation in UD as evidenced by neuroimaging experiments on cognitive and/or emotional processing. Neuroimaging experiments published from January 1, 1997, to October 1, 2015, were identified by a literature search of PubMed, Web of Science, and Google Scholar using different combinations of the terms fMRI (functional magnetic resonance imaging), PET (positron emission tomography), neural, major depression, depression, major depressive disorder, unipolar depression, dysthymia, emotion, emotional, affective, cognitive, task, memory, working memory, inhibition, control, n-back, and Stroop. Neuroimaging experiments (using fMRI or PET) reporting whole-brain results of group comparisons between adults with UD and healthy control individuals as coordinates in a standard anatomic reference space and using an emotional or/and cognitive challenging task were selected. Coordinates reported to show significant activation differences between UD and healthy controls during emotional or cognitive processing were extracted. By using the revised activation likelihood estimation algorithm, different meta-analyses were calculated. Meta-analyses tested for brain regions consistently found to show aberrant brain activation in UD compared with controls. Analyses were calculated across all emotional processing experiments, all cognitive processing experiments, positive emotion processing, negative emotion processing, experiments using emotional face stimuli, experiments with a sex discrimination task, and memory processing. All meta-analyses were calculated across experiments independent of reporting an increase or decrease of activity in

The Dopamine Imbalance Hypothesis of Fatigue in Multiple Sclerosis and Other Neurological Disorders.

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Ekaterina eDobryakova

2015-03-01

Full Text Available Fatigue is one of the most pervasive symptoms of multiple sclerosis (MS, and has engendered hundreds of investigations on the topic. While there is a growing literature using various methods to study fatigue, a unified theory of fatigue in MS is yet to emerge. In the current review, we synthesize findings from neuroimaging, pharmacological, neuropsychological and immunological studies of fatigue in MS, which point to a specific hypothesis of fatigue in MS: the dopamine imbalance hypothesis. The communication between the striatum and prefrontal cortex is reliant on dopamine, a modulatory neurotransmitter. Neuroimaging findings suggest that fatigue results from the disruption of communication between these regions. Supporting the dopamine imbalance hypothesis, structural and functional neuroimaging studies show abnormalities in the frontal and striatal regions that are heavily innervated by dopamine neurons. Further, dopaminergic psychostimulant medication has been shown to alleviate fatigue in individuals with traumatic brain injury, chronic fatigue syndrome and in cancer patients, also indicating that dopamine might play an important role in fatigue perception. This paper reviews the structural and functional neuroimaging evidence as well as pharmacological studies that suggest that dopamine plays a critical role in the phenomenon of fatigue. We conclude with how specific aspects of the dopamine imbalance hypothesis can be tested in future research.

Neuroimaging in pediatric traumatic head injury: diagnostic considerations and relationships to neurobehavioral outcome.

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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.

Is the statistic value all we should care about in neuroimaging?

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Chen, Gang; Taylor, Paul A; Cox, Robert W

2017-02-15

Here we address an important issue that has been embedded within the neuroimaging community for a long time: the absence of effect estimates in results reporting in the literature. The statistic value itself, as a dimensionless measure, does not provide information on the biophysical interpretation of a study, and it certainly does not represent the whole picture of a study. Unfortunately, in contrast to standard practice in most scientific fields, effect (or amplitude) estimates are usually not provided in most results reporting in the current neuroimaging publications and presentations. Possible reasons underlying this general trend include (1) lack of general awareness, (2) software limitations, (3) inaccurate estimation of the BOLD response, and (4) poor modeling due to our relatively limited understanding of FMRI signal components. However, as we discuss here, such reporting damages the reliability and interpretability of the scientific findings themselves, and there is in fact no overwhelming reason for such a practice to persist. In order to promote meaningful interpretation, cross validation, reproducibility, meta and power analyses in neuroimaging, we strongly suggest that, as part of good scientific practice, effect estimates should be reported together with their corresponding statistic values. We provide several easily adaptable recommendations for facilitating this process. Published by Elsevier Inc.

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.

Modal bifurcation in a high-Tc superconducting levitation system

International Nuclear Information System (INIS)

Taguchi, D; Fujiwara, S; Sugiura, T

2011-01-01

This paper deals with modal bifurcation of a multi-degree-of-freedom high-T c superconducting levitation system. As modeling of large-scale high-T c superconducting levitation applications, where plural superconducting bulks are often used, it can be helpful to consider a system constituting of multiple oscillators magnetically coupled with each other. This paper investigates nonlinear dynamics of two permanent magnets levitated above high-T c superconducting bulks and placed between two fixed permanent magnets without contact. First, the nonlinear equations of motion of the levitated magnets were derived. Then the method of averaging was applied to them. It can be found from the obtained solutions that this nonlinear two degree-of-freedom system can have two asymmetric modes, in addition to a symmetric mode and an antisymmetric mode both of which also exist in the linearized system. One of the backbone curves in the frequency response shows a modal bifurcation where the two stable asymmetric modes mentioned above appear with destabilization of the antisymmetric mode, thus leading to modal localization. These analytical predictions have been confirmed in our numerical analysis and experiments of free vibration and forced vibration. These results, never predicted by linear analysis, can be important for application of high-T c superconducting levitation systems.

Eye and hand motor interactions with the Symbol Digit Modalities Test in early multiple sclerosis.

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Nygaard, Gro O; de Rodez Benavent, Sigrid A; Harbo, Hanne F; Laeng, Bruno; Sowa, Piotr; Damangir, Soheil; Bernhard Nilsen, Kristian; Etholm, Lars; Tønnesen, Siren; Kerty, Emilia; Drolsum, Liv; Inge Landrø, Nils; Celius, Elisabeth G

2015-11-01

Eye and hand motor dysfunction may be present early in the disease course of relapsing-remitting multiple sclerosis (RRMS), and can affect the results on visual and written cognitive tests. We aimed to test for differences in saccadic initiation time (SI time) between RRMS patients and healthy controls, and whether SI time and hand motor speed interacted with the written version of the Symbol Digit Modalities Test (wSDMT). Patients with RRMS (N = 44, age 35.1 ± 7.3 years), time since diagnosis < 3 years and matched controls (N = 41, age 33.2 ± 6.8 years) were examined with ophthalmological, neurological and neuropsychological tests, as well as structural MRI (white matter lesion load (WMLL) and brainstem lesions), visual evoked potentials (VEP) and eye-tracker examinations of saccades. SI time was longer in RRMS than controls (p < 0.05). SI time was not related to the Paced Auditory Serial Addition Test (PASAT), WMLL or to the presence of brainstem lesions. 9 hole peg test (9HP) correlated significantly with WMLL (r = 0.58, p < 0.01). Both SI time and 9HP correlated negatively with the results of wSDMT (r = -0.32, p < 0.05, r = -0.47, p < 0.01), but none correlated with the results of PASAT. RRMS patients have an increased SI time compared to controls. Cognitive tests results, exemplified by the wSDMT, may be confounded by eye and hand motor function. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

The utility of neuroimaging in the management of dementia

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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.

Cognitive and emotional processes during dreaming: a neuroimaging view.

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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.

Nervous System Injury and Neuroimaging of Zika Virus Infection

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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

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.

A Review of Transcranial Magnetic Stimulation and Multimodal Neuroimaging to Characterize Post-Stroke Neuroplasticity

Science.gov (United States)

Auriat, Angela M.; Neva, Jason L.; Peters, Sue; Ferris, Jennifer K.; Boyd, Lara A.

2015-01-01

Following stroke, the brain undergoes various stages of recovery where the central nervous system can reorganize neural circuitry (neuroplasticity) both spontaneously and with the aid of behavioral rehabilitation and non-invasive brain stimulation. Multiple neuroimaging techniques can characterize common structural and functional stroke-related deficits, and importantly, help predict recovery of function. Diffusion tensor imaging (DTI) typically reveals increased overall diffusivity throughout the brain following stroke, and is capable of indexing the extent of white matter damage. Magnetic resonance spectroscopy (MRS) provides an index of metabolic changes in surviving neural tissue after stroke, serving as a marker of brain function. The neural correlates of altered brain activity after stroke have been demonstrated by abnormal activation of sensorimotor cortices during task performance, and at rest, using functional magnetic resonance imaging (fMRI). Electroencephalography (EEG) has been used to characterize motor dysfunction in terms of increased cortical amplitude in the sensorimotor regions when performing upper limb movement, indicating abnormally increased cognitive effort and planning in individuals with stroke. Transcranial magnetic stimulation (TMS) work reveals changes in ipsilesional and contralesional cortical excitability in the sensorimotor cortices. The severity of motor deficits indexed using TMS has been linked to the magnitude of activity imbalance between the sensorimotor cortices. In this paper, we will provide a narrative review of data from studies utilizing DTI, MRS, fMRI, EEG, and brain stimulation techniques focusing on TMS and its combination with uni- and multimodal neuroimaging methods to assess recovery after stroke. Approaches that delineate the best measures with which to predict or positively alter outcomes will be highlighted. PMID:26579069

Oscillatory neuronal activity reflects lexical-semantic feature integration within and across sensory modalities in distributed cortical networks.

Science.gov (United States)

van Ackeren, Markus J; Schneider, Till R; Müsch, Kathrin; Rueschemeyer, Shirley-Ann

2014-10-22

Research from the previous decade suggests that word meaning is partially stored in distributed modality-specific cortical networks. However, little is known about the mechanisms by which semantic content from multiple modalities is integrated into a coherent multisensory representation. Therefore we aimed to characterize differences between integration of lexical-semantic information from a single modality compared with two sensory modalities. We used magnetoencephalography in humans to investigate changes in oscillatory neuronal activity while participants verified two features for a given target word (e.g., "bus"). Feature pairs consisted of either two features from the same modality (visual: "red," "big") or different modalities (auditory and visual: "red," "loud"). The results suggest that integrating modality-specific features of the target word is associated with enhanced high-frequency power (80-120 Hz), while integrating features from different modalities is associated with a sustained increase in low-frequency power (2-8 Hz). Source reconstruction revealed a peak in the anterior temporal lobe for low-frequency and high-frequency effects. These results suggest that integrating lexical-semantic knowledge at different cortical scales is reflected in frequency-specific oscillatory neuronal activity in unisensory and multisensory association networks. Copyright © 2014 the authors 0270-6474/14/3314318-06$15.00/0.

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

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

Dual-modality NIRF-MRI cubosomes and hexosomes: High throughput formulation and in vivo biodistribution

Energy Technology Data Exchange (ETDEWEB)

Tran, Nhiem, E-mail: nhiem.tran@rmit.edu.au [CSIRO Manufacturing, Clayton, Victoria 3168 (Australia); Australian Synchrotron, Clayton, Victoria 3168 (Australia); RMIT University, Melbourne, Victoria 3000 (Australia); Bye, Nicole; Moffat, Bradford A. [Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, Victoria 3010 (Australia); Wright, David K. [Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, Victoria 3010 (Australia); The Florey Institute of Neuroscience and Mental Health, Parkville, Victoria 3052 (Australia); Cuddihy, Andrew [Myeloma Research Group, Australian Centre for Blood Diseases, Monash Central Clinical School, The Alfred Hospital, Melbourne, Victoria 3004 (Australia); Hinton, Tracey M. [CSIRO Australian Animal Health Laboratory, East Geelong, Victoria 3219 (Australia); Hawley, Adrian M. [Australian Synchrotron, Clayton, Victoria 3168 (Australia); Reynolds, Nicholas P. [CSIRO Manufacturing, Clayton, Victoria 3168 (Australia); ARC Training Centre for Biodevices, Faculty of Science Engineering and Technology, Swinburne University of Technology, Melbourne, Victoria 3122 (Australia); Waddington, Lynne J.; Mulet, Xavier [CSIRO Manufacturing, Clayton, Victoria 3168 (Australia); Turnley, Ann M. [Department of Anatomy and Neuroscience, The University of Melbourne, Parkville, Victoria 3010 (Australia); Morganti-Kossmann, M. Cristina [Australian New Zealand Intensive Care Research Centre, Monash University, Victoria 3800 (Australia); Department of Child Health, Barrow Neurological Institute, University of Arizona, Phoenix, AZ 85004 (United States); Muir, Benjamin W., E-mail: ben.muir@csiro.au [CSIRO Manufacturing, Clayton, Victoria 3168 (Australia)

2017-02-01

Engineered nanoparticles with multiple complementary imaging modalities are of great benefit to the rapid treatment and diagnosis of disease in various organs. Herein, we report the formulation of cubosomes and hexosomes that carry multiple amphiphilic imaging contrast agents in their self-assembled lipid bilayers. This is the first report of the use of both near infrared fluorescent (NIRF) imaging and gadolinium lipid based magnetic resonance (MR) imaging modalities in cubosomes and hexosomes. High-throughput screening was used to rapidly optimize formulations with desirable nano-architectures and low in vitro cytotoxicity. The dual-modal imaging nanoparticles in vivo biodistribution and organ specific contrast enhancement were then studied. The NIRF in vivo imaging results indicated accumulation of both cubosomes and hexosomes in the liver and spleen of mice up to 20 h post-injection. Remarkably, the biodistribution of the nanoparticle formulations was affected by the mesophase (i.e. cubic or hexagonal), a finding of significant importance for the future use of these compounds, with hexosomes showing higher accumulation in the spleen than the liver compared to cubosomes. Furthermore, in vivo MRI data of animals injected with either type of lyotropic liquid crystal nanoparticle displayed enhanced contrast in the liver and spleen. - Highlights: • Dual modality NIRF-MR imaging self-assembled lipid nanoparticles were formulated. • The nanoparticles showed cubic and hexagonal internal nanostructures. • Biodistribution experiments revealed accumulation of both cubosomes and hexosomes in spleen and liver of mice. • Pre-clinical MRI displayed enhanced contrast in spleen and liver of mice that received either cubosomes or hexosomes.

Dual-modality NIRF-MRI cubosomes and hexosomes: High throughput formulation and in vivo biodistribution

International Nuclear Information System (INIS)

Tran, Nhiem; Bye, Nicole; Moffat, Bradford A.; Wright, David K.; Cuddihy, Andrew; Hinton, Tracey M.; Hawley, Adrian M.; Reynolds, Nicholas P.; Waddington, Lynne J.; Mulet, Xavier; Turnley, Ann M.; Morganti-Kossmann, M. Cristina; Muir, Benjamin W.

2017-01-01

Engineered nanoparticles with multiple complementary imaging modalities are of great benefit to the rapid treatment and diagnosis of disease in various organs. Herein, we report the formulation of cubosomes and hexosomes that carry multiple amphiphilic imaging contrast agents in their self-assembled lipid bilayers. This is the first report of the use of both near infrared fluorescent (NIRF) imaging and gadolinium lipid based magnetic resonance (MR) imaging modalities in cubosomes and hexosomes. High-throughput screening was used to rapidly optimize formulations with desirable nano-architectures and low in vitro cytotoxicity. The dual-modal imaging nanoparticles in vivo biodistribution and organ specific contrast enhancement were then studied. The NIRF in vivo imaging results indicated accumulation of both cubosomes and hexosomes in the liver and spleen of mice up to 20 h post-injection. Remarkably, the biodistribution of the nanoparticle formulations was affected by the mesophase (i.e. cubic or hexagonal), a finding of significant importance for the future use of these compounds, with hexosomes showing higher accumulation in the spleen than the liver compared to cubosomes. Furthermore, in vivo MRI data of animals injected with either type of lyotropic liquid crystal nanoparticle displayed enhanced contrast in the liver and spleen. - Highlights: • Dual modality NIRF-MR imaging self-assembled lipid nanoparticles were formulated. • The nanoparticles showed cubic and hexagonal internal nanostructures. • Biodistribution experiments revealed accumulation of both cubosomes and hexosomes in spleen and liver of mice. • Pre-clinical MRI displayed enhanced contrast in spleen and liver of mice that received either cubosomes or hexosomes.

Modality independence of order coding in working memory: Evidence from cross-modal order interference at recall.

Science.gov (United States)

Vandierendonck, André

2016-01-01

Working memory researchers do not agree on whether order in serial recall is encoded by dedicated modality-specific systems or by a more general modality-independent system. Although previous research supports the existence of autonomous modality-specific systems, it has been shown that serial recognition memory is prone to cross-modal order interference by concurrent tasks. The present study used a serial recall task, which was performed in a single-task condition and in a dual-task condition with an embedded memory task in the retention interval. The modality of the serial task was either verbal or visuospatial, and the embedded tasks were in the other modality and required either serial or item recall. Care was taken to avoid modality overlaps during presentation and recall. In Experiment 1, visuospatial but not verbal serial recall was more impaired when the embedded task was an order than when it was an item task. Using a more difficult verbal serial recall task, verbal serial recall was also more impaired by another order recall task in Experiment 2. These findings are consistent with the hypothesis of modality-independent order coding. The implications for views on short-term recall and the multicomponent view of working memory are discussed.

The ENIGMA Consortium: large-scale collaborative analyses of neuroimaging and genetic data.

Science.gov (United States)

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

2014-06-01

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, genetics, and medicine, ENIGMA studies have analyzed neuroimaging data from over 12,826 subjects. In addition, data from 12,171 individuals were provided by the CHARGE consortium for replication of findings, in a total of 24,997 subjects. By meta-analyzing results from many sites, ENIGMA has detected factors that affect the brain that no individual site could detect on its own, and that require larger numbers of subjects than any individual neuroimaging study has currently collected. ENIGMA's first project was a genome-wide association study identifying common variants in the genome associated with hippocampal volume or intracranial volume. Continuing work is exploring genetic associations with subcortical volumes (ENIGMA2) and white matter microstructure (ENIGMA-DTI). Working groups also focus on understanding how schizophrenia, bipolar illness, major depression and attention deficit/hyperactivity disorder (ADHD) affect the brain. We review the current progress of the ENIGMA Consortium, along with challenges and unexpected discoveries made on the way.

Pure spinal multiple sclerosis: A possible novel entity within the multiple sclerosis disease spectrum.

Science.gov (United States)

Schee, Jie Ping; Viswanathan, Shanthi

2018-05-01

We identified five female patients retrospectively with relapsing short-segment partial myelitis whose clinical and paraclinical features were suggestive of cord involvement of multiple sclerosis (MS)-type albeit not rigidly fulfilling the 2017 McDonald criteria. Notably, these patients had not developed any typical MS-like brain lesions despite repeated neuroimaging assessments over years. Comprehensive work-up for differential diagnoses of MS and other causes of transverse myelitis particularly neuromyelitis optica spectrum disorders had been consistently negative on longitudinal follow-up. Thus, we postulate a possible entity of pure spinal MS which may represent a novel forme fruste within the MS disease spectrum.

Image and Dose Simulation in Support of New Imaging Modalities

International Nuclear Information System (INIS)

Kuruvilla Verghese

2002-01-01

This report summarizes the highlights of the research performed under the 2-year NEER grant from the Department of Energy. The primary outcome of the work was a new Monte Carlo code, MCMIS-DS, for Monte Carlo for Mammography Image Simulation including Differential Sampling. The code was written to generate simulated images and dose distributions from two different new digital x-ray imaging modalities, namely, synchrotron imaging (SI) and a slot geometry digital mammography system called Fisher Senoscan. A differential sampling scheme was added to the code to generate multiple images that included variations in the parameters of the measurement system and the object in a single execution of the code. The code is to serve multiple purposes; (1) to answer questions regarding the contribution of scattered photons to images, (2) for use in design optimization studies, and (3) to do up to second-order perturbation studies to assess the effects of design parameter variations and/or physical parameters of the object (the breast) without having to re-run the code for each set of varied parameters. The accuracy and fidelity of the code were validated by a large variety of benchmark studies using published data and also using experimental results from mammography phantoms on both imaging modalities

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)

Optimal Modality Selection for Cooperative Human-Robot Task Completion.

Science.gov (United States)

Jacob, Mithun George; Wachs, Juan P

2016-12-01

Human-robot cooperation in complex environments must be fast, accurate, and resilient. This requires efficient communication channels where robots need to assimilate information using a plethora of verbal and nonverbal modalities such as hand gestures, speech, and gaze. However, even though hybrid human-robot communication frameworks and multimodal communication have been studied, a systematic methodology for designing multimodal interfaces does not exist. This paper addresses the gap by proposing a novel methodology to generate multimodal lexicons which maximizes multiple performance metrics over a wide range of communication modalities (i.e., lexicons). The metrics are obtained through a mixture of simulation and real-world experiments. The methodology is tested in a surgical setting where a robot cooperates with a surgeon to complete a mock abdominal incision and closure task by delivering surgical instruments. Experimental results show that predicted optimal lexicons significantly outperform predicted suboptimal lexicons (p human-robot collision) and the differences in the lexicons are analyzed.

Bimodal extinction without cross-modal extinction.

OpenAIRE

Inhoff, A W; Rafal, R D; Posner, M J

1992-01-01

Three patients with unilateral neurological injury were clinically examined. All showed consistent unilateral extinction in the tactile and visual modalities on simultaneous intramodal stimulation. There was virtually no evidence for cross-modal extinction, however, so that contralateral stimulation of one modality would have extinguished perception of ipsilateral stimuli in the other modality. It is concluded that the attentional system controlling the encoding of tactile and visual stimuli ...

A Comparison of Therapeutic Modalities for Septated Tuberculous PleuraI Effusion on US

Energy Technology Data Exchange (ETDEWEB)

Cho, In Hwan; Kim, Kyeong Ah; Kim, Chul Joong; Kang, Eun Young; Cha, In Ho [Dae Rim St. Mary' s Hospital, Seoul (Korea, Republic of); Sim, Jae Jung [Korea University College of Medicine, Seoul (Korea, Republic of)

1995-12-15

To evaluate the utility of ultrasonography as a guide of determination of therapeutic modality an dto compare the therapeutic effects of modalities in patients with tuberculous pleural effusion. This study included 47 patients who had multiple septations on ultrasonography. We classified ultrasonographic pattern of pleural effusion into three groups according to pattern of septation : linear(n=6),moderate(n=19), honeycombing(n=22). We also classified therapeutic modalities into three groups : thoracentesis group(n=13), percutaneous catheter drainage group(n=11), intrapleural urokinase instillation group(n=23). We assessed the early and late therapeutic effects of these groups prospectively with follow-up chest radiographs. There was statistically no significant difference in therapeutic effect among the groups that had linear and moderate septa on ultrasonography(p<0.01). In patients with honeycombing septa, the therapeutic effects of catheter group and urokinase group were superior to conservative thoracentesis group(p<0.01). In urokinase group,mean duration of drainage(6.6 days) was significantly shorter than catheter group's(12.4 days) (p<0.01). Pattern of septation on ultrasonography could be an useful factor for determination of the therapeutic modality in patients with tuberculous pleural effusion. Percutaneous catheter drainage with urokinase instillation is a good therapeutic modality with shortened duration of drainage in treatment of pleural effusion with honeycombing septae

A Comparison of Therapeutic Modalities for Septated Tuberculous PleuraI Effusion on US

International Nuclear Information System (INIS)

Cho, In Hwan; Kim, Kyeong Ah; Kim, Chul Joong; Kang, Eun Young; Cha, In Ho; Sim, Jae Jung

1995-01-01

To evaluate the utility of ultrasonography as a guide of determination of therapeutic modality an dto compare the therapeutic effects of modalities in patients with tuberculous pleural effusion. This study included 47 patients who had multiple septations on ultrasonography. We classified ultrasonographic pattern of pleural effusion into three groups according to pattern of septation : linear(n=6),moderate(n=19), honeycombing(n=22). We also classified therapeutic modalities into three groups : thoracentesis group(n=13), percutaneous catheter drainage group(n=11), intrapleural urokinase instillation group(n=23). We assessed the early and late therapeutic effects of these groups prospectively with follow-up chest radiographs. There was statistically no significant difference in therapeutic effect among the groups that had linear and moderate septa on ultrasonography(p<0.01). In patients with honeycombing septa, the therapeutic effects of catheter group and urokinase group were superior to conservative thoracentesis group(p<0.01). In urokinase group,mean duration of drainage(6.6 days) was significantly shorter than catheter group's(12.4 days) (p<0.01). Pattern of septation on ultrasonography could be an useful factor for determination of the therapeutic modality in patients with tuberculous pleural effusion. Percutaneous catheter drainage with urokinase instillation is a good therapeutic modality with shortened duration of drainage in treatment of pleural effusion with honeycombing septae

Modal logics are coalgebraic

NARCIS (Netherlands)

Cirstea, C.; Kurz, A.; Pattinson, D.; Schröder, L.; Venema, Y.

2011-01-01

Applications of modal logics are abundant in computer science, and a large number of structurally different modal logics have been successfully employed in a diverse spectrum of application contexts. Coalgebraic semantics, on the other hand, provides a uniform and encompassing view on the large

Active Vibration Suppression of a 3-DOF Flexible Parallel Manipulator Using Efficient Modal Control

Directory of Open Access Journals (Sweden)

Quan Zhang

2014-01-01

Full Text Available This paper addresses the dynamic modeling and efficient modal control of a planar parallel manipulator (PPM with three flexible linkages actuated by linear ultrasonic motors (LUSM. To achieve active vibration control, multiple lead zirconate titanate (PZT transducers are mounted on the flexible links as vibration sensors and actuators. Based on Lagrange’s equations, the dynamic model of the flexible links is derived with the dynamics of PZT actuators incorporated. Using the assumed mode method (AMM, the elastic motion of the flexible links are discretized under the assumptions of pinned-free boundary conditions, and the assumed mode shapes are validated through experimental modal test. Efficient modal control (EMC, in which the feedback forces in different modes are determined according to the vibration amplitude or energy of their own, is employed to control the PZT actuators to realize active vibration suppression. Modal filters are developed to extract the modal displacements and velocities from the vibration sensors. Numerical simulation and vibration control experiments are conducted to verify the proposed dynamic model and controller. The results show that the EMC method has the capability of suppressing multimode vibration simultaneously, and both the structural and residual vibrations of the flexible links are effectively suppressed using EMC approach.

Numerical analysis of modal tomography for solar multi-conjugate adaptive optics

International Nuclear Information System (INIS)

Dong Bing; Ren Deqing; Zhang Xi

2012-01-01

Multi-conjugate adaptive optics (MCAO) can considerably extend the corrected field of view with respect to classical adaptive optics, which will benefit solar observation in many aspects. In solar MCAO, the Sun structure is utilized to provide multiple guide stars and a modal tomography approach is adopted to implement three-dimensional wavefront restorations. The principle of modal tomography is briefly reviewed and a numerical simulation model is built with three equivalent turbulent layers and a different number of guide stars. Our simulation results show that at least six guide stars are required for an accurate wavefront reconstruction in the case of three layers, and only three guide stars are needed in the two layer case. Finally, eigenmode analysis results are given to reveal the singular modes that cannot be precisely retrieved in the tomography process.

The modal study

International Nuclear Information System (INIS)

Cook, J.R.

1988-01-01

The term ''Modal Study'' refers to a research program conducted for the Nuclear Regulatory Commission (NRC) on the level of protection provided by NRC-certified packages during the shipment of spent nuclear fuel form U.S. power reactors. The objective of the study was to examine the response of the packages to actual highway and railway accident conditions. The Modal Study results show that NRC-certified spent fuel casks would perform their safety functions under severe, actual accident conditions. The study also explains how NRC's cask design conditions, which are expressed in engineering terms, relate to actual accident conditions, with which the public is more familiar. The Modal Study, along with other transportation studies, physical testing of casks, and the spent fuel shipment safety record confirm the view that casks provide a high level of public safety during spent fuel transport

Tinnitus Neural Mechanisms and Structural Changes in the Brain: The Contribution of Neuroimaging Research

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Simonetti, Patricia

2015-03-01

Full Text Available Introduction Tinnitus is an abnormal perception of sound in the absence of an external stimulus. Chronic tinnitus usually has a high impact in many aspects of patients' lives, such as emotional stress, sleep disturbance, concentration difficulties, and so on. These strong reactions are usually attributed to central nervous system involvement. Neuroimaging has revealed the implication of brain structures in the auditory system. Objective This systematic review points out neuroimaging studies that contribute to identifying the structures involved in the pathophysiological mechanism of generation and persistence of various forms of tinnitus. Data Synthesis Functional imaging research reveals that tinnitus perception is associated with the involvement of the nonauditory brain areas, including the front parietal area; the limbic system, which consists of the anterior cingulate cortex, anterior insula, and amygdala; and the hippocampal and parahippocampal area. Conclusion The neuroimaging research confirms the involvement of the mechanisms of memory and cognition in the persistence of perception, anxiety, distress, and suffering associated with tinnitus.

Neuroimaging in Parkinsonism: a study with magnetic resonance and spectroscopy as tools in the differential diagnosis

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Vasconcellos, Luiz Felipe Rocha [1Hospital dos Servidores do Estado, Rio de Janeiro RJ (Brazil)], e-mail: luizneurol@terra.com.br; Novis, Sergio A. Pereira; Rosso, Ana Lucia Z. [Hospital Universitario Clementino Fraga Filho (HUCFF), Rio de Janeiro, RJ (Brazil); Moreira, Denise Madeira [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Neurologia Deolindo Couto; Leite, Ana Claudia C.B. [Fundacao Oswaldo Cruz (FIOCRUZ), Rio de Janeiro, RJ (Brazil)

2009-03-15

The differential diagnosis of Parkinsonism based on clinical features, sometimes may be difficult. Diagnostic tests in these cases might be useful, especially magnetic resonance imaging, a noninvasive exam, not as expensive as positron emission tomography, and provides a good basis for anatomical analysis. The magnetic resonance spectroscopy analyzes cerebral metabolism, yielding inconsistent results in parkinsonian disorders. We selected 40 individuals for magnetic resonance imaging and spectroscopy analysis, 12 with Parkinson's disease, 11 with progressive supranuclear palsy, 7 with multiple system atrophy (parkinsonian type), and 10 individuals without any psychiatric or neurological disorders (controls). Clinical scales included Hoenh and Yahr, unified Parkinson's disease rating scale and mini mental status examination. The results showed that patients with Parkinson's disease and controls presented the same aspects on neuroimaging, with few or absence of abnormalities, and supranuclear progressive palsy and multiple system atrophy showed abnormalities, some of which statistically significant. Thus, magnetic resonance imaging and spectroscopy could be useful as a tool in differential diagnosis of Parkinsonism. (author)

Perception of Scenes in Different Sensory Modalities: A Result of Modal Completion.

Science.gov (United States)

Gruber, Ronald R; Block, Richard A

2017-01-01

Dynamic perception includes amodal and modal completion, along with apparent movement. It fills temporal gaps for single objects. In 2 experiments, using 6 stimulus presentation conditions involving 3 sensory modalities, participants experienced 8-10 sequential stimuli (200 ms each) with interstimulus intervals (ISIs) of 0.25-7.0 s. Experiments focused on spatiotemporal completion (walking), featural completion (object changing), auditory, completion (falling bomb), and haptic changes (insect crawling). After each trial, participants judged whether they experienced the process of "happening " or whether they simply knew that the process must have occurred. The phenomenon was frequency independent, being reported at short ISIs but not at long ISIs. The phenomenon involves dynamic modal completion and possibly also conceptual processes.

Making MR Imaging Child's Play - Pediatric Neuroimaging Protocol, Guidelines and Procedure

Science.gov (United States)

Raschle, Nora M.; Lee, Michelle; Buechler, Roman; Christodoulou, Joanna A.; Chang, Maria; Vakil, Monica; Stering, Patrice L.; Gaab, Nadine

2009-01-01

Within the last decade there has been an increase in the use of structural and functional magnetic resonance imaging (fMRI) to investigate the neural basis of human perception, cognition and behavior 1, 2. Moreover, this non-invasive imaging method has grown into a tool for clinicians and researchers to explore typical and atypical brain development. Although advances in neuroimaging tools and techniques are apparent, (f)MRI in young pediatric populations remains relatively infrequent 2. Practical as well as technical challenges when imaging children present clinicians and research teams with a unique set of problems 3, 2. To name just a few, the child participants are challenged by a need for motivation, alertness and cooperation. Anxiety may be an additional factor to be addressed. Researchers or clinicians need to consider time constraints, movement restriction, scanner background noise and unfamiliarity with the MR scanner environment2,4-10. A progressive use of functional and structural neuroimaging in younger age groups, however, could further add to our understanding of brain development. As an example, several research groups are currently working towards early detection of developmental disorders, potentially even before children present associated behavioral characteristics e.g.11. Various strategies and techniques have been reported as a means to ensure comfort and cooperation of young children during neuroimaging sessions. Play therapy 12, behavioral approaches 13, 14,15, 16-18 and simulation 19, the use of mock scanner areas 20,21, basic relaxation 22 and a combination of these techniques 23 have all been shown to improve the participant's compliance and thus MRI data quality. Even more importantly, these strategies have proven to increase the comfort of families and children involved 12. One of the main advances of such techniques for the clinical practice is the possibility of avoiding sedation or general anesthesia (GA) as a way to manage children

Reliability and equivalence of alternate forms for the Symbol Digit Modalities Test: implications for multiple sclerosis clinical trials.

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Benedict, Ralph H B; Smerbeck, Audrey; Parikh, Rajavi; Rodgers, Jonathan; Cadavid, Diego; Erlanger, David

2012-09-01

Cognitive impairment is common in multiple sclerosis (MS), but is seldom assessed in clinical trials investigating the effects of disease-modifying therapies. The Symbol Digit Modalities Test (SDMT) is a particularly promising tool due to its sensitivity and robust correlation with brain magnetic resonance imaging (MRI) and vocational disability. Unfortunately, there are no validated alternate SDMT forms, which are needed to mitigate practice effects. The aim of the study was to assess the reliability and equivalence of SDMT alternate forms. Twenty-five healthy participants completed each of five alternate versions of the SDMT - the standard form, two versions from the Rao Brief Repeatable Battery, and two forms specifically designed for this study. Order effects were controlled using a Latin-square research design. All five versions of the SDMT produced mean values within 3 raw score points of one another. Three forms were very consistent, and not different by conservative statistical tests. The SDMT test-retest reliability using these forms was good to excellent, with all r values exceeding 0.80. For the first time, we find good evidence that at least three alternate versions of the SDMT are of equivalent difficulty in healthy adults. The forms are reliable, and can be implemented in clinical trials emphasizing cognitive outcomes.

Can Emotional and Behavioral Dysregulation in Youth Be Decoded from Functional Neuroimaging?

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Liana C L Portugal

Full Text Available High comorbidity among pediatric disorders characterized by behavioral and emotional dysregulation poses problems for diagnosis and treatment, and suggests that these disorders may be better conceptualized as dimensions of abnormal behaviors. Furthermore, identifying neuroimaging biomarkers related to dimensional measures of behavior may provide targets to guide individualized treatment. We aimed to use functional neuroimaging and pattern regression techniques to determine whether patterns of brain activity could accurately decode individual-level severity on a dimensional scale measuring behavioural and emotional dysregulation at two different time points.A sample of fifty-seven youth (mean age: 14.5 years; 32 males was selected from a multi-site study of youth with parent-reported behavioral and emotional dysregulation. Participants performed a block-design reward paradigm during functional Magnetic Resonance Imaging (fMRI. Pattern regression analyses consisted of Relevance Vector Regression (RVR and two cross-validation strategies implemented in the Pattern Recognition for Neuroimaging toolbox (PRoNTo. Medication was treated as a binary confounding variable. Decoded and actual clinical scores were compared using Pearson's correlation coefficient (r and mean squared error (MSE to evaluate the models. Permutation test was applied to estimate significance levels.Relevance Vector Regression identified patterns of neural activity associated with symptoms of behavioral and emotional dysregulation at the initial study screen and close to the fMRI scanning session. The correlation and the mean squared error between actual and decoded symptoms were significant at the initial study screen and close to the fMRI scanning session. However, after controlling for potential medication effects, results remained significant only for decoding symptoms at the initial study screen. Neural regions with the highest contribution to the pattern regression model

The search for neuroimaging biomarkers of Alzheimer's disease with advanced MRI techniques

International Nuclear Information System (INIS)

Li, Tie-Qiang; Wahlund, Lars-Olof

2011-01-01

The aim of this review is to examine the recent literature on using advanced magnetic resonance imaging (MRI) techniques for finding neuroimaging biomarkers that are sensitive to the detection of risks for Alzheimer's disease (AD). Since structural MRI techniques, such as brain structural volumetry and voxel based morphometry (VBM), have been widely used for AD studies and extensively reviewed, we will only briefly touch on the topics of volumetry and morphometry. The focus of the current review is about the more recent developments in the search for AD neuroimaging biomarkers with functional MRI (fMRI), resting-state functional connectivity MRI (fcMRI), diffusion tensor imaging (DTI), arterial spin-labeling (ASL), and magnetic resonance spectroscopy (MRS)

FAKTOR PENENTU STRUKTUR MODAL: STUDI EMPIRIK PADA PERUSAHAAN MULTIFINANSIAL

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Siti Ridloah

2010-09-01

Full Text Available Penelitian ini bertujuan untuk mengetahui pengaruh variabel struktur aktiva, ukuran perusahaan, operating leverage, profitabilitas, likuiditas dan pertumbuhan penjualan terhadap Struktur Modal perusahaan sektor keuangan serta mengetahui variabel manakah yang paling berpengaruh terhadap stuktur modal. Populasi dalam penelitian ini adalah semua perusahaan sektor keuangan multifinansial yang terdaftar di BEI yang memiliki laporan keuangan dalam ICMD tahun 2008. Penentuan sampel penelitian ini menggunakan metode purposive sampling. Hasil analisis regresi menunjukkan bahwa ada pengaruh secara simultan variabel independen terhadap Struktur Modal. Hanya ada tiga variabel independen yang berpengaruh signifikan secara parsial terhadap variabel dependen yaitu ukuran perusahaan, profitabilitas dan likuiditas. Dari variabel-variabel tersebut, variabel yang paling berpengaruh terhadap stuktur modal adalah ukuran perusahaan. Saran yang penulis sampaikan dalam penelitian ini, bahwa untuk mencapai Struktur Modal yang optimal, perusahaan perlu meningkatkan profitabilitas, likuiditas dan ukuran perusahaan dengan cara meningkatkan profit margin dan meningkatkan asset yang dimiliki perusahaan. This study aims to determine the effect of asset structure variables, firm Size, operating leverage, profitability, liquidity and growth in sales of corporate capital structure of the financial sector as well as knowing which variables most affect the capital structure. The populations of this study were all multifinansial financial sector companies have been listed on the Stock Exchange which has ICMD financial statements in 2008. Purposive sampling method is used to analyse the samples of this study. The results of multiple regression analysis showed that there is a simultaneous effect of independent variables of corporate capital structure of the financial sector. There are only three independent variables that significantly influence the dependent variable that is

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

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...

A Causal Theory of Modality

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José Tomás Alvarado

2009-08-01

Full Text Available This work presents a causal conception of metaphysical modality in which a state of affairs is metaphysically possible if and only if it can be caused (in the past, the present or the future by current entities. The conception is contrasted with what is called the “combinatorial” conception of modality, in which everything can co-exist with anything else. This work explains how the notion of ‘causality’ should be construed in the causal theory, what difference exists between modalities thus defined from nomological modality, how accessibility relations between possible worlds should be interpreted, and what is the relation between the causal conception and the necessity of origin.

How the Blind “See” Braille and the Deaf “Hear” Sign: Lessons from fMRI on the Cross-Modal Plasticity, Integration, and Learning

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Norihiro Sadato

2011-10-01

Full Text Available What does the visual cortex of the blind do during Braille reading? This process involves converting simple tactile information into meaningful patterns that have lexical and semantic properties. The perceptual processing of Braille might be mediated by the somatosensory system, whereas visual letter identity is accomplished within the visual system in sighted people. Recent advances in functional neuroimaging techniques have enabled exploration of the neural substrates of Braille reading (Sadato et al. 1996, 1998, 2002, Cohen et al. 1997, 1999. The primary visual cortex of early-onset blind subjects is functionally relevant to Braille reading, suggesting that the brain shows remarkable plasticity that potentially permits the additional processing of tactile information in the visual cortical areas. Similar cross-modal plasticity is observed by the auditory deprivation: Sign language activates the auditory cortex of deaf subjects (Neville et al. 1999, Nishimura et al. 1999, Sadato et al. 2004. Cross-modal activation can be seen in the sighted and hearing subjects. For example, the tactile shape discrimination of two dimensional (2D shapes (Mah-Jong tiles activated the visual cortex by expert players (Saito et al. 2006, and the lip-reading (visual phonetics (Sadato et al. 2004 or key touch reading by pianists (Hasegawa et al. 2004 activates the auditory cortex of hearing subjects. Thus the cross-modal plasticity by sensory deprivation and cross-modal integration through the learning may share their neural substrates. To clarify the distribution of the neural substrates and their dynamics during cross-modal association learning within several hours, we conducted audio-visual paired association learning of delayed-matching-to-sample type tasks (Tanabe et al. 2005. Each trial consisted of the successive presentation of a pair of stimuli. Subjects had to find pre-defined audio-visual or visuo-visual pairs in a trial and error manner with feedback in

Clinical profile and neuroimaging in pediatric optic neuritis in Indian population: A case series

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Rutika Khadse

2017-01-01

Full Text Available Purpose of the study: The purpose of this study was to report clinical features, neuroimaging, and visual outcome in pediatric optic neuritis (ON in Indian population. Materials and Methods: This is a retrospective study of children up to the age of 16 years, diagnosed with ON, that presented at pediatric and neuroophthalmology clinic of a tertiary eye care center, in South India, within the period of 2010–2015. Results: We identified 62 eyes of 40 children diagnosed as ON within the study period. The mean age was 11.15 ± 3.24 years (1–15 years with mean follow-up of 13 months. In this series, there was female preponderance (67%. Mean logarithm of the minimum angle of resolution visual acuity at presentation was 1.14 ± 0.93, which after treatment recovered to 0.10 ± 0.26 at final visit (P < 0.001. Involvement was bilateral in 22 children (55% and recurrent in 3 eyes of 3 children. Preceding febrile illness was reported in seven cases (18%. Four (10% cases were diagnosed as multiple sclerosis (MS, one with neuromyelitis optica , and one with acute disseminated encephalomyelitis. One case was associated with tuberculous meningitis, 1 with septicemia, and 1 with bilateral maxillary sinusitis. Neuroimaging studies of optic nerve in 14 children demonstrated isolated optic nerve enhancement. Magnetic resonance imaging brain revealed white matter T2 hyperintense lesions separate from optic nerve in ten cases, of which four cases were diagnosed as MS. Conclusions: Bilateral presentation was common, association with MS was low. Papillitis was more frequent than retrobulbar neuritis and prognosis was good in pediatric ON in Indian population.

Noise elimination algorithm for modal analysis

Energy Technology Data Exchange (ETDEWEB)

Bao, X. X., E-mail: baoxingxian@upc.edu.cn [Department of Naval Architecture and Ocean Engineering, China University of Petroleum (East China), Qingdao 266580 (China); Li, C. L. [Key Laboratory of Marine Geology and Environment, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071 (China); Xiong, C. B. [The First Institute of Oceanography, State Oceanic Administration, Qingdao 266061 (China)

2015-07-27

Modal analysis is an ongoing interdisciplinary physical issue. Modal parameters estimation is applied to determine the dynamic characteristics of structures under vibration excitation. Modal analysis is more challenging for the measured vibration response signals are contaminated with noise. This study develops a mathematical algorithm of structured low rank approximation combined with the complex exponential method to estimate the modal parameters. Physical experiments using a steel cantilever beam with ten accelerometers mounted, excited by an impulse load, demonstrate that this method can significantly eliminate noise from measured signals and accurately identify the modal frequencies and damping ratios. This study provides a fundamental mechanism of noise elimination using structured low rank approximation in physical fields.

Cross-modal decoupling in temporal attention.

Science.gov (United States)

Mühlberg, Stefanie; Oriolo, Giovanni; Soto-Faraco, Salvador

2014-06-01

Prior studies have repeatedly reported behavioural benefits to events occurring at attended, compared to unattended, points in time. It has been suggested that, as for spatial orienting, temporal orienting of attention spreads across sensory modalities in a synergistic fashion. However, the consequences of cross-modal temporal orienting of attention remain poorly understood. One challenge is that the passage of time leads to an increase in event predictability throughout a trial, thus making it difficult to interpret possible effects (or lack thereof). Here we used a design that avoids complete temporal predictability to investigate whether attending to a sensory modality (vision or touch) at a point in time confers beneficial access to events in the other, non-attended, sensory modality (touch or vision, respectively). In contrast to previous studies and to what happens with spatial attention, we found that events in one (unattended) modality do not automatically benefit from happening at the time point when another modality is expected. Instead, it seems that attention can be deployed in time with relative independence for different sensory modalities. Based on these findings, we argue that temporal orienting of attention can be cross-modally decoupled in order to flexibly react according to the environmental demands, and that the efficiency of this selective decoupling unfolds in time. © 2014 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.

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)

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)

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...

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.

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.

Analysis of the relationships between type 2 diabetes status, glycemic control, and neuroimaging measures in the Diabetes Heart Study Mind.

Science.gov (United States)

Raffield, Laura M; Cox, Amanda J; Freedman, Barry I; Hugenschmidt, Christina E; Hsu, Fang-Chi; Wagner, Benjamin C; Xu, Jianzhao; Maldjian, Joseph A; Bowden, Donald W

2016-06-01

To examine the relationships between type 2 diabetes (T2D) status, glycemic control, and T2D duration with magnetic resonance imaging (MRI)-derived neuroimaging measures in European Americans from the Diabetes Heart Study (DHS) Mind cohort. Relationships were examined using marginal models with generalized estimating equations in 784 participants from 514 DHS Mind families. Fasting plasma glucose, glycated hemoglobin, and diabetes duration were analyzed in 682 participants with T2D. Models were adjusted for potential confounders, including age, sex, history of cardiovascular disease, smoking, educational attainment, and use of statins or blood pressure medications. Association was tested with gray and white matter volume, white matter lesion volume, gray matter cerebral blood flow, and white and gray matter fractional anisotropy and mean diffusivity. Adjusting for multiple comparisons, T2D status was associated with reduced white matter volume (p = 2.48 × 10(-6)) and reduced gray and white matter fractional anisotropy (p ≤ 0.001) in fully adjusted models, with a trend toward increased white matter lesion volume (p = 0.008) and increased gray and white matter mean diffusivity (p ≤ 0.031). Among T2D-affected participants, neither fasting glucose, glycated hemoglobin, nor diabetes duration were associated with the neuroimaging measures assessed (p > 0.05). While T2D was significantly associated with MRI-derived neuroimaging measures, differences in glycemic control in T2D-affected individuals in the DHS Mind study do not appear to significantly contribute to variation in these measures. This supports the idea that the presence or absence of T2D, not fine gradations of glycemic control, may be more significantly associated with age-related changes in the brain.

The Modality-Match Effect in Recognition Memory

Science.gov (United States)

Mulligan, Neil W.; Osborn, Katherine

2009-01-01

The modality-match effect in recognition refers to superior memory for words presented in the same modality at study and test. Prior research on this effect is ambiguous and inconsistent. The present study demonstrates that the modality-match effect is found when modality is rendered salient at either encoding or retrieval. Specifically, in…

Thermal-recovery of modal instability in rod fiber amplifiers

DEFF Research Database (Denmark)

Jørgensen, Mette Marie; Laurila, Marko; Noordegraaf, Danny

2013-01-01

We investigate the temporal dynamics of Modal instabilities (MI) in ROD fiber amplifiers using a 100 μm core rod fiber in a single-pass amplifier configuration, and we achieve ~200W of extracted output power before the onset of MI. Above the MI threshold, we investigate the temporal dynamics of b...... and thermally annealed between each test series. We find that the MI threshold degrades as it is reached multiple times, but is recovered by thermal annealing. We also find that the test history of the rods affects the temporal dynamics....

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.

Decentralized modal identification using sparse blind source separation

International Nuclear Information System (INIS)

Sadhu, A; Hazra, B; Narasimhan, S; Pandey, M D

2011-01-01

Popular ambient vibration-based system identification methods process information collected from a dense array of sensors centrally to yield the modal properties. In such methods, the need for a centralized processing unit capable of satisfying large memory and processing demands is unavoidable. With the advent of wireless smart sensor networks, it is now possible to process information locally at the sensor level, instead. The information at the individual sensor level can then be concatenated to obtain the global structure characteristics. A novel decentralized algorithm based on wavelet transforms to infer global structure mode information using measurements obtained using a small group of sensors at a time is proposed in this paper. The focus of the paper is on algorithmic development, while the actual hardware and software implementation is not pursued here. The problem of identification is cast within the framework of under-determined blind source separation invoking transformations of measurements to the time–frequency domain resulting in a sparse representation. The partial mode shape coefficients so identified are then combined to yield complete modal information. The transformations are undertaken using stationary wavelet packet transform (SWPT), yielding a sparse representation in the wavelet domain. Principal component analysis (PCA) is then performed on the resulting wavelet coefficients, yielding the partial mixing matrix coefficients from a few measurement channels at a time. This process is repeated using measurements obtained from multiple sensor groups, and the results so obtained from each group are concatenated to obtain the global modal characteristics of the structure

Decentralized modal identification using sparse blind source separation

Science.gov (United States)

Sadhu, A.; Hazra, B.; Narasimhan, S.; Pandey, M. D.

2011-12-01

Popular ambient vibration-based system identification methods process information collected from a dense array of sensors centrally to yield the modal properties. In such methods, the need for a centralized processing unit capable of satisfying large memory and processing demands is unavoidable. With the advent of wireless smart sensor networks, it is now possible to process information locally at the sensor level, instead. The information at the individual sensor level can then be concatenated to obtain the global structure characteristics. A novel decentralized algorithm based on wavelet transforms to infer global structure mode information using measurements obtained using a small group of sensors at a time is proposed in this paper. The focus of the paper is on algorithmic development, while the actual hardware and software implementation is not pursued here. The problem of identification is cast within the framework of under-determined blind source separation invoking transformations of measurements to the time-frequency domain resulting in a sparse representation. The partial mode shape coefficients so identified are then combined to yield complete modal information. The transformations are undertaken using stationary wavelet packet transform (SWPT), yielding a sparse representation in the wavelet domain. Principal component analysis (PCA) is then performed on the resulting wavelet coefficients, yielding the partial mixing matrix coefficients from a few measurement channels at a time. This process is repeated using measurements obtained from multiple sensor groups, and the results so obtained from each group are concatenated to obtain the global modal characteristics of the structure.

Kinerja Keuangan Daerah dan Pembiayaan Belanja Modal Kabupaten Merangin

Directory of Open Access Journals (Sweden)

Elliya Agus

2016-09-01

Full Text Available Abstract. This research aimed to test and obtain empirical evidence of a direct effect of the components of financial performance of local governments to capital expenditure Merangin Regency in 2001-2015. The results showed that the degree of decentralization is still very low as the average over 15 years amounted to only 5.16% were categorized as very reendah. It is claimed that PAD Merangin Regency is still a major effect on revenues, seen from efectifivity PAD and PAD Merangin Regency efficiency has been very effective and efficient. The results of multiple linear regression with the variables DOF, effectiveness and efficiency of significant positive effect on capital spending. This suggests that any increase in the financial performance Capital expenditure will also rise. Keywords: Financial Performance, Capital Expenditures, Decentralization Abstrak Penelitian ini bertujuan untuk mengetahui kinerja anggaran keungan daerah Kabupaten Merangin menggunakan pendekatan rasio keuangan untuk mengukur derajat desentralisasi, tingkat efisiensi dan efektifitas keuagan daerah, serta mengetahui, menguji dan memperoleh bukti empiris pengaruh langsung komponen kinerja keuangan pemerintah daerah terhadap alokasi belanja modal Kabupaten Merangin tahun 2001-2015. Hasil penelitian menunjukkan bahwa derajat desentralisasi masih sangat rendah dimana rata-rata selama 15 tahun hanya sebesar 5,16 % yang termasuk dalam kategori sangat rendah.  Hal ini menyatakan bahwa Pendapatan Asli Daerah (PAD Kabupaten Merangin masih belum berpengaruh besar terhadap pendapatan daerah, dilihat dari efektifivitas  dan efisiensi Pendapatan Asli Daerah Kabupaten Merangin sudah sangat efektif dan efisien. Hasil dari regresi linear berganda dengan variabel derajat otonomi fiskal, efektifitas dan efisiensi  keuangan daerah berpengaruh positif signifikan terhadap belanja modal.  Hal ini menunjukkan bahwa setiap kenaikan Kinerja keuangan maka Belanja Modal juga akan ikut naik. Kata

Preferential reasoning for modal logics

CSIR Research Space (South Africa)

Britz, K

2011-11-01

Full Text Available Modal logic is the foundation for a versatile and well-established class of knowledge representation formalisms in artificial intelligence. Enriching modal logics with non-monotonic reasoning capabilities such as preferential reasoning as developed...

Kajian Eksperimental Parameter Modal Bangunan Dua Lantai dengan Metode Modal Analisis

Directory of Open Access Journals (Sweden)

Islahuddin Islahuddin

2016-12-01

Full Text Available Abstrak: Pengukuran getaran merupakan kegiatan yang umum dilakukan dalam perawatan prediktif. Perawatan prediktifbiasanya menggunakan pengukuran sinyal getaran untuk mendeteksi kerusakan yang terjadi pada mesin. Sinyalgetaran yang terukur tersebut, kemudian ditransformasikan dalam bentuk grafik fungsi respon frekuensi (FRF.Selanjutnya FRF diolah sedemikian rupasehingga diperoleh modus getar struktur. Dari modus getar yang diperoleh,maka dapat dianalisa kemungkinan kerusakan yang terjadi pada mesin dengan melihat besarnya amplitudo getarannya.Penelitian ini bertujuan untuk menganalisa karakteristik dinamik dari sistem getaran yang terjadi pada model strukturbangunan dua lantai. Pengujian dilakukan denganmemberikan gaya eksitasi menggunakan impact hammer.Akselerometer digunakan mengukur sinyal getaran yang terjadi pada struktur. Posisi penempatan akselerometerdilakukan bervariasi untuk delapan titik pengujian yang berbeda. Sedangkan posisi pemberian gaya eksitasi tetap untuksemua titik pengujian. Pada penelitian ini menggunakan metode modal analisis eksperimen untuk mengetahuikarakteristik dinamik dari model struktur bangunan dua lantai. Teknik modal analisis ini digunakan untuk mendapatkanparameter modal seperti frekuensi, rasio redaman, dan modus getar. Hasil yang diperoleh dari penelitian inimenunjukkan bahwafrekuensi pribadipertama pada amplitudo maksimum mempunyai nilai yang sama, yaitu 2,313 Hz.Sedangkan untuk frekuensi pribadi kedua pada amplitudo maksimumnya terdapat perbedaan, yaitu pada titik pengujian3 dan 7. Hal ini dapat disebabkan oleh pemberian gaya eksitasi yang tidak sama dengan titik-titik pengujian yang lain.Kata kunci: Karakteristik dinamik, analisis modal eksperimen, frekuensi pribadi, FRF Abstract: Measuring vibration is an activity which is generally carried out in a predictive maintenance. In maintaining, vibratesignal measurement is usually used for machine damage detection. The signal measurement is then being

Stability, structure and scale: improvements in multi-modal vessel extraction for SEEG trajectory planning.

Science.gov (United States)

Zuluaga, Maria A; Rodionov, Roman; Nowell, Mark; Achhala, Sufyan; Zombori, Gergely; Mendelson, Alex F; Cardoso, M Jorge; Miserocchi, Anna; McEvoy, Andrew W; Duncan, John S; Ourselin, Sébastien

2015-08-01

Brain vessels are among the most critical landmarks that need to be assessed for mitigating surgical risks in stereo-electroencephalography (SEEG) implantation. Intracranial haemorrhage is the most common complication associated with implantation, carrying significantly associated morbidity. SEEG planning is done pre-operatively to identify avascular trajectories for the electrodes. In current practice, neurosurgeons have no assistance in the planning of electrode trajectories. There is great interest in developing computer-assisted planning systems that can optimise the safety profile of electrode trajectories, maximising the distance to critical structures. This paper presents a method that integrates the concepts of scale, neighbourhood structure and feature stability with the aim of improving robustness and accuracy of vessel extraction within a SEEG planning system. The developed method accounts for scale and vicinity of a voxel by formulating the problem within a multi-scale tensor voting framework. Feature stability is achieved through a similarity measure that evaluates the multi-modal consistency in vesselness responses. The proposed measurement allows the combination of multiple images modalities into a single image that is used within the planning system to visualise critical vessels. Twelve paired data sets from two image modalities available within the planning system were used for evaluation. The mean Dice similarity coefficient was 0.89 ± 0.04, representing a statistically significantly improvement when compared to a semi-automated single human rater, single-modality segmentation protocol used in clinical practice (0.80 ± 0.03). Multi-modal vessel extraction is superior to semi-automated single-modality segmentation, indicating the possibility of safer SEEG planning, with reduced patient morbidity.

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

Multi-modality molecular imaging: pre-clinical laboratory configuration

Science.gov (United States)

Wu, Yanjun; Wellen, Jeremy W.; Sarkar, Susanta K.

2006-02-01

In recent years, the prevalence of in vivo molecular imaging applications has rapidly increased. Here we report on the construction of a multi-modality imaging facility in a pharmaceutical setting that is expected to further advance existing capabilities for in vivo imaging of drug distribution and the interaction with their target. The imaging instrumentation in our facility includes a microPET scanner, a four wavelength time-domain optical imaging scanner, a 9.4T/30cm MRI scanner and a SPECT/X-ray CT scanner. An electronics shop and a computer room dedicated to image analysis are additional features of the facility. The layout of the facility was designed with a central animal preparation room surrounded by separate laboratory rooms for each of the major imaging modalities to accommodate the work-flow of simultaneous in vivo imaging experiments. This report will focus on the design of and anticipated applications for our microPET and optical imaging laboratory spaces. Additionally, we will discuss efforts to maximize the daily throughput of animal scans through development of efficient experimental work-flows and the use of multiple animals in a single scanning session.

The modality effect of ego depletion: Auditory task modality reduces ego depletion.

Science.gov (United States)

Li, Qiong; Wang, Zhenhong

2016-08-01

An initial act of self-control that impairs subsequent acts of self-control is called ego depletion. The ego depletion phenomenon has been observed consistently. The modality effect refers to the effect of the presentation modality on the processing of stimuli. The modality effect was also robustly found in a large body of research. However, no study to date has examined the modality effects of ego depletion. This issue was addressed in the current study. In Experiment 1, after all participants completed a handgrip task, one group's participants completed a visual attention regulation task and the other group's participants completed an auditory attention regulation task, and then all participants again completed a handgrip task. The ego depletion phenomenon was observed in both the visual and the auditory attention regulation task. Moreover, participants who completed the visual task performed worse on the handgrip task than participants who completed the auditory task, which indicated that there was high ego depletion in the visual task condition. In Experiment 2, participants completed an initial task that either did or did not deplete self-control resources, and then they completed a second visual or auditory attention control task. The results indicated that depleted participants performed better on the auditory attention control task than the visual attention control task. These findings suggest that altering task modality may reduce ego depletion. © 2016 Scandinavian Psychological Associations and John Wiley & Sons Ltd.

Completeness for flat modal fixpoint logics

NARCIS (Netherlands)

Santocanale, L.; Venema, Y.

2010-01-01

This paper exhibits a general and uniform method to prove axiomatic completeness for certain modal fixpoint logics. Given a set Γ of modal formulas of the form γ(x,p1,…,pn), where x occurs only positively in γ, we obtain the flat modal fixpoint language L♯(Γ) by adding to the language of polymodal

Fatigue in multiple sclerosis: neural correlates and the role of non-invasive brain stimulation

Directory of Open Access Journals (Sweden)

Moussa A. Chalah

2015-11-01

Full Text Available Multiple sclerosis (MS is a chronic progressive inflammatory disease of the central nervous system and the major cause of non-traumatic disability in young adults. Fatigue is a frequent symptom reported by the majority of MS patients during their disease course and drastically af-fects their quality of life. Despite its significant prevalence and impact, the underlying patho-physiological mechanisms are not well elucidated. MS fatigue is still considered the result of multifactorial and complex constellations, and is commonly classified into primary fatigue related to the pathological changes of the disease itself, and secondary fatigue attributed to mimicking symptoms, comorbid sleep and mood disorders, and medications side effects. Data from neuroimaging, neurophysiology, neuroendocrine and neuroimmune studies have raised hypotheses regarding the origin of this symptom, some of which have succeeded in identifying an association between MS fatigue and structural or functional abnormalities within various brain networks. Hence, the aim of this work is to reappraise the neural correlates of MS fatigue and to discuss the rationale for the emergent use of noninvasive brain stimulation (NIBS techniques as potential treatments. This will include a presentation of the various NIBS modalities and a proposition of their potential mechanisms of action in this context. Specific issues related to the value of transcranial direct current stimulation will be addressed.

Music to My Eyes: Cross-Modal Interactions in the Perception of Emotions in Musical Performance

Science.gov (United States)

Vines, Bradley W.; Krumhansl, Carol L.; Wanderley, Marcelo M.; Dalca, Ioana M.; Levitin, Daniel J.

2011-01-01

We investigate non-verbal communication through expressive body movement and musical sound, to reveal higher cognitive processes involved in the integration of emotion from multiple sensory modalities. Participants heard, saw, or both heard and saw recordings of a Stravinsky solo clarinet piece, performed with three distinct expressive styles:…

Vocabulary acquisition in aphasia: Modality can matter.

Science.gov (United States)

Tuomiranta, Leena; Grönroos, Ann-Mari; Martin, Nadine; Laine, Matti

2014-11-01

The present case study investigated modality-specific aspects of novel word acquisition in aphasia. It was prompted by recent aphasia case studies indicating great interindividual variability in the ability to learn and maintain novel words in aphasia. Moreover, two previous case studies revealed a striking effect of input modality by showing effective word learning and re-learning via visual input only (Kohen, Sola, Tuomiranta, Laine, & Martin, 2012; Tuomiranta et al., 2014). The present participant TS with chronic nonfluent aphasia and post-semantic anomia was administered novel word-referent learning tasks. In the first experiment, the learning phase included simultaneous phonological and orthographic input, while the follow-up was probed separately for spoken and written responses. In the second experiment, we studied the effect of four different input and output modality combinations on her ability to learn to name the novel items. In the first experiment, TS's spoken naming performance during the learning phase was just within the range of healthy controls. Maintenance declined and remained outside that range during the whole 6-month follow-up. However, TS maintained the learned words better in written than in spoken naming throughout the follow-up, and in written naming, her maintenance stayed within the control's range up to 8 weeks post-training. The second experiment indicated that the best learning outcome was achieved with orthographic input. Orthographic input combined with orthographic output resulted in fast and accurate learning of the novel words. Interestingly, TS's test profile was opposite to her learning profile, as she repeated better than she read aloud in the linguistic background assessment. The results from the present case highlight the importance of multiple learning channels for word acquisition in individuals with aphasia. Probing the functionality of different input and output channels for learning may also prove valuable in tailoring

The diagnostic yield of neuroimaging in sixth nerve palsy - Sankara Nethralaya Abducens Palsy Study (SNAPS: Report 1

Directory of Open Access Journals (Sweden)

Akshay Gopinathan Nair

2014-01-01

Full Text Available Aims: The aim was to assess the etiology of sixth nerve palsy and on the basis of our data, to formulate a diagnostic algorithm for the management in sixth nerve palsy. Design: Retrospective chart review. Results: Of the 104 neurologically isolated cases, 9 cases were attributable to trauma, and 95 (86.36% cases were classified as nontraumatic, neurologically isolated cases. Of the 95 nontraumatic, isolated cases of sixth nerve palsy, 52 cases were associated with vasculopathic risk factors, namely diabetes and hypertension and were classified as vasculopathic sixth nerve palsy (54.7%, and those with a history of sixth nerve palsy from birth (6 cases were classified as congenital sixth nerve palsy (6.3%. Of the rest, neuroimaging alone yielded a cause in 18 of the 37 cases (48.64%. Of the other 19 cases where neuroimaging did not yield a cause, 6 cases were attributed to preceding history of infection (3 upper respiratory tract infection and 3 viral illnesses, 2 cases of sixth nerve palsy were found to be a false localizing sign in idiopathic intracranial hypertension and in 11 cases, the cause was undetermined. In these idiopathic cases of isolated sixth nerve palsy, neuroimaging yielded no positive findings. Conclusions: In the absence of risk factors, a suggestive history, or positive laboratory and clinical findings, neuroimaging can serve as a useful diagnostic tool in identifying the exact cause of sixth nerve palsy. Furthermore, we recommend an algorithm to assess the need for neuroimaging in sixth nerve palsy.

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

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

The Alzheimer's Disease Neuroimaging Initiative: A review of papers published since its inception

Science.gov (United States)

Weiner, Michael W.; Veitch, Dallas P.; Aisen, Paul S.; Beckett, Laurel A.; Cairns, Nigel J.; Green, Robert C.; Harvey, Danielle; Jack, Clifford R.; Jagust, William; Liu, Enchi; Morris, John C.; Petersen, Ronald C.; Saykin, Andrew J.; Schmidt, Mark E.; Shaw, Leslie; Shen, Li; Siuciak, Judith A.; Soares, Holly; Toga, Arthur W.; Trojanowski, John Q.

2014-01-01

The Alzheimer's Disease Neuroimaging Initiative (ADNI) is an ongoing, longitudinal, multicenter study designed to develop clinical, imaging, genetic, and biochemical biomarkers for the early detection and tracking of Alzheimer's disease (AD). The study aimed to enroll 400 subjects with early mild cognitive impairment (MCI), 200 subjects with early AD, and 200 normal control subjects; $67 million funding was provided by both the public and private sectors, including the National Institute on Aging, 13 pharmaceutical companies, and 2 foundations that provided support through the Foundation for the National Institutes of Health. This article reviews all papers published since the inception of the initiative and summarizes the results as of February 2011. The major accomplishments of ADNI have been as follows: (1) the development of standardized methods for clinical tests, magnetic resonance imaging (MRI), positron emission tomography (PET), and cerebrospinal fluid (CSF) biomarkers in a multicenter setting; (2) elucidation of the patterns and rates of change of imaging and CSF biomarker measurements in control subjects, MCI patients, and AD patients. CSF biomarkers are consistent with disease trajectories predicted by β-amyloid cascade (Hardy, J Alzheimers Dis 2006;9(Suppl 3):151–3) and tau-mediated neurodegeneration hypotheses for AD, whereas brain atrophy and hypometabolism levels show predicted patterns but exhibit differing rates of change depending on region and disease severity; (3) the assessment of alternative methods of diagnostic categorization. Currently, the best classifiers combine optimum features from multiple modalities, including MRI, [18F]-fluorodeoxyglucose-PET, CSF biomarkers, and clinical tests; (4) the development of methods for the early detection of AD. CSF biomarkers, β-amyloid 42 and tau, as well as amyloid PET may reflect the earliest steps in AD pathology in mildly symptomatic or even nonsymptomatic subjects, and are leading candidates

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

Load Estimation from Natural input Modal Analysis

DEFF Research Database (Denmark)

Aenlle, Manuel López; Brincker, Rune; Canteli, Alfonso Fernández

2005-01-01

One application of Natural Input Modal Analysis consists in estimating the unknown load acting on structures such as wind loads, wave loads, traffic loads, etc. In this paper, a procedure to determine loading from a truncated modal model, as well as the results of an experimental testing programme...... estimation. In the experimental program a small structure subjected to vibration was used to estimate the loading from the measurements and the experimental modal space. The modal parameters were estimated by Natural Input Modal Analysis and the scaling factors of the mode shapes obtained by the mass change...

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.

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 ...

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...

Quality and quantity of diffuse and focal white matter disease and cognitive disability of patients with multiple sclerosis.

Science.gov (United States)

Bomboi, Giuseppe; Ikonomidou, Vasiliki N; Pellegrini, Stefano; Stern, Susan K; Gallo, Antonio; Auh, Sungyoung; Evangelou, Iordanis E; Agarwal, Jhalak; Pellicano, Clelia; Ohayon, Joan M; Cantor, Fredric K; Ehrmantraut, Mary; McFarland, Henry F; Kane, Robert L; Bagnato, Francesca

2011-04-01

Using high-field magnetic resonance imaging (MRI), we investigated the relationships between white matter (WM) lesion volume (LV), normal-appearing WM (NAWM) normalized volume, WM-lesion and NAWM magnetization transfer ratios (MTRs), brain parenchyma fraction (BPF), and cognitive impairment (CI) in multiple sclerosis (MS). Twenty-four patients and 24 healthy volunteers (age, sex, and years of education-matched) underwent a 3.0 Tesla (3T) scan and evaluation of depression, fatigue, and CI using the Minimal Assessment of Cognitive Function in MS (MACFIMS) battery. In this clinically relatively well-preserved cohort of patients (median score on the Expanded Disability Status Scale=1.5), CI was detected on Symbol Digit Modalities Test (SDMT), California Verbal Learning Test-II (CVLT-II), and Controlled Oral Word Association Test. MT data were available in 19 pairs on whom correlation analyses were performed. Associations were seen between SDMT and normalized NAWM volume (P=.034, r=.502), CVLT-II long delay and normalized NAWM volume (P=.012, r=.563), WM-LV (P=.024, r=.514), and BPF (P=.002, r=.666). The use of 3T MRI in a sample of clinically stable MS patients shows the importance of WM disease in hampering processing speed and word retrieval. Copyright © 2010 by the American Society of Neuroimaging.

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

Tensor-based fusion of EEG and FMRI to understand neurological changes in Schizophrenia

DEFF Research Database (Denmark)

Evrim, Acar Ataman; Levin-Schwartz, Yuri; Calhoun, Vince D.

2016-01-01

Neuroimaging modalities such as functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) provide information about neurological functions in complementary spatiotemporal resolutions; therefore, fusion of these modalities is expected to provide better understanding of brain...

On Modal Refinement and Consistency

DEFF Research Database (Denmark)

Nyman, Ulrik; Larsen, Kim Guldstrand; Wasowski, Andrzej

2007-01-01

Almost 20 years after the original conception, we revisit several fundamental question about modal transition systems. First, we demonstrate the incompleteness of the standard modal refinement using a counterexample due to Hüttel. Deciding any refinement, complete with respect to the standard...

Interactive natural language acquisition in a multi-modal recurrent neural architecture

Science.gov (United States)

Heinrich, Stefan; Wermter, Stefan

2018-01-01

For the complex human brain that enables us to communicate in natural language, we gathered good understandings of principles underlying language acquisition and processing, knowledge about sociocultural conditions, and insights into activity patterns in the brain. However, we were not yet able to understand the behavioural and mechanistic characteristics for natural language and how mechanisms in the brain allow to acquire and process language. In bridging the insights from behavioural psychology and neuroscience, the goal of this paper is to contribute a computational understanding of appropriate characteristics that favour language acquisition. Accordingly, we provide concepts and refinements in cognitive modelling regarding principles and mechanisms in the brain and propose a neurocognitively plausible model for embodied language acquisition from real-world interaction of a humanoid robot with its environment. In particular, the architecture consists of a continuous time recurrent neural network, where parts have different leakage characteristics and thus operate on multiple timescales for every modality and the association of the higher level nodes of all modalities into cell assemblies. The model is capable of learning language production grounded in both, temporal dynamic somatosensation and vision, and features hierarchical concept abstraction, concept decomposition, multi-modal integration, and self-organisation of latent representations.

Modal bifurcation in a high-T{sub c} superconducting levitation system

Energy Technology Data Exchange (ETDEWEB)

Taguchi, D; Fujiwara, S; Sugiura, T, E-mail: sugiura@mech.keio.ac.jp [Department of Mechanical Engineering, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, kohoku-ku, Yokohama 223-8522 (Japan)

2011-05-15

This paper deals with modal bifurcation of a multi-degree-of-freedom high-T{sub c} superconducting levitation system. As modeling of large-scale high-T{sub c} superconducting levitation applications, where plural superconducting bulks are often used, it can be helpful to consider a system constituting of multiple oscillators magnetically coupled with each other. This paper investigates nonlinear dynamics of two permanent magnets levitated above high-T{sub c} superconducting bulks and placed between two fixed permanent magnets without contact. First, the nonlinear equations of motion of the levitated magnets were derived. Then the method of averaging was applied to them. It can be found from the obtained solutions that this nonlinear two degree-of-freedom system can have two asymmetric modes, in addition to a symmetric mode and an antisymmetric mode both of which also exist in the linearized system. One of the backbone curves in the frequency response shows a modal bifurcation where the two stable asymmetric modes mentioned above appear with destabilization of the antisymmetric mode, thus leading to modal localization. These analytical predictions have been confirmed in our numerical analysis and experiments of free vibration and forced vibration. These results, never predicted by linear analysis, can be important for application of high-T{sub c} superconducting levitation systems.

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.

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.)

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.)

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).

Multimodality imaging features of hereditary multiple exostoses

OpenAIRE

Kok, H K; Fitzgerald, L; Campbell, N; Lyburn, I D; Munk, P L; Buckley, O; Torreggiani, W C

2013-01-01

Hereditary multiple exostoses (HME) or diaphyseal aclasis is an inherited disorder characterised by the formation of multiple osteochondromas, which are cartilage-capped osseous outgrowths, and the development of associated osseous deformities. Individuals with HME may be asymptomatic or develop clinical symptoms, which prompt imaging studies. Different modalities ranging from plain radiographs to cross-sectional and nuclear medicine imaging studies can be helpful in the diagnosis and detecti...

Experienced Sensory Modalities in Dream Recall

OpenAIRE

岡田, 斉

2000-01-01

The purpose of the present study is to survey the frequency of visual, auditory, kinaesthetic, cutaneous, organic, gustatory, and olfactory experience in dream recall. A total of 1267 undergraduate students completed a dream recall frequency questionnaire, which contained a question about dream recall frequency and about recall frequency of seven sensory modalities. Results showed that seven sensory modalities were divided into two groups; normally perceived sensory modalities in dreaming, wh...

[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.

Short-Term Memory in Mathematics-Proficient and Mathematics-Disabled Students as a Function of Input-Modality/Output-Modality Pairings.

Science.gov (United States)

Webster, Raymond E.

1980-01-01

A significant two-way input modality by output modality interaction suggested that short term memory capacity among the groups differed as a function of the modality used to present the items in combination with the output response required. (Author/CL)

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

Krull dimension in modal logic

NARCIS (Netherlands)

Bezhanishvili, G.; Bezhanishvili, N.; Lucero-Bryan, J.; van Mill, J.

2017-01-01

We develop the theory of Krull dimension for S4-algebras and Heyting algebras. This leads to the concept of modal Krull dimension for topological spaces. We compare modal Krull dimension to other well-known dimension functions, and show that it can detect differences between topological spaces that

Modal Logics for Cryptographic Processes

DEFF Research Database (Denmark)

Frendrup, U.; Huttel, Hans; Jensen, N. J.

2002-01-01

We present three modal logics for the spi-calculus and show that they capture strong versions of the environment sensitive bisimulation introduced by Boreale et al. Our logics differ from conventional modal logics for process calculi in that they allow us to describe the knowledge of an attacker ...

Load Estimation from Modal Parameters

DEFF Research Database (Denmark)

Aenlle, Manuel López; Brincker, Rune; Fernández, Pelayo Fernández

2007-01-01

In Natural Input Modal Analysis the modal parameters are estimated just from the responses while the loading is not recorded. However, engineers are sometimes interested in knowing some features of the loading acting on a structure. In this paper, a procedure to determine the loading from a FRF m...

Characterization of identification errors and uses in localization of poor modal correlation

Science.gov (United States)

Martin, Guillaume; Balmes, Etienne; Chancelier, Thierry

2017-05-01

While modal identification is a mature subject, very few studies address the characterization of errors associated with components of a mode shape. This is particularly important in test/analysis correlation procedures, where the Modal Assurance Criterion is used to pair modes and to localize at which sensors discrepancies occur. Poor correlation is usually attributed to modeling errors, but clearly identification errors also occur. In particular with 3D Scanning Laser Doppler Vibrometer measurement, many transfer functions are measured. As a result individual validation of each measurement cannot be performed manually in a reasonable time frame and a notable fraction of measurements is expected to be fairly noisy leading to poor identification of the associated mode shape components. The paper first addresses measurements and introduces multiple criteria. The error measures the difference between test and synthesized transfer functions around each resonance and can be used to localize poorly identified modal components. For intermediate error values, diagnostic of the origin of the error is needed. The level evaluates the transfer function amplitude in the vicinity of a given mode and can be used to eliminate sensors with low responses. A Noise Over Signal indicator, product of error and level, is then shown to be relevant to detect poorly excited modes and errors due to modal property shifts between test batches. Finally, a contribution is introduced to evaluate the visibility of a mode in each transfer. Using tests on a drum brake component, these indicators are shown to provide relevant insight into the quality of measurements. In a second part, test/analysis correlation is addressed with a focus on the localization of sources of poor mode shape correlation. The MACCo algorithm, which sorts sensors by the impact of their removal on a MAC computation, is shown to be particularly relevant. Combined with the error it avoids keeping erroneous modal components

Heterogeneity within autism spectrum disorders: what have we learned from neuroimaging studies?

Directory of Open Access Journals (Sweden)

Rhoshel Krystyna Lenroot

2013-10-01

Full Text Available Autism spectrum disorders (ASD display significant heterogeneity. Although most neuroimaging studies in ASD have been designed to identify commonalities among affected individuals, rather than differences, some studies have explored variation within ASD. There have been two general types of approaches used for this in the neuroimaging literature to date: comparison of subgroups within ASD, and analyses using dimensional measures to link clinical variation to brain differences. This review focuses on structural and functional magnetic resonance imaging studies that have used these approaches to begin to explore heterogeneity between individuals with ASD. Although this type of data is yet sparse, recognition is growing of the limitations of behaviourally defined categorical diagnoses for understanding neurobiology. Study designs that are more informative regarding the sources of heterogeneity in ASD have the potential to improve our understanding of the neurobiological processes underlying ASD.

Causal Inference for Cross-Modal Action Selection: A Computational Study in a Decision Making Framework.

Science.gov (United States)

Daemi, Mehdi; Harris, Laurence R; Crawford, J Douglas

2016-01-01

Animals try to make sense of sensory information from multiple modalities by categorizing them into perceptions of individual or multiple external objects or internal concepts. For example, the brain constructs sensory, spatial representations of the locations of visual and auditory stimuli in the visual and auditory cortices based on retinal and cochlear stimulations. Currently, it is not known how the brain compares the temporal and spatial features of these sensory representations to decide whether they originate from the same or separate sources in space. Here, we propose a computational model of how the brain might solve such a task. We reduce the visual and auditory information to time-varying, finite-dimensional signals. We introduce controlled, leaky integrators as working memory that retains the sensory information for the limited time-course of task implementation. We propose our model within an evidence-based, decision-making framework, where the alternative plan units are saliency maps of space. A spatiotemporal similarity measure, computed directly from the unimodal signals, is suggested as the criterion to infer common or separate causes. We provide simulations that (1) validate our model against behavioral, experimental results in tasks where the participants were asked to report common or separate causes for cross-modal stimuli presented with arbitrary spatial and temporal disparities. (2) Predict the behavior in novel experiments where stimuli have different combinations of spatial, temporal, and reliability features. (3) Illustrate the dynamics of the proposed internal system. These results confirm our spatiotemporal similarity measure as a viable criterion for causal inference, and our decision-making framework as a viable mechanism for target selection, which may be used by the brain in cross-modal situations. Further, we suggest that a similar approach can be extended to other cognitive problems where working memory is a limiting factor, such

Diagnosis and Characterization of Patellofemoral Instability: Review of Available Imaging Modalities.

Science.gov (United States)

Haj-Mirzaian, Arya; Thawait, Gaurav K; Tanaka, Miho J; Demehri, Shadpour

2017-06-01

Patellofemoral instability (PI) is defined as single or multiple episodes of patellar dislocation. Imaging modalities are useful for characterization of patellar malalignment, maltracking, underlying morphologic abnormalities, and stabilizing soft-tissue injuries. Using these findings, orthopedic surgeons can decide when to operate, determine the best operation, and measure degree of correction postoperatively in PI patients. Also, these methods assist with PI diagnosis in some suspicious cases. Magnetic resonance imaging is the preferred method especially in the setting of acute dislocations. Multidetector computed tomography allows a more accurate assessment for malalignment such as patellar tilt and lateral subluxation and secondary osteoarthritis. Dynamic magnetic resonance imaging and 4-dimensional computed tomography have been introduced for better kinematic assessment of the patellofemoral maltracking during extension-flexion motions. In this review article, we will discuss the currently available evidence regarding both the conventional and the novel imaging modalities that can be used for diagnosis and characterization of PI.

Multi-modal neuroimaging in premanifest and early Huntington's disease: 18 month longitudinal data from the IMAGE-HD study.

Science.gov (United States)

Domínguez D, Juan F; Egan, Gary F; Gray, Marcus A; Poudel, Govinda R; Churchyard, Andrew; Chua, Phyllis; Stout, Julie C; Georgiou-Karistianis, Nellie

2013-01-01

IMAGE-HD is an Australian based multi-modal longitudinal magnetic resonance imaging (MRI) study in premanifest and early symptomatic Huntington's disease (pre-HD and symp-HD, respectively). In this investigation we sought to determine the sensitivity of imaging methods to detect macrostructural (volume) and microstructural (diffusivity) longitudinal change in HD. We used a 3T MRI scanner to acquire T1 and diffusion weighted images at baseline and 18 months in 31 pre-HD, 31 symp-HD and 29 controls. Volume was measured across the whole brain, and volume and diffusion measures were ascertained for caudate and putamen. We observed a range of significant volumetric and, for the first time, diffusion changes over 18 months in both pre-HD and symp-HD, relative to controls, detectable at the brain-wide level (volume change in grey and white matter) and in caudate and putamen (volume and diffusivity change). Importantly, longitudinal volume change in the caudate was the only measure that discriminated between groups across all stages of disease: far from diagnosis (>15 years), close to diagnosis (fractional anisotropy, FA), only longitudinal FA change was sensitive to group differences, but only after diagnosis. These findings further confirm caudate atrophy as one of the most sensitive and early biomarkers of neurodegeneration in HD. They also highlight that different tissue properties have varying schedules in their ability to discriminate between groups along disease progression and may therefore inform biomarker selection for future therapeutic interventions.

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.

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...

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,

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...

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,

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

The modality effect and echoic persistence.

Science.gov (United States)

Watkins, O C; Watkins, M J

1980-09-01

The modality effect refers to the higher level of recall of the last few items of a list when presentation is auditory as opposed to visual. It is usually attributed to echoic memory. The effect may be sharply reduced by an ostensibly irrelevant auditory item appended to the end of the list. Previous research suggests that this "suffix effect" arises only when the suffix item occurs within 2 sec of the last list item. This finding strengthens the widely held assumption that echoic information decays within 2 sec, and has led to the assumption that if echoic information is to be useful in serial recall it must first be encoded into a more durable modality-independent form. Both assumptions conflict with the research reported here. The first two experiments demonstrate substantial suffix effects with suffix delays of 2 and 4 sec, indicating that echoic information lasts at least 4 sec. This finding implies that echoic information may aid recall directly, an implication that was supported in Experiments 3 and 4. In Experiment 3 serial recall was interrupted with a brief distractor task. The modality effect was smaller when this task was auditory than when it was visual, suggesting that echoic information was still available immediately prior to recency recall. In Experiment 4 list presentation was broken by a 4-sec pause; the modalities of the list halves were combined factorially. Interest focused on the recency positions of the first half. A modality effect was found at these positions when the second half was visual but not when it was auditory. This is contrary to the hypothesis that echoic information is encoded before recall, but is consistent with the hypothesis that echoic information is encoded before recall, but is consistent with the alternative hypothesis that echoic information is used directly at recall. The final two experiments concern the modality effect found when a delay is interpolated between list presentation and recall. Experiment 5 showed that

Modular sequent calculi for classical modal logics

NARCIS (Netherlands)

Gilbert, David; Maffezioli, Paolo

This paper develops sequent calculi for several classical modal logics. Utilizing a polymodal translation of the standard modal language, we are able to establish a base system for the minimal classical modal logic E from which we generate extensions (to include M, C, and N) in a modular manner. Our

Fluoroscopic-guided radiofrequency ablation of the basivertebral nerve: application and analysis with multiple imaging modalities in an ovine model (Invited Paper)

Science.gov (United States)

Bergeron, Jeffrey A.; Eskey, Cliff J.; Attawia, Mohammed; Patel, Samit J.; Ryan, Thomas P.; Pellegrino, Richard; Sutton, Jeffrey; Crombie, John; Paul, B. T.; Hoopes, P. J.

2005-04-01

Pathologic involvement of the basivertebral nerve, an intraosseous vertebral nerve found in humans and most mammalian species, may play a role in some forms of back pain. This study was designed to assess the feasibility and effects of the percutaneous delivery of radiofrequency (RF) energy to thermally ablate the basivertebral nerve in the lumbar vertebrae of mature sheep. Using fluoroscopic guidance, a RF bipolar device was placed and a thermal dose delivered to lumbar vertebral bodies in sheep. Post-treatment assessment included multiple magnetic resonance imaging (MRI) techniques and computed tomography (CT). These data were analyzed and correlated to histopathology and morphometry findings to describe the cellular and boney structural changes resulting from the treatment. Imaging modalities MRI and CT can be implemented to non-invasively describe treatment region and volume, marrow cellular effects, and bone density alterations immediately following RF treatment and during convalescence. Such imaging can be utilized to assess treatment effects and refine the thermal dose to vertebral body volume ratio used in treatment planning. This information will be used to improve the therapeutic ratio and develop a treatment protocol for human applications.

Interesting images: Multiple coronary artery aneurysms.

Science.gov (United States)

Howard, Jonathon M; Viswanath, Omar; Armas, Alfredo; Santana, Orlando; Rosen, Gerald P

2017-01-01

We present the case of a 65-year-old male who presented with stable angina and dyspnea on exertion. His initial workup yielded a positive treadmill stress test for reversible apical ischemia, and transthoracic echocardiogram demonstrated impaired systolic function. Cardiac catheterization was then performed, revealing severe atherosclerotic disease including multiple coronary artery aneurysms. As a result, the patient was advised to and subsequently underwent a coronary artery bypass graft. This case highlights the presence of multiple coronary artery aneurysms and the ability to appreciate these pathologic findings on multiple imaging modalities, including coronary angiogram, transesophageal echocardiography, and direct visualization through the surgical field.

LapTrain: multi-modality training curriculum for laparoscopic cholecystectomy-results of a randomized controlled trial.

Science.gov (United States)

Kowalewski, K F; Garrow, C R; Proctor, T; Preukschas, A A; Friedrich, M; Müller, P C; Kenngott, H G; Fischer, L; Müller-Stich, B P; Nickel, F

2018-02-12

Multiple training modalities for laparoscopy have different advantages, but little research has been conducted on the benefit of a training program that includes multiple different training methods compared to one method only. This study aimed to evaluate benefits of a combined multi-modality training program for surgical residents. Laparoscopic cholecystectomy (LC) was performed on a porcine liver as the pre-test. Randomization was stratified for experience to the multi-modality Training group (12 h of training on Virtual Reality (VR) and box trainer) or Control group (no training). The post-test consisted of a VR LC and porcine LC. Performance was rated with the Global Operative Assessment of Laparoscopic Skills (GOALS) score by blinded experts. Training (n = 33) and Control (n = 31) were similar in the pre-test (GOALS: 13.7 ± 3.4 vs. 14.7 ± 2.6; p = 0.198; operation time 57.0 ± 18.1 vs. 63.4 ± 17.5 min; p = 0.191). In the post-test porcine LC, Training had improved GOALS scores (+ 2.84 ± 2.85 points, p < 0.001), while Control did not (+ 0.55 ± 2.34 points, p = 0.154). Operation time in the post-test was shorter for Training vs. Control (40.0 ± 17.0 vs. 55.0 ± 22.2 min; p = 0.012). Junior residents improved GOALS scores to the level of senior residents (pre-test: 13.7 ± 2.7 vs. 18.3 ± 2.9; p = 0.010; post-test: 15.5 ± 3.4 vs. 18.8 ± 3.8; p = 0.120) but senior residents remained faster (50.1 ± 20.6 vs. 25.0 ± 1.9 min; p < 0.001). No differences were found between groups on the post-test VR trainer. Structured multi-modality training is beneficial for novices to improve basics and overcome the initial learning curve in laparoscopy as well as to decrease operation time for LCs in different stages of experience. Future studies should evaluate multi-modality training in comparison with single modalities. German Clinical Trials Register DRKS00011040.

Does Modality Matter? The Effects of Reading, Listening, and Dual Modality on Comprehension

Directory of Open Access Journals (Sweden)

Beth A. Rogowsky

2016-09-01

Full Text Available With advancing technology, there is increasing interest in differences between listening versus reading comprehension or doing both simultaneously. Ninety-one participants were randomly assigned to one of three groups that received the same instructional material (the preface and a chapter from a non-fiction book, but each in a different input modality (digital audiobook, e-text, dual modality. After completing the material, participants took the same comprehension test in written form to establish both immediate comprehension (Time 1 and 2-week retention (Time 2. No statistically significant differences were found for any analyses pertaining to effects of the three different instructional conditions on comprehension at Time 1 or Time 2. Additional analyses showed that both males and females in each condition recalled an equal amount of information, regardless of whether they listened to an audiobook, read from an electronic tablet, or both listened and read simultaneously (dual modality.

The search for neuroimaging biomarkers of Alzheimer's disease with advanced MRI techniques

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Li, Tie-Qiang (Karolinska Huddinge - Medical Physics, Stockholm (Sweden)), email: tieqiang.li@karolinska.se; Wahlund, Lars-Olof (Dept. of Neurobiology, Care Sciences and Society, Karolinska Institute, Stockholm (Sweden))

2011-02-15

The aim of this review is to examine the recent literature on using advanced magnetic resonance imaging (MRI) techniques for finding neuroimaging biomarkers that are sensitive to the detection of risks for Alzheimer's disease (AD). Since structural MRI techniques, such as brain structural volumetry and voxel based morphometry (VBM), have been widely used for AD studies and extensively reviewed, we will only briefly touch on the topics of volumetry and morphometry. The focus of the current review is about the more recent developments in the search for AD neuroimaging biomarkers with functional MRI (fMRI), resting-state functional connectivity MRI (fcMRI), diffusion tensor imaging (DTI), arterial spin-labeling (ASL), and magnetic resonance spectroscopy (MRS)

Parametric modal transition systems

DEFF Research Database (Denmark)

Beneš, Nikola; Křetínský, Jan; Larsen, Kim Guldstrand

2011-01-01

Modal transition systems (MTS) is a well-studied specification formalism of reactive systems supporting a step-wise refinement methodology. Despite its many advantages, the formalism as well as its currently known extensions are incapable of expressing some practically needed aspects in the refin......Modal transition systems (MTS) is a well-studied specification formalism of reactive systems supporting a step-wise refinement methodology. Despite its many advantages, the formalism as well as its currently known extensions are incapable of expressing some practically needed aspects...

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/.

Dual-modality single particle orientation and rotational tracking of intracellular transport of nanocargos.

Science.gov (United States)

Sun, Wei; Gu, Yan; Wang, Gufeng; Fang, Ning

2012-01-17

The single particle orientation and rotational tracking (SPORT) technique was introduced recently to follow the rotational motion of plasmonic gold nanorod under a differential interference contrast (DIC) microscope. In biological studies, however, cellular activities usually involve a multiplicity of molecules; thus, tracking the motion of a single molecule/object is insufficient. Fluorescence-based techniques have long been used to follow the spatial and temporal distributions of biomolecules of interest thanks to the availability of multiplexing fluorescent probes. To know the type and number of molecules and the timing of their involvement in a biological process under investigation by SPORT, we constructed a dual-modality DIC/fluorescence microscope to simultaneously image fluorescently tagged biomolecules and plasmonic nanoprobes in living cells. With the dual-modality SPORT technique, the microtubule-based intracellular transport can be unambiguously identified while the dynamic orientation of nanometer-sized cargos can be monitored at video rate. Furthermore, the active transport on the microtubule can be easily separated from the diffusion before the nanocargo docks on the microtubule or after it undocks from the microtubule. The potential of dual-modality SPORT is demonstrated for shedding new light on unresolved questions in intracellular transport.

Combined modalities: chemotherapy/radiotherapy. Meeting summary

International Nuclear Information System (INIS)

Phillips, T.L.

1979-01-01

The effects of combined modalities, the standardization of terminology, the mechanisms of chemotherapeutic interactions with radiation and responses of normal and tumor systems are summarized from information presented at the Conference on Combined Modalities

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

A modal characterization of Peirce algebras

NARCIS (Netherlands)

M. de Rijke (Maarten)

1995-01-01

textabstractPeirce algebras combine sets, relations and various operations linking the two in a unifying setting.This note offers a modal perspective on Peirce algebras.It uses modal logic to characterize the full Peirce algebras.

Experimental evaluation of a quasi-modal parameter based rotor foundation identification technique

Science.gov (United States)

Yu, Minli; Liu, Jike; Feng, Ningsheng; Hahn, Eric J.

2017-12-01

Correct modelling of the foundation of rotating machinery is an invaluable asset in model-based rotor dynamic study. One attractive approach for such purpose is to identify the relevant modal parameters of an equivalent foundation using the motion measurements of rotor and foundation at the bearing supports. Previous research showed that, a complex quasi-modal parameter based system identification technique could be feasible for this purpose; however, the technique was only validated by identifying simple structures under harmonic excitation. In this paper, such identification technique is further extended and evaluated by identifying the foundation of a numerical rotor-bearing-foundation system and an experimental rotor rig respectively. In the identification of rotor foundation with multiple bearing supports, all application points of excitation forces transmitted through bearings need to be included; however the assumed vibration modes far outside the rotor operating speed cannot or not necessary to be identified. The extended identification technique allows one to identify correctly an equivalent foundation with fewer modes than the assumed number of degrees of freedom, essentially by generalising the technique to be able to handle rectangular complex modal matrices. The extended technique is robust in numerical and experimental validation and is therefore likely to be applicable in the field.

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.

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,

Identification of multiple modes of axisymmetric or circularly repetitive structures

International Nuclear Information System (INIS)

Kopff, P.

1983-01-01

The axisymmetric structures, or those composed with circularly repetitive elements, often display multiple modes, which are not easy to separate by modal identification of experimental responses. To be able to solve in situ some problems related to the vibrational behaviour of reactor vessels or other such huge structures, ELECTRICITY DE FRANCE developed a few years ago, experimental capabilities providing heavy harmonic driving forces, and elaborate data acquisition, signal processing and modal identification software, self-contained in an integrated mobile test facility. The modal analysis techniques we have developed with the LABORATOIRE DE MECANIQUE Appliquee of University of BESANCON (FRANCE) were especially suited for identification of multiple or separation of quasi-multiple modes, i.e. very close and strongly coupled resonances. Besides, the curve fitting methods involved, compute the same complex eigen-frequencies for all the vibration pick-ups, for better accuracy of the related eigen-vector components. Moreover, the latest extensions of these algorithms give us the means to deal with non-linear behaviour. The performances of these programs are drawn from some experimental results on axisymmetric or circularly repetitive structure, we tested in our laboratory to validate the computational hypothesis used in models for seismic responses of breeder reactor vessels. (orig.)

Multi-modal neuroimaging in premanifest and early Huntington's disease: 18 month longitudinal data from the IMAGE-HD study.

Directory of Open Access Journals (Sweden)

Juan F Domínguez D

Full Text Available IMAGE-HD is an Australian based multi-modal longitudinal magnetic resonance imaging (MRI study in premanifest and early symptomatic Huntington's disease (pre-HD and symp-HD, respectively. In this investigation we sought to determine the sensitivity of imaging methods to detect macrostructural (volume and microstructural (diffusivity longitudinal change in HD. We used a 3T MRI scanner to acquire T1 and diffusion weighted images at baseline and 18 months in 31 pre-HD, 31 symp-HD and 29 controls. Volume was measured across the whole brain, and volume and diffusion measures were ascertained for caudate and putamen. We observed a range of significant volumetric and, for the first time, diffusion changes over 18 months in both pre-HD and symp-HD, relative to controls, detectable at the brain-wide level (volume change in grey and white matter and in caudate and putamen (volume and diffusivity change. Importantly, longitudinal volume change in the caudate was the only measure that discriminated between groups across all stages of disease: far from diagnosis (>15 years, close to diagnosis (<15 years and after diagnosis. Of the two diffusion metrics (mean diffusivity, MD; fractional anisotropy, FA, only longitudinal FA change was sensitive to group differences, but only after diagnosis. These findings further confirm caudate atrophy as one of the most sensitive and early biomarkers of neurodegeneration in HD. They also highlight that different tissue properties have varying schedules in their ability to discriminate between groups along disease progression and may therefore inform biomarker selection for future therapeutic interventions.

Hypnosis and pain perception: An Activation Likelihood Estimation (ALE) meta-analysis of functional neuroimaging studies.

Science.gov (United States)

Del Casale, Antonio; Ferracuti, Stefano; Rapinesi, Chiara; De Rossi, Pietro; Angeletti, Gloria; Sani, Gabriele; Kotzalidis, Georgios D; Girardi, Paolo

2015-12-01

Several studies reported that hypnosis can modulate pain perception and tolerance by affecting cortical and subcortical activity in brain regions involved in these processes. We conducted an Activation Likelihood Estimation (ALE) meta-analysis on functional neuroimaging studies of pain perception under hypnosis to identify brain activation-deactivation patterns occurring during hypnotic suggestions aiming at pain reduction, including hypnotic analgesic, pleasant, or depersonalization suggestions (HASs). We searched the PubMed, Embase and PsycInfo databases; we included papers published in peer-reviewed journals dealing with functional neuroimaging and hypnosis-modulated pain perception. The ALE meta-analysis encompassed data from 75 healthy volunteers reported in 8 functional neuroimaging studies. HASs during experimentally-induced pain compared to control conditions correlated with significant activations of the right anterior cingulate cortex (Brodmann's Area [BA] 32), left superior frontal gyrus (BA 6), and right insula, and deactivation of right midline nuclei of the thalamus. HASs during experimental pain impact both cortical and subcortical brain activity. The anterior cingulate, left superior frontal, and right insular cortices activation increases could induce a thalamic deactivation (top-down inhibition), which may correlate with reductions in pain intensity. Copyright © 2016 Elsevier Ltd. All rights reserved.

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...

An investigation of response and stimulus modality transfer effects after dual-task training in younger and older.

Science.gov (United States)

Lussier, Maxime; Gagnon, Christine; Bherer, Louis

2012-01-01

It has been shown that dual-task training leads to significant improvement in dual-task performance in younger and older adults. However, the extent to which training benefits to untrained tasks requires further investigation. The present study assessed (a) whether dual-task training leads to cross-modality transfer in untrained tasks using new stimuli and/or motor responses modalities, (b) whether transfer effects are related to improved ability to prepare and maintain multiple task-set and/or enhanced response coordination, (c) whether there are age-related differences in transfer effects. Twenty-three younger and 23 older adults were randomly assigned to dual-task training or control conditions. All participants were assessed before and after training on three dual-task transfer conditions; (1) stimulus modality transfer (2) response modality transfer (3) stimulus and response modalities transfer task. Training group showed larger improvement than the control group in the three transfer dual-task conditions, which suggests that training leads to more than specific learning of stimuli/response associations. Attentional costs analyses showed that training led to improved dual-task cost, only in conditions that involved new stimuli or response modalities, but not both. Moreover, training did not lead to a reduced task-set cost in the transfer conditions, which suggests some limitations in transfer effects that can be expected. Overall, the present study supports the notion that cognitive plasticity for attentional control is preserved in late adulthood.

Effectiveness of Psychotherapy in Personality Disorders Not Otherwise Specified: A Comparison of Different Treatment Modalities.

Science.gov (United States)

Horn, Eva K; Bartak, Anna; Meerman, Anke M M A; Rossum, Bert V; Ziegler, Uli M; Thunnissen, Moniek; Soons, Mirjam; Andrea, Helene; Hamers, Elisabeth F M; Emmelkamp, Paul M G; Stijnen, Theo; Busschbach, Jan J V; Verheul, Roel

2015-01-01

Although personality disorder not otherwise specified (PDNOS) is highly prevalent and associated with a high burden of disease, only a few treatment studies in this patient group exist. This study is the first to investigate the effectiveness of different modalities of psychotherapy in patients with PDNOS, i.e., short-term (up to 6 months) and long-term (more than 6 months) outpatient, day hospital, and inpatient psychotherapy. A total of 205 patients with PDNOS were assigned to one of six treatment modalities. Effectiveness was assessed over 60 months after baseline. The primary outcome measure was symptom severity, and the secondary outcome measures included psychosocial functioning and quality of life. The study design was quasi-experimental, and the multiple propensity score was used to control for initial differences between treatment groups. All treatment modalities showed positive outcomes, especially in terms of improvements of symptom severity and social role functioning. At 12-month follow-up, after adjustment for initial differences between the treatment groups, short-term outpatient psychotherapy and short-term inpatient psychotherapy showed most improvement and generally outperformed the other modalities concerning symptom severity. At 60 months after baseline, effectiveness remained but observed differences between modalities mostly diminished. Patients with PDNOS benefit from psychotherapy both at short-term and long-term follow-up. Short-term outpatient psychotherapy and short-term inpatient psychotherapy seem to be superior to the other treatment modalities at 12-month follow-up. At 60-month follow-up, treatments showed mostly comparable effectiveness. The effectiveness of different modalities of psychotherapy in patients with PDNOS (i.e., short-term vs long-term; outpatient versus day hospital versus inpatient psychotherapy) has not yet been compared. Different modalities of psychotherapy are effective for patients with PDNOS, and positive

Combined Modality Approaches in the Management of Adult Glioblastoma

International Nuclear Information System (INIS)

Shirazi, Haider A.; Grimm, Sean; Raizer, Jeffrey; Mehta, Minesh P.

2011-01-01

Over the past two decades, management of newly diagnosed glioblastoma has undergone significant evolution. While surgery has long been a mainstay of management for this disease, and while radiotherapy has a proven survival role, initial efforts at radiotherapy dose escalation, use of radiosurgery, brachytherapy, and altered fractionation did not improve patient survival. Recently, multiple modality therapy integrating maximal safe resection, postoperative radiation, and new systemic therapies have resulted in improved patient outcomes compared with older regimens utilizing surgery and postoperative radiation alone. Numerous trials are currently underway investigating the combination of surgery, radiation, and systemic therapy with targeted agents to find ways to further improve outcomes for adults with glioblastoma.

Combined Modality Approaches in the Management of Adult Glioblastoma

Energy Technology Data Exchange (ETDEWEB)

Shirazi, Haider A. [Department of Radiation Oncology, Feinberg School of Medicine, Northwestern University, Chicago, IL (United States); Grimm, Sean; Raizer, Jeffrey [Department of Neurology, Feinberg School of Medicine, Northwestern University, Chicago, IL (United States); Mehta, Minesh P., E-mail: mmehta@nmff.org [Department of Radiation Oncology, Feinberg School of Medicine, Northwestern University, Chicago, IL (United States)

2011-10-28

Over the past two decades, management of newly diagnosed glioblastoma has undergone significant evolution. While surgery has long been a mainstay of management for this disease, and while radiotherapy has a proven survival role, initial efforts at radiotherapy dose escalation, use of radiosurgery, brachytherapy, and altered fractionation did not improve patient survival. Recently, multiple modality therapy integrating maximal safe resection, postoperative radiation, and new systemic therapies have resulted in improved patient outcomes compared with older regimens utilizing surgery and postoperative radiation alone. Numerous trials are currently underway investigating the combination of surgery, radiation, and systemic therapy with targeted agents to find ways to further improve outcomes for adults with glioblastoma.

Imaging abusive head trauma: why use both computed tomography and magnetic resonance imaging?

Energy Technology Data Exchange (ETDEWEB)

Vazquez, Elida; Delgado, Ignacio; Sanchez-Montanez, Angel [Hospital Universitario Vall d' Hebron, UAB, Pediatric Radiology Department, Barcelona (Spain); Fabrega, Anna [Hospital Universitario Vall d' Hebron, UAB, Department of Pediatrics, Barcelona (Spain); Cano, Paola [Hospital Universitario Vall d' Hebron, UAB, Pediatric Neurosurgery, Barcelona (Spain); Martin, Nieves [Hospital Universitario Vall d' Hebron, UAB, Pediatric Ophthalmology, Barcelona (Spain)

2014-12-15

Abusive head trauma is the leading cause of death in child abuse cases. The majority of victims are infants younger than 1 year old, with the average age between 3 and 8 months, although these injuries can be seen in children up to 5 years old. Many victims have a history of previous abuse and the diagnosis is frequently delayed. Neuroimaging is often crucial for establishing the diagnosis of abusive head trauma as it detects occult injury in 37% of cases. Several imaging patterns are considered to be particularly associated with abusive head trauma. The presence of subdural hematoma, especially in multiple locations, such as the interhemispheric region, over the convexity and in the posterior fossa, is significantly associated with abusive head trauma. Although CT is the recommended first-line imaging modality for suspected abusive head trauma, early MRI is increasingly used alongside CT because it provides a better estimation of shear injuries, hypoxic-ischemic insult and the timing of lesions. This article presents a review of the use and clinical indications of the most pertinent neuroimaging modalities for the diagnosis of abusive head trauma, emphasizing the newer and more sensitive techniques that may be useful to better characterize the nature and evolution of the injury. (orig.)

Imaging abusive head trauma: why use both computed tomography and magnetic resonance imaging?

International Nuclear Information System (INIS)

Vazquez, Elida; Delgado, Ignacio; Sanchez-Montanez, Angel; Fabrega, Anna; Cano, Paola; Martin, Nieves

2014-01-01

Abusive head trauma is the leading cause of death in child abuse cases. The majority of victims are infants younger than 1 year old, with the average age between 3 and 8 months, although these injuries can be seen in children up to 5 years old. Many victims have a history of previous abuse and the diagnosis is frequently delayed. Neuroimaging is often crucial for establishing the diagnosis of abusive head trauma as it detects occult injury in 37% of cases. Several imaging patterns are considered to be particularly associated with abusive head trauma. The presence of subdural hematoma, especially in multiple locations, such as the interhemispheric region, over the convexity and in the posterior fossa, is significantly associated with abusive head trauma. Although CT is the recommended first-line imaging modality for suspected abusive head trauma, early MRI is increasingly used alongside CT because it provides a better estimation of shear injuries, hypoxic-ischemic insult and the timing of lesions. This article presents a review of the use and clinical indications of the most pertinent neuroimaging modalities for the diagnosis of abusive head trauma, emphasizing the newer and more sensitive techniques that may be useful to better characterize the nature and evolution of the injury. (orig.)

The PolyMAX Frequency-Domain Method: A New Standard for Modal Parameter Estimation?

Directory of Open Access Journals (Sweden)

Bart Peeters

2004-01-01

Full Text Available Recently, a new non-iterative frequency-domain parameter estimation method was proposed. It is based on a (weighted least-squares approach and uses multiple-input-multiple-output frequency response functions as primary data. This so-called “PolyMAX” or polyreference least-squares complex frequency-domain method can be implemented in a very similar way as the industry standard polyreference (time-domain least-squares complex exponential method: in a first step a stabilisation diagram is constructed containing frequency, damping and participation information. Next, the mode shapes are found in a second least-squares step, based on the user selection of stable poles. One of the specific advantages of the technique lies in the very stable identification of the system poles and participation factors as a function of the specified system order, leading to easy-to-interpret stabilisation diagrams. This implies a potential for automating the method and to apply it to “difficult” estimation cases such as high-order and/or highly damped systems with large modal overlap. Some real-life automotive and aerospace case studies are discussed. PolyMAX is compared with classical methods concerning stability, accuracy of the estimated modal parameters and quality of the frequency response function synthesis.

Photodynamic therapy for multiple primary lung cancer

International Nuclear Information System (INIS)

Konaka, C.; Okunaka, T.; Sakai, H.; Furukawa, K.; Hayata, Y.; Kato, H.

1992-01-01

In recent years, multiple primary lung cancers have been reported with greater frequency. As for the treatment of multiple primary lung cancer, operative excision is usually difficult for all lesions due to problems of pulmonary function. PDT is a good therapeutic modality in the treatment of multiple primary lung cancer, especially central type lung cancer, for preservation of lung function. Since 1980, 50 patients of endoscopically-evaluated early stage lung cancers have been treated with PDT at Tokyo Medical College. Within this group, 16 patients were classified as having multiple primary lung cancers. This paper evaluates the effectiveness of PDT in the treatment of these patients with multiple primary bronchogenic carcinoma. (author). 6 refs., 2 tabs

Conceptual and methodological challenges for neuroimaging studies of autistic spectrum disorders

Directory of Open Access Journals (Sweden)

Mazzone Luigi

2010-03-01

Full Text Available 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 conceptual and methodological challenges that complicate the interpretation of findings from neuroimaging studies in ASDs, and that future imaging studies should address through improved designs. These include: (1 identification and implementation of tasks that more specifically target the neural processes of interest, while avoiding the confusion that the symptoms of ASD may impose on both the performance of the task and the detection of brain activations; (2 the inconsistency that disease heterogeneity in persons with ASD can generate on research findings, particularly heterogeneity of symptoms, symptom severity, differences in IQ, total brain volume, and psychiatric comorbidity; and (3 the problems with interpretation of findings from cross-sectional studies of persons with ASD across differing age groups. Failure to address these challenges will continue to hinder our ability to distinguish findings that outline the causes of ASDs from brain processes that represent downstream or compensatory responses to the presence of the disease. Here we propose strategies to address these issues: 1 the use of simple and elementary tasks, that are easier to understand for autistic subjects; 2 the scanning of a more homogenous group of persons with ASDs, preferably at younger age; 3 the performance of longitudinal studies, that may provide more straight forward and reliable results. We believe that this would allow for a better understanding of both the central pathogenic

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

An improved EMD method for modal identification and a combined static-dynamic method for damage detection

Science.gov (United States)

Yang, Jinping; Li, Peizhen; Yang, Youfa; Xu, Dian

2018-04-01

Empirical mode decomposition (EMD) is a highly adaptable signal processing method. However, the EMD approach has certain drawbacks, including distortions from end effects and mode mixing. In the present study, these two problems are addressed using an end extension method based on the support vector regression machine (SVRM) and a modal decomposition method based on the characteristics of the Hilbert transform. The algorithm includes two steps: using the SVRM, the time series data are extended at both endpoints to reduce the end effects, and then, a modified EMD method using the characteristics of the Hilbert transform is performed on the resulting signal to reduce mode mixing. A new combined static-dynamic method for identifying structural damage is presented. This method combines the static and dynamic information in an equilibrium equation that can be solved using the Moore-Penrose generalized matrix inverse. The combination method uses the differences in displacements of the structure with and without damage and variations in the modal force vector. Tests on a four-story, steel-frame structure were conducted to obtain static and dynamic responses of the structure. The modal parameters are identified using data from the dynamic tests and improved EMD method. The new method is shown to be more accurate and effective than the traditional EMD method. Through tests with a shear-type test frame, the higher performance of the proposed static-dynamic damage detection approach, which can detect both single and multiple damage locations and the degree of the damage, is demonstrated. For structures with multiple damage, the combined approach is more effective than either the static or dynamic method. The proposed EMD method and static-dynamic damage detection method offer improved modal identification and damage detection, respectively, in structures.

The effects of presentation pace and modality on learning a multimedia science lesson

Science.gov (United States)

Chung, Wen-Hung

Working memory is a system that consists of multiple components. The visuospatial sketchpad is the main entrance for visual and spatial information, whereas acoustic and verbal information is processed in the phonological loop. The central executive works as a coordinator of information from these two subsystems. Numerous studies have shown that working memory has a very limited capacity. Based on these characteristics of working memory, theories such as cognitive load theory and the cognitive theory of multimedia learning provide multimedia design principles. One of these principles is that when verbal information accompanying pictures is presented in audio mode instead of visually, learning can be more effective than if both text and pictures are presented visually. This is called the modality effect. However, some studies have found that the modality effect does not occur in some situations. In most experiments examining the modality effect, the multimedia is presented as system-paced. If learners are able to repeat listening as many times as they need, the superiority of spoken text over visual text seems lessened. One aim of this study was to examine the modality effect in a learner-controlled condition. This study also used the one-word-at-a-time technique to investigate whether the modality effect would still occur if both reading and listening rates were equal. There were 182 college students recruited for this study. Participants were randomly assigned to seven groups: a self-paced listening group, a self-paced reading group, a self text-block reading group, a general-paced listening group, a general-paced reading group, a fast-paced listening group, and a fast-paced reading group. The experimental material was a cardiovascular multimedia module. A three-by-two between-subjects design was used to test the main effect. Results showed that modality effect was still present but not between the self-paced listening group and the self text-block reading group

Eigenvectors phase correction in inverse modal problem

Science.gov (United States)

Qiao, Guandong; Rahmatalla, Salam

2017-12-01

The solution of the inverse modal problem for the spatial parameters of mechanical and structural systems is heavily dependent on the quality of the modal parameters obtained from the experiments. While experimental and environmental noises will always exist during modal testing, the resulting modal parameters are expected to be corrupted with different levels of noise. A novel methodology is presented in this work to mitigate the errors in the eigenvectors when solving the inverse modal problem for the spatial parameters. The phases of the eigenvector component were utilized as design variables within an optimization problem that minimizes the difference between the calculated and experimental transfer functions. The equation of motion in terms of the modal and spatial parameters was used as a constraint in the optimization problem. Constraints that reserve the positive and semi-positive definiteness and the inter-connectivity of the spatial matrices were implemented using semi-definite programming. Numerical examples utilizing noisy eigenvectors with augmented Gaussian white noise of 1%, 5%, and 10% were used to demonstrate the efficacy of the proposed method. The results showed that the proposed method is superior when compared with a known method in the literature.

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…

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…

[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.

Deep Multimodal Pain Recognition: A Database and Comparison of Spatio-Temporal Visual Modalities

DEFF Research Database (Denmark)

Haque, Mohammad Ahsanul; Nasrollahi, Kamal; Moeslund, Thomas B.

2018-01-01

, exploiting both spatial and temporal information of the face to assess pain level, and second, incorporating multiple visual modalities to capture complementary face information related to pain. Most works in the literature focus on merely exploiting spatial information on chromatic (RGB) video data...... recognition performance of pain levels in comparison to isolated ones. In particular, the combination of RGB, D, and T in an early fusion fashion achieved the best recognition rate....

Comparative study of the neuropsychological and neuroimaging evaluations in children with dyslexia.

Science.gov (United States)

Arduini, Rodrigo Genaro; Capellini, Simone Aparecida; Ciasca, Sylvia Maria

2006-06-01

We analyzed retrospectively the neuroimaging exams of children with a confirmed diagnosis of dyslexia and correlated our findings with the evaluation of higher cortical functions. We studied 34 medical files of patients of the Ambulatory of Neuro-difficulties in Learning, FCM/UNICAMP. All of them had been sent to the ambulatory with primary or secondary complaints of difficulties at school and were submitted to neuropsychological evaluation and imaging exam (SPECT). From the children evaluated 58.8% had exams presenting dysfunction with 47% presenting hypoperfusion in the temporal lobe. As for the higher cortical functions, the most affected abilities were reading, writing and memory. There was significance between the hypoperfused areas and the variables schooling, reading, writing, memory and mathematic reasoning. The SPECTs showed hypoperfusion in areas involved in the reading and writing processes. Both are equivalent in terms of involved functional areas and are similar in children with or without specific dysfunctions in neuroimaging.

Neuroimaging in aphasia treatment research: Consensus and practical guidelines for data analysis

Science.gov (United States)

Meinzer, Marcus; Beeson, Pélagie M.; Cappa, Stefano; Crinion, Jenny; Kiran, Swathi; Saur, Dorothee; Parrish, Todd; Crosson, Bruce; Thompson, Cynthia K.

2012-01-01

Functional magnetic resonance imaging is the most widely used imaging technique to study treatment-induced recovery in post-stroke aphasia. The longitudinal design of such studies adds to the challenges researchers face when studying patient populations with brain damage in cross-sectional settings. The present review focuses on issues specifically relevant to neuroimaging data analysis in aphasia treatment research identified in discussions among international researchers at the Neuroimaging in Aphasia Treatment Research Workshop held at Northwestern University (Evanston, Illinois, USA). In particular, we aim to provide the reader with a critical review of unique problems related to the pre-processing, statistical modeling and interpretation of such data sets. Despite the fact that data analysis procedures critically depend on specific design features of a given study, we aim to discuss and communicate a basic set of practical guidelines that should be applicable to a wide range of studies and useful as a reference for researchers pursuing this line of research. PMID:22387474

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.

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

Response Modality Variations Affect Determinations of Children's Learning Styles.

Science.gov (United States)

Janowitz, Jeffrey M.

The Swassing-Barbe Modality Index (SBMI) uses visual, auditory, and tactile inputs, but only reconstructed output, to measure children's modality strengths. In this experiment, the SBMI's three input modalities were crossed with two output modalities (spoken and drawn) in addition to the reconstructed standard to result in nine treatment…

History of Civil Engineering Modal Analysis

DEFF Research Database (Denmark)

Brincker, Rune

2008-01-01

techniques are available for civil engineering modal analysis. The testing of civil structures defers from the traditional modal testing in the sense, that very often it is difficult, or sometimes impossible, to artificially excite a large civil engineering structure. Also, many times, even though...

Different patterns of modality dominance across development.

Science.gov (United States)

Barnhart, Wesley R; Rivera, Samuel; Robinson, Christopher W

2018-01-01

The present study sought to better understand how children, young adults, and older adults attend and respond to multisensory information. In Experiment 1, young adults were presented with two spoken words, two pictures, or two word-picture pairings and they had to determine if the two stimuli/pairings were exactly the same or different. Pairing the words and pictures together slowed down visual but not auditory response times and delayed the latency of first fixations, both of which are consistent with a proposed mechanism underlying auditory dominance. Experiment 2 examined the development of modality dominance in children, young adults, and older adults. Cross-modal presentation attenuated visual accuracy and slowed down visual response times in children, whereas older adults showed the opposite pattern, with cross-modal presentation attenuating auditory accuracy and slowing down auditory response times. Cross-modal presentation also delayed first fixations in children and young adults. Mechanisms underlying modality dominance and multisensory processing are discussed. Copyright © 2017 Elsevier B.V. All rights reserved.

The influence of the visual modality on language structure and conventionalization: insights from sign language and gesture.

Science.gov (United States)

Perniss, Pamela; Özyürek, Asli; Morgan, Gary

2015-01-01

For humans, the ability to communicate and use language is instantiated not only in the vocal modality but also in the visual modality. The main examples of this are sign languages and (co-speech) gestures. Sign languages, the natural languages of Deaf communities, use systematic and conventionalized movements of the hands, face, and body for linguistic expression. Co-speech gestures, though non-linguistic, are produced in tight semantic and temporal integration with speech and constitute an integral part of language together with speech. The articles in this issue explore and document how gestures and sign languages are similar or different and how communicative expression in the visual modality can change from being gestural to grammatical in nature through processes of conventionalization. As such, this issue contributes to our understanding of how the visual modality shapes language and the emergence of linguistic structure in newly developing systems. Studying the relationship between signs and gestures provides a new window onto the human ability to recruit multiple levels of representation (e.g., categorical, gradient, iconic, abstract) in the service of using or creating conventionalized communicative systems. Copyright © 2015 Cognitive Science Society, Inc.

Intention, false beliefs, and delusional jealousy: insights into the right hemisphere from neurological patients and neuroimaging studies.

Science.gov (United States)

Ortigue, Stephanie; Bianchi-Demicheli, Francesco

2011-01-01

Jealousy sits high atop of a list comprised of the most human emotional experiences, although its nature, rationale, and origin are poorly understood. In the past decade, a series of neurological case reports and neuroimaging findings have been particularly helpful in piecing together jealousy's puzzle. In order to understand and quantify the neurological factors that might be important in jealousy, we reviewed the current literature in this specific field. We made an electronic search, and examined all literature with at least an English abstract, through Mars 2010. The search identified a total of 20 neurological patients, who experienced jealousy in relation with a neurological disorder; and 22 healthy individuals, who experienced jealousy under experimental neuroimaging settings. Most of the clinical cases of reported jealousy after a stroke had delusional-type jealousy. Right hemispheric stroke was the most frequently reported neurological disorder in these patients, although there was a wide range of more diffuse neurological disorders that may be reported to be associated with different other types of jealousy. This is in line with recent neuroimaging data on false beliefs, moral judgments, and intention [mis]understanding. Together the present findings provide physicians and psychologists with a potential for high impact in understanding the neural mechanisms and treatment of jealousy. By combining findings from case reports and neuroimaging data, the present article allows for a novel and unique perspective, and explores new directions into the neurological jealous mind.

Multilayer modal actuator-based piezoelectric transformers.

Science.gov (United States)

Huang, Yao-Tien; Wu, Wen-Jong; Wang, Yen-Chieh; Lee, Chih-Kung

2007-02-01

An innovative, multilayer piezoelectric transformer equipped with a full modal filtering input electrode is reported herein. This modal-shaped electrode, based on the orthogonal property of structural vibration modes, is characterized by full modal filtering to ensure that only the desired vibration mode is excited during operation. The newly developed piezoelectric transformer is comprised of three layers: a multilayered input layer, an insulation layer, and a single output layer. The electrode shape of the input layer is derived from its structural vibration modal shape, which takes advantage of the orthogonal property of the vibration modes to achieve a full modal filtering effect. The insulation layer possesses two functions: first, to couple the mechanical vibration energy between the input and output, and second, to provide electrical insulation between the two layers. To meet the two functions, a low temperature, co-fired ceramic (LTCC) was used to provide the high mechanical rigidity and high electrical insulation. It can be shown that this newly developed piezoelectric transformer has the advantage of possessing a more efficient energy transfer and a wider optimal working frequency range when compared to traditional piezoelectric transformers. A multilayer piezoelectric, transformer-based inverter applicable for use in LCD monitors or portable displays is presented as well.

Uni-, bi- and tri-modal warning signals: effects of temporal parameters and sensory modality on perceived urgency

NARCIS (Netherlands)

van Erp, Johannes Bernardus Fransiscus; Toet, Alexander; Janssen, Joris B.

Multi-sensory warnings can potentially enhance risk communication. Hereto we investigated how temporal signal parameters affect perceived urgency within and across modalities. In an experiment, 78 observers rated the perceived urgency of uni-, bi-, and/or tri-modal stimuli as function of 25

Uni-, bi- and tri-modal warning signals : Effects of temporal parameters and sensory modality on perceived urgency

NARCIS (Netherlands)

Erp, J.B.F. van; Toet, A.; Janssen, J.B.

2015-01-01

Multi-sensory warnings can potentially enhance risk communication. Hereto we investigated how temporal signal parameters affect perceived urgency within and across modalities. In an experiment, 78 observers rated the perceived urgency of uni-, bi-, and/or tri-modal stimuli as function of 25

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)

Accelerometer-based estimation and modal velocity feedback vibration control of a stress-ribbon bridge with pneumatic muscles

International Nuclear Information System (INIS)

Liu, Xiaohan; Goldack, Arndt; Schlaich, Mike; Schauer, Thomas; Bleicher, Achim

2016-01-01

Lightweight footbridges are very elegant but also prone to vibration. By employing active vibration control, smart footbridges could accomplish not only the architectural concept but also the required serviceability and comfort. Inertial sensors such as accelerometers allow the estimation of nodal velocities and displacements. A Kalman filter together with a band-limited multiple Fourier linear combiner (BMFLC) is applied to enable a drift-free estimation of these signals for the quasi-periodic motion under pedestrian excitation without extra information from other kinds of auxiliary sensors. The modal velocities of the structure are determined by using a second Kalman filter with the known applied actuator forces as inputs and the estimated nodal displacement and velocities as measurements. The obtained multi-modal velocities are then used for feedback control. An ultra-lightweight stress-ribbon footbridge built in the Peter-Behrens- Halle at the Technische Universitat Berlin served as the research object. Using two inertial sensors in optimal points we can estimate the dominant modal characteristics of this bridge. Real-time implementation and evaluation results of the proposed estimator will be presented in comparison to signals derived from classical displacement encoders. The real-time estimated modal velocities were applied in a multi-modal velocity feedback vibration control scheme with lightweight pneumatic muscle actuators. Experimental results demonstrate the feasibility of using inertial sensors for active vibration control of lightweight footbridges. (paper)

Accelerometer-based estimation and modal velocity feedback vibration control of a stress-ribbon bridge with pneumatic muscles

Science.gov (United States)

Liu, Xiaohan; Schauer, Thomas; Goldack, Arndt; Bleicher, Achim; Schlaich, Mike

2016-09-01

Lightweight footbridges are very elegant but also prone to vibration. By employing active vibration control, smart footbridges could accomplish not only the architectural concept but also the required serviceability and comfort. Inertial sensors such as accelerometers allow the estimation of nodal velocities and displacements. A Kalman filter together with a band-limited multiple Fourier linear combiner (BMFLC) is applied to enable a drift-free estimation of these signals for the quasi-periodic motion under pedestrian excitation without extra information from other kinds of auxiliary sensors. The modal velocities of the structure are determined by using a second Kalman filter with the known applied actuator forces as inputs and the estimated nodal displacement and velocities as measurements. The obtained multi-modal velocities are then used for feedback control. An ultra-lightweight stress-ribbon footbridge built in the Peter-Behrens- Halle at the Technische Universitat Berlin served as the research object. Using two inertial sensors in optimal points we can estimate the dominant modal characteristics of this bridge. Real-time implementation and evaluation results of the proposed estimator will be presented in comparison to signals derived from classical displacement encoders. The real-time estimated modal velocities were applied in a multi-modal velocity feedback vibration control scheme with lightweight pneumatic muscle actuators. Experimental results demonstrate the feasibility of using inertial sensors for active vibration control of lightweight footbridges.

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

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.

A Modal Approach to Compact MIMO Antenna Design

Science.gov (United States)

Yang, Binbin

MIMO (Multiple-Input Multiple-Output) technology offers new possibilities for wireless communication through transmission over multiple spatial channels, and enables linear increases in spectral efficiency as the number of the transmitting and receiving antennas increases. However, the physical implementation of such systems in compact devices encounters many physical constraints mainly from the design of multi-antennas. First, an antenna's bandwidth decreases dramatically as its electrical size reduces, a fact known as antenna Q limit; secondly, multiple antennas closely spaced tend to couple with each other, undermining MIMO performance. Though different MIMO antenna designs have been proposed in the literature, there is still a lack of a systematic design methodology and knowledge of performance limits. In this dissertation, we employ characteristic mode theory (CMT) as a powerful tool for MIMO antenna analysis and design. CMT allows us to examine each physical mode of the antenna aperture, and to access its many physical parameters without even exciting the antenna. For the first time, we propose efficient circuit models for MIMO antennas of arbitrary geometry using this modal decomposition technique. Those circuit models demonstrate the powerful physical insight of CMT for MIMO antenna modeling, and simplify MIMO antenna design problem to just the design of specific antenna structural modes and a modal feed network, making possible the separate design of antenna aperture and feeds. We therefore develop a feed-independent shape synthesis technique for optimization of broadband multi-mode apertures. Combining the shape synthesis and circuit modeling techniques for MIMO antennas, we propose a shape-first feed-next design methodology for MIMO antennas, and designed and fabricated two planar MIMO antennas, each occupying an aperture much smaller than the regular size of lambda/2 x lambda/2. Facilitated by the newly developed source formulation for antenna stored

Three-valued logics in modal logic

NARCIS (Netherlands)

Kooi, Barteld; Tamminga, Allard

2013-01-01

Every truth-functional three-valued propositional logic can be conservatively translated into the modal logic S5. We prove this claim constructively in two steps. First, we define a Translation Manual that converts any propositional formula of any three-valued logic into a modal formula. Second, we

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.)

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...

Validation of Alzheimer's disease CSF and plasma biological markers: the multicentre reliability study of the pilot European Alzheimer's Disease Neuroimaging Initiative (E-ADNI)

DEFF Research Database (Denmark)

Buerger, Katharina; Frisoni, Giovanni; Uspenskaya, Olga

2009-01-01

BACKGROUND: Alzheimer's Disease Neuroimaging Initiatives ("ADNI") aim to validate neuroimaging and biochemical markers of Alzheimer's disease (AD). Data of the pilot European-ADNI (E-ADNI) biological marker programme of cerebrospinal fluid (CSF) and plasma candidate biomarkers are reported. METHO...

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

MEDCIS: Multi-Modality Epilepsy Data Capture and Integration System.

Science.gov (United States)

Zhang, Guo-Qiang; Cui, Licong; Lhatoo, Samden; Schuele, Stephan U; Sahoo, Satya S

2014-01-01

Sudden Unexpected Death in Epilepsy (SUDEP) is the leading mode of epilepsy-related death and is most common in patients with intractable, frequent, and continuing seizures. A statistically significant cohort of patients for SUDEP study requires meticulous, prospective follow up of a large population that is at an elevated risk, best represented by the Epilepsy Monitoring Unit (EMU) patient population. Multiple EMUs need to collaborate, share data for building a larger cohort of potential SUDEP patient using a state-of-the-art informatics infrastructure. To address the challenges of data integration and data access from multiple EMUs, we developed the Multi-Modality Epilepsy Data Capture and Integration System (MEDCIS) that combines retrospective clinical free text processing using NLP, prospective structured data capture using an ontology-driven interface, interfaces for cohort search and signal visualization, all in a single integrated environment. A dedicated Epilepsy and Seizure Ontology (EpSO) has been used to streamline the user interfaces, enhance its usability, and enable mappings across distributed databases so that federated queries can be executed. MEDCIS contained 936 patient data sets from the EMUs of University Hospitals Case Medical Center (UH CMC) in Cleveland and Northwestern Memorial Hospital (NMH) in Chicago. Patients from UH CMC and NMH were stored in different databases and then federated through MEDCIS using EpSO and our mapping module. More than 77GB of multi-modal signal data were processed using the Cloudwave pipeline and made available for rendering through the web-interface. About 74% of the 40 open clinical questions of interest were answerable accurately using the EpSO-driven VISual AGregagator and Explorer (VISAGE) interface. Questions not directly answerable were either due to their inherent computational complexity, the unavailability of primary information, or the scope of concept that has been formulated in the existing Ep

Fuzzy Reasoning Based on First-Order Modal Logic,

NARCIS (Netherlands)

Zhang, Xiaoru; Zhang, Z.; Sui, Y.; Huang, Z.

2008-01-01

As an extension of traditional modal logics, this paper proposes a fuzzy first-order modal logic based on believable degree, and gives out a description of the fuzzy first-order modal logic based on constant domain semantics. In order to make the reasoning procedure between the fuzzy assertions

A Multi-Modality Deep Network for Cold-Start Recommendation

Directory of Open Access Journals (Sweden)

Mingxuan Sun

2018-03-01

Full Text Available Collaborative filtering (CF approaches, which provide recommendations based on ratings or purchase history, perform well for users and items with sufficient interactions. However, CF approaches suffer from the cold-start problem for users and items with few ratings. Hybrid recommender systems that combine collaborative filtering and content-based approaches have been proved as an effective way to alleviate the cold-start issue. Integrating contents from multiple heterogeneous data sources such as reviews and product images is challenging for two reasons. Firstly, mapping contents in different modalities from the original feature space to a joint lower-dimensional space is difficult since they have intrinsically different characteristics and statistical properties, such as sparse texts and dense images. Secondly, most algorithms only use content features as the prior knowledge to improve the estimation of user and item profiles but the ratings do not directly provide feedback to guide feature extraction. To tackle these challenges, we propose a tightly-coupled deep network model for fusing heterogeneous modalities, to avoid tedious feature extraction in specific domains, and to enable two-way information propagation from both content and rating information. Experiments on large-scale Amazon product data in book and movie domains demonstrate the effectiveness of the proposed model for cold-start recommendation.

Modality prediction of biomedical literature images using multimodal feature representation

Directory of Open Access Journals (Sweden)

Pelka, Obioma

2016-08-01

Full Text Available This paper presents the modelling approaches performed to automatically predict the modality of images found in biomedical literature. Various state-of-the-art visual features such as Bag-of-Keypoints computed with dense SIFT descriptors, texture features and Joint Composite Descriptors were used for visual image representation. Text representation was obtained by vector quantisation on a Bag-of-Words dictionary generated using attribute importance derived from a χ-test. Computing the principal components separately on each feature, dimension reduction as well as computational load reduction was achieved. Various multiple feature fusions were adopted to supplement visual image information with corresponding text information. The improvement obtained when using multimodal features vs. visual or text features was detected, analysed and evaluated. Random Forest models with 100 to 500 deep trees grown by resampling, a multi class linear kernel SVM with C=0.05 and a late fusion of the two classifiers were used for modality prediction. A Random Forest classifier achieved a higher accuracy and computed Bag-of-Keypoints with dense SIFT descriptors proved to be a better approach than with Lowe SIFT.

A Bayesian spatial model for neuroimaging data based on biologically informed basis functions.

Science.gov (United States)

Huertas, Ismael; Oldehinkel, Marianne; van Oort, Erik S B; Garcia-Solis, David; Mir, Pablo; Beckmann, Christian F; Marquand, Andre F

2017-11-01

The dominant approach to neuroimaging data analysis employs the voxel as the unit of computation. While convenient, voxels lack biological meaning and their size is arbitrarily determined by the resolution of the image. Here, we propose a multivariate spatial model in which neuroimaging data are characterised as a linearly weighted combination of multiscale basis functions which map onto underlying brain nuclei or networks or nuclei. In this model, the elementary building blocks are derived to reflect the functional anatomy of the brain during the resting state. This model is estimated using a Bayesian framework which accurately quantifies uncertainty and automatically finds the most accurate and parsimonious combination of basis functions describing the data. We demonstrate the utility of this framework by predicting quantitative SPECT images of striatal dopamine function and we compare a variety of basis sets including generic isotropic functions, anatomical representations of the striatum derived from structural MRI, and two different soft functional parcellations of the striatum derived from resting-state fMRI (rfMRI). We found that a combination of ∼50 multiscale functional basis functions accurately represented the striatal dopamine activity, and that functional basis functions derived from an advanced parcellation technique known as Instantaneous Connectivity Parcellation (ICP) provided the most parsimonious models of dopamine function. Importantly, functional basis functions derived from resting fMRI were more accurate than both structural and generic basis sets in representing dopamine function in the striatum for a fixed model order. We demonstrate the translational validity of our framework by constructing classification models for discriminating parkinsonian disorders and their subtypes. Here, we show that ICP approach is the only basis set that performs well across all comparisons and performs better overall than the classical voxel-based approach

Direct calculation of modal contributions to thermal conductivity via Green–Kubo modal analysis

International Nuclear Information System (INIS)

Lv, Wei; Henry, Asegun

2016-01-01

We derived a new method for direct calculation of the modal contributions to thermal conductivity, which is termed Green–Kubo modal analysis (GKMA). The GKMA method combines the lattice dynamics formalism with the Green–Kubo formula for thermal conductivity, such that the thermal conductivity becomes a direct summation of modal contributions, where one need not define the phonon velocity. As a result, the GKMA method can be applied to any material/group of atoms, where the atoms vibrate around stable equilibrium positions, which includes non-stoichiometric compounds, random alloys, amorphous materials and even rigid molecules. By using molecular dynamics simulations to obtain the time history of each mode’s contribution to the heat current, one naturally includes anharmonicity to full order and can obtain insight into the interactions between different modes through the cross-correlations. As an example, we applied the GMKA method to crystalline and amorphous silicon. The modal contributions at each frequency result from the analysis and thereby allow one to apply a quantum correction to the mode heat capacity to determine the temperature dependence of thermal conductivity. The predicted temperature dependent thermal conductivity for amorphous silicon shows the best agreement with experiments to date. The GKMA method provides new insight into the nature of phonon transport, as it casts the problem in terms of mode–mode correlation instead of scattering, and provides a general unified formalism that can be used to understand phonon–phonon interactions in essentially any class of materials or structures where the atoms vibrate around stable equilibrium sites. (paper)

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...

Modality effects in implicit artificial grammar learning: An EEG study.

Science.gov (United States)

Silva, Susana; Folia, Vasiliki; Inácio, Filomena; Castro, São Luís; Petersson, Karl Magnus

2018-05-15

Recently, it has been proposed that sequence learning engages a combination of modality-specific operating networks and modality-independent computational principles. In the present study, we compared the behavioural and EEG outcomes of implicit artificial grammar learning in the visual vs. auditory modality. We controlled for the influence of surface characteristics of sequences (Associative Chunk Strength), thus focusing on the strictly structural aspects of sequence learning, and we adapted the paradigms to compensate for known frailties of the visual modality compared to audition (temporal presentation, fast presentation rate). The behavioural outcomes were similar across modalities. Favouring the idea of modality-specificity, ERPs in response to grammar violations differed in topography and latency (earlier and more anterior component in the visual modality), and ERPs in response to surface features emerged only in the auditory modality. In favour of modality-independence, we observed three common functional properties in the late ERPs of the two grammars: both were free of interactions between structural and surface influences, both were more extended in a grammaticality classification test than in a preference classification test, and both correlated positively and strongly with theta event-related-synchronization during baseline testing. Our findings support the idea of modality-specificity combined with modality-independence, and suggest that memory for visual vs. auditory sequences may largely contribute to cross-modal differences. Copyright © 2018 Elsevier B.V. All rights reserved.

The metaphysics of quantum mechanics: Modal interpretations

Science.gov (United States)

Gluck, Stuart Murray

2004-11-01

This dissertation begins with the argument that a preferred way of doing metaphysics is through philosophy of physics. An understanding of quantum physics is vital to answering questions such as: What counts as an individual object in physical ontology? Is the universe fundamentally indeterministic? Are indiscernibles identical? This study explores how the various modal interpretations of quantum mechanics answer these sorts of questions; modal accounts are one of the two classes of interpretations along with so-called collapse accounts. This study suggests a new alternative within the class of modal views that yields a more plausible ontology, one in which the Principle of the Identity of Indisceribles is necessarily true. Next, it shows that modal interpretations can consistently deny that the universe must be fundamentally indeterministic so long as they accept certain other metaphysical commitments: either a perfect initial distribution of states in the universe or some form of primitive dispositional properties. Finally, the study sketches out a future research project for modal interpretations based on developing quantified quantum logic.

The research progress of dual-modality probes for molecular imaging

International Nuclear Information System (INIS)

Cao Feng; Chen Yue

2010-01-01

Various imaging modalities have been exploited to investigate the anatomic or functional dissemination of tissues in the body. However, no single imaging modality allows overall structural, functional, and molecular information as each imaging modality has its own unique strengths and weaknesses. The combination of two imaging modalities that investigates the strengths of different methods might offer the prospect of improved diagnostic abilities. As more and more dual-modality imaging system have become clinically adopted, significant progress has been made toward the creation of dual-modality imaging probes, which can be used as novel tools for future multimodality systems. These all-in-one probes take full advantage of two different imaging modalities and could provide comprehensive information for clinical diagnostics. This review discusses the advantages and challenges in developing dual-modality imaging probes. (authors)

Dissociating the Representation of Action- and Sound-Related Concepts in Middle Temporal Cortex

Science.gov (United States)

Kiefer, Markus; Trumpp, Natalie; Herrnberger, Barbel; Sim, Eun-Jin; Hoenig, Klaus; Pulvermuller, Friedemann

2012-01-01

Modality-specific models of conceptual memory propose close links between concepts and the sensory-motor systems. Neuroimaging studies found, in different subject groups, that action-related and sound-related concepts activated different parts of posterior middle temporal gyrus (pMTG), suggesting a modality-specific representation of conceptual…

The thalamus and multiple sclerosis: modern views on pathologic, imaging, and clinical aspects.

Science.gov (United States)

Minagar, Alireza; Barnett, Michael H; Benedict, Ralph H B; Pelletier, Daniel; Pirko, Istvan; Sahraian, Mohamad Ali; Frohman, Elliott; Zivadinov, Robert

2013-01-08

The paired thalamic nuclei are gray matter (GM) structures on both sides of the third ventricle that play major roles in cortical activation, relaying sensory information to the higher cortical centers that influence cognition. Multiple sclerosis (MS) is an immune-mediated disease of the human CNS that affects both the white matter (WM) and GM. A number of clinical observations as well as recent neuropathologic and neuroimaging studies have clearly demonstrated extensive involvement of the thalamus, basal ganglia, and neocortex in patients with MS. Modern MRI techniques permit visualization of GM lesions and measurement of atrophy. These contemporary methods have fundamentally altered our understanding of the pathophysiologic nature of MS. Evidence confirms the contention that GM injury can be detected in the earliest phases of MS, and that iron deposition and atrophy of deep gray nuclei are closely related to the magnitude of inflammation. Extensive involvement of GM, and particularly of the thalamus, is associated with a wide range of clinical manifestations including cognitive decline, motor deficits, fatigue, painful syndromes, and ocular motility disturbances in patients with MS. In this review, we characterize the neuropathologic, neuroimaging, and clinical features of thalamic involvement in MS. Further, we underscore the contention that neuropathologic and neuroimaging correlative investigations of thalamic derangements in MS may elucidate not heretofore considered pathobiological underpinnings germane to understanding the ontogeny, magnitude, and progression of the disease process.

Verifying different-modality properties for concepts produces switching costs.

Science.gov (United States)

Pecher, Diane; Zeelenberg, René; Barsalou, Lawrence W

2003-03-01

According to perceptual symbol systems, sensorimotor simulations underlie the representation of concepts. It follows that sensorimotor phenomena should arise in conceptual processing. Previous studies have shown that switching from one modality to another during perceptual processing incurs a processing cost. If perceptual simulation underlies conceptual processing, then verifying the properties of concepts should exhibit a switching cost as well. For example, verifying a property in the auditory modality (e.g., BLENDER-loud) should be slower after verifying a property in a different modality (e.g., CRANBERRIES-tart) than after verifying a property in the same modality (e.g., LEAVES-rustling). Only words were presented to subjects, and there were no instructions to use imagery. Nevertheless, switching modalities incurred a cost, analogous to the cost of switching modalities in perception. A second experiment showed that this effect was not due to associative priming between properties in the same modality. These results support the hypothesis that perceptual simulation underlies conceptual processing.

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,

Rewriting the Script: Multiple Modalities in a High School Humanities Classroom

Science.gov (United States)

Block, Joshua

2014-01-01

In this article, Joshua Block states that his high school students are creators discovering how to express their ideas and emotions in multiple, complex ways. He teaches students who write their lives through words on pages as they fill journal after journal. There are others who constantly write and create in the form of tweets, photos, videos,…

Modal Testing of Mechanical Structures subject to Operational Excitation Forces

DEFF Research Database (Denmark)

Møller, N.; Brincker, Rune; Herlufsen, H.

2001-01-01

Operational Modal Analysis also known as Output Only Modal Analysis has in the recent years been used for extracting modal parameters of civil engineering structures and is now becoming popular for mechanical structures. The advantage of the method is that no artificial excitation need to be appl......Operational Modal Analysis also known as Output Only Modal Analysis has in the recent years been used for extracting modal parameters of civil engineering structures and is now becoming popular for mechanical structures. The advantage of the method is that no artificial excitation need...

A frequency domain global parameter estimation method for multiple reference frequency response measurements

Science.gov (United States)

Shih, C. Y.; Tsuei, Y. G.; Allemang, R. J.; Brown, D. L.

1988-10-01

A method of using the matrix Auto-Regressive Moving Average (ARMA) model in the Laplace domain for multiple-reference global parameter identification is presented. This method is particularly applicable to the area of modal analysis where high modal density exists. The method is also applicable when multiple reference frequency response functions are used to characterise linear systems. In order to facilitate the mathematical solution, the Forsythe orthogonal polynomial is used to reduce the ill-conditioning of the formulated equations and to decouple the normal matrix into two reduced matrix blocks. A Complex Mode Indicator Function (CMIF) is introduced, which can be used to determine the proper order of the rational polynomials.

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.

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

Directory of Open Access Journals (Sweden)

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

Combining non-invasive transcranial brain stimulation with neuroimaging and electrophysiology: Current approaches and future perspectives

DEFF Research Database (Denmark)

Bergmann, Til Ole; Karabanov, Anke; Hartwigsen, Gesa

2016-01-01

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...... 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...

Contemporary imaging of mild TBI: the journey toward diffusion tensor imaging to assess neuronal damage.

Science.gov (United States)

Fox, W Christopher; Park, Min S; Belverud, Shawn; Klugh, Arnett; Rivet, Dennis; Tomlin, Jeffrey M

2013-04-01

To follow the progression of neuroimaging as a means of non-invasive evaluation of mild traumatic brain injury (mTBI) in order to provide recommendations based on reproducible, defined imaging findings. A comprehensive literature review and analysis of contemporary published articles was performed to study the progression of neuroimaging findings as a non-invasive 'biomarker' for mTBI. Multiple imaging modalities exist to support the evaluation of patients with mTBI, including ultrasound (US), computed tomography (CT), single photon emission computed tomography (SPECT), positron emission tomography (PET), and magnetic resonance imaging (MRI). These techniques continue to evolve with the development of fractional anisotropy (FA), fiber tractography (FT), and diffusion tensor imaging (DTI). Modern imaging techniques, when applied in the appropriate clinical setting, may serve as a valuable tool for diagnosis and management of patients with mTBI. An understanding of modern neuroanatomical imaging will enhance our ability to analyse injury and recognize the manifestations of mTBI.

The role of red blood cell scintigraphy in the multiple-modality imaging diagnosis of a rare case of diffuse hepatic hemangiomatosis in an adult

Directory of Open Access Journals (Sweden)

Ernesto Cason

2013-03-01

Full Text Available Introduction: Angiomas are one of the most common primary tumors of the liver. Diffuse hepatic angiomatosis, however, is quite rare and usually observed in pediatric patients. We report a rare case of diffuse hepatic hemangiomatosis in a 33-year-old woman. Case report: The patient presented with abdominal pain and a palpable upper abdominal mass. Abdominal CT and magnetic resonance imaging (MRI findings suggested diffuse hepatic hemangiomatosis, but this finding was not confirmed by subsequent contrast-enhanced abdominal ultrasonography (US. The patient then underwent single photon emission computed tomography (SPECT/CT scintigraphy with Tc-99m-labeling of red blood cells (RBC. This examination revealed increased uptake of labeled erythrocytes in several of the hepatic lesions corresponding to CT and RM findings, thereby confirming the clinical hypothesis of diffuse hepatic hemangiomatosis. Discussion: RBC scintigraphy with SPECT/CT can facilitate the comparison of other crosssectional imaging methods such as CT and MRI. This case highlights the importance of a multiple-modality approach in the imaging diagnosis of this condition.