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Sample records for related cortical potentials

  1. Influence of spontaneous rhythm on movement-related cortical potential

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    Yao, Lin; Chen, Mei Lin; Sheng, Xinjun

    2017-01-01

    We have recently developed an associative Brain-Computer Interface (BCI) for neuromodulation in chronic and acute stroke patients that leads to functional improvements. The control signal is the movement related cortical potential (MRCP) that develops prior to movement execution. The MRCP increases...

  2. Perceived exertion during muscle fatigue as reflected in movement-related cortical potentials: an event-related potential study.

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    Guo, Feng; Sun, Yong-Jun; Zhang, Ri-Hui

    2017-02-08

    The aim of this study was to explore the mechanism on perceived exertion during muscle fatigue. A total of 15 individuals in the fatigue group and 13 individuals in the nonfatigue group were recruited into this study, performing 200 intermittent handgrip contractions with 30% maximal voluntary contraction. The force, surface electromyography (sEMG), movement-related cortical potentials (MRCPs), and rating perception of effort (RPE) were combined to evaluate the perceived exertion during muscle fatigue. The maximal handgrip force significantly decreased (Pfatigue. The RPE scores reported by the individuals and the motor potential amplitude of MRCPs in the fatigue group significantly increased (Pfatigue but could also reflect the peripheral local muscle fatigue.

  3. A Review of Techniques for Detection of Movement Intention Using Movement-Related Cortical Potentials

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    Aqsa Shakeel

    2015-01-01

    Full Text Available The movement-related cortical potential (MRCP is a low-frequency negative shift in the electroencephalography (EEG recording that takes place about 2 seconds prior to voluntary movement production. MRCP replicates the cortical processes employed in planning and preparation of movement. In this study, we recapitulate the features such as signal’s acquisition, processing, and enhancement and different electrode montages used for EEG data recoding from different studies that used MRCPs to predict the upcoming real or imaginary movement. An authentic identification of human movement intention, accompanying the knowledge of the limb engaged in the performance and its direction of movement, has a potential implication in the control of external devices. This information could be helpful in development of a proficient patient-driven rehabilitation tool based on brain-computer interfaces (BCIs. Such a BCI paradigm with shorter response time appears more natural to the amputees and can also induce plasticity in brain. Along with different training schedules, this can lead to restoration of motor control in stroke patients.

  4. Classification of Hand Grasp Kinetics and Types Using Movement-Related Cortical Potentials and EEG Rhythms

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    Mads Jochumsen

    2017-01-01

    Full Text Available Detection of single-trial movement intentions from EEG is paramount for brain-computer interfacing in neurorehabilitation. These movement intentions contain task-related information and if this is decoded, the neurorehabilitation could potentially be optimized. The aim of this study was to classify single-trial movement intentions associated with two levels of force and speed and three different grasp types using EEG rhythms and components of the movement-related cortical potential (MRCP as features. The feature importance was used to estimate encoding of discriminative information. Two data sets were used. 29 healthy subjects executed and imagined different hand movements, while EEG was recorded over the contralateral sensorimotor cortex. The following features were extracted: delta, theta, mu/alpha, beta, and gamma rhythms, readiness potential, negative slope, and motor potential of the MRCP. Sequential forward selection was performed, and classification was performed using linear discriminant analysis and support vector machines. Limited classification accuracies were obtained from the EEG rhythms and MRCP-components: 0.48±0.05 (grasp types, 0.41±0.07 (kinetic profiles, motor execution, and 0.39±0.08 (kinetic profiles, motor imagination. Delta activity contributed the most but all features provided discriminative information. These findings suggest that information from the entire EEG spectrum is needed to discriminate between task-related parameters from single-trial movement intentions.

  5. Movement-related cortical potentials in paraplegic patients: abnormal patterns and considerations for BCI-rehabilitation

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    Ren eXu

    2014-08-01

    Full Text Available Non-invasive EEG-based Brain-Computer Interfaces (BCI can be promising for the motor neuro-rehabilitation of paraplegic patients. However, this shall require detailed knowledge of the abnormalities in the EEG signatures of paraplegic patients. The association of abnormalities in different subgroups of patients and their relation to the sensorimotor integration are relevant for the design, implementation and use of BCI systems in patient populations. This study explores the patterns of abnormalities of movement related cortical potentials (MRCP during motor imagery tasks of feet and right hand in patients with paraplegia (including the subgroups with/without central neuropathic pain and complete/incomplete injury patients and the level of distinctiveness of abnormalities in these groups using pattern classification. The most notable observed abnormalities were the amplified execution negativity and its slower rebound in the patient group. The potential underlying mechanisms behind these changes and other minor dissimilarities in patients’ subgroups, as well as the relevance to BCI applications, are discussed. The findings are of interest from a neurological perspective as well as for BCI-assisted neuro-rehabilitation and therapy.

  6. Detection of movement intention from single-trial movement-related cortical potentials

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    Niazi, Imran Khan; Jiang, Ning; Tiberghien, Olivier; Feldbæk Nielsen, Jørgen; Dremstrup, Kim; Farina, Dario

    2011-10-01

    Detection of movement intention from neural signals combined with assistive technologies may be used for effective neurofeedback in rehabilitation. In order to promote plasticity, a causal relation between intended actions (detected for example from the EEG) and the corresponding feedback should be established. This requires reliable detection of motor intentions. In this study, we propose a method to detect movements from EEG with limited latency. In a self-paced asynchronous BCI paradigm, the initial negative phase of the movement-related cortical potentials (MRCPs), extracted from multi-channel scalp EEG was used to detect motor execution/imagination in healthy subjects and stroke patients. For MRCP detection, it was demonstrated that a new optimized spatial filtering technique led to better accuracy than a large Laplacian spatial filter and common spatial pattern. With the optimized spatial filter, the true positive rate (TPR) for detection of movement execution in healthy subjects (n = 15) was 82.5 ± 7.8%, with latency of -66.6 ± 121 ms. Although TPR decreased with motor imagination in healthy subject (n = 10, 64.5 ± 5.33%) and with attempted movements in stroke patients (n = 5, 55.01 ± 12.01%), the results are promising for the application of this approach to provide patient-driven real-time neurofeedback.

  7. Electrocorticographic Temporal Alteration Mapping: A Clinical Technique for Mapping the Motor Cortex with Movement-Related Cortical Potentials

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    Zehan Wu

    2017-06-01

    Full Text Available We propose electrocorticographic temporal alteration mapping (ETAM for motor cortex mapping by utilizing movement-related cortical potentials (MRCPs within the low-frequency band [0.05-3] Hz. This MRCP waveform-based temporal domain approach was compared with the state-of-the-art electrocorticographic frequency alteration mapping (EFAM, which is based on frequency spectrum dynamics. Five patients (two epilepsy cases and three tumor cases were enrolled in the study. Each patient underwent intraoperative direct electrocortical stimulation (DECS procedure for motor cortex localization. Moreover, the patients were required to perform simple brisk wrist extension task during awake craniotomy surgery. Cross-validation results showed that the proposed ETAM method had high sensitivity (81.8% and specificity (94.3% in identifying sites which exhibited positive DECS motor responses. Moreover, although the sensitivity of the ETAM and EFAM approaches was not significantly different, ETAM had greater specificity compared with EFAM (94.3 vs. 86.1%. These results indicate that for the intraoperative functional brain mapping, ETAM is a promising novel approach for motor cortex localization with the potential to reduce the need for cortical electrical stimulation.

  8. Cortical Auditory Disorders: A Case of Non-Verbal Disturbances Assessed with Event-Related Brain Potentials

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    Sönke Johannes

    1998-01-01

    Full Text Available In the auditory modality, there has been a considerable debate about some aspects of cortical disorders, especially about auditory forms of agnosia. Agnosia refers to an impaired comprehension of sensory information in the absence of deficits in primary sensory processes. In the non-verbal domain, sound agnosia and amusia have been reported but are frequently accompanied by language deficits whereas pure deficits are rare. Absolute pitch and musicians’ musical abilities have been associated with left hemispheric functions. We report the case of a right handed sound engineer with the absolute pitch who developed sound agnosia and amusia in the absence of verbal deficits after a right perisylvian stroke. His disabilities were assessed with the Seashore Test of Musical Functions, the tests of Wertheim and Botez (Wertheim and Botez, Brain 84, 1961, 19–30 and by event-related potentials (ERP recorded in a modified 'oddball paradigm’. Auditory ERP revealed a dissociation between the amplitudes of the P3a and P3b subcomponents with the P3b being reduced in amplitude while the P3a was undisturbed. This is interpreted as reflecting disturbances in target detection processes as indexed by the P3b. The findings that contradict some aspects of current knowledge about left/right hemispheric specialization in musical processing are discussed and related to the literature concerning cortical auditory disorders.

  9. Cortical auditory disorders: a case of non-verbal disturbances assessed with event-related brain potentials.

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    Johannes, Sönke; Jöbges, Michael E.; Dengler, Reinhard; Münte, Thomas F.

    1998-01-01

    In the auditory modality, there has been a considerable debate about some aspects of cortical disorders, especially about auditory forms of agnosia. Agnosia refers to an impaired comprehension of sensory information in the absence of deficits in primary sensory processes. In the non-verbal domain, sound agnosia and amusia have been reported but are frequently accompanied by language deficits whereas pure deficits are rare. Absolute pitch and musicians' musical abilities have been associated with left hemispheric functions. We report the case of a right handed sound engineer with the absolute pitch who developed sound agnosia and amusia in the absence of verbal deficits after a right perisylvian stroke. His disabilities were assessed with the Seashore Test of Musical Functions, the tests of Wertheim and Botez (Wertheim and Botez, Brain 84, 1961, 19-30) and by event-related potentials (ERP) recorded in a modified 'oddball paradigm'. Auditory ERP revealed a dissociation between the amplitudes of the P3a and P3b subcomponents with the P3b being reduced in amplitude while the P3a was undisturbed. This is interpreted as reflecting disturbances in target detection processes as indexed by the P3b. The findings that contradict some aspects of current knowledge about left/right hemispheric specialization in musical processing are discussed and related to the literature concerning cortical auditory disorders.

  10. Influence of attention alternation on movement-related cortical potentials in healthy individuals and stroke patients

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    Aliakbaryhosseinabadi, Susan; Kostic, Vladimir; Pavlovic, Aleksandra

    2017-01-01

    Objective In this study, we analyzed the influence of artificially imposed attention variations using the auditory oddball paradigm on the cortical activity associated to motor preparation/execution. Methods EEG signals from Cz and its surrounding channels were recorded during three sets of ankle...... and accuracy deteriorated with attention diversion. Conclusion Attention diversion has a significant influence on MRCP features and detection parameters, although these changes were counteracted by the application of the laplacian method. Significance Brain–computer interfaces for neuromodulation that use...... the MRCP as the control signal are robust to changes in attention. However, attention must be monitored since it plays a key role in plasticity induction. Here we demonstrate that this can be achieved using the single channel Cz....

  11. Influence of dual-tasking with different levels of attention diversion on characteristics of the movement-related cortical potential.

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    Aliakbaryhosseinabadi, Susan; Kamavuako, Ernest Nlandu; Jiang, Ning; Farina, Dario; Mrachacz-Kersting, Natalie

    2017-11-01

    Dual tasking is defined as performing two tasks concurrently and has been shown to have a significant effect on attention directed to the performance of the main task. In this study, an attention diversion task with two different levels was administered while participants had to complete a cue-based motor task consisting of foot dorsiflexion. An auditory oddball task with two levels of complexity was implemented to divert the user's attention. Electroencephalographic (EEG) recordings were made from nine single channels. Event-related potentials (ERPs) confirmed that the oddball task of counting a sequence of two tones decreased the auditory P300 amplitude more than the oddball task of counting one target tone among three different tones. Pre-movement features quantified from the movement-related cortical potential (MRCP) were changed significantly between single and dual-task conditions in motor and fronto-central channels. There was a significant delay in movement detection for the case of single tone counting in two motor channels only (237.1-247.4ms). For the task of sequence counting, motor cortex and frontal channels showed a significant delay in MRCP detection (232.1-250.5ms). This study investigated the effect of attention diversion in dual-task conditions by analysing both ERPs and MRCPs in single channels. The higher attention diversion lead to a significant reduction in specific MRCP features of the motor task. These results suggest that attention division in dual-tasking situations plays an important role in movement execution and detection. This has important implications in designing real-time brain-computer interface systems. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Pain Modulation in Waking and Hypnosis in Women: Event-Related Potentials and Sources of Cortical Activity

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    De Pascalis, Vilfredo; Varriale, Vincenzo; Cacace, Immacolata

    2015-01-01

    Using a strict subject selection procedure, we tested in High and Low Hypnotizable subjects (HHs and LHs) whether treatments of hypoalgesia and hyperalgesia, as compared to a relaxation-control, differentially affected subjective pain ratings and somatosensory event-related potentials (SERPs) during painful electric stimulation. Treatments were administered in waking and hypnosis conditions. LHs showed little differentiation in pain and distress ratings between hypoalgesia and hyperalgesia treatments, whereas HHs showed a greater spread in the instructed direction. HHs had larger prefrontal N140 and P200 waves of the SERPs during hypnotic hyperalgesia as compared to relaxation-control treatment. Importantly, HHs showed significant smaller frontocentral N140 and frontotemporal P200 waves during hypnotic hypoalgesia. LHs did not show significant differences for these SERP waves among treatments in both waking and hypnosis conditions. Source localization (sLORETA) method revealed significant activations of the bilateral primary somatosensory (BA3), middle frontal gyrus (BA6) and anterior cingulate cortices (BA24). Activity of these contralateral regions significantly correlated with subjective numerical pain scores for control treatment in waking condition. Moreover, multivariate regression analyses distinguished the contralateral BA3 as the only region reflecting a stable pattern of pain coding changes across all treatments in waking and hypnosis conditions. More direct testing showed that hypnosis reduced the strength of the association of pain modulation and brain activity changes at BA3. sLORETA in HHs revealed, for the N140 wave, that during hypnotic hyperalgesia, there was an increased activity within medial, supramarginal and superior frontal gyri, and cingulated gyrus (BA32), while for the P200 wave, activity was increased in the superior (BA22), middle (BA37), inferior temporal (BA19) gyri and superior parietal lobule (BA7). Hypnotic hypoalgesia in HHs, for N

  13. Pain modulation in waking and hypnosis in women: event-related potentials and sources of cortical activity.

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    Vilfredo De Pascalis

    Full Text Available Using a strict subject selection procedure, we tested in High and Low Hypnotizable subjects (HHs and LHs whether treatments of hypoalgesia and hyperalgesia, as compared to a relaxation-control, differentially affected subjective pain ratings and somatosensory event-related potentials (SERPs during painful electric stimulation. Treatments were administered in waking and hypnosis conditions. LHs showed little differentiation in pain and distress ratings between hypoalgesia and hyperalgesia treatments, whereas HHs showed a greater spread in the instructed direction. HHs had larger prefrontal N140 and P200 waves of the SERPs during hypnotic hyperalgesia as compared to relaxation-control treatment. Importantly, HHs showed significant smaller frontocentral N140 and frontotemporal P200 waves during hypnotic hypoalgesia. LHs did not show significant differences for these SERP waves among treatments in both waking and hypnosis conditions. Source localization (sLORETA method revealed significant activations of the bilateral primary somatosensory (BA3, middle frontal gyrus (BA6 and anterior cingulate cortices (BA24. Activity of these contralateral regions significantly correlated with subjective numerical pain scores for control treatment in waking condition. Moreover, multivariate regression analyses distinguished the contralateral BA3 as the only region reflecting a stable pattern of pain coding changes across all treatments in waking and hypnosis conditions. More direct testing showed that hypnosis reduced the strength of the association of pain modulation and brain activity changes at BA3. sLORETA in HHs revealed, for the N140 wave, that during hypnotic hyperalgesia, there was an increased activity within medial, supramarginal and superior frontal gyri, and cingulated gyrus (BA32, while for the P200 wave, activity was increased in the superior (BA22, middle (BA37, inferior temporal (BA19 gyri and superior parietal lobule (BA7. Hypnotic hypoalgesia in

  14. STOP-EVENT-RELATED POTENTIALS FROM INTRACRANIAL ELECTRODES REVEAL A KEY ROLE OF PREMOTOR AND MOTOR CORTICES IN STOPPING ONGOING MOVEMENTS

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    Maurizio eMattia

    2012-06-01

    Full Text Available In humans, the ability to withhold manual motor responses seems to rely on a right-lateralized frontal–basal ganglia–thalamic network, including the pre-supplementary motor area and the inferior frontal gyrus. These areas should drive subthalamic nuclei to implement movement inhibition via the hyperdirect pathway. The output of this network is expected to influence those cortical areas underlying limb movement preparation and initiation, i.e. premotor (PMA and primary motor (M1 cortices. Electroencephalographic (EEG studies have shown an enhancement of the N200/P300 complex in the event-related potentials (ERPs when a planned reaching movement is successfully stopped after the presentation of an infrequent stop-signal. PMA and M1 have been suggested as possible neural sources of this ERP complex but, due to the limited spatial resolution of scalp EEG, it is not yet clear which cortical areas contribute to its generation. To elucidate the role of motor cortices, we recorded epicortical ERPs from the lateral surface of the fronto-temporal lobes of five pharmacoresistant epileptic patients performing a reaching version of the countermanding task while undergoing presurgical monitoring. We consistently found a stereotyped ERP complex on a single-trial level when a movement was successfully cancelled. These ERPs were selectively expressed in M1, PMA and Brodmann's area (BA 9 and their onsets preceded the end of the stop process, suggesting a causal involvement in this executive function. Such ERPs also occurred in unsuccessful-stop trials, that is, when subjects moved despite the occurrence of a stop-signal, mostly when they had long reaction times. These findings support the hypothesis that motor cortices are the final target of the inhibitory command elaborated by the frontal–basal ganglia–thalamic network.

  15. Slow cortical evoked potentials after noise exposure

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    von Wedel, H; Opitz, H J

    1979-07-01

    Human cortical evoked potentials under conditions of stimuation are registrated in the post-stimulatory phase of a five minutes lasting equally masking white noise (90 dB HL). Changes of the evoked potentials during adaptation, possible analogy with high tone losses after noise representation and the origin of tinnitus are examined. Stimulation was started 3 sec after the off-effect of the noise. For five minutes periodically tone bursts were represented. Each train of stimulation consists of tone bursts of three frequencies: 2 kcs, 4 kcs, 8 kcs. The 0.5 sec lasting tones were separated by pauses of 2 sec. During the experiment stimulation and analysis were controlled by a computer. Changes in latency and amplitudes of the cortical evoked potentials were registered. Changes of the adaptation patterns as a function of the poststimulatory time are discussed.

  16. Cortical reactions to verbal abuse: event-related brain potentials reflecting the processing of socially threatening words.

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    Wabnitz, Pascal; Martens, Ulla; Neuner, Frank

    2012-09-12

    Human information processing is sensitive to aversive stimuli, in particular to negative cues that indicate a threat to physical integrity. We investigated the extent to which these findings can be transferred to stimuli that are associated with a social rather than a physical threat. Event-related potentials were recorded during silent reading of neutral, positive, physically threatening, and socially threatening words, whereby socially threatening words were represented by swear words. We found facilitated processing of positive and physically threatening words in contrast to both neutral and socially threatening words at a first potential that emerged at about 120 ms after stimulus onset. At a semantic processing stage reflected by the N400, processing of all classes of affective words, including socially threatening words, differed from neutral words. We conclude that socially threatening words as well as neutral words capture more attentional resources than positive and physically threatening words at early stages. However, social threatening words are processed in a manner similar to other emotional words and different from neutral words at higher levels.

  17. Differences in visuo-motor control in skilled vs. novice martial arts athletes during sustained and transient attention tasks: a motor-related cortical potential study.

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    Sanchez-Lopez, Javier; Fernandez, Thalia; Silva-Pereyra, Juan; Martinez Mesa, Juan A; Di Russo, Francesco

    2014-01-01

    Cognitive and motor processes are essential for optimal athletic performance. Individuals trained in different skills and sports may have specialized cognitive abilities and motor strategies related to the characteristics of the activity and the effects of training and expertise. Most studies have investigated differences in motor-related cortical potential (MRCP) during self-paced tasks in athletes but not in stimulus-related tasks. The aim of the present study was to identify the differences in performance and MRCP between skilled and novice martial arts athletes during two different types of tasks: a sustained attention task and a transient attention task. Behavioral and electrophysiological data from twenty-two martial arts athletes were obtained while they performed a continuous performance task (CPT) to measure sustained attention and a cued continuous performance task (c-CPT) to measure transient attention. MRCP components were analyzed and compared between groups. Electrophysiological data in the CPT task indicated larger prefrontal positive activity and greater posterior negativity distribution prior to a motor response in the skilled athletes, while novices showed a significantly larger response-related P3 after a motor response in centro-parietal areas. A different effect occurred in the c-CPT task in which the novice athletes showed strong prefrontal positive activity before a motor response and a large response-related P3, while in skilled athletes, the prefrontal activity was absent. We propose that during the CPT, skilled athletes were able to allocate two different but related processes simultaneously according to CPT demand, which requires controlled attention and controlled motor responses. On the other hand, in the c-CPT, skilled athletes showed better cue facilitation, which permitted a major economy of resources and "automatic" or less controlled responses to relevant stimuli. In conclusion, the present data suggest that motor expertise

  18. Relating Cortical Wave Dynamics to Learning and Remembering

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    Eduardo Mercado III

    2014-12-01

    Full Text Available Electrical waves propagate across sensory and motor cortices in stereotypical patterns. These waves have been described as potentially facilitating sensory processing when they travel through sensory cortex, as guiding movement preparation and performance when they travel across motor cortex, and as possibly promoting synaptic plasticity and the consolidation of memory traces, especially during sleep. Here, an alternative theoretical framework is suggested that integrates Pavlovian hypotheses about learning and cortical function with concepts from contemporary proceduralist theories of memory. The proposed framework postulates that sensory-evoked cortical waves are gradually modified across repeated experiences such that the waves more effectively differentiate sensory events, and so that the waves are more likely to reverberate. It is argued that the qualities of cortical waves—their origins, form, intensity, speed, periodicity, extent, and trajectories —are a function of both the structural organization of neural circuits and ongoing reverberations resulting from previously experienced events. It is hypothesized that experience-dependent cortical plasticity, both in the short- and long-term, modulates the qualities of cortical waves, thereby enabling individuals to make progressively more precise distinctions between complex sensory events, and to reconstruct components of previously experienced events. Unlike most current neurobiological theories of learning and memory mechanisms, this hypothesis does not assume that synaptic plasticity, or any other form of neural plasticity, serves to store physical records of previously experienced events for later reactivation. Rather, the reorganization of cortical circuits may alter the potential for certain wave patterns to arise and persist. Understanding what factors determine the spatiotemporal dynamics of cortical waves, how structural changes affect their qualities, and how wave dynamics

  19. Cortical modulation of short-latency TMS-evoked potentials

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    Domenica eVeniero

    2013-01-01

    Full Text Available Transcranial magnetic stimulation - electroencephalogram (TMS-EEG co-registration offers the opportunity to test reactivity of brain areas across distinct conditions through TMS-evoked potentials (TEPs. Several TEPs have been described, their functional meaning being largely unknown. In particular, short-latency potentials peaking at 5 (P5 and 8 (N8 ms after the TMS pulse have been recently described, but because of their huge amplitude, the problem of whether their origin is cortical or not has been opened. To gain information about these components, we employed a protocol that modulates primary motor cortex excitability (MI through an exclusively cortical phenomena: low frequency stimulation of premotor area (PMC. TMS was applied simultaneously with EEG recording from 70 electrodes. Amplitude of TEPs evoked by 200 single-pulses TMS delivered over MI at 110% of resting motor threshold was measured before and after applying 900 TMS conditioning stimuli to left premotor cortex with 1 Hz repetition rate. Single subject analyses showed reduction in TEPs amplitude after PMC conditioning in a sample of participants and increase in TEPs amplitude in two subjects. No effects were found on corticospinal excitability as recorded by motor evoked potentials (MEPs. Furthermore, correlation analysis showed an inverse relation between the effects of the conditioning protocol on P5-N8 complex amplitude and MEPs amplitude. Because the effects of the used protocol have been ascribed to a cortical interaction between premotor area and MI, we suggest that despite the sign of P5-N8 amplitude modulation is not consistent across participant, this modulation could indicate, at least in part, their cortical origin. We conclude that with an accurate experimental procedure early-latency components can be used to evaluate the reactivity of the stimulated cortex.

  20. One Size Fits All? Slow Cortical Potentials Neurofeedback: A Review

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    Mayer, Kerstin; Wyckoff, Sarah N.; Strehl, Ute

    2013-01-01

    Objective: The intent of this manuscript was to review all published studies on slow cortical potentials (SCP) neurofeedback for the treatment of ADHD, with emphasis on neurophysiological rationale, study design, protocol, outcomes, and limitations. Method: For review, PubMed, MEDLINE, ERIC, and Google Scholar searches identified six studies and…

  1. Ultrasonically-induced electrical potentials in demineralized bovine cortical bone

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    Mori, Shunki; Makino, Taiki; Koyama, Daisuke; Takayanagi, Shinji; Yanagitani, Takahiko; Matsukawa, Mami

    2018-04-01

    While the low-intensity pulsed ultrasound technique has proved useful for healing of bone fractures, the ultrasound healing mechanism is not yet understood. To understand the initial physical effects of the ultrasound irradiation process on bone, we have studied the anisotropic piezoelectric properties of bone in the MHz range. Bone is known to be composed of collagen and hydroxyapatite (HAp) and shows strong elastic anisotropy. In this study, the effects of HAp on the piezoelectricity were investigated experimentally. To remove the HAp crystallites from the bovine cortical bone, demineralization was performed using ethylene diamine tetra-acetic acid (EDTA) solutions. To investigate the piezoelectricity, we have fabricated ultrasound transducers using the cortical bone or demineralized cortical bone. The induced electrical potentials due to the piezoelectricity were observed as the output of these transducers under pulsed ultrasound irradiation in the MHz range. The cortical bone transducer (before mineralization) showed anisotropic piezoelectric behavior. When the ultrasound irradiation was applied normal to the transducer surface, the observed induced electrical potentials had minimum values. The potential increased under off-axis ultrasound irradiation with changes in polarization. In the demineralized bone transducer case, however, the anisotropic behavior was not observed in the induced electrical potentials. These results therefore indicate that the HAp crystallites affect the piezoelectric characteristics of bone.

  2. Jealousy increased by induced relative left frontal cortical activity.

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    Kelley, Nicholas J; Eastwick, Paul W; Harmon-Jones, Eddie; Schmeichel, Brandon J

    2015-10-01

    Asymmetric frontal cortical activity may be one key to the process linking social exclusion to jealous feelings. The current research examined the causal role of asymmetric frontal brain activity in modulating jealousy in response to social exclusion. Transcranial direct-current stimulation (tDCS) over the frontal cortex to manipulate asymmetric frontal cortical activity was combined with a modified version of the Cyberball paradigm designed to induce jealousy. After receiving 15 min of tDCS, participants were excluded by a desired partner and reported how jealous they felt. Among individuals who were excluded, tDCS to increase relative left frontal cortical activity caused greater levels of self-reported jealousy compared to tDCS to increase relative right frontal cortical activity or sham stimulation. Limitations concerning the specificity of this effect and implications for the role of the asymmetric prefrontal cortical activity in motivated behaviors are discussed. (c) 2015 APA, all rights reserved).

  3. Intermediate Latency-Evoked Potentials of Multimodal Cortical Vestibular Areas: Galvanic Stimulation

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    Stefan Kammermeier

    2017-11-01

    Full Text Available IntroductionHuman multimodal vestibular cortical regions are bilaterally anterior insulae and posterior opercula, where characteristic vestibular-related cortical potentials were previously reported under acoustic otolith stimulation. Galvanic vestibular stimulation likely influences semicircular canals preferentially. Galvanic stimulation was compared to previously established data under acoustic stimulation.Methods14 healthy right-handed subjects, who were also included in the previous acoustic potential study, showed normal acoustic and galvanic vestibular-evoked myogenic potentials. They received 2,000 galvanic binaural bipolar stimuli for each side during EEG recording.ResultsVestibular cortical potentials were found in all 14 subjects and in the pooled data of all subjects (“grand average” bilaterally. Anterior insula and posterior operculum were activated exclusively under galvanic stimulation at 25, 35, 50, and 80 ms; frontal regions at 30 and 45 ms. Potentials at 70 ms in frontal regions and at 110 ms at all of the involved regions could also be recorded; these events were also found using acoustic stimulation in our previous study.ConclusionGalvanic semicircular canal stimulation evokes specific potentials in addition to those also found with acoustic otolith stimulation in identically located regions of the vestibular cortex. Vestibular cortical regions activate differently by galvanic and acoustic input at the peripheral sensory level.SignificanceDifferential effects in vestibular cortical-evoked potentials may see clinical use in specific vertigo disorders.

  4. Towards an optimal paradigm for simultaneously recording cortical and brainstem auditory evoked potentials.

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    Bidelman, Gavin M

    2015-02-15

    Simultaneous recording of brainstem and cortical event-related brain potentials (ERPs) may offer a valuable tool for understanding the early neural transcription of behaviorally relevant sounds and the hierarchy of signal processing operating at multiple levels of the auditory system. To date, dual recordings have been challenged by technological and physiological limitations including different optimal parameters necessary to elicit each class of ERP (e.g., differential adaptation/habitation effects and number of trials to obtain adequate response signal-to-noise ratio). We investigated a new stimulus paradigm for concurrent recording of the auditory brainstem frequency-following response (FFR) and cortical ERPs. The paradigm is "optimal" in that it uses a clustered stimulus presentation and variable interstimulus interval (ISI) to (i) achieve the most ideal acquisition parameters for eliciting subcortical and cortical responses, (ii) obtain an adequate number of trials to detect each class of response, and (iii) minimize neural adaptation/habituation effects. Comparison between clustered and traditional (fixed, slow ISI) stimulus paradigms revealed minimal change in amplitude or latencies of either the brainstem FFR or cortical ERP. The clustered paradigm offered over a 3× increase in recording efficiency compared to conventional (fixed ISI presentation) and thus, a more rapid protocol for obtaining dual brainstem-cortical recordings in individual listeners. We infer that faster recording of subcortical and cortical potentials might allow more complete and sensitive testing of neurophysiological function and aid in the differential assessment of auditory function. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Mapping human brain networks with cortico-cortical evoked potentials

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    Keller, Corey J.; Honey, Christopher J.; Mégevand, Pierre; Entz, Laszlo; Ulbert, Istvan; Mehta, Ashesh D.

    2014-01-01

    The cerebral cortex forms a sheet of neurons organized into a network of interconnected modules that is highly expanded in humans and presumably enables our most refined sensory and cognitive abilities. The links of this network form a fundamental aspect of its organization, and a great deal of research is focusing on understanding how information flows within and between different regions. However, an often-overlooked element of this connectivity regards a causal, hierarchical structure of regions, whereby certain nodes of the cortical network may exert greater influence over the others. While this is difficult to ascertain non-invasively, patients undergoing invasive electrode monitoring for epilepsy provide a unique window into this aspect of cortical organization. In this review, we highlight the potential for cortico-cortical evoked potential (CCEP) mapping to directly measure neuronal propagation across large-scale brain networks with spatio-temporal resolution that is superior to traditional neuroimaging methods. We first introduce effective connectivity and discuss the mechanisms underlying CCEP generation. Next, we highlight how CCEP mapping has begun to provide insight into the neural basis of non-invasive imaging signals. Finally, we present a novel approach to perturbing and measuring brain network function during cognitive processing. The direct measurement of CCEPs in response to electrical stimulation represents a potentially powerful clinical and basic science tool for probing the large-scale networks of the human cerebral cortex. PMID:25180306

  6. Cortical evoked potentials to an auditory illusion: binaural beats.

    Science.gov (United States)

    Pratt, Hillel; Starr, Arnold; Michalewski, Henry J; Dimitrijevic, Andrew; Bleich, Naomi; Mittelman, Nomi

    2009-08-01

    To define brain activity corresponding to an auditory illusion of 3 and 6Hz binaural beats in 250Hz or 1000Hz base frequencies, and compare it to the sound onset response. Event-Related Potentials (ERPs) were recorded in response to unmodulated tones of 250 or 1000Hz to one ear and 3 or 6Hz higher to the other, creating an illusion of amplitude modulations (beats) of 3Hz and 6Hz, in base frequencies of 250Hz and 1000Hz. Tones were 2000ms in duration and presented with approximately 1s intervals. Latency, amplitude and source current density estimates of ERP components to tone onset and subsequent beats-evoked oscillations were determined and compared across beat frequencies with both base frequencies. All stimuli evoked tone-onset P(50), N(100) and P(200) components followed by oscillations corresponding to the beat frequency, and a subsequent tone-offset complex. Beats-evoked oscillations were higher in amplitude with the low base frequency and to the low beat frequency. Sources of the beats-evoked oscillations across all stimulus conditions located mostly to left lateral and inferior temporal lobe areas in all stimulus conditions. Onset-evoked components were not different across stimulus conditions; P(50) had significantly different sources than the beats-evoked oscillations; and N(100) and P(200) sources located to the same temporal lobe regions as beats-evoked oscillations, but were bilateral and also included frontal and parietal contributions. Neural activity with slightly different volley frequencies from left and right ear converges and interacts in the central auditory brainstem pathways to generate beats of neural activity to modulate activities in the left temporal lobe, giving rise to the illusion of binaural beats. Cortical potentials recorded to binaural beats are distinct from onset responses. Brain activity corresponding to an auditory illusion of low frequency beats can be recorded from the scalp.

  7. Low and High-Frequency Field Potentials of Cortical Networks ...

    Science.gov (United States)

    Neural networks grown on microelectrode arrays (MEAs) have become an important, high content in vitro assay for assessing neuronal function. MEA experiments typically examine high- frequency (HF) (>200 Hz) spikes, and bursts which can be used to discriminate between different pharmacological agents/chemicals. However, normal brain activity is additionally composed of integrated low-frequency (0.5-100 Hz) field potentials (LFPs) which are filtered out of MEA recordings. The objective of this study was to characterize the relationship between HF and LFP neural network signals, and to assess the relative sensitivity of LFPs to selected neurotoxicants. Rat primary cortical cultures were grown on glass, single-well MEA chips. Spontaneous activity was sampled at 25 kHz and recorded (5 min) (Multi-Channel Systems) from mature networks (14 days in vitro). HF (spike, mean firing rate, MFR) and LF (power spectrum, amplitude) components were extracted from each network and served as its baseline (BL). Next, each chip was treated with either 1) a positive control, bicuculline (BIC, 25μM) or domoic acid (DA, 0.3μM), 2) or a negative control, acetaminophen (ACE, 100μM) or glyphosate (GLY, 100μM), 3) a solvent control (H2O or DMSO:EtOH), or 4) a neurotoxicant, (carbaryl, CAR 5, 30μM ; lindane, LIN 1, 10μM; permethrin, PERM 25, 50μM; triadimefon, TRI 5, 65μM). Post treatment, 5 mins of spontaneous activity was recorded and analyzed. As expected posit

  8. Decoupling Action Potential Bias from Cortical Local Field Potentials

    Directory of Open Access Journals (Sweden)

    Stephen V. David

    2010-01-01

    Full Text Available Neurophysiologists have recently become interested in studying neuronal population activity through local field potential (LFP recordings during experiments that also record the activity of single neurons. This experimental approach differs from early LFP studies because it uses high impendence electrodes that can also isolate single neuron activity. A possible complication for such studies is that the synaptic potentials and action potentials of the small subset of isolated neurons may contribute disproportionately to the LFP signal, biasing activity in the larger nearby neuronal population to appear synchronous and cotuned with these neurons. To address this problem, we used linear filtering techniques to remove features correlated with spike events from LFP recordings. This filtering procedure can be applied for well-isolated single units or multiunit activity. We illustrate the effects of this correction in simulation and on spike data recorded from primary auditory cortex. We find that local spiking activity can explain a significant portion of LFP power at most recording sites and demonstrate that removing the spike-correlated component can affect measurements of auditory tuning of the LFP.

  9. Cortical Interneuron Subtypes Vary in Their Axonal Action Potential Properties.

    Science.gov (United States)

    Casale, Amanda E; Foust, Amanda J; Bal, Thierry; McCormick, David A

    2015-11-25

    The role of interneurons in cortical microcircuits is strongly influenced by their passive and active electrical properties. Although different types of interneurons exhibit unique electrophysiological properties recorded at the soma, it is not yet clear whether these differences are also manifested in other neuronal compartments. To address this question, we have used voltage-sensitive dye to image the propagation of action potentials into the fine collaterals of axons and dendrites in two of the largest cortical interneuron subtypes in the mouse: fast-spiking interneurons, which are typically basket or chandelier neurons; and somatostatin containing interneurons, which are typically regular spiking Martinotti cells. We found that fast-spiking and somatostatin-expressing interneurons differed in their electrophysiological characteristics along their entire dendrosomatoaxonal extent. The action potentials generated in the somata and axons, including axon collaterals, of somatostatin-expressing interneurons are significantly broader than those generated in the same compartments of fast-spiking inhibitory interneurons. In addition, action potentials back-propagated into the dendrites of somatostatin-expressing interneurons much more readily than fast-spiking interneurons. Pharmacological investigations suggested that axonal action potential repolarization in both cell types depends critically upon Kv1 channels, whereas the axonal and somatic action potentials of somatostatin-expressing interneurons also depend on BK Ca(2+)-activated K(+) channels. These results indicate that the two broad classes of interneurons studied here have expressly different subcellular physiological properties, allowing them to perform unique computational roles in cortical circuit operations. Neurons in the cerebral cortex are of two major types: excitatory and inhibitory. The proper balance of excitation and inhibition in the brain is critical for its operation. Neurons contain three main

  10. Is empathy necessary to comprehend the emotional faces? The empathic effect on attentional mechanisms (eye movements), cortical correlates (N200 event-related potentials) and facial behaviour (electromyography) in face processing.

    Science.gov (United States)

    Balconi, Michela; Canavesio, Ylenia

    2016-01-01

    The present research explored the effect of social empathy on processing emotional facial expressions. Previous evidence suggested a close relationship between emotional empathy and both the ability to detect facial emotions and the attentional mechanisms involved. A multi-measure approach was adopted: we investigated the association between trait empathy (Balanced Emotional Empathy Scale) and individuals' performance (response times; RTs), attentional mechanisms (eye movements; number and duration of fixations), correlates of cortical activation (event-related potential (ERP) N200 component), and facial responsiveness (facial zygomatic and corrugator activity). Trait empathy was found to affect face detection performance (reduced RTs), attentional processes (more scanning eye movements in specific areas of interest), ERP salience effect (increased N200 amplitude), and electromyographic activity (more facial responses). A second important result was the demonstration of strong, direct correlations among these measures. We suggest that empathy may function as a social facilitator of the processes underlying the detection of facial emotion, and a general "facial response effect" is proposed to explain these results. We assumed that empathy influences cognitive and the facial responsiveness, such that empathic individuals are more skilful in processing facial emotion.

  11. Cortical somatosensory-evoked potentials during spine surgery in patients with neuromuscular and idiopathic scoliosis under propofol-remifentanil anaesthesia

    NARCIS (Netherlands)

    Hermanns, H.; Lipfert, P.; Meier, S.; Jetzek-Zader, M.; Krauspe, R.; Stevens, M. F.

    2007-01-01

    BACKGROUND: Intraoperative monitoring of the spinal cord via cortical somatosensory-evoked potentials (SSEP) is a routine during spinal surgery. However, especially in neuromuscular scoliosis, the reliability of cortical SSEP has been questioned. Therefore, we compared the feasibility of cortical

  12. Clozapine potentiation of GABA mediated cortical inhibition in treatment resistant schizophrenia.

    Science.gov (United States)

    Kaster, Tyler S; de Jesus, Danilo; Radhu, Natasha; Farzan, Faranak; Blumberger, Daniel M; Rajji, Tarek K; Fitzgerald, Paul B; Daskalakis, Zafiris J

    2015-07-01

    Cortical inhibition (CI) deficits have been demonstrated in schizophrenia using transcranial magnetic stimulation (TMS). These CI deficits may be related to decreased GABA activity which may be involved in schizophrenia pathophysiology. Previous cross-sectional studies have also demonstrated greater CI in patients treated with clozapine than other typical/atypical antipsychotics. However, it is not clear if these differences in CI are a result of treatment-resistant illness which necessitates clozapine or are related to clozapine treatment. TMS measures of CI (i.e., cortical silent period (CSP) and short-interval cortical inhibition (SICI)) were measured over the motor cortex in 16 patients with schizophrenia before starting clozapine, then 6 weeks and 6 months after starting clozapine. CSP was significantly longer after 6 weeks of treatment with clozapine (p=0.014). From 6 weeks to 6 months, there was no significant difference in CSP (p>0.05). Short-interval cortical inhibition (SICI) was not significantly different at any time after treatment with clozapine (p>0.05). This prospective-longitudinal study demonstrates that treatment with clozapine is associated with an increase in GABAB mediated inhibitory neurotransmission. Potentiation of GABAB may be a novel neurotransmitter mechanism that is involved in the pathophysiology and treatment of schizophrenia. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Membrane potential dynamics of populations of cortical neurons during auditory streaming

    Science.gov (United States)

    Farley, Brandon J.

    2015-01-01

    How a mixture of acoustic sources is perceptually organized into discrete auditory objects remains unclear. One current hypothesis postulates that perceptual segregation of different sources is related to the spatiotemporal separation of cortical responses induced by each acoustic source or stream. In the present study, the dynamics of subthreshold membrane potential activity were measured across the entire tonotopic axis of the rodent primary auditory cortex during the auditory streaming paradigm using voltage-sensitive dye imaging. Consistent with the proposed hypothesis, we observed enhanced spatiotemporal segregation of cortical responses to alternating tone sequences as their frequency separation or presentation rate was increased, both manipulations known to promote stream segregation. However, across most streaming paradigm conditions tested, a substantial cortical region maintaining a response to both tones coexisted with more peripheral cortical regions responding more selectively to one of them. We propose that these coexisting subthreshold representation types could provide neural substrates to support the flexible switching between the integrated and segregated streaming percepts. PMID:26269558

  14. Sexual orientation related differences in cortical thickness in male individuals.

    Directory of Open Access Journals (Sweden)

    Christoph Abé

    Full Text Available Previous neuroimaging studies demonstrated sex and also sexual orientation related structural and functional differences in the human brain. Genetic information and effects of sex hormones are assumed to contribute to the male/female differentiation of the brain, and similar effects could play a role in processes influencing human's sexual orientation. However, questions about the origin and development of a person's sexual orientation remain unanswered, and research on sexual orientation related neurobiological characteristics is still very limited. To contribute to a better understanding of the neurobiology of sexual orientation, we used magnetic resonance imaging (MRI in order to compare regional cortical thickness (Cth and subcortical volumes of homosexual men (hoM, heterosexual men (heM and heterosexual women (heW. hoM (and heW had thinner cortices primarily in visual areas and smaller thalamus volumes than heM, in which hoM and heW did not differ. Our results support previous studies, which suggest cerebral differences between hoM and heM in regions, where sex differences have been reported, which are frequently proposed to underlie biological mechanisms. Thus, our results contribute to a better understanding of the neurobiology of sexual orientation.

  15. Sexual orientation related differences in cortical thickness in male individuals.

    Science.gov (United States)

    Abé, Christoph; Johansson, Emilia; Allzén, Elin; Savic, Ivanka

    2014-01-01

    Previous neuroimaging studies demonstrated sex and also sexual orientation related structural and functional differences in the human brain. Genetic information and effects of sex hormones are assumed to contribute to the male/female differentiation of the brain, and similar effects could play a role in processes influencing human's sexual orientation. However, questions about the origin and development of a person's sexual orientation remain unanswered, and research on sexual orientation related neurobiological characteristics is still very limited. To contribute to a better understanding of the neurobiology of sexual orientation, we used magnetic resonance imaging (MRI) in order to compare regional cortical thickness (Cth) and subcortical volumes of homosexual men (hoM), heterosexual men (heM) and heterosexual women (heW). hoM (and heW) had thinner cortices primarily in visual areas and smaller thalamus volumes than heM, in which hoM and heW did not differ. Our results support previous studies, which suggest cerebral differences between hoM and heM in regions, where sex differences have been reported, which are frequently proposed to underlie biological mechanisms. Thus, our results contribute to a better understanding of the neurobiology of sexual orientation.

  16. Prepulse inhibition of auditory change-related cortical responses

    Directory of Open Access Journals (Sweden)

    Inui Koji

    2012-10-01

    Full Text Available Abstract Background Prepulse inhibition (PPI of the startle response is an important tool to investigate the biology of schizophrenia. PPI is usually observed by use of a startle reflex such as blinking following an intense sound. A similar phenomenon has not been reported for cortical responses. Results In 12 healthy subjects, change-related cortical activity in response to an abrupt increase of sound pressure by 5 dB above the background of 65 dB SPL (test stimulus was measured using magnetoencephalography. The test stimulus evoked a clear cortical response peaking at around 130 ms (Change-N1m. In Experiment 1, effects of the intensity of a prepulse (0.5 ~ 5 dB on the test response were examined using a paired stimulation paradigm. In Experiment 2, effects of the interval between the prepulse and test stimulus were examined using interstimulus intervals (ISIs of 50 ~ 350 ms. When the test stimulus was preceded by the prepulse, the Change-N1m was more strongly inhibited by a stronger prepulse (Experiment 1 and a shorter ISI prepulse (Experiment 2. In addition, the amplitude of the test Change-N1m correlated positively with both the amplitude of the prepulse-evoked response and the degree of inhibition, suggesting that subjects who are more sensitive to the auditory change are more strongly inhibited by the prepulse. Conclusions Since Change-N1m is easy to measure and control, it would be a valuable tool to investigate mechanisms of sensory gating or the biology of certain mental diseases such as schizophrenia.

  17. Cortical functional connectivity decodes subconscious, task-irrelevant threat-related emotion processing

    OpenAIRE

    Pantazatos, Spiro P.; Talati, Ardesheer; Pavlidis, Paul; Hirsch, Joy

    2012-01-01

    It is currently unclear to what extent cortical structures are required for and engaged during subconscious processing of biologically salient affective stimuli (i.e. the ‘low-road’ vs. ‘many-roads’ hypotheses). Here we show that cortical-cortical and cortical-subcortical functional connectivity (FC) contain substantially more information, relative to subcortical-subcortical FC (i.e. ‘subcortical alarm’ and other limbic regions), that predicts subliminal fearful face processing within individ...

  18. [Patterns of action potential firing in cortical neurons of neonatal mice and their electrophysiological property].

    Science.gov (United States)

    Furong, Liu; Shengtian, L I

    2016-05-25

    To investigate patterns of action potential firing in cortical heurons of neonatal mice and their electrophysiological properties. The passive and active membrane properties of cortical neurons from 3-d neonatal mice were observed by whole-cell patch clamp with different voltage and current mode. Three patterns of action potential firing were identified in response to depolarized current injection. The effects of action potential firing patterns on voltage-dependent inward and outward current were found. Neurons with three different firing patterns had different thresholds of depolarized current. In the morphology analysis of action potential, the three type neurons were different in rise time, duration, amplitude and threshold of the first action potential evoked by 80 pA current injection. The passive properties were similar in three patterns of action potential firing. These results indicate that newborn cortical neurons exhibit different patterns of action potential firing with different action potential parameters such as shape and threshold.

  19. Linear distributed source modeling of local field potentials recorded with intra-cortical electrode arrays.

    Directory of Open Access Journals (Sweden)

    Rikkert Hindriks

    Full Text Available Planar intra-cortical electrode (Utah arrays provide a unique window into the spatial organization of cortical activity. Reconstruction of the current source density (CSD underlying such recordings, however, requires "inverting" Poisson's equation. For inter-laminar recordings, this is commonly done by the CSD method, which consists in taking the second-order spatial derivative of the recorded local field potentials (LFPs. Although the CSD method has been tremendously successful in mapping the current generators underlying inter-laminar LFPs, its application to planar recordings is more challenging. While for inter-laminar recordings the CSD method seems reasonably robust against violations of its assumptions, is it unclear as to what extent this holds for planar recordings. One of the objectives of this study is to characterize the conditions under which the CSD method can be successfully applied to Utah array data. Using forward modeling, we find that for spatially coherent CSDs, the CSD method yields inaccurate reconstructions due to volume-conducted contamination from currents in deeper cortical layers. An alternative approach is to "invert" a constructed forward model. The advantage of this approach is that any a priori knowledge about the geometrical and electrical properties of the tissue can be taken into account. Although several inverse methods have been proposed for LFP data, the applicability of existing electroencephalographic (EEG and magnetoencephalographic (MEG inverse methods to LFP data is largely unexplored. Another objective of our study therefore, is to assess the applicability of the most commonly used EEG/MEG inverse methods to Utah array data. Our main conclusion is that these inverse methods provide more accurate CSD reconstructions than the CSD method. We illustrate the inverse methods using event-related potentials recorded from primary visual cortex of a macaque monkey during a motion discrimination task.

  20. Age-Related Changes in Trabecular and Cortical Bone Microstructure

    Directory of Open Access Journals (Sweden)

    Huayue Chen

    2013-01-01

    Full Text Available The elderly population has substantially increased worldwide. Aging is a complex process, and the effects of aging are myriad and insidious, leading to progressive deterioration of various organs, including the skeleton. Age-related bone loss and resultant osteoporosis in the elderly population increase the risk for fractures and morbidity. Osteoporosis is one of the most common conditions associated with aging, and age is an independent risk factor for osteoporotic fractures. With the development of noninvasive imaging techniques such as computed tomography (CT, micro-CT, and high resolution peripheral quantitative CT (HR-pQCT, imaging of the bone architecture provides important information about age-related changes in bone microstructure and estimates of bone strength. In the past two decades, studies of human specimens using imaging techniques have revealed decreased bone strength in older adults compared with younger adults. The present paper addresses recently studied age-related changes in trabecular and cortical bone microstructure based primarily on HR-pQCT and micro-CT. We specifically focus on the three-dimensional microstructure of the vertebrae, femoral neck, and distal radius, which are common osteoporotic fracture sites.

  1. Age-related changes in trabecular and cortical bone microstructure.

    Science.gov (United States)

    Chen, Huayue; Zhou, Xiangrong; Fujita, Hiroshi; Onozuka, Minoru; Kubo, Kin-Ya

    2013-01-01

    The elderly population has substantially increased worldwide. Aging is a complex process, and the effects of aging are myriad and insidious, leading to progressive deterioration of various organs, including the skeleton. Age-related bone loss and resultant osteoporosis in the elderly population increase the risk for fractures and morbidity. Osteoporosis is one of the most common conditions associated with aging, and age is an independent risk factor for osteoporotic fractures. With the development of noninvasive imaging techniques such as computed tomography (CT), micro-CT, and high resolution peripheral quantitative CT (HR-pQCT), imaging of the bone architecture provides important information about age-related changes in bone microstructure and estimates of bone strength. In the past two decades, studies of human specimens using imaging techniques have revealed decreased bone strength in older adults compared with younger adults. The present paper addresses recently studied age-related changes in trabecular and cortical bone microstructure based primarily on HR-pQCT and micro-CT. We specifically focus on the three-dimensional microstructure of the vertebrae, femoral neck, and distal radius, which are common osteoporotic fracture sites.

  2. Exercising self-control increases relative left frontal cortical activation.

    Science.gov (United States)

    Schmeichel, Brandon J; Crowell, Adrienne; Harmon-Jones, Eddie

    2016-02-01

    Self-control refers to the capacity to override or alter a predominant response tendency. The current experiment tested the hypothesis that exercising self-control temporarily increases approach motivation, as revealed by patterns of electrical activity in the prefrontal cortex. Participants completed a writing task that did vs did not require them to exercise self-control. Then they viewed pictures known to evoke positive, negative or neutral affect. We assessed electroencephalographic (EEG) activity while participants viewed the pictures, and participants reported their trait levels of behavioral inhibition system (BIS) and behavioral activation system (BAS) sensitivity at the end of the study. We found that exercising (vs not exercising) self-control increased relative left frontal cortical activity during picture viewing, particularly among individuals with relatively higher BAS than BIS, and particularly during positive picture viewing. A similar but weaker pattern emerged during negative picture viewing. The results suggest that exercising self-control temporarily increases approach motivation, which may help to explain the aftereffects of self-control (i.e. ego depletion). © The Author (2015). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  3. Neurofeedback using real-time near-infrared spectroscopy enhances motor imagery related cortical activation.

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    Masahito Mihara

    Full Text Available Accumulating evidence indicates that motor imagery and motor execution share common neural networks. Accordingly, mental practices in the form of motor imagery have been implemented in rehabilitation regimes of stroke patients with favorable results. Because direct monitoring of motor imagery is difficult, feedback of cortical activities related to motor imagery (neurofeedback could help to enhance efficacy of mental practice with motor imagery. To determine the feasibility and efficacy of a real-time neurofeedback system mediated by near-infrared spectroscopy (NIRS, two separate experiments were performed. Experiment 1 was used in five subjects to evaluate whether real-time cortical oxygenated hemoglobin signal feedback during a motor execution task correlated with reference hemoglobin signals computed off-line. Results demonstrated that the NIRS-mediated neurofeedback system reliably detected oxygenated hemoglobin signal changes in real-time. In Experiment 2, 21 subjects performed motor imagery of finger movements with feedback from relevant cortical signals and irrelevant sham signals. Real neurofeedback induced significantly greater activation of the contralateral premotor cortex and greater self-assessment scores for kinesthetic motor imagery compared with sham feedback. These findings suggested the feasibility and potential effectiveness of a NIRS-mediated real-time neurofeedback system on performance of kinesthetic motor imagery. However, these results warrant further clinical trials to determine whether this system could enhance the effects of mental practice in stroke patients.

  4. Slow pre-movement cortical potentials do not reflect individual response to therapy in writer's cramp

    DEFF Research Database (Denmark)

    Zeuner, K E; Peller, M; Knutzen, A

    2009-01-01

    OBJECTIVE: To investigate whether movement-related cortical potentials (MRCP) provide a physiological correlate that indicates the response to treatment in patients with writer's cramp. METHODS: In 21 patients with writer's cramp, who underwent 4 weeks of limb immobilization followed by re...... apart. RESULTS: Patients benefited from the therapeutical intervention (Zeuner et al., 2008). They showed no abnormalities of the MRCPs at baseline. In controls, MRCPs did not significantly change after 4 weeks. In patients, immobilization and re-training had no effect on MRCPs. There was no correlation......-training for 8 weeks, we recorded MRCPs preceding a self-initiated brisk finger abduction movement. MRCP measurements of pre-movement activity were performed at baseline, after the end of immobilization and four and 8 weeks of re-training. We examined 12 controls, who received no intervention, twice 4 weeks...

  5. The cortical spatiotemporal correlate of otolith stimulation: Vestibular evoked potentials by body translations.

    Science.gov (United States)

    Ertl, M; Moser, M; Boegle, R; Conrad, J; Zu Eulenburg, P; Dieterich, M

    2017-07-15

    The vestibular organ senses linear and rotational acceleration of the head during active and passive motion. These signals are necessary for bipedal locomotion, navigation, the coordination of eye and head movements in 3D space. The temporal dynamics of vestibular processing in cortical structures have hardly been studied in humans, let alone with natural stimulation. The aim was to investigate the cortical vestibular network related to natural otolith stimulation using a hexapod motion platform. We conducted two experiments, 1. to estimate the sources of the vestibular evoked potentials (VestEPs) by means of distributed source localization (n=49), and 2. to reveal modulations of the VestEPs through the underlying acceleration intensity (n=24). For both experiments subjects were accelerated along the main axis (left/right, up/down, fore/aft) while the EEG was recorded. We were able to identify five VestEPs (P1, N1, P2, N2, P3) with latencies between 38 and 461 ms as well as an evoked beta-band response peaking with a latency of 68 ms in all subjects and for all acceleration directions. Source localization gave the cingulate sulcus visual (CSv) area and the opercular-insular region as the main origin of the evoked potentials. No lateralization effects due to handedness could be observed. In the second experiment, area CSv was shown to be integral in the processing of acceleration intensities as sensed by the otolith organs, hinting at its potential role in ego-motion detection. These robust VestEPs could be used to investigate the mechanisms of inter-regional interaction in the natural context of vestibular processing and multisensory integration. Copyright © 2017 Elsevier Inc. All rights reserved.

  6. Noninvasive scalp recording of cortical auditory evoked potentials in the alert macaque monkey.

    Science.gov (United States)

    Itoh, Kosuke; Nejime, Masafumi; Konoike, Naho; Nakada, Tsutomu; Nakamura, Katsuki

    2015-09-01

    Scalp-recorded evoked potentials (EP) provide researchers and clinicians with irreplaceable means for recording stimulus-related neural activities in the human brain, due to its high temporal resolution, handiness, and, perhaps more importantly, non-invasiveness. This work recorded the scalp cortical auditory EP (CAEP) in unanesthetized monkeys by using methods that are essentially identical to those applied to humans. Young adult rhesus monkeys (Macaca mulatta, 5-7 years old) were seated in a monkey chair, and their head movements were partially restricted by polystyrene blocks and tension poles placed around their head. Individual electrodes were fixated on their scalp using collodion according to the 10-20 system. Pure tone stimuli were presented while electroencephalograms were recorded from up to nineteen channels, including an electrooculogram channel. In all monkeys (n = 3), the recorded CAEP comprised a series of positive and negative deflections, labeled here as macaque P1 (mP1), macaque N1 (mN1), macaque P2 (mP2), and macaque N2 (mN2), and these transient responses to sound onset were followed by a sustained potential that continued for the duration of the sound, labeled the macaque sustained potential (mSP). mP1, mN2 and mSP were the prominent responses, and they had maximal amplitudes over frontal/central midline electrode sites, consistent with generators in auditory cortices. The study represents the first noninvasive scalp recording of CAEP in alert rhesus monkeys, to our knowledge. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Event-related cortical processing in neuropathic pain under long-term spinal cord stimulation.

    Science.gov (United States)

    Weigel, Ralf; Capelle, H Holger; Flor, Herta; Krauss, Joachim K

    2015-01-01

    Several mechanisms were suggested in the past to explain the beneficial effect of spinal cord stimulation (SCS) in patients suffering from neuropathic pain. Little is known about potential supraspinal mechanisms. In this study cortical signaling of patients with neuropathic pain and successful long-term treatment with SCS was analyzed. Observational study. University hospital, neurosurgical department, outpatient clinic for movement disorders and pain, institute for cognitive and clinical neuroscience. Nine patients with neuropathic pain of a lower extremity with a lasting response to chronic SCS were included. Cortical activity was analyzed using event-related potentials of the electroencephalogram after non-painful and painful stimulation. Each patient was tested under the effect of long-term SCS and 24 hours after cessation of SCS. Cortical areas involved in the peaks of evoked potentials were localized using a source localization method based on a fixed dipole model. Detection threshold and intensity of non-painful stimulation did not differ significantly on both sides. Pain threshold was significantly lower on the neuropathic side under the effect of SCS (P = 0.03). Bilateral pain thresholds were significantly lower (P = 0.03 healthy side, P = 0.003 neuropathic side) in 5 patients with increased pain after cessation of SCS. Under the effect of SCS cortical negativities (N1, N2, N3) and positivities (P1) demonstrated bilaterally comparable amplitudes. After cessation of SCS, decreased threshold for peripheral stimulation resulted in lowered negativities on both sides. The positivity P1 was differentially regulated and was reduced more contralateral to the unaffected side. N2 was localized at the sensory representation of the leg within the homunculus. The main vector of P1 was localized within the cingular cortex (CC) and moved more anteriorly under the effect of SCS. The exact time span that SCS continues to have an effect is not known. However, due to patient

  8. Relating normalization to neuronal populations across cortical areas.

    Science.gov (United States)

    Ruff, Douglas A; Alberts, Joshua J; Cohen, Marlene R

    2016-09-01

    Normalization, which divisively scales neuronal responses to multiple stimuli, is thought to underlie many sensory, motor, and cognitive processes. In every study where it has been investigated, neurons measured in the same brain area under identical conditions exhibit a range of normalization, ranging from suppression by nonpreferred stimuli (strong normalization) to additive responses to combinations of stimuli (no normalization). Normalization has been hypothesized to arise from interactions between neuronal populations, either in the same or different brain areas, but current models of normalization are not mechanistic and focus on trial-averaged responses. To gain insight into the mechanisms underlying normalization, we examined interactions between neurons that exhibit different degrees of normalization. We recorded from multiple neurons in three cortical areas while rhesus monkeys viewed superimposed drifting gratings. We found that neurons showing strong normalization shared less trial-to-trial variability with other neurons in the same cortical area and more variability with neurons in other cortical areas than did units with weak normalization. Furthermore, the cortical organization of normalization was not random: neurons recorded on nearby electrodes tended to exhibit similar amounts of normalization. Together, our results suggest that normalization reflects a neuron's role in its local network and that modulatory factors like normalization share the topographic organization typical of sensory tuning properties. Copyright © 2016 the American Physiological Society.

  9. Brain activation in motor sequence learning is related to the level of native cortical excitability.

    Directory of Open Access Journals (Sweden)

    Silke Lissek

    Full Text Available Cortical excitability may be subject to changes through training and learning. Motor training can increase cortical excitability in motor cortex, and facilitation of motor cortical excitability has been shown to be positively correlated with improvements in performance in simple motor tasks. Thus cortical excitability may tentatively be considered as a marker of learning and use-dependent plasticity. Previous studies focused on changes in cortical excitability brought about by learning processes, however, the relation between native levels of cortical excitability on the one hand and brain activation and behavioral parameters on the other is as yet unknown. In the present study we investigated the role of differential native motor cortical excitability for learning a motor sequencing task with regard to post-training changes in excitability, behavioral performance and involvement of brain regions. Our motor task required our participants to reproduce and improvise over a pre-learned motor sequence. Over both task conditions, participants with low cortical excitability (CElo showed significantly higher BOLD activation in task-relevant brain regions than participants with high cortical excitability (CEhi. In contrast, CElo and CEhi groups did not exhibit differences in percentage of correct responses and improvisation level. Moreover, cortical excitability did not change significantly after learning and training in either group, with the exception of a significant decrease in facilitatory excitability in the CEhi group. The present data suggest that the native, unmanipulated level of cortical excitability is related to brain activation intensity, but not to performance quality. The higher BOLD mean signal intensity during the motor task might reflect a compensatory mechanism in CElo participants.

  10. Warm Body Temperature Facilitates Energy Efficient Cortical Action Potentials

    Science.gov (United States)

    Yu, Yuguo; Hill, Adam P.; McCormick, David A.

    2012-01-01

    The energy efficiency of neural signal transmission is important not only as a limiting factor in brain architecture, but it also influences the interpretation of functional brain imaging signals. Action potential generation in mammalian, versus invertebrate, axons is remarkably energy efficient. Here we demonstrate that this increase in energy efficiency is due largely to a warmer body temperature. Increases in temperature result in an exponential increase in energy efficiency for single action potentials by increasing the rate of Na+ channel inactivation, resulting in a marked reduction in overlap of the inward Na+, and outward K+, currents and a shortening of action potential duration. This increase in single spike efficiency is, however, counterbalanced by a temperature-dependent decrease in the amplitude and duration of the spike afterhyperpolarization, resulting in a nonlinear increase in the spike firing rate, particularly at temperatures above approximately 35°C. Interestingly, the total energy cost, as measured by the multiplication of total Na+ entry per spike and average firing rate in response to a constant input, reaches a global minimum between 37–42°C. Our results indicate that increases in temperature result in an unexpected increase in energy efficiency, especially near normal body temperature, thus allowing the brain to utilize an energy efficient neural code. PMID:22511855

  11. Warm body temperature facilitates energy efficient cortical action potentials.

    Directory of Open Access Journals (Sweden)

    Yuguo Yu

    Full Text Available The energy efficiency of neural signal transmission is important not only as a limiting factor in brain architecture, but it also influences the interpretation of functional brain imaging signals. Action potential generation in mammalian, versus invertebrate, axons is remarkably energy efficient. Here we demonstrate that this increase in energy efficiency is due largely to a warmer body temperature. Increases in temperature result in an exponential increase in energy efficiency for single action potentials by increasing the rate of Na(+ channel inactivation, resulting in a marked reduction in overlap of the inward Na(+, and outward K(+, currents and a shortening of action potential duration. This increase in single spike efficiency is, however, counterbalanced by a temperature-dependent decrease in the amplitude and duration of the spike afterhyperpolarization, resulting in a nonlinear increase in the spike firing rate, particularly at temperatures above approximately 35°C. Interestingly, the total energy cost, as measured by the multiplication of total Na(+ entry per spike and average firing rate in response to a constant input, reaches a global minimum between 37-42°C. Our results indicate that increases in temperature result in an unexpected increase in energy efficiency, especially near normal body temperature, thus allowing the brain to utilize an energy efficient neural code.

  12. The Beat Goes on: Rhythmic Modulation of Cortical Potentials by Imagined Tapping

    Science.gov (United States)

    Osman, Allen; Albert, Robert; Ridderinkhof, K. Richard; Band, Guido; van der Molen, Maurits

    2006-01-01

    A frequency analysis was used to tag cortical activity from imagined rhythmic movements. Participants synchronized overt and imagined taps with brief visual stimuli presented at a constant rate, alternating between left and right index fingers. Brain potentials were recorded from across the scalp and topographic maps made of their power at the…

  13. The role of asymmetric frontal cortical activity in emotion-related phenomena: a review and update.

    Science.gov (United States)

    Harmon-Jones, Eddie; Gable, Philip A; Peterson, Carly K

    2010-07-01

    Conceptual and empirical approaches to the study of the role of asymmetric frontal cortical activity in emotional processes are reviewed. Although early research suggested that greater left than right frontal cortical activity was associated with positive affect, more recent research, primarily on anger, suggests that greater left than right frontal cortical activity is associated with approach motivation, which can be positive (e.g., enthusiasm) or negative in valence (e.g., anger). In addition to reviewing this research on anger, research on guilt, bipolar disorder, and various types of positive affect is reviewed with relation to their association with asymmetric frontal cortical activity. The reviewed research not only contributes to a more complete understanding of the emotive functions of asymmetric frontal cortical activity, but it also points to the importance of considering motivational direction as separate from affective valence in psychological models of emotional space. Copyright © 2009 Elsevier B.V. All rights reserved.

  14. Cortical Local Field Potential Power Is Associated with Behavioral Detection of Near-threshold Stimuli in the Rat Whisker System: Dissociation between Orbitofrontal and Somatosensory Cortices.

    Science.gov (United States)

    Rickard, Rachel E; Young, Andrew M J; Gerdjikov, Todor V

    2018-01-01

    There is growing evidence that ongoing brain oscillations may represent a key regulator of attentional processes and as such may contribute to behavioral performance in psychophysical tasks. OFC appears to be involved in the top-down modulation of sensory processing; however, the specific contribution of ongoing OFC oscillations to perception has not been characterized. Here we used the rat whiskers as a model system to further characterize the relationship between cortical state and tactile detection. Head-fixed rats were trained to report the presence of a vibrotactile stimulus (frequency = 60 Hz, duration = 2 sec, deflection amplitude = 0.01-0.5 mm) applied to a single vibrissa. We calculated power spectra of local field potentials preceding the onset of near-threshold stimuli from microelectrodes chronically implanted in OFC and somatosensory cortex. We found a dissociation between slow oscillation power in the two regions in relation to detection probability: Higher OFC but not somatosensory delta power was associated with increased detection probability. Furthermore, coherence between OFC and barrel cortex was reduced preceding successful detection. Consistent with the role of OFC in attention, our results identify a cortical network whose activity is differentially modulated before successful tactile detection.

  15. Demineralized Freeze-Dried Bovine Cortical Bone: Its Potential for Guided Bone Regeneration Membrane

    Directory of Open Access Journals (Sweden)

    David B. Kamadjaja

    2017-01-01

    Full Text Available Background. Bovine pericardium collagen membrane (BPCM had been widely used in guided bone regeneration (GBR whose manufacturing process usually required chemical cross-linking to prolong its biodegradation. However, cross-linking of collagen fibrils was associated with poorer tissue integration and delayed vascular invasion. Objective. This study evaluated the potential of bovine cortical bone collagen membrane for GBR by evaluating its antigenicity potential, cytotoxicity, immune and tissue response, and biodegradation behaviors. Material and Methods. Antigenicity potential of demineralized freeze-dried bovine cortical bone membrane (DFDBCBM was done with histology-based anticellularity evaluation, while cytotoxicity was analyzed using MTT Assay. Evaluation of immune response, tissue response, and biodegradation was done by randomly implanting DFDBCBM and BPCM in rat’s subcutaneous dorsum. Samples were collected at 2, 5, and 7 days and 7, 14, 21, and 28 days for biocompatibility and tissue response-biodegradation study, respectively. Result. DFDBCBM, histologically, showed no retained cells; however, it showed some level of in vitro cytotoxicity. In vivo study exhibited increased immune response to DFDBCBM in early healing phase; however, normal tissue response and degradation rate were observed up to 4 weeks after DFDBCBM implantation. Conclusion. Demineralized freeze-dried bovine cortical bone membrane showed potential for clinical application; however, it needs to be optimized in its biocompatibility to fulfill all requirements for GBR membrane.

  16. Restriction Spectrum Imaging As a Potential Measure of Cortical Neurite Density in Autism

    OpenAIRE

    Carper, Ruth A.; Treiber, Jeffrey M.; White, Nathan S.; Kohli, Jiwandeep S.; M?ller, Ralph-Axel

    2017-01-01

    Autism postmortem studies have shown various cytoarchitectural anomalies in cortical and limbic areas including increased cell packing density, laminar disorganization, and narrowed minicolumns. However, there is little evidence on dendritic and axonal organization in ASD. Recent imaging techniques have the potential for non-invasive, in vivo studies of small-scale structure in the human brain, including gray matter. Here, Restriction Spectrum Imaging (RSI), a multi-shell diffusion-weighted i...

  17. Background noise can enhance cortical auditory evoked potentials under certain conditions.

    Science.gov (United States)

    Papesh, Melissa A; Billings, Curtis J; Baltzell, Lucas S

    2015-07-01

    To use cortical auditory evoked potentials (CAEPs) to understand neural encoding in background noise and the conditions under which noise enhances CAEP responses. CAEPs from 16 normal-hearing listeners were recorded using the speech syllable/ba/presented in quiet and speech-shaped noise at signal-to-noise ratios of 10 and 30dB. The syllable was presented binaurally and monaurally at two presentation rates. The amplitudes of N1 and N2 peaks were often significantly enhanced in the presence of low-level background noise relative to quiet conditions, while P1 and P2 amplitudes were consistently reduced in noise. P1 and P2 amplitudes were significantly larger during binaural compared to monaural presentations, while N1 and N2 peaks were similar between binaural and monaural conditions. Methodological choices impact CAEP peaks in very different ways. Negative peaks can be enhanced by background noise in certain conditions, while positive peaks are generally enhanced by binaural presentations. Methodological choices significantly impact CAEPs acquired in quiet and in noise. If CAEPs are to be used as a tool to explore signal encoding in noise, scientists must be cognizant of how differences in acquisition and processing protocols selectively shape CAEP responses. Published by Elsevier Ireland Ltd.

  18. Cortical Double-Opponent Cells in Color Perception: Perceptual Scaling and Chromatic Visual Evoked Potentials.

    Science.gov (United States)

    Nunez, Valerie; Shapley, Robert M; Gordon, James

    2018-01-01

    In the early visual cortex V1, there are currently only two known neural substrates for color perception: single-opponent and double-opponent cells. Our aim was to explore the relative contributions of these neurons to color perception. We measured the perceptual scaling of color saturation for equiluminant color checkerboard patterns (designed to stimulate double-opponent neurons preferentially) and uniformly colored squares (designed to stimulate only single-opponent neurons) at several cone contrasts. The spatially integrative responses of single-opponent neurons would produce the same response magnitude for checkerboards as for uniform squares of the same space-averaged cone contrast. However, perceived saturation of color checkerboards was higher than for the corresponding squares. The perceptual results therefore imply that double-opponent cells are involved in color perception of patterns. We also measured the chromatic visual evoked potential (cVEP) produced by the same stimuli; checkerboard cVEPs were much larger than those for corresponding squares, implying that double-opponent cells also contribute to the cVEP response. The total Fourier power of the cVEP grew sublinearly with cone contrast. However, the 6-Hz Fourier component's power grew linearly with contrast-like saturation perception. This may also indicate that cortical coding of color depends on response dynamics.

  19. Visual cortical somatosensory and brainstem auditory evoked potentials following incidental irradiation of the rhombencephalon

    International Nuclear Information System (INIS)

    Nightingale, S.; Schofield, I.S.; Dawes, P.J.D.K.

    1984-01-01

    Visual, cortical somatosensory and brainstem auditory evoked potentials were recorded before incidental irradiation of the rhombencephalon during radiotherapy in and around the middle ear, and at 11 weeks and eight months after completion of treatment. No patient experienced neurological symptoms during this period. No consistent changes in evoked potentials were found. The failure to demonstrate subclinical radiation-induced demyelination suggests either that the syndrome of early-delayed radiation rhombencephalopathy occurs in an idiosyncratic manner, or that any subclinical lesions are not detectable by serial evoked potential recordings. (author)

  20. Visual cortical somatosensory and brainstem auditory evoked potentials following incidental irradiation of the rhombencephalon

    Energy Technology Data Exchange (ETDEWEB)

    Nightingale, S. (Royal Victoria Infirmary, Newcastle upon Tyne (UK)); Schofield, I.S.; Dawes, P.J.D.K. (Newcastle upon Tyne Univ. (UK). Newcastle General Hospital)

    1984-01-01

    Visual, cortical somatosensory and brainstem auditory evoked potentials were recorded before incidental irradiation of the rhombencephalon during radiotherapy in and around the middle ear, and at 11 weeks and eight months after completion of treatment. No patient experienced neurological symptoms during this period. No consistent changes in evoked potentials were found. The failure to demonstrate subclinical radiation-induced demyelination suggests either that the syndrome of early-delayed radiation rhombencephalopathy occurs in an idiosyncratic manner, or that any subclinical lesions are not detectable by serial evoked potential recordings.

  1. State and location dependence of action potential metabolic cost in cortical pyramidal neurons.

    Science.gov (United States)

    Hallermann, Stefan; de Kock, Christiaan P J; Stuart, Greg J; Kole, Maarten H P

    2012-06-03

    Action potential generation and conduction requires large quantities of energy to restore Na(+) and K(+) ion gradients. We investigated the subcellular location and voltage dependence of this metabolic cost in rat neocortical pyramidal neurons. Using Na(+)/K(+) charge overlap as a measure of action potential energy efficiency, we found that action potential initiation in the axon initial segment (AIS) and forward propagation into the axon were energetically inefficient, depending on the resting membrane potential. In contrast, action potential backpropagation into dendrites was efficient. Computer simulations predicted that, although the AIS and nodes of Ranvier had the highest metabolic cost per membrane area, action potential backpropagation into the dendrites and forward propagation into axon collaterals dominated energy consumption in cortical pyramidal neurons. Finally, we found that the high metabolic cost of action potential initiation and propagation down the axon is a trade-off between energy minimization and maximization of the conduction reliability of high-frequency action potentials.

  2. Cortical potentials in an auditory oddball task reflect individual differences in working memory capacity.

    Science.gov (United States)

    Yurgil, Kate A; Golob, Edward J

    2013-12-01

    This study determined whether auditory cortical responses associated with mechanisms of attention vary with individual differences in working memory capacity (WMC) and perceptual load. The operation span test defined subjects with low versus high WMC, who then discriminated target/nontarget tones while EEG was recorded. Infrequent white noise distracters were presented at midline or ±90° locations, and perceptual load was manipulated by varying nontarget frequency. Amplitude of the N100 to distracters was negatively correlated with WMC. Relative to targets, only high WMC subjects showed attenuated N100 amplitudes to nontargets. In the higher WMC group, increased perceptual load was associated with decreased P3a amplitudes to distracters and longer-lasting negative slow wave to nontargets. Results show that auditory cortical processing is associated with multiple facets of attention related to WMC and possibly higher-level cognition. Copyright © 2013 Society for Psychophysiological Research.

  3. Gaming is related to enhanced working memory performance and task-related cortical activity.

    Science.gov (United States)

    Moisala, M; Salmela, V; Hietajärvi, L; Carlson, S; Vuontela, V; Lonka, K; Hakkarainen, K; Salmela-Aro, K; Alho, K

    2017-01-15

    Gaming experience has been suggested to lead to performance enhancements in a wide variety of working memory tasks. Previous studies have, however, mostly focused on adult expert gamers and have not included measurements of both behavioral performance and brain activity. In the current study, 167 adolescents and young adults (aged 13-24 years) with different amounts of gaming experience performed an n-back working memory task with vowels, with the sensory modality of the vowel stream switching between audition and vision at random intervals. We studied the relationship between self-reported daily gaming activity, working memory (n-back) task performance and related brain activity measured using functional magnetic resonance imaging (fMRI). The results revealed that the extent of daily gaming activity was related to enhancements in both performance accuracy and speed during the most demanding (2-back) level of the working memory task. This improved working memory performance was accompanied by enhanced recruitment of a fronto-parietal cortical network, especially the dorsolateral prefrontal cortex. In contrast, during the less demanding (1-back) level of the task, gaming was associated with decreased activity in the same cortical regions. Our results suggest that a greater degree of daily gaming experience is associated with better working memory functioning and task difficulty-dependent modulation in fronto-parietal brain activity already in adolescence and even when non-expert gamers are studied. The direction of causality within this association cannot be inferred with certainty due to the correlational nature of the current study. Copyright © 2016 Elsevier B.V. All rights reserved.

  4. Dynamics of action potential backpropagation in basal dendrites of prefrontal cortical pyramidal neurons.

    Science.gov (United States)

    Zhou, Wen-Liang; Yan, Ping; Wuskell, Joseph P; Loew, Leslie M; Antic, Srdjan D

    2008-02-01

    Basal dendrites of neocortical pyramidal neurons are relatively short and directly attached to the cell body. This allows electrical signals arising in basal dendrites to strongly influence the neuronal output. Likewise, somatic action potentials (APs) should readily propagate back into the basilar dendritic tree to influence synaptic plasticity. Two recent studies, however, determined that sodium APs are severely attenuated in basal dendrites of cortical pyramidal cells, so that they completely fail in distal dendritic segments. Here we used the latest improvements in the voltage-sensitive dye imaging technique (Zhou et al., 2007) to study AP backpropagation in basal dendrites of layer 5 pyramidal neurons of the rat prefrontal cortex. With a signal-to-noise ratio of > 15 and minimal temporal averaging (only four sweeps) we were able to sample AP waveforms from the very last segments of individual dendritic branches (dendritic tips). We found that in short- (< 150 microm) and medium (150-200 microm in length)-range basal dendrites APs backpropagated with modest changes in AP half-width or AP rise-time. The lack of substantial changes in AP shape and dynamics of rise is inconsistent with the AP-failure model. The lack of substantial amplitude boosting of the third AP in the high-frequency burst also suggests that in short- and medium-range basal dendrites backpropagating APs were not severely attenuated. Our results show that the AP-failure concept does not apply in all basal dendrites of the rat prefrontal cortex. The majority of synaptic contacts in the basilar dendritic tree actually received significant AP-associated electrical and calcium transients.

  5. Electrophysiological potentials reveal cortical mechanisms for mental imagery, mental simulation, and grounded (embodied cognition

    Directory of Open Access Journals (Sweden)

    Haline E. Schendan

    2012-09-01

    Full Text Available Grounded cognition theory proposes that cognition, including meaning, is grounded in sensorimotor processing. The mechanism for grounding cognition is mental simulation, which is a type of mental imagery that re-enacts modal processing. To reveal top-down, cortical mechanisms for mental simulation of shape, event-related potentials were recorded to face and object pictures preceded by mental imagery of a picture. Mental imagery of the identical face or object (congruous condition facilitated not only categorical perception (VPP/N170 but also later visual knowledge (N3[00] complex and linguistic knowledge (N400 for faces more than objects, and strategic semantic analysis (late positive complex between 200 and 700 ms. The later effects resembled semantic congruity effects with pictures. Mental imagery also facilitated category decisions, as a P3(00 peaked earlier for congruous than incongruous (other category pictures, resembling the case when identical pictures repeat immediately. Thus mental imagery mimics semantic congruity and immediate repetition priming processes with pictures. Perception control results showed the opposite for faces and were in the same direction for objects: Perceptual repetition adapts (and so impairs processing of perceived faces from categorical perception onwards, but primes processing of objects during categorical perception, visual knowledge processes, and strategic semantic analysis. For both imagery and perception, differences between faces and objects support domain-specificity and indicate that cognition is grounded in modal processing. Altogether, this direct neural evidence reveals that top-down processes of mental imagery sustain an imagistic representation that mimics perception well enough to prime subsequent perception and cognition. This also suggests that automatic mental simulation of the visual shape of faces and objects operates between 200 and 400 ms, and strategic mental simulation operates between

  6. Functional states of rat cortical circuits during the unpredictable availability of a reward-related cue.

    Science.gov (United States)

    Fernández-Lamo, Iván; Sánchez-Campusano, Raudel; Gruart, Agnès; Delgado-García, José M

    2016-11-21

    Proper performance of acquired abilities can be disturbed by the unexpected occurrence of external changes. Rats trained with an operant conditioning task (to press a lever in order to obtain a food pellet) using a fixed-ratio (1:1) schedule were subsequently placed in a Skinner box in which the lever could be removed randomly. Field postsynaptic potentials (fPSPs) were chronically evoked in perforant pathway-hippocampal CA1 (PP-CA1), CA1-subiculum (CA1-SUB), CA1-medial prefrontal cortex (CA1-mPFC), mPFC-nucleus accumbens (mPFC-NAc), and mPFC-basolateral amygdala (mPFC-BLA) synapses during lever IN and lever OUT situations. While lever presses were accompanied by a significant increase in fPSP slopes at the five synapses, the unpredictable absence of the lever were accompanied by decreased fPSP slopes in all, except PP-CA1 synapses. Spectral analysis of local field potentials (LFPs) recorded when the animal approached the corresponding area in the lever OUT situation presented lower spectral powers than during lever IN occasions for all recording sites, apart from CA1. Thus, the unpredictable availability of a reward-related cue modified the activity of cortical and subcortical areas related with the acquisition of operant learning tasks, suggesting an immediate functional reorganization of these neural circuits to address the changed situation and to modify ongoing behaviors accordingly.

  7. Influence of body position on cortical pain-related somatosensory processing: an ERP study.

    Directory of Open Access Journals (Sweden)

    Chiara Spironelli

    Full Text Available BACKGROUND: Despite the consistent information available on the physiological changes induced by head down bed rest, a condition which simulates space microgravity, our knowledge on the possible perceptual-cortical alterations is still poor. The present study investigated the effects of 2-h head-down bed rest on subjective and cortical responses elicited by electrical, pain-related somatosensory stimulation. METHODOLOGY/PRINCIPAL FINDINGS: Twenty male subjects were randomly assigned to two groups, head-down bed rest (BR or sitting control condition. Starting from individual electrical thresholds, Somatosensory Evoked Potentials were elicited by electrical stimuli administered randomly to the left wrist and divided into four conditions: control painless condition, electrical pain threshold, 30% above pain threshold, 30% below pain threshold. Subjective pain ratings collected during the EEG session showed significantly reduced pain perception in BR compared to Control group. Statistical analysis on four electrode clusters and sLORETA source analysis revealed, in sitting controls, a P1 component (40-50 ms in the right somatosensory cortex, whereas it was bilateral and differently located in BR group. Controls' N1 (80-90 ms had widespread right hemisphere activation, involving also anterior cingulate, whereas BR group showed primary somatosensory cortex activation. The P2 (190-220 ms was larger in left-central locations of Controls compared with BR group. CONCLUSIONS/SIGNIFICANCE: Head-down bed rest was associated to an overall decrease of pain sensitivity and an altered pain network also outside the primary somatosensory cortex. Results have implications not only for astronauts' health and spaceflight risks, but also for the clinical aspects of pain detection in bedridden patients at risk of fatal undetected complications.

  8. Membrane potential and response properties of populations of cortical neurons in the high conductance state

    International Nuclear Information System (INIS)

    Moreno-Bote, Ruben; Parga, Nestor

    2005-01-01

    Because of intense synaptic activity, cortical neurons are in a high conductance state. We show that this state has important consequences on the properties of a population of independent model neurons with conductance-based synapses. Using an adiabaticlike approximation we study both the membrane potential and the firing probability distributions across the population. We find that the latter is bimodal in such a way that at any particular moment some neurons are inactive while others are active. The population rate and the response variability are also characterized

  9. Do gravity-related sensory information enable the enhancement of cortical proprioceptive inputs when planning a step in microgravity?

    Directory of Open Access Journals (Sweden)

    Anahid H Saradjian

    Full Text Available We recently found that the cortical response to proprioceptive stimulation was greater when participants were planning a step than when they stood still, and that this sensory facilitation was suppressed in microgravity. The aim of the present study was to test whether the absence of gravity-related sensory afferents during movement planning in microgravity prevented the proprioceptive cortical processing to be enhanced. We reestablished a reference frame in microgravity by providing and translating a horizontal support on which the participants were standing and verified whether this procedure restored the proprioceptive facilitation. The slight translation of the base of support (lateral direction, which occurred prior to step initiation, stimulated at least cutaneous and vestibular receptors. The sensitivity to proprioceptive stimulation was assessed by measuring the amplitude of the cortical somatosensory-evoked potential (SEP, over the Cz electrode following the vibration of the leg muscle. The vibration lasted 1 s and the participants were asked to either initiate a step at the vibration offset or to remain still. We found that the early SEP (90-160 ms was smaller when the platform was translated than when it remained stationary, revealing the existence of an interference phenomenon (i.e., when proprioceptive stimulation is preceded by the stimulation of different sensory modalities evoked by the platform translation. By contrast, the late SEP (550 ms post proprioceptive stimulation onset was greater when the translation preceded the vibration compared to a condition without pre-stimulation (i.e., no translation. This suggests that restoring a body reference system which is impaired in microgravity allowed a greater proprioceptive cortical processing. Importantly, however, the late SEP was similarly increased when participants either produced a step or remained still. We propose that the absence of step-induced facilitation of

  10. The developing human brain: age-related changes in cortical, subcortical, and cerebellar anatomy.

    Science.gov (United States)

    Sussman, Dafna; Leung, Rachel C; Chakravarty, M Mallar; Lerch, Jason P; Taylor, Margot J

    2016-04-01

    This study is the first to characterize normal development and sex differences across neuroanatomical structures in cortical, subcortical, and cerebellar brain regions in a single large cohort. One hundred and ninety-two magnetic resonance images were examined from 96 typically developing females and 96 age-matched typically developing males from 4 to 18 years of age. Image segmentation of the cortex was conducted with CIVET, while that of the cerebellum, hippocampi, thalamus, and basal ganglia were conducted using the MAGeT algorithm. Cortical thickness analysis revealed that most cortical regions decrease linearly, while surface area increases linearly with age. Volume relative to total cerebrum followed a quadratic trend with age, with only the left supramarginal gyrus showing sexual dimorphism. Hippocampal relative volume increased linearly, while the thalamus, caudate, and putamen decreased linearly, and the cerebellum did not change with age. The relative volumes of several subcortical subregions followed inverted U-shaped trends that peaked at ~12 years of age. Many subcortical structures were found to be larger in females than in males, independently of age, while others showed a sex-by-age interaction. This study provides a comprehensive assessment of cortical, subcortical, and cerebellar growth patterns during normal development, and draws attention to the role of sex on neuroanatomical maturation throughout childhood and adolescence.

  11. Cortical thickness development of human primary visual cortex related to the age of blindness onset.

    Science.gov (United States)

    Li, Qiaojun; Song, Ming; Xu, Jiayuan; Qin, Wen; Yu, Chunshui; Jiang, Tianzi

    2017-08-01

    Blindness primarily induces structural alteration in the primary visual cortex (V1). Some studies have found that the early blind subjects had a thicker V1 compared to sighted controls, whereas late blind subjects showed no significant differences in the V1. This implies that the age of blindness onset may exert significant effects on the development of cortical thickness of the V1. However, no previous research used a trajectory of the age of blindness onset-related changes to investigate these effects. Here we explored this issue by mapping the cortical thickness trajectory of the V1 against the age of blindness onset using data from 99 blind individuals whose age of blindness onset ranged from birth to 34 years. We found that the cortical thickness of the V1 could be fitted well with a quadratic curve in both the left (F = 11.59, P = 3 × 10 -5 ) and right hemispheres (F = 6.54, P = 2 × 10 -3 ). Specifically, the cortical thickness of the V1 thinned rapidly during childhood and adolescence and did not change significantly thereafter. This trend was not observed in the primary auditory cortex (A1), primary motor cortex (M1), or primary somatosensory cortex (S1). These results provide evidence that an onset of blindness before adulthood significantly affects the cortical thickness of the V1 and suggest a critical period for cortical development of the human V1.

  12. Intra- and interregional cortical interactions related to sharp-wave ripples and dentate spikes.

    Science.gov (United States)

    Headley, Drew B; Kanta, Vasiliki; Paré, Denis

    2017-02-01

    The hippocampus generates population events termed sharp-wave ripples (SWRs) and dentate spikes (DSs). While little is known about DSs, SWR-related hippocampal discharges during sleep are thought to replay prior waking activity, reactivating the cortical networks that encoded the initial experience. During slow-wave sleep, such reactivations likely occur during up-states, when most cortical neurons are depolarized. However, most studies have examined the relationship between SWRs and up-states measured in single neocortical regions. As a result, it is currently unclear whether SWRs are associated with particular patterns of widely distributed cortical activity. Additionally, no such investigation has been carried out for DSs. The present study addressed these questions by recording SWRs and DSs from the dorsal hippocampus simultaneously with prefrontal, sensory (visual and auditory), perirhinal, and entorhinal cortices in naturally sleeping rats. We found that SWRs and DSs were associated with up-states in all cortical regions. Up-states coinciding with DSs and SWRs exhibited increased unit activity, power in the gamma band, and intraregional gamma coherence. Unexpectedly, interregional gamma coherence rose much more strongly in relation to DSs than to SWRs. Whereas the increase in gamma coherence was time locked to DSs, that seen in relation to SWRs was not. These observations suggest that SWRs are related to the strength of up-state activation within individual regions throughout the neocortex but not so much to gamma coherence between different regions. Perhaps more importantly, DSs coincided with stronger periods of interregional gamma coherence, suggesting that they play a more important role than previously assumed. Off-line cortico-hippocampal interactions are thought to support memory consolidation. We surveyed the relationship between hippocampal sharp-wave ripples (SWRs) and dentate spikes (DSs) with up-states across multiple cortical regions. SWRs and

  13. The neostriatal mosaic: striatal patch-matrix organization is related to cortical lamination.

    Science.gov (United States)

    Gerfen, C R

    1989-10-20

    The basal ganglia, of which the striatum is the major component, process inputs from virtually all cerebral cortical areas to affect motor, emotional, and cognitive behaviors. Insights into how these seemingly disparate functions may be integrated have emerged from studies that have demonstrated that the mammalian striatum is composed of two compartments arranged as a mosaic, the patches and the matrix, which differ in their neurochemical and neuroanatomical properties. In this study, projections from prefrontal, cingulate, and motor cortical areas to the striatal compartments were examined with the Phaseolus vulgaris-leucoagglutinin (PHA-L) anterograde axonal tracer in rats. Each cortical area projects to both the patches and the matrix of the striatum; however, deep layer V and layer VI corticostriatal neurons project principally to the patches, whereas superficial layer V and layer III and II corticostriatal neurons project principally to the matrix. The relative contribution of patch and matrix corticostriatal projections varies among the cortical areas examined such that allocortical areas provide a greater number of inputs to the patches than to the matrix, whereas the reverse obtains for neocortical areas. These results demonstrate that the compartmental organization of corticostriatal inputs is related to their laminar origin and secondarily to the cytoarchitectonic area of origin.

  14. Correlates of a single cortical action potential in the epidural EEG

    Science.gov (United States)

    Teleńczuk, Bartosz; Baker, Stuart N; Kempter, Richard; Curio, Gabriel

    2015-01-01

    To identify the correlates of a single cortical action potential in surface EEG, we recorded simultaneously epidural EEG and single-unit activity in the primary somatosensory cortex of awake macaque monkeys. By averaging over EEG segments coincident with more than hundred thousand single spikes, we found short-lived (≈ 0.5 ms) triphasic EEG deflections dominated by high-frequency components > 800 Hz. The peak-to-peak amplitude of the grand-averaged spike correlate was 80 nV, which matched theoretical predictions, while single-neuron amplitudes ranged from 12 to 966 nV. Combining these estimates with post-stimulus-time histograms of single-unit responses to median-nerve stimulation allowed us to predict the shape of the evoked epidural EEG response and to estimate the number of contributing neurons. These findings establish spiking activity of cortical neurons as a primary building block of high-frequency epidural EEG, which thus can serve as a quantitative macroscopic marker of neuronal spikes. PMID:25554430

  15. Cortical delta-opioid receptors potentiate K+ homeostasis during anoxia and oxygen-glucose deprivation.

    Science.gov (United States)

    Chao, Dongman; Donnelly, David F; Feng, Yin; Bazzy-Asaad, Alia; Xia, Ying

    2007-02-01

    Central neurons are extremely vulnerable to hypoxic/ischemic insult, which is a major cause of neurologic morbidity and mortality as a consequence of neuronal dysfunction and death. Our recent work has shown that delta-opioid receptor (DOR) is neuroprotective against hypoxic and excitotoxic stress, although the underlying mechanisms remain unclear. Because hypoxia/ischemia disrupts ionic homeostasis with an increase in extracellular K(+), which plays a role in neuronal death, we asked whether DOR activation preserves K(+) homeostasis during hypoxic/ischemic stress. To test this hypothesis, extracellular recordings with K(+)-sensitive microelectrodes were performed in mouse cortical slices under anoxia or oxygen-glucose deprivation (OGD). The main findings in this study are that (1) DOR activation with [D-Ala(2), D-Leu(5)]-enkephalinamide attenuated the anoxia- and OGD-induced increase in extracellular K(+) and decrease in DC potential in cortical slices; (2) DOR inhibition with naltrindole, a DOR antagonist, completely abolished the DOR-mediated prevention of increase in extracellular K(+) and decrease in DC potential; (3) inhibition of protein kinase A (PKA) with N-(2-[p-bromocinnamylamino]-ethyl)-5-isoquinolinesulfonamide dihydrochloride had no effect on the DOR protection; and (4) inhibition of protein kinase C (PKC) with chelerythrine chloride reduced the DOR protection, whereas the PKC activator (phorbol 12-myristate 13-acetate) mimicked the effect of DOR activation on K(+) homeostasis. These data suggest that activation of DOR protects the cortex against anoxia- or ODG-induced derangement of potassium homeostasis, and this protection occurs via a PKC-dependent and PKA-independent pathway. We conclude that an important aspect of DOR-mediated neuroprotection is its early action against derangement of K(+) homeostasis during anoxia or ischemia.

  16. Small Lesion Size Is Associated with Sleep-Related Epilepsy in Focal Cortical Dysplasia Type II

    Directory of Open Access Journals (Sweden)

    Bo Jin

    2018-02-01

    Full Text Available ObjectiveTo investigate the neuroimaging and clinical features associated with sleep-related epilepsy (SRE in patients with focal cortical dysplasia (FCD type II.MethodsPatients with histopathologically proven FCD type II were included from three epilepsy centers. SRE was defined according to the video EEG findings and seizure history. Cortical surface reconstruction and volume calculation were performed using FreeSurfer. The lesions were manually delineated on T1 volumetric MRI using the ITK-SNAP software. The lesion volumes were normalized by the intracranial volume of each patient. The lesions were classified as small or large by placing a threshold based on quantitative (whether the lesion was detected on MRI report and qualitative (volume criteria.ResultsA total of 77 consecutive patients were included. Of them, 36 had SRE and 41 had non-SRE. An earlier age of epilepsy onset, high seizure frequency, regional interictal EEG findings, and favorable surgical outcome were characteristic in both groups. Small lesions were defined as those having a volume <3,217 mm3. In total, 60.9% of the patients with SRE (25/41 had small FCD lesion, which was significantly higher than the non-SRE group (9/34, 26.5%, p = 0.005. Small lesion size was the only predictor significantly associated with SRE in the overall type II group by multivariate analyses (p = 0.016. Although the proportion of patients who had frontal FCD and SRE was higher than non-frontal FCD (54.5 vs. 27.3%, p = 0.043, the relationship between SRE and lesion location was not confirmed by multivariate analysis. Thalamic volume and seizure semiology were not statistically different between the SRE and non-SRE group. The significant association between lesion size and SRE was reproducible in type IIb and IIa subgroups.SignificanceSRE is common in patients with FCD type II. Small FCD type II lesions are significantly associated with SRE. Although our findings cannot be applied to

  17. Evoked potentials in large-scale cortical networks elicited by TMS of the visual cortex

    Science.gov (United States)

    Grossman, Emily D.; Srinivasan, Ramesh

    2011-01-01

    Single pulses of transcranial magnetic stimulation (TMS) result in distal and long-lasting oscillations, a finding directly challenging the virtual lesion hypothesis. Previous research supporting this finding has primarily come from stimulation of the motor cortex. We have used single-pulse TMS with simultaneous EEG to target seven brain regions, six of which belong to the visual system [left and right primary visual area V1, motion-sensitive human middle temporal cortex, and a ventral temporal region], as determined with functional MRI-guided neuronavigation, and a vertex “control” site to measure the network effects of the TMS pulse. We found the TMS-evoked potential (TMS-EP) over visual cortex consists mostly of site-dependent theta- and alphaband oscillations. These site-dependent oscillations extended beyond the stimulation site to functionally connected cortical regions and correspond to time windows where the EEG responses maximally diverge (40, 200, and 385 ms). Correlations revealed two site-independent oscillations ∼350 ms after the TMS pulse: a theta-band oscillation carried by the frontal cortex, and an alpha-band oscillation over parietal and frontal cortical regions. A manipulation of stimulation intensity at one stimulation site (right hemisphere V1-V3) revealed sensitivity to the stimulation intensity at different regions of cortex, evidence of intensity tuning in regions distal to the site of stimulation. Together these results suggest that a TMS pulse applied to the visual cortex has a complex effect on brain function, engaging multiple brain networks functionally connected to the visual system with both invariant and site-specific spatiotemporal dynamics. With this characterization of TMS, we propose an alternative to the virtual lesion hypothesis. Rather than a technique that simulates lesions, we propose TMS generates natural brain signals and engages functional networks. PMID:21715670

  18. TMS-induced cortical potentiation during wakefulness locally increases slow wave activity during sleep.

    Directory of Open Access Journals (Sweden)

    Reto Huber

    2007-03-01

    Full Text Available Sleep slow wave activity (SWA is thought to reflect sleep need, increasing in proportion to the length of prior wakefulness and decreasing during sleep. However, the process responsible for SWA regulation is not known. We showed recently that SWA increases locally after a learning task involving a circumscribed brain region, suggesting that SWA may reflect plastic changes triggered by learning.To test this hypothesis directly, we used transcranial magnetic stimulation (TMS in conjunction with high-density EEG in humans. We show that 5-Hz TMS applied to motor cortex induces a localized potentiation of TMS-evoked cortical EEG responses. We then show that, in the sleep episode following 5-Hz TMS, SWA increases markedly (+39.1+/-17.4%, p<0.01, n = 10. Electrode coregistration with magnetic resonance images localized the increase in SWA to the same premotor site as the maximum TMS-induced potentiation during wakefulness. Moreover, the magnitude of potentiation during wakefulness predicts the local increase in SWA during sleep.These results provide direct evidence for a link between plastic changes and the local regulation of sleep need.

  19. Audiovisual functional magnetic resonance imaging adaptation reveals multisensory integration effects in object-related sensory cortices.

    Science.gov (United States)

    Doehrmann, Oliver; Weigelt, Sarah; Altmann, Christian F; Kaiser, Jochen; Naumer, Marcus J

    2010-03-03

    Information integration across different sensory modalities contributes to object recognition, the generation of associations and long-term memory representations. Here, we used functional magnetic resonance imaging adaptation to investigate the presence of sensory integrative effects at cortical levels as early as nonprimary auditory and extrastriate visual cortices, which are implicated in intermediate stages of object processing. Stimulation consisted of an adapting audiovisual stimulus S(1) and a subsequent stimulus S(2) from the same basic-level category (e.g., cat). The stimuli were carefully balanced with respect to stimulus complexity and semantic congruency and presented in four experimental conditions: (1) the same image and vocalization for S(1) and S(2), (2) the same image and a different vocalization, (3) different images and the same vocalization, or (4) different images and vocalizations. This two-by-two factorial design allowed us to assess the contributions of auditory and visual stimulus repetitions and changes in a statistically orthogonal manner. Responses in visual regions of right fusiform gyrus and right lateral occipital cortex were reduced for repeated visual stimuli (repetition suppression). Surprisingly, left lateral occipital cortex showed stronger responses to repeated auditory stimuli (repetition enhancement). Similarly, auditory regions of interest of the right middle superior temporal gyrus and sulcus exhibited repetition suppression to auditory repetitions and repetition enhancement to visual repetitions. Our findings of crossmodal repetition-related effects in cortices of the respective other sensory modality add to the emerging view that in human subjects sensory integrative mechanisms operate on earlier cortical processing levels than previously assumed.

  20. Predictive value of neurological examination for early cortical responses to somatosensory evoked potentials in patients with postanoxic coma

    NARCIS (Netherlands)

    Bouwes, Aline; Binnekade, Jan M.; Verbaan, Bart W.; Zandbergen, Eveline G. J.; Koelman, Johannes H. T. M.; Weinstein, Henry C.; Hijdra, Albert; Horn, Janneke

    2012-01-01

    Bilateral absence of cortical N20 responses of median nerve somatosensory evoked potentials (SEP) predicts poor neurological outcome in postanoxic coma after cardiopulmonary resuscitation (CPR). Although SEP is easy to perform and available in most hospitals, it is worthwhile to know how

  1. Sensory information in local field potentials and spikes from visual and auditory cortices: time scales and frequency bands.

    Science.gov (United States)

    Belitski, Andrei; Panzeri, Stefano; Magri, Cesare; Logothetis, Nikos K; Kayser, Christoph

    2010-12-01

    Studies analyzing sensory cortical processing or trying to decode brain activity often rely on a combination of different electrophysiological signals, such as local field potentials (LFPs) and spiking activity. Understanding the relation between these signals and sensory stimuli and between different components of these signals is hence of great interest. We here provide an analysis of LFPs and spiking activity recorded from visual and auditory cortex during stimulation with natural stimuli. In particular, we focus on the time scales on which different components of these signals are informative about the stimulus, and on the dependencies between different components of these signals. Addressing the first question, we find that stimulus information in low frequency bands (50 Hz), in contrast, is scale dependent, and is larger when the energy is averaged over several hundreds of milliseconds. Indeed, combined analysis of signal reliability and information revealed that the energy of slow LFP fluctuations is well related to the stimulus even when considering individual or few cycles, while the energy of fast LFP oscillations carries information only when averaged over many cycles. Addressing the second question, we find that stimulus information in different LFP bands, and in different LFP bands and spiking activity, is largely independent regardless of time scale or sensory system. Taken together, these findings suggest that different LFP bands represent dynamic natural stimuli on distinct time scales and together provide a potentially rich source of information for sensory processing or decoding brain activity.

  2. Assessment of hearing threshold in adults with hearing loss using an automated system of cortical auditory evoked potential detection

    Directory of Open Access Journals (Sweden)

    Alessandra Spada Durante

    Full Text Available Abstract Introduction: The use of hearing aids by individuals with hearing loss brings a better quality of life. Access to and benefit from these devices may be compromised in patients who present difficulties or limitations in traditional behavioral audiological evaluation, such as newborns and small children, individuals with auditory neuropathy spectrum, autism, and intellectual deficits, and in adults and the elderly with dementia. These populations (or individuals are unable to undergo a behavioral assessment, and generate a growing demand for objective methods to assess hearing. Cortical auditory evoked potentials have been used for decades to estimate hearing thresholds. Current technological advances have lead to the development of equipment that allows their clinical use, with features that enable greater accuracy, sensitivity, and specificity, and the possibility of automated detection, analysis, and recording of cortical responses. Objective: To determine and correlate behavioral auditory thresholds with cortical auditory thresholds obtained from an automated response analysis technique. Methods: The study included 52 adults, divided into two groups: 21 adults with moderate to severe hearing loss (study group; and 31 adults with normal hearing (control group. An automated system of detection, analysis, and recording of cortical responses (HEARLab® was used to record the behavioral and cortical thresholds. The subjects remained awake in an acoustically treated environment. Altogether, 150 tone bursts at 500, 1000, 2000, and 4000 Hz were presented through insert earphones in descending-ascending intensity. The lowest level at which the subject detected the sound stimulus was defined as the behavioral (hearing threshold (BT. The lowest level at which a cortical response was observed was defined as the cortical electrophysiological threshold. These two responses were correlated using linear regression. Results: The cortical

  3. Assessment of hearing threshold in adults with hearing loss using an automated system of cortical auditory evoked potential detection.

    Science.gov (United States)

    Durante, Alessandra Spada; Wieselberg, Margarita Bernal; Roque, Nayara; Carvalho, Sheila; Pucci, Beatriz; Gudayol, Nicolly; de Almeida, Kátia

    The use of hearing aids by individuals with hearing loss brings a better quality of life. Access to and benefit from these devices may be compromised in patients who present difficulties or limitations in traditional behavioral audiological evaluation, such as newborns and small children, individuals with auditory neuropathy spectrum, autism, and intellectual deficits, and in adults and the elderly with dementia. These populations (or individuals) are unable to undergo a behavioral assessment, and generate a growing demand for objective methods to assess hearing. Cortical auditory evoked potentials have been used for decades to estimate hearing thresholds. Current technological advances have lead to the development of equipment that allows their clinical use, with features that enable greater accuracy, sensitivity, and specificity, and the possibility of automated detection, analysis, and recording of cortical responses. To determine and correlate behavioral auditory thresholds with cortical auditory thresholds obtained from an automated response analysis technique. The study included 52 adults, divided into two groups: 21 adults with moderate to severe hearing loss (study group); and 31 adults with normal hearing (control group). An automated system of detection, analysis, and recording of cortical responses (HEARLab ® ) was used to record the behavioral and cortical thresholds. The subjects remained awake in an acoustically treated environment. Altogether, 150 tone bursts at 500, 1000, 2000, and 4000Hz were presented through insert earphones in descending-ascending intensity. The lowest level at which the subject detected the sound stimulus was defined as the behavioral (hearing) threshold (BT). The lowest level at which a cortical response was observed was defined as the cortical electrophysiological threshold. These two responses were correlated using linear regression. The cortical electrophysiological threshold was, on average, 7.8dB higher than the

  4. Focal cortical dysplasias: surgical outcome in 67 patients in relation to histological subtypes and dual pathology.

    Science.gov (United States)

    Fauser, Susanne; Schulze-Bonhage, Andreas; Honegger, Juergen; Carmona, Hans; Huppertz, Hans-Juergen; Pantazis, Georgios; Rona, Sabine; Bast, Thomas; Strobl, Karl; Steinhoff, Bernhard J; Korinthenberg, Rudolf; Rating, Dietz; Volk, Benedikt; Zentner, Josef

    2004-11-01

    The purpose of this study was to assess whether the histological subtype of focal cortical dysplasia and dual pathology affect surgical outcome in patients with medically intractable epilepsy due to focal cortical dysplasia (FCD). We retrospectively analysed the outcome of 67 patients from 2 to 66 years of age at follow-up periods of 6 to 48 months after epilepsy surgery. Histological subtypes were classified according to Palmini and included a few cases with mild histological abnormalities corresponding to the definition of mild malformations of cortical development. The seizure outcome was classified according to Engel and evaluated at the last follow-up visit as well as at follow-up periods of 12 and 24 months after surgery. The outcome in patients with FCD and additional hippocampal pathology (dual pathology) was analysed separately. Distribution of histological subtypes differed in temporal and extratemporal localization, with a significantly higher extratemporal prevalence of FCD type 2. There was a tendency towards better postsurgical outcome related to the last follow-up visit in patients with more subtle abnormalities classified as mild malformations of cortical development (mMCD) (63% Engel Ia), FCD type 1a (67% Engel Ia) and FCD type 1b (55% Engel Ia) compared with patients with FCD type 2a (43% Engel Ia) and FCD type 2b (Taylor type) (50% Engel Ia). Considering the outcome at follow-up periods over 12 and 24 months, complete seizure-freedom was achieved significantly more often in patients with FCD type 1 and mMCD than with FCD type 2, and seizure reduction by less than 75% (Engel IV) occurred in more patients with FCD type 2a compared with the other subgroups. This tendency was seen in the whole patient group and in the extratemporal subgroup. Patients with dual pathology almost always had temporal lobe epilepsy; the outcome in this patient group was generally favourable (66% complete seizure-freedom at the last follow-up visit). The outcome remained

  5. Pattern evoked cortical potential topography and positron emission computed tomography in cases with homonymous quadrantanopsia

    International Nuclear Information System (INIS)

    Kakisu, Yonetsugu; Adachi-Usami, Emiko; Kuroda, Noriko; Kawamura, Mitsuru; Yamazaki, Toshiro.

    1985-01-01

    Pattern evoked cortical potentials (PVECPs) and positron emission computed tomography (PET) were studied in two cases with lower homonymous quadrantanopsia caused by occlusion or hemorrhages of the artery of the optic radiation. Using 15 O 2 and C 15 O 2 as a tracer, PET was performed at rest under opened eye stimulation on 6 cm and 8 cm transverse section above the orbito-meatal line. On OM-6 level where the visual cortex of right and left hemisphere received the upper visual field information, symmetrical images of 15 O 2 and C 15 O 2 uptake were found. However, they were lateralized at the non-affected hemisphere in the images of OM-8 level, which corresponded to the anatomical lesion. The PVECP topogram recorded to the stimulation of the right and left lower quadrant visual field was studied by a 16 channel recording system. The positive maxima at the peak latency of P100 were found only at the non-affected hemisphere. It was, thus, proved that PVECP topogram and PET findings could demonstrate the functional abnormalities of the visual cortex in accordance with visual field defect measured by subjective perimetry. (author)

  6. Contributions of polygenic risk for obesity to PTSD-related metabolic syndrome and cortical thickness.

    Science.gov (United States)

    Wolf, Erika J; Miller, Danielle R; Logue, Mark W; Sumner, Jennifer; Stoop, Tawni B; Leritz, Elizabeth C; Hayes, Jasmeet P; Stone, Annjanette; Schichman, Steven A; McGlinchey, Regina E; Milberg, William P; Miller, Mark W

    2017-10-01

    Research suggests that posttraumatic stress disorder (PTSD) is associated with metabolic syndrome (MetS) and that PTSD-associated MetS is related to decreased cortical thickness. However, the role of genetic factors in these associations is unclear. This study evaluated contributions of polygenic obesity risk and PTSD to MetS and of MetS and polygenic obesity risk to cortical thickness. 196 white, non-Hispanic veterans of the wars in Iraq and Afghanistan underwent clinical diagnostic interviews, physiological assessments, and genome-wide genotyping; 168 also completed magnetic resonance imaging scans. Polygenic risk scores (PRSs) for obesity were calculated from results of a prior genome-wide association study (Speliotes et al., 2010) and PTSD and MetS severity factor scores were obtained. Obesity PRS (β=0.15, p=0.009) and PTSD (β=0.17, p=0.005) predicted MetS and interacted such that the association between PTSD and MetS was stronger in individuals with greater polygenic obesity risk (β=0.13, p=0.02). Whole-brain vertex-wise analyses suggested that obesity PRS interacted with MetS to predict decreased cortical thickness in left rostral middle frontal gyrus (β=-0.40, pobesity genetic risk increases stress-related metabolic pathology, and compounds the ill health effects of MetS on the brain. Genetic proclivity towards MetS should be considered in PTSD patients when prescribing psychotropic medications with adverse metabolic profiles. Results are consistent with a growing literature suggestive of PTSD-related accelerated aging. Published by Elsevier Inc.

  7. Human cortical activity related to unilateral movements. A high resolution EEG study.

    Science.gov (United States)

    Urbano, A; Babiloni, C; Onorati, P; Babiloni, F

    1996-12-20

    In the present study a modern high resolution electroencephalography (EEG) technique was used to investigate the dynamic functional topography of human cortical activity related to simple unilateral internally triggered finger movements. The sensorimotor area (M1-S1) contralateral to the movement as well as the supplementary motor area (SMA) and to a lesser extent the ipsilateral M1-S1 were active during the preparation and execution of these movements. These findings suggest that both hemispheres may cooperate in both planning and production of simple unilateral volitional acts.

  8. Cortical activity in the left and right hemispheres during language-related brain functions

    DEFF Research Database (Denmark)

    Lassen, N A; Larsen, B

    1980-01-01

    of cortical activity seen during various language functions, emphasizing the practically symmetrical involvement in both hemispheres. A case of auditive agnosia (with complete cortical word deafness but preserved pure tone thresholds) is presented. The patient's normal speech constitutes evidence...

  9. Cortical deficits of emotional face processing in adults with ADHD: its relation to social cognition and executive function.

    Science.gov (United States)

    Ibáñez, Agustin; Petroni, Agustin; Urquina, Hugo; Torrente, Fernando; Torralva, Teresa; Hurtado, Esteban; Guex, Raphael; Blenkmann, Alejandro; Beltrachini, Leandro; Muravchik, Carlos; Baez, Sandra; Cetkovich, Marcelo; Sigman, Mariano; Lischinsky, Alicia; Manes, Facundo

    2011-01-01

    Although it has been shown that adults with attention-deficit hyperactivity disorder (ADHD) have impaired social cognition, no previous study has reported the brain correlates of face valence processing. This study looked for behavioral, neuropsychological, and electrophysiological markers of emotion processing for faces (N170) in adult ADHD compared to controls matched by age, gender, educational level, and handedness. We designed an event-related potential (ERP) study based on a dual valence task (DVT), in which faces and words were presented to test the effects of stimulus type (faces, words, or face-word stimuli) and valence (positive versus negative). Individual signatures of cognitive functioning in participants with ADHD and controls were assessed with a comprehensive neuropsychological evaluation, including executive functioning (EF) and theory of mind (ToM). Compared to controls, the adult ADHD group showed deficits in N170 emotion modulation for facial stimuli. These N170 impairments were observed in the absence of any deficit in facial structural processing, suggesting a specific ADHD impairment in early facial emotion modulation. The cortical current density mapping of N170 yielded a main neural source of N170 at posterior section of fusiform gyrus (maximum at left hemisphere for words and right hemisphere for faces and simultaneous stimuli). Neural generators of N170 (fusiform gyrus) were reduced in ADHD. In those patients, N170 emotion processing was associated with performance on an emotional inference ToM task, and N170 from simultaneous stimuli was associated with EF, especially working memory. This is the first report to reveal an adult ADHD-specific impairment in the cortical modulation of emotion for faces and an association between N170 cortical measures and ToM and EF.

  10. Chromatic spatial contrast sensitivity estimated by visual evoked cortical potential and psychophysics

    Science.gov (United States)

    Barboni, M.T.S.; Gomes, B.D.; Souza, G.S.; Rodrigues, A.R.; Ventura, D.F.; Silveira, L.C.L.

    2013-01-01

    The purpose of the present study was to measure contrast sensitivity to equiluminant gratings using steady-state visual evoked cortical potential (ssVECP) and psychophysics. Six healthy volunteers were evaluated with ssVECPs and psychophysics. The visual stimuli were red-green or blue-yellow horizontal sinusoidal gratings, 5° × 5°, 34.3 cd/m2 mean luminance, presented at 6 Hz. Eight spatial frequencies from 0.2 to 8 cpd were used, each presented at 8 contrast levels. Contrast threshold was obtained by extrapolating second harmonic amplitude values to zero. Psychophysical contrast thresholds were measured using stimuli at 6 Hz and static presentation. Contrast sensitivity was calculated as the inverse function of the pooled cone contrast threshold. ssVECP and both psychophysical contrast sensitivity functions (CSFs) were low-pass functions for red-green gratings. For electrophysiology, the highest contrast sensitivity values were found at 0.4 cpd (1.95 ± 0.15). ssVECP CSF was similar to dynamic psychophysical CSF, while static CSF had higher values ranging from 0.4 to 6 cpd (P chromatic functions showed no specific tuning shape; however, at high spatial frequencies the evoked potentials showed higher contrast sensitivity than the psychophysical methods (P chromatic red-green CSFs in agreement with psychophysical thresholds, mainly if the same temporal properties are applied to the stimulus. For blue-yellow CSF, correlation between electrophysiology and psychophysics was poor at high spatial frequency, possibly due to a greater effect of chromatic aberration on this kind of stimulus. PMID:23369980

  11. Acetylcholinesterase potentiates [3H]fluorowillardiine and [3H]AMPA binding to rat cortical membranes

    International Nuclear Information System (INIS)

    Olivera, S.; Rodriguez-Ithurralde, D.; Henley, J.M.

    1999-01-01

    In addition to its action at cholinergic synapses acetylcholinesterase (AChE) has been proposed to modulate neuronal activity by mechanisms unrelated to the hydrolysis of acetylcholine. We have investigated the effects of AChE on the binding of the specific AMPA receptor agonists (S)-[ 3 H]5-fluorowillardiine ([ 3 H]FW) and [ 3 H]AMPA to rat cortical membranes. Pretreatment of membranes with AChE causes a dose-dependent increase in the binding of both radiolabelled agonists with a maximal increase to ∼60% above control. This increase is completely blocked by the specific AChE inhibitors propidium, physostigmine, DFP and BW 284C51. AChE pretreatment had no effect on [ 3 H]kainate binding. [ 3 H]FW binding to membranes from young (15-day-old) rats is four orders of magnitude more sensitive to AChE modulation than membranes from adult rats (EC 50 values of 4x10 -5 and 0.1 unit/ml, respectively) although the total percentage increase in binding is similar. Furthermore, the AChE-induced potentiation of [ 3 H]FW binding is Ca 2+ - and temperature-dependent suggesting an enzymatic action for AChE in this system. Saturation binding experiments with [ 3 H]FW to adult membranes reveal high and low affinity binding sites and demonstrate that the main action of AChE is to increase the B max of both sites. These findings suggest that modulation of AMPA receptors could provide a molecular mechanism of action for the previously reported effects of AChE in synapse formation, synaptic plasticity and neurodegeneration. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  12. Relation between hippocampal damage and cerebral cortical function in Alzheimer's disease

    International Nuclear Information System (INIS)

    Hanyu, Haruo; Asano, Tetsuichi; Kogure, Daiji; Sakurai, Hirofumi; Iwamoto, Toshihiko; Takasaki, Masaru

    2000-01-01

    We investigated the relation between hippocampal damage and cerebral cortical dysfunction in Alzheimer's disease (AD) using MRI and SPECT. Nineteen patients with AD and 10 control subjects were studied. Hippocampal damage (including hippocampal formation, entorhinal cortex, and parahippocampal white matter) was assessed to evaluate the severity of atrophy and the magnetization transfer ratio (MTR) and cerebral cortical dysfunction was evaluated by quantitative cerebral blood flow (CBF) measurements using SPECT with 99mTc-ECD. Compared with controls, patients with AD had significantly more atrophy of the medial temporal lobe and a decrease in MTRs of the hippocampus and parahippocampus. There were significant correlations between the severity of hippocampal damage and regional CBF in temporoparietal lobes. Mini-Mental State Examination scores significantly correlated with the severity of hippocampal damage and regional CBFs in temporoparietal lobes. These results suggest that the functional effect of hippocampal damage occurs in temporoparietal lobes in AD, probably due to neuronal disconnections between hippocampal areas (including the entorhinal cortex) and temporoparietal lobes. (author)

  13. Slow cortical potential and theta/beta neurofeedback training in adults: effects on attentional processes, and motor system excitability

    OpenAIRE

    Petra eStuder; Oliver eKratz; Holger eGevensleben; Aribert eRothenberger; Gunther H Moll; Martin eHautzinger; Hartmut eHeinrich; Hartmut eHeinrich

    2014-01-01

    Neurofeedback (NF) is being successfully applied, among others, in children with ADHD and as a peak performance training in healthy subjects. However, the neuronal mechanisms mediating a successful NF training have not yet been sufficiently uncovered for both theta/beta (T/B), and slow cortical potential (SCP) training, two protocols established in NF in ADHD. In the present randomized controlled investigation in adults without a clinical diagnosis (n = 59), the specificity of the effects of ...

  14. Slow cortical potential and theta/beta neurofeedback training in adults: effects on attentional processes and motor system excitability

    OpenAIRE

    Studer, Petra; Kratz, Oliver; Gevensleben, Holger; Rothenberger, Aribert; Moll, Gunther H.; Hautzinger, Martin; Heinrich, Hartmut

    2014-01-01

    Neurofeedback (NF) is being successfully applied, among others, in children with attention deficit/hyperactivity disorder (ADHD) and as a peak performance training in healthy subjects. However, the neuronal mechanisms mediating a successful NF training have not yet been sufficiently uncovered for both theta/beta (T/B), and slow cortical potential (SCP) training, two protocols established in NF in ADHD. In the present, randomized, controlled investigation in adults without a clinical diagnosis...

  15. Age-related changes in cortical and trabecular bone mineral status: A quantitative CT study in lumbar vertebrae

    International Nuclear Information System (INIS)

    Tanno, M.; Horiuchi, T.; Nakajima, I.; Maeda, S.; Igarashi, M.; Yamada, H.

    2000-01-01

    To investigate the age and sex dependence of the bone mineral status of human lumbar vertebrae with special regard to differences between cortical and trabecular bone. The study group comprised 125 normal Japanese healthy volunteers (54 males and 71 females), and was subdivided into adult male and female groups (subjects younger than 40 years), intermediate male and female groups (ages ranging between 41 and 64 years) and old male and female groups (subjects older than 65 years). The cortical bone mineral status was estimated using a single-energy quantitative CT (SE-QCT) technique, whereas trabecular bone mineral density (BMD) was estimated using a dual-energy (DE-QCT) technique. A considerable gender difference in the age-related cortical bone status was found. There was a significant reduction of the mean values of the cortical volume and BMD in the old female group compared with those obtained in the old male group. The results suggest that in men, cortical and trabecular bone volume decrease very little with age. In women, cortical volume and BMD and trabecular BMD decrease with age while trabecular bone volume does not. The study showed that all variables had higher values in men than in women and that the difference increased with age

  16. Developmental patterns of postictal refractoriness and potentiation akin to cortical stimulation

    Czech Academy of Sciences Publication Activity Database

    Mareš, Pavel; Kubová, Hana

    2015-01-01

    Roč. 56, č. 1 (2015), e10-e14 ISSN 0013-9580 R&D Projects: GA MŠk(CZ) LH11015; GA ČR(CZ) GAP302/10/0971 Institutional support: RVO:67985823 Keywords : cortical epileptic afterdischarges * ontogeny * postictal period Subject RIV: FH - Neurology Impact factor: 4.706, year: 2015

  17. GABA-B antagonist potentiates cortical epileptic afterdischarges in immature rats

    Czech Academy of Sciences Publication Activity Database

    Mareš, Pavel

    2005-01-01

    Roč. 46, č. S6 (2005), s. 358-358 ISSN 0013-9580. [International Epilepsy Congress /26./. 28.08.2005-01.09.2005, Paris] Institutional research plan: CEZ:AV0Z50110509 Keywords : GAGA-B antagonist * cortical afterdischarges * immature rat Subject RIV: ED - Physiology

  18. Consequences of Laughter Upon Trunk Compression and Cortical Activation: Linear and Polynomial Relations

    Science.gov (United States)

    Svebak, Sven

    2016-01-01

    Results from two studies of biological consequences of laughter are reported. A proposed inhibitory brain mechanism was tested in Study 1. It aims to protect against trunk compression that can cause health hazards during vigorous laughter. Compression may be maximal during moderate durations and, for protective reasons, moderate in enduring vigorous laughs. Twenty-five university students volunteered to see a candid camera film. Laughter responses (LR) and the superimposed ha-responses were operationally assessed by mercury-filled strain gauges strapped around the trunk. On average, the thorax compression amplitudes exceeded those of the abdomen, and greater amplitudes were seen in the males than in the females after correction for resting trunk circumference. Regression analyses supported polynomial relations because medium LR durations were associated with particularly high thorax amplitudes. In Study 2, power changes were computed in the beta and alpha EEG frequency bands of the parietal cortex from before to after exposure to the comedy “Dinner for one” in 56 university students. Highly significant linear relations were calculated between the number of laughs and post-exposure cortical activation (increase of beta, decrease of alpha) due to high activation after frequent laughter. The results from Study 1 supported the hypothesis of a protective brain mechanism that is activated during long LRs to reduce the risk of harm to vital organs in the trunk cavity. The results in Study 2 supported a linear cortical activation and, thus, provided evidence for a biological correlate to the subjective experience of mental refreshment after laughter. PMID:27547260

  19. Sleep-related hippocampo-cortical interplay during emotional memory recollection.

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    Virginie Sterpenich

    2007-10-01

    Full Text Available Emotional events are usually better remembered than neutral ones. This effect is mediated in part by a modulation of the hippocampus by the amygdala. Sleep plays a role in the consolidation of declarative memory. We examined the impact of sleep and lack of sleep on the consolidation of emotional (negative and positive memories at the macroscopic systems level. Using functional MRI (fMRI, we compared the neural correlates of successful recollection by humans of emotional and neutral stimuli, 72 h after encoding, with or without total sleep deprivation during the first post-encoding night. In contrast to recollection of neutral and positive stimuli, which was deteriorated by sleep deprivation, similar recollection levels were achieved for negative stimuli in both groups. Successful recollection of emotional stimuli elicited larger responses in the hippocampus and various cortical areas, including the medial prefrontal cortex, in the sleep group than in the sleep deprived group. This effect was consistent across subjects for negative items but depended linearly on individual memory performance for positive items. In addition, the hippocampus and medial prefrontal cortex were functionally more connected during recollection of either negative or positive than neutral items, and more so in sleeping than in sleep-deprived subjects. In the sleep-deprived group, recollection of negative items elicited larger responses in the amygdala and an occipital area than in the sleep group. In contrast, no such difference in brain responses between groups was associated with recollection of positive stimuli. The results suggest that the emotional significance of memories influences their sleep-dependent systems-level consolidation. The recruitment of hippocampo-neocortical networks during recollection is enhanced after sleep and is hindered by sleep deprivation. After sleep deprivation, recollection of negative, potentially dangerous, memories recruits an alternate

  20. Slow cortical potential and theta/beta neurofeedback training in adults: effects on attentional processes, and motor system excitability

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    Petra eStuder

    2014-07-01

    Full Text Available Neurofeedback (NF is being successfully applied, among others, in children with ADHD and as a peak performance training in healthy subjects. However, the neuronal mechanisms mediating a successful NF training have not yet been sufficiently uncovered for both theta/beta (T/B, and slow cortical potential (SCP training, two protocols established in NF in ADHD. In the present randomized controlled investigation in adults without a clinical diagnosis (n = 59, the specificity of the effects of these two NF protocols on attentional processes, and motor system excitability were to be examined, focusing on the underlying neuronal mechanisms. NF training consisted of 10 double sessions, and self-regulation skills were analyzed. Pre- and post-training assessments encompassed performance and event-related potential measures during an attention task, and motor system excitability assessed by transcranial magnetic stimulation. Some NF protocol specific effects have been obtained. However, due to the limited sample size medium effects didn’t reach the level of significance. Self-regulation abilities during negativity trials of the SCP training were associated with increased contingent negative variation amplitudes, indicating improved resource allocation during cognitive preparation. Theta/beta training was associated with increased response speed and decreased target-P3 amplitudes after successful theta/beta regulation suggested reduced attentional resources necessary for stimulus evaluation. Motor system excitability effects after theta/beta training paralleled the effects of methylphenidate. Overall, our results are limited by the non-sufficiently acquired self-regulation skills, but some specific effects between good and poor learners could be described. Future studies with larger sample sizes and sufficient acquisition of self-regulation skills are needed to further evaluate the protocol specific effects on attention and motor system excitability

  1. Recent advancements in diffusion MRI for investigating cortical development after preterm birth—potential and pitfalls

    OpenAIRE

    Dudink, J.; Pieterman, K.; Leemans, A.; Kleinnijenhuis, M.; van Cappellen van Walsum, A. M.; Hoebeek, F. E.

    2015-01-01

    Preterm infants are born during a critical period of brain maturation, in which even subtle events can result in substantial behavioral, motor and cognitive deficits, as well as psychiatric diseases. Recent evidence shows that the main source for these devastating disabilities is not necessarily white matter (WM) damage but could also be disruptions of cortical microstructure. Animal studies showed how moderate hypoxic-ischemic conditions did not result in significant neuronal loss in the dev...

  2. Multidrug Resistance-Related Protein 1 (MRP1) Function and Localization Depend on Cortical Actin

    NARCIS (Netherlands)

    Hummel, Ina; Klappe, Karin; Ercan, Cigdem; Kok, Jan Willem

    MRP1 (ABCC1) is known to be localized in lipid rafts. Here we show in two different cell lines that localization of Mrp1/MRP1 (Abcc1/ABCC1) in lipid rafts and its function as an efflux pump are dependent on cortical actin. Latrunculin B disrupts both cortical actin and actin stress fibers. This

  3. Growth and Age-Related Abnormalities in Cortical Structure and Fracture Risk

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    Ego Seeman

    2015-12-01

    Full Text Available Vertebral fractures and trabecular bone loss have dominated thinking and research into the pathogenesis and the structural basis of bone fragility during the last 70 years. However, 80% of all fractures are non-vertebral and occur at regions assembled using large amounts of cortical bone; only 20% of fractures are vertebral. Moreover, ~80% of the skeleton is cortical and ~70% of all bone loss is cortical even though trabecular bone is lost more rapidly than cortical bone. Bone is lost because remodelling becomes unbalanced after midlife. Most cortical bone loss occurs by intracortical, not endocortical remodelling. Each remodelling event removes more bone than deposited enlarging existing canals which eventually coalesce eroding and thinning the cortex from 'within.' Thus, there is a need to study the decay of cortical as well as trabecular bone, and to develop drugs that restore the strength of both types of bone. It is now possible to accurately quantify cortical porosity and trabecular decay in vivo. The challenges still to be met are to determine whether measurement of porosity identifies persons at risk for fracture, whether this approach is compliments information obtained using bone densitometry, and whether changes in cortical porosity and other microstructural traits have the sensitivity to serve as surrogates of treatment success or failure.

  4. Therapeutic potential of the novel hybrid molecule JM-20 against focal cortical ischemia in rats

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    Yanier Núñez Figueredo

    2016-08-01

    Full Text Available Context: Despite the great mortality and morbidity of stroke, treatment options remain limited. We previously showed that JM-20, a novel synthetic molecule, possessed a strong neuroprotective effect in rats subjected to transient middle cerebral artery occlusion. However, to verify the robustness of the pre-clinical neuroprotective effects of JM-20 to get good prognosis in the translation to the clinic, it is necessary to use other experimental models of brain ischemia. Aims: To evaluate the neuroprotective effects of JM-20 following the onset of permanent focal cerebral ischemia induced in rats by thermocoagulation of blood into pial blood vessels of cerebral cortices. Methods: Ischemic lesion was induced by thermocoagulation of blood into pial blood vessels of primary motor and somatosensory cortices. Behavioral performance was evaluated by the cylinder testing for a period of 2, 3 and 7 days after surgery, and was followed by histopathological study in brain cortex stained with hematoxylin- eosin. Results: Ischemic injury resulted in impaired function of the forelimb evidenced by high asymmetry punctuation, and caused histopathological alterations indicative of tissue damage at cerebral cortex. JM-20 treatment (4 and 8 mg/kg significantly decreased asymmetry scores and histological alterations with a marked preservation of cortical neurons. Conclusions: The effects of permanent brain ischemia were strongly attenuated by JM-20 administration, which expands and improves the current preclinical data of JM-20 as neuroprotector against cerebral ischemia, and strongly support the examination of its translation to the clinic to treat acute ischemic stroke.

  5. Characterization of Peripheral Activity States and Cortical Local Field Potentials of Mice in an Elevated Plus Maze Test.

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    Okonogi, Toya; Nakayama, Ryota; Sasaki, Takuya; Ikegaya, Yuji

    2018-01-01

    Elevated plus maze (EPM) tests have been used to assess animal anxiety levels. Little information is known regarding how physiological activity patterns of the brain-body system are altered during EPM tests. Herein, we monitored cortical local field potentials (LFPs), electrocardiograms (ECGs), electromyograms (EMGs), and respiratory signals in individual mice that were repeatedly exposed to EPM tests. On average, mouse heart rates were higher in open arms. In closed arms, the mice occasionally showed decreased heart and respiratory rates lasting for several seconds or minutes, characterized as low-peripheral activity states of peripheral signals. The low-activity states were observed only when the animals were in closed arms, and the frequencies of the states increased as the testing days proceeded. During the low-activity states, the delta and theta powers of cortical LFPs were significantly increased and decreased, respectively. These results demonstrate that cortical oscillations crucially depend on whether an animal exhibits low-activity states in peripheral organs rather than the EPM arm in which the animal is located. These results suggest that combining behavioral tests with physiological makers enables a more accurate evaluation of rodent mental states.

  6. Characterization of Peripheral Activity States and Cortical Local Field Potentials of Mice in an Elevated Plus Maze Test

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    Toya Okonogi

    2018-04-01

    Full Text Available Elevated plus maze (EPM tests have been used to assess animal anxiety levels. Little information is known regarding how physiological activity patterns of the brain-body system are altered during EPM tests. Herein, we monitored cortical local field potentials (LFPs, electrocardiograms (ECGs, electromyograms (EMGs, and respiratory signals in individual mice that were repeatedly exposed to EPM tests. On average, mouse heart rates were higher in open arms. In closed arms, the mice occasionally showed decreased heart and respiratory rates lasting for several seconds or minutes, characterized as low-peripheral activity states of peripheral signals. The low-activity states were observed only when the animals were in closed arms, and the frequencies of the states increased as the testing days proceeded. During the low-activity states, the delta and theta powers of cortical LFPs were significantly increased and decreased, respectively. These results demonstrate that cortical oscillations crucially depend on whether an animal exhibits low-activity states in peripheral organs rather than the EPM arm in which the animal is located. These results suggest that combining behavioral tests with physiological makers enables a more accurate evaluation of rodent mental states.

  7. Women Build Long Bones With Less Cortical Mass Relative to Body Size and Bone Size Compared With Men.

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    Jepsen, Karl J; Bigelow, Erin M R; Schlecht, Stephen H

    2015-08-01

    The twofold greater lifetime risk of fracturing a bone for white women compared with white men and black women has been attributed in part to differences in how the skeletal system accumulates bone mass during growth. On average, women build more slender long bones with less cortical area compared with men. Although slender bones are known to have a naturally lower cortical area compared with wider bones, it remains unclear whether the relatively lower cortical area of women is consistent with their increased slenderness or is reduced beyond that expected for the sex-specific differences in bone size and body size. Whether this sexual dimorphism is consistent with ethnic background and is recapitulated in the widely used mouse model also remains unclear. We asked (1) do black women build bones with reduced cortical area compared with black men; (2) do white women build bones with reduced cortical area compared with white men; and (3) do female mice build bones with reduced cortical area compared with male mice? Bone strength and cross-sectional morphology of adult human and mouse bone were calculated from quantitative CT images of the femoral midshaft. The data were tested for normality and regression analyses were used to test for differences in cortical area between men and women after adjusting for body size and bone size by general linear model (GLM). Linear regression analysis showed that the femurs of black women had 11% lower cortical area compared with those of black men after adjusting for body size and bone size (women: mean=357.7 mm2; 95% confidence interval [CI], 347.9-367.5 mm2; men: mean=400.1 mm2; 95% CI, 391.5-408.7 mm2; effect size=1.2; pbone size (women: mean=350.1 mm2; 95% CI, 340.4-359.8 mm2; men: mean=394.3 mm2; 95% CI, 386.5-402.1 mm2; effect size=1.3; pbone size (female: mean=0.73 mm2; 95% CI, 0.71-0.74 mm2; male: mean=0.70 mm2; 95% CI, 0.68-0.71 mm2; effect size=0.74; p=0.04, GLM). Female femurs are not simply a more slender version of male

  8. Explaining the high voice superiority effect in polyphonic music: evidence from cortical evoked potentials and peripheral auditory models.

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    Trainor, Laurel J; Marie, Céline; Bruce, Ian C; Bidelman, Gavin M

    2014-02-01

    Natural auditory environments contain multiple simultaneously-sounding objects and the auditory system must parse the incoming complex sound wave they collectively create into parts that represent each of these individual objects. Music often similarly requires processing of more than one voice or stream at the same time, and behavioral studies demonstrate that human listeners show a systematic perceptual bias in processing the highest voice in multi-voiced music. Here, we review studies utilizing event-related brain potentials (ERPs), which support the notions that (1) separate memory traces are formed for two simultaneous voices (even without conscious awareness) in auditory cortex and (2) adults show more robust encoding (i.e., larger ERP responses) to deviant pitches in the higher than in the lower voice, indicating better encoding of the former. Furthermore, infants also show this high-voice superiority effect, suggesting that the perceptual dominance observed across studies might result from neurophysiological characteristics of the peripheral auditory system. Although musically untrained adults show smaller responses in general than musically trained adults, both groups similarly show a more robust cortical representation of the higher than of the lower voice. Finally, years of experience playing a bass-range instrument reduces but does not reverse the high voice superiority effect, indicating that although it can be modified, it is not highly neuroplastic. Results of new modeling experiments examined the possibility that characteristics of middle-ear filtering and cochlear dynamics (e.g., suppression) reflected in auditory nerve firing patterns might account for the higher-voice superiority effect. Simulations show that both place and temporal AN coding schemes well-predict a high-voice superiority across a wide range of interval spacings and registers. Collectively, we infer an innate, peripheral origin for the higher-voice superiority observed in human

  9. Age-related decline in functional connectivity of the vestibular cortical network.

    Science.gov (United States)

    Cyran, Carolin Anna Maria; Boegle, Rainer; Stephan, Thomas; Dieterich, Marianne; Glasauer, Stefan

    2016-04-01

    In the elderly, major complaints include dizziness and an increasing number of falls, possibly related to an altered processing of vestibular sensory input. In this study, we therefore investigate age-related changes induced by processing of vestibular sensory stimulation. While previous functional imaging studies of healthy aging have investigated brain function during task performance or at rest, we used galvanic vestibular stimulation during functional MRI in a task-free sensory stimulation paradigm to study the effect of healthy aging on central vestibular processing, which might only become apparent during stimulation processing. Since aging may affect signatures of brain function beyond the BOLD-signal amplitude-such as functional connectivity or temporal signal variability--we employed independent component analysis and partial least squares analysis of temporal signal variability. We tested for age-associated changes unrelated to vestibular processing, using a motor paradigm, voxel-based morphometry and diffusion tensor imaging. This allows us to control for general age-related modifications, possibly originating from vascular, atrophic or structural connectivity changes. Age-correlated decreases of functional connectivity and increases of BOLD--signal variability were associated with multisensory vestibular networks. In contrast, no age-related functional connectivity changes were detected in somatosensory networks or during the motor paradigm. The functional connectivity decrease was not due to structural changes but to a decrease in response amplitude. In synopsis, our data suggest that both the age-dependent functional connectivity decrease and the variability increase may be due to deteriorating reciprocal cortico-cortical inhibition with age and related to multimodal vestibular integration of sensory inputs.

  10. Slow cortical potentials and "inner time consciousness" - A neuro-phenomenal hypothesis about the "width of present".

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    Northoff, Georg

    2016-05-01

    William James postulated a "stream of consciousness" that presupposes temporal continuity. The neuronal mechanisms underlying the construction of such temporal continuity remain unclear, however, in my contribution, I propose a neuro-phenomenal hypothesis that is based on slow cortical potentials and their extension of the present moment as described in the phenomenal term of "width of present". More specifically, I focus on the way the brain's neural activity needs to be encoded in order to make possible the "stream of consciousness." This leads us again to the low-frequency fluctuations of the brain's neural activity and more specifically to slow cortical potentials (SCPs). Due to their long phase duration as low-frequency fluctuations, SCPs can integrate different stimuli and their associated neural activity from different regions in one converging region. Such integration may be central for consciousness to occur, as it was recently postulated by He and Raichle. They leave open, however, the question of the exact neuronal mechanisms, like the encoding strategy, that make possible the association of the otherwise purely neuronal SCP with consciousness and its phenomenal features. I hypothesize that SCPs allow for linking and connecting different discrete points in physical time by encoding their statistically based temporal differences rather than the single discrete time points by themselves. This presupposes difference-based coding rather than stimulus-based coding. The encoding of such statistically based temporal differences makes it possible to "go beyond" the merely physical features of the stimuli; that is, their single discrete time points and their conduction delays (as related to their neural processing in the brain). This, in turn, makes possible the constitution of "local temporal continuity" of neural activity in one particular region. The concept of "local temporal continuity" signifies the linkage and integration of different discrete time points

  11. Event-related potentials, cognition, and behavior: a biological approach.

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    Kotchoubey, Boris

    2006-01-01

    The prevailing cognitive-psychological accounts of event-related brain potentials (ERPs) assume that ERP components manifest information processing operations leading from stimulus to response. Since this view encounters numerous difficulties already analyzed in previous studies, an alternative view is presented here that regards cortical control of behavior as a repetitive sensorimotor cycle consisting of two phases: (i) feedforward anticipation and (ii) feedback cortical performance. This view allows us to interpret in an integrative manner numerous data obtained from very different domains of ERP studies: from biophysics of ERP waves to their relationship to the processing of language, in which verbal behavior is viewed as likewise controlled by the same two basic control processes: feedforward (hypothesis building) and feedback (hypothesis checking). The proposed approach is intentionally simplified, explaining numerous effects on the basis of few assumptions and relating several levels of analysis: neurophysiology, macroelectrical processes (i.e. ERPs), cognition and behavior. It can, therefore, be regarded as a first approximation to a general theory of ERPs.

  12. The impact of musicianship on the cortical mechanisms related to separating speech from background noise.

    Science.gov (United States)

    Zendel, Benjamin Rich; Tremblay, Charles-David; Belleville, Sylvie; Peretz, Isabelle

    2015-05-01

    Musicians have enhanced auditory processing abilities. In some studies, these abilities are paralleled by an improved understanding of speech in noisy environments, partially due to more robust encoding of speech signals in noise at the level of the brainstem. Little is known about the impact of musicianship on attention-dependent cortical activity related to lexical access during a speech-in-noise task. To address this issue, we presented musicians and nonmusicians with single words mixed with three levels of background noise, across two conditions, while monitoring electrical brain activity. In the active condition, listeners repeated the words aloud, and in the passive condition, they ignored the words and watched a silent film. When background noise was most intense, musicians repeated more words correctly compared with nonmusicians. Auditory evoked responses were attenuated and delayed with the addition of background noise. In musicians, P1 amplitude was marginally enhanced during active listening and was related to task performance in the most difficult listening condition. By comparing ERPs from the active and passive conditions, we isolated an N400 related to lexical access. The amplitude of the N400 was not influenced by the level of background noise in musicians, whereas N400 amplitude increased with the level of background noise in nonmusicians. In nonmusicians, the increase in N400 amplitude was related to a reduction in task performance. In musicians only, there was a rightward shift of the sources contributing to the N400 as the level of background noise increased. This pattern of results supports the hypothesis that encoding of speech in noise is more robust in musicians and suggests that this facilitates lexical access. Moreover, the shift in sources suggests that musicians, to a greater extent than nonmusicians, may increasingly rely on acoustic cues to understand speech in noise.

  13. Spatial adaptation of the cortical visual evoked potential of the cat.

    Science.gov (United States)

    Bonds, A B

    1984-06-01

    Adaptation that is spatially specific for the adapting pattern has been seen psychophysically in humans. This is indirect evidence for independent analyzers (putatively single units) that are specific for orientation and spatial frequency in the human visual system, but it is unclear how global adaptation characteristics may be related to single unit performance. Spatially specific adaptation was sought in the cat visual evoked potential (VEP), with a view towards relating this phenomenon with what we know of cat single units. Adaptation to sine-wave gratings results in a temporary loss of cat VEP amplitude, with induction and recovery similar to that seen in human psychophysical experiments. The amplitude loss was specific for both the spatial frequency and orientation of the adapting pattern. The bandwidth of adaptation was not unlike the average selectivity of a population of cat single units.

  14. A novel approach for monitoring writing interferences during navigated transcranial magnetic stimulation mappings of writing related cortical areas.

    Science.gov (United States)

    Rogić Vidaković, Maja; Gabelica, Dragan; Vujović, Igor; Šoda, Joško; Batarelo, Nikolina; Džimbeg, Andrija; Zmajević Schönwald, Marina; Rotim, Krešimir; Đogaš, Zoran

    2015-11-30

    It has recently been shown that navigated repetitive transcranial magnetic stimulation (nTMS) is useful in preoperative neurosurgical mapping of motor and language brain areas. In TMS mapping of motor cortices the evoked responses can be quantitatively monitored by electromyographic (EMG) recordings. No such setup exists for monitoring of writing during nTMS mappings of writing related cortical areas. We present a novel approach for monitoring writing during nTMS mappings of motor writing related cortical areas. To our best knowledge, this is the first demonstration of quantitative monitoring of motor evoked responses from hand by EMG, and of pen related activity during writing with our custom made pen, together with the application of chronometric TMS design and patterned protocol of rTMS. The method was applied in four healthy subjects participating in writing during nTMS mapping of the premotor cortical area corresponding to BA 6 and close to the superior frontal sulcus. The results showed that stimulation impaired writing in all subjects. The corresponding spectra of measured signal related to writing movements was observed in the frequency band 0-20 Hz. Magnetic stimulation affected writing by suppressing normal writing frequency band. The proposed setup for monitoring of writing provides additional quantitative data for monitoring and the analysis of rTMS induced writing response modifications. The setup can be useful for investigation of neurophysiologic mechanisms of writing, for therapeutic effects of nTMS, and in preoperative mapping of language cortical areas in patients undergoing brain surgery. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Potential Protection of Coeloglossum viride var. Bracteatum Extract against Oxidative Stress in Rat Cortical Neurons

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    Zhe Guo

    2013-01-01

    Full Text Available The present study explored the neuroprotective effect of Coeloglossum viride var. bracteatum extract (CE against oxidative stress in rat cortical neurons. The results demonstrated that administration of CE inhibited hydrogen peroxide-induced neurotoxicity tested by MTT, LDH release, and TUNEL assays. We further found that CE inhibited the activation of caspase-3 (Csp3 induced by hydrogen peroxide. Moreover, CE was found to reverse the hydrogen peroxide-induced downregulation of active AKT and Bcl-2. We then showed that the neuroprotective effect of CE was blocked by adding the AKT inhibitor, Ly294002. Thus, our data strongly indicated that CE played a neuroprotective role against oxidative stress-induced neurotoxicity.

  16. A philosophical perspective on the relation between cortical midline structures and the self

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    Kristina eMusholt

    2013-09-01

    Full Text Available In recent years there has been increasing evidence that an area in the brain called the cortical midline structures (CMS is implicated in what has been termed self-related processing. This article will discuss recent evidence for the relation between CMS and self-consciousness in light of several important philosophical distinctions. First, we should distinguish between being a self (i.e., being a subject of conscious experience and being aware of being a self (i.e., being able to think about oneself as such. While the former consists in having a first-person perspective on the world, the latter requires the ability to explicitly represent one’s own perspective as such. Further, we should distinguish between being aware of oneself 'as subject' and being aware of oneself 'as object'. The focus of existing studies investigating the relation between CMS and self has been predominantly on the ability to think about oneself (and in particular thinking of oneself 'as object', while the more basic aspects involved in being a self have been neglected. However, it is important to widen the scope of the cognitive neuroscience to include the latter, not least because this might have important implications for a better understanding of disorders of the self, such as those involved in schizophrenia. In order to do so, cognitive neuroscience should work together with philosophy, including phenomenology. Second, we need to distinguish between personal and subpersonal level explanations. It will be argued that although it is important to respect this distinction, in principle, some subpersonal facts can enter into constitutive conditions of personal level phenomena. However, in order for this to be possible, one needs both careful conceptual analysis and knowledge about relevant cognitive mechanisms.

  17. Passive language mapping combining real-time oscillation analysis with cortico-cortical evoked potentials for awake craniotomy.

    Science.gov (United States)

    Tamura, Yukie; Ogawa, Hiroshi; Kapeller, Christoph; Prueckl, Robert; Takeuchi, Fumiya; Anei, Ryogo; Ritaccio, Anthony; Guger, Christoph; Kamada, Kyousuke

    2016-12-01

    OBJECTIVE Electrocortical stimulation (ECS) is the gold standard for functional brain mapping; however, precise functional mapping is still difficult in patients with language deficits. High gamma activity (HGA) between 80 and 140 Hz on electrocorticography is assumed to reflect localized cortical processing, whereas the cortico-cortical evoked potential (CCEP) can reflect bidirectional responses evoked by monophasic pulse stimuli to the language cortices when there is no patient cooperation. The authors propose the use of "passive" mapping by combining HGA mapping and CCEP recording without active tasks during conscious resections of brain tumors. METHODS Five patients, each with an intraaxial tumor in their dominant hemisphere, underwent conscious resection of their lesion with passive mapping. The authors performed functional localization for the receptive language area, using real-time HGA mapping, by listening passively to linguistic sounds. Furthermore, single electrical pulses were delivered to the identified receptive temporal language area to detect CCEPs in the frontal lobe. All mapping results were validated by ECS, and the sensitivity and specificity were evaluated. RESULTS Linguistic HGA mapping quickly identified the language area in the temporal lobe. Electrical stimulation by linguistic HGA mapping to the identified temporal receptive language area evoked CCEPs on the frontal lobe. The combination of linguistic HGA and frontal CCEPs needed no patient cooperation or effort. In this small case series, the sensitivity and specificity were 93.8% and 89%, respectively. CONCLUSIONS The described technique allows for simple and quick functional brain mapping with higher sensitivity and specificity than ECS mapping. The authors believe that this could improve the reliability of functional brain mapping and facilitate rational and objective operations. Passive mapping also sheds light on the underlying physiological mechanisms of language in the human brain.

  18. Cortical oscillations related to processing congruent and incongruent grapheme-phoneme pairs.

    Science.gov (United States)

    Herdman, Anthony T; Fujioka, Takako; Chau, Wilkin; Ross, Bernhard; Pantev, Christo; Picton, Terence W

    2006-05-15

    In this study, we investigated changes in cortical oscillations following congruent and incongruent grapheme-phoneme stimuli. Hiragana graphemes and phonemes were simultaneously presented as congruent or incongruent audiovisual stimuli to native Japanese-speaking participants. The discriminative reaction time was 57 ms shorter for congruent than incongruent stimuli. Analysis of MEG responses using synthetic aperture magnetometry (SAM) revealed that congruent stimuli evoked larger 2-10 Hz activity in the left auditory cortex within the first 250 ms after stimulus onset, and smaller 2-16 Hz activity in bilateral visual cortices between 250 and 500 ms. These results indicate that congruent visual input can modify cortical activity in the left auditory cortex.

  19. Acute stress exposure preceding transient global brain ischemia exacerbates the decrease in cortical remodeling potential in the rat retrosplenial cortex.

    Science.gov (United States)

    Kutsuna, Nobuo; Yamashita, Akiko; Eriguchi, Takashi; Oshima, Hideki; Suma, Takeshi; Sakatani, Kaoru; Yamamoto, Takamitsu; Yoshino, Atsuo; Katayama, Yoichi

    2014-01-01

    Doublecortin (DCX)-immunoreactive (-ir) cells are candidates that play key roles in adult cortical remodeling. We have previously reported that DCX-ir cells decrease after stress exposure or global brain ischemia (GBI) in the cingulate cortex (Cg) of rats. Herein, we investigate whether the decrease in DCX-ir cells is exacerbated after GBI due to acute stress exposure preconditioning. Twenty rats were divided into 3 groups: acute stress exposure before GBI (Group P), non-stress exposure before GBI (Group G), and controls (Group C). Acute stress or GBI was induced by a forced swim paradigm or by transient bilateral common carotid artery occlusion, respectively. DCX-ir cells were investigated in the anterior cingulate cortex (ACC) and retrosplenial cortex (RS). The number of DCX-ir cells per unit area (mm(2)) decreased after GBI with or without stress preconditioning in the ACC and in the RS (ANOVA followed by a Tukey-type test, P<0.001). Moreover, compared to Group G, the number in Group P decreased significantly in RS (P<0.05), though not significantly in ACC. Many of the DCX-ir cells were co-localized with the GABAergic neuronal marker parvalbumin. The present study indicates that cortical remodeling potential of GABAergic neurons of Cg decreases after GBI, and moreover, the ratio of the decrease is exacerbated by acute stress preconditioning in the RS. Copyright © 2013 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.

  20. A novel method for device-related electroencephalography artifact suppression to explore cochlear implant-related cortical changes in single-sided deafness.

    Science.gov (United States)

    Kim, Kyungsoo; Punte, Andrea Kleine; Mertens, Griet; Van de Heyning, Paul; Park, Kyung-Joon; Choi, Hongsoo; Choi, Ji-Woong; Song, Jae-Jin

    2015-11-30

    Quantitative electroencephalography (qEEG) is effective when used to analyze ongoing cortical oscillations in cochlear implant (CI) users. However, localization of cortical activity in such users via qEEG is confounded by the presence of artifacts produced by the device itself. Typically, independent component analysis (ICA) is used to remove CI artifacts in auditory evoked EEG signals collected upon brief stimulation and it is effective for auditory evoked potentials (AEPs). However, AEPs do not reflect the daily environments of patients, and thus, continuous EEG data that are closer to such environments are desirable. In this case, device-related artifacts in EEG data are difficult to remove selectively via ICA due to over-completion of EEG data removal in the absence of preprocessing. EEGs were recorded for a long time under conditions of continuous auditory stimulation. To obviate the over-completion problem, we limited the frequency of CI artifacts to a significant characteristic peak and apply ICA artifact removal. Topographic brain mapping results analyzed via band-limited (BL)-ICA exhibited a better energy distribution, matched to the CI location, than data obtained using conventional ICA. Also, source localization data verified that BL-ICA effectively removed CI artifacts. The proposed method selectively removes CI artifacts from continuous EEG recordings, while ICA removal method shows residual peak and removes important brain activity signals. CI artifacts in EEG data obtained during continuous passive listening can be effectively removed with the aid of BL-ICA, opening up new EEG research possibilities in subjects with CIs. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Bone fragility induced by X-ray irradiation in relation to cortical bone-mineral content

    International Nuclear Information System (INIS)

    Nyaruba, M.M.; Yamamoto, I.; Morita, R.; Kimura, H.

    1998-01-01

    The purpose of this study was to investigate the effects of fractional irradiation on the biomechanical properties of bone in the rat in relation to the cortical bone-mineral content (BMC), and to compare these effects with those brought about by single-dose irradiation. Seventy-five veteran female Wistar rats were divided into 4 groups. Group 1 was the control group. The left tibiae of the remaining rats were exposed to irradiation. Group 2 received one single dose of X-rays at 10-60 Gy. Groups 3 and 4 received fractional irradiation up to different cumulative doses (10-60 Gy): group 3 received 2.5 Gy once a day; group 4 received 1.25 Gy twice a day. Twenty-four weeks after irradiation, the rats were killed and the BMC in each tibial diaphysis was determined by dual-energy X-ray absorptiometry (DXA). The bones were then loaded to failure in a three-point bending test. The control group showed no difference (p>0.05) between left and right tibiae, neither in BMC nor in the maximum load at fracture. Single-dose irradiation caused a 16% (p=0.0366) decrease in the maximum load at 40 Gy, and a 19% (p=0.008) decrease at 60 Gy. The once-daily fractional dose of irradiation caused a 10% (p=0.0022) decrease in the maximum load of the irradiated tibiae at 60 Gy when compared to the intact contralateral tibiae. The twice-daily fractional dose of irradiation had no observable effect on the maximum load of the irradiated tibiae. Neither fractional irradiation modality had an effect on BMC. (orig./MG)

  2. Inactivation of basolateral amygdala specifically eliminates palatability-related information in cortical sensory responses.

    Science.gov (United States)

    Piette, Caitlin E; Baez-Santiago, Madelyn A; Reid, Emily E; Katz, Donald B; Moran, Anan

    2012-07-18

    Evidence indirectly implicates the amygdala as the primary processor of emotional information used by cortex to drive appropriate behavioral responses to stimuli. Taste provides an ideal system with which to test this hypothesis directly, as neurons in both basolateral amygdala (BLA) and gustatory cortex (GC)-anatomically interconnected nodes of the gustatory system-code the emotional valence of taste stimuli (i.e., palatability), in firing rate responses that progress similarly through "epochs." The fact that palatability-related firing appears one epoch earlier in BLA than GC is broadly consistent with the hypothesis that such information may propagate from the former to the latter. Here, we provide evidence supporting this hypothesis, assaying taste responses in small GC single-neuron ensembles before, during, and after temporarily inactivating BLA in awake rats. BLA inactivation (BLAx) changed responses in 98% of taste-responsive GC neurons, altering the entirety of every taste response in many neurons. Most changes involved reductions in firing rate, but regardless of the direction of change, the effect of BLAx was epoch-specific: while firing rates were changed, the taste specificity of responses remained stable; information about taste palatability, however, which normally resides in the "Late" epoch, was reduced in magnitude across the entire GC sample and outright eliminated in most neurons. Only in the specific minority of neurons for which BLAx enhanced responses did palatability specificity survive undiminished. Our data therefore provide direct evidence that BLA is a necessary component of GC gustatory processing, and that cortical palatability processing in particular is, in part, a function of BLA activity.

  3. Age-related weakness of proximal muscle studied with motor cortical mapping: a TMS study.

    Directory of Open Access Journals (Sweden)

    Ela B Plow

    Full Text Available Aging-related weakness is due in part to degeneration within the central nervous system. However, it is unknown how changes to the representation of corticospinal output in the primary motor cortex (M1 relate to such weakness. Transcranial magnetic stimulation (TMS is a noninvasive method of cortical stimulation that can map representation of corticospinal output devoted to a muscle. Using TMS, we examined age-related alterations in maps devoted to biceps brachii muscle to determine whether they predicted its age-induced weakness. Forty-seven right-handed subjects participated: 20 young (22.6 ± 0.90 years and 27 old (74.96 ± 1.35 years. We measured strength as force of elbow flexion and electromyographic activation of biceps brachii during maximum voluntary contraction. Mapping variables included: 1 center of gravity or weighted mean location of corticospinal output, 2 size of map, 3 volume or excitation of corticospinal output, and 4 response density or corticospinal excitation per unit area. Center of gravity was more anterior in old than in young (p<0.001, though there was no significant difference in strength between the age groups. Map size, volume, and response density showed no significant difference between groups. Regardless of age, center of gravity significantly predicted strength (β = -0.34, p = 0.005, while volume adjacent to the core of map predicted voluntary activation of biceps (β = 0.32, p = 0.008. Overall, the anterior shift of the map in older adults may reflect an adaptive change that allowed for the maintenance of strength. Laterally located center of gravity and higher excitation in the region adjacent to the core in weaker individuals could reflect compensatory recruitment of synergistic muscles. Thus, our study substantiates the role of M1 in adapting to aging-related weakness and subtending strength and muscle activation across age groups. Mapping from M1 may offer foundation for an examination of mechanisms that

  4. Parallel prefrontal pathways reach distinct excitatory and inhibitory systems in memory-related rhinal cortices.

    Science.gov (United States)

    Bunce, Jamie G; Zikopoulos, Basilis; Feinberg, Marcia; Barbas, Helen

    2013-12-15

    To investigate how prefrontal cortices impinge on medial temporal cortices we labeled pathways from the anterior cingulate cortex (ACC) and posterior orbitofrontal cortex (pOFC) in rhesus monkeys to compare their relationship with excitatory and inhibitory systems in rhinal cortices. The ACC pathway terminated mostly in areas 28 and 35 with a high proportion of large terminals, whereas the pOFC pathway terminated mostly through small terminals in area 36 and sparsely in areas 28 and 35. Both pathways terminated in all layers. Simultaneous labeling of pathways and distinct neurochemical classes of inhibitory neurons, followed by analyses of appositions of presynaptic and postsynaptic fluorescent signal, or synapses, showed overall predominant association with spines of putative excitatory neurons, but also significant interactions with presumed inhibitory neurons labeled for calretinin, calbindin, or parvalbumin. In the upper layers of areas 28 and 35 the ACC pathway was associated with dendrites of neurons labeled with calretinin, which are thought to disinhibit neighboring excitatory neurons, suggesting facilitated hippocampal access. In contrast, in area 36 pOFC axons were associated with dendrites of calbindin neurons, which are poised to reduce noise and enhance signal. In the deep layers, both pathways innervated mostly dendrites of parvalbumin neurons, which strongly inhibit neighboring excitatory neurons, suggesting gating of hippocampal output to other cortices. These findings suggest that the ACC, associated with attention and context, and the pOFC, associated with emotional valuation, have distinct contributions to memory in rhinal cortices, in processes that are disrupted in psychiatric diseases. Copyright © 2013 Wiley Periodicals, Inc.

  5. Neonatal pain-related stress, functional cortical activity and visual-perceptual abilities in school-age children born at extremely low gestational age.

    Science.gov (United States)

    Doesburg, Sam M; Chau, Cecil M; Cheung, Teresa P L; Moiseev, Alexander; Ribary, Urs; Herdman, Anthony T; Miller, Steven P; Cepeda, Ivan L; Synnes, Anne; Grunau, Ruth E

    2013-10-01

    Children born very prematurely (pain-related stress during neonatal intensive care has been proposed to contribute to altered neurocognitive development in these children. Due to critical periods in the development of thalamocortical systems, the immature brain of infants born at extremely low gestational age (ELGA; pain. In a cohort of school-age children followed since birth we assessed relations between functional brain activity measured using magnetoencephalogragy (MEG), visual-perceptual abilities and cumulative neonatal pain. We demonstrated alterations in the spectral structure of spontaneous cortical oscillatory activity in ELGA children at school-age. Cumulative neonatal pain-related stress was associated with changes in background cortical rhythmicity in these children, and these alterations in spontaneous brain oscillations were negatively correlated with visual-perceptual abilities at school-age, and were not driven by potentially confounding neonatal variables. These findings provide the first evidence linking neonatal pain-related stress, the development of functional brain activity, and school-age cognitive outcome in these vulnerable children. Copyright © 2013 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

  6. Modulation of task-related cortical connectivity in the acute and subacute phase after stroke

    DEFF Research Database (Denmark)

    Larsen, Lisbeth H.; Zibrandtsen, Ivan C.; Wienecke, Troels

    2018-01-01

    The functional relevance of cortical reorganization post-stroke is still not well understood. In this study, we investigated task-specific modulation of cortical connectivity between neural oscillations in key motor regions during the early phase after stroke. EEG and EMG recordings were examined...... from 15 patients and 18 controls during a precision grip task using the affected hand. Each patient attended two sessions in the acute and subacute phase (median of 3 and 34 days) post-stroke. Dynamic causal modelling (DCM) for induced responses was used to investigate task-specific modulations...... of oscillatory couplings in a bilateral network comprising supplementary motor area (SMA), dorsal premotor cortex (PMd) and primary motor cortex (M1). Fourteen models were constructed for each subject, and the input induced by the experimental manipulation (task) was set to inferior parietal lobule (IPL...

  7. Dominant and opponent relations in cortical function: An EEG study of exam performance and stress

    Directory of Open Access Journals (Sweden)

    Lucia P. Pavlova

    2017-12-01

    Full Text Available This paper analyzes the opponent dynamics of human motivational and affective processes, as conceptualized by RS Solomon, from the position of AA Ukhtomsky’s neurophysiological principle of the dominant and its applications in the field of human electroencephalographic analysis. As an experimental model, we investigate the dynamics of cortical activity in students submitting university final course oral examinations in naturalistic settings, and show that successful performance in these settings depends on the presence of specific types of cortical activation patterns, involving high indices of left-hemispheric and frontal cortical dominance, whereas the lack thereof predicts poor performance on the task, and seems to be associated with difficulties in the executive regulation of cognitive (intellectual and motivational processes in these highly demanding and stressful conditions. Based on such knowledge, improved educational and therapeutic interventions can be suggested which take into account individual variability in the neurocognitive mechanisms underlying adaptation to motivationally and intellectually challenging, stressful tasks, such as oral university exams. Some implications of this research for opponent-process theory and its closer integration into current neuroscience research on acquired motivations are discussed.

  8. Age-related changes in cortical bone mass: data from a German female cohort

    International Nuclear Information System (INIS)

    Toledo, V.A. Molina; Jergas, M.

    2006-01-01

    To describe data from digital radiogrammetry (DXR) in an unselected German female cohort over a wide age range. Using a retrospective study design we analyzed radiographs of the hand from 540 German women (aged 5-96 years) using an automated assessment of cortical thickness, metacarpal index (MCI), and estimated cortical bone mineral density (DXR-BMD) on digitized radiographs. Both hands were radiographed in 97 women. In this group DXR-BMD and cortical thickness were significantly higher in the right metacarpals while there was no significant difference in MCI. To study the association with age we differentiated young ( 45 years). In young women all parameters increased significantly with age in a linear fashion (r=0.8 for DXR-BMD, r=0.7 for MCI). In those aged 25-45 years DXR-BMD and MCI were highest (peak bone mass). In women aged 45 or older all parameters decreased with age in an almost linear fashion with an annual change ranging from 0.7% to 0.9%. Our results for an unselected German female cohort indicate that DXR is a reliable, widely available osteodensitometric technique based on the refinement of conventional radiogrammetry. These findings are comparable to those from other studies and represent a valid resource for clinical application and for comparisons with other ethnic groups. (orig.)

  9. Neonatal pain-related stress predicts cortical thickness at age 7 years in children born very preterm.

    Directory of Open Access Journals (Sweden)

    Manon Ranger

    Full Text Available Altered brain development is evident in children born very preterm (24-32 weeks gestational age, including reduction in gray and white matter volumes, and thinner cortex, from infancy to adolescence compared to term-born peers. However, many questions remain regarding the etiology. Infants born very preterm are exposed to repeated procedural pain-related stress during a period of very rapid brain development. In this vulnerable population, we have previously found that neonatal pain-related stress is associated with atypical brain development from birth to term-equivalent age. Our present aim was to evaluate whether neonatal pain-related stress (adjusted for clinical confounders of prematurity is associated with altered cortical thickness in very preterm children at school age.42 right-handed children born very preterm (24-32 weeks gestational age followed longitudinally from birth underwent 3-D T1 MRI neuroimaging at mean age 7.9 yrs. Children with severe brain injury and major motor/sensory/cognitive impairment were excluded. Regional cortical thickness was calculated using custom developed software utilizing FreeSurfer segmentation data. The association between neonatal pain-related stress (defined as the number of skin-breaking procedures accounting for clinical confounders (gestational age, illness severity, infection, mechanical ventilation, surgeries, and morphine exposure, was examined in relation to cortical thickness using constrained principal component analysis followed by generalized linear modeling.After correcting for multiple comparisons and adjusting for neonatal clinical factors, greater neonatal pain-related stress was associated with significantly thinner cortex in 21/66 cerebral regions (p-values ranged from 0.00001 to 0.014, predominately in the frontal and parietal lobes.In very preterm children without major sensory, motor or cognitive impairments, neonatal pain-related stress appears to be associated with thinner cortex

  10. Neonatal pain-related stress predicts cortical thickness at age 7 years in children born very preterm.

    Science.gov (United States)

    Ranger, Manon; Chau, Cecil M Y; Garg, Amanmeet; Woodward, Todd S; Beg, Mirza Faisal; Bjornson, Bruce; Poskitt, Kenneth; Fitzpatrick, Kevin; Synnes, Anne R; Miller, Steven P; Grunau, Ruth E

    2013-01-01

    Altered brain development is evident in children born very preterm (24-32 weeks gestational age), including reduction in gray and white matter volumes, and thinner cortex, from infancy to adolescence compared to term-born peers. However, many questions remain regarding the etiology. Infants born very preterm are exposed to repeated procedural pain-related stress during a period of very rapid brain development. In this vulnerable population, we have previously found that neonatal pain-related stress is associated with atypical brain development from birth to term-equivalent age. Our present aim was to evaluate whether neonatal pain-related stress (adjusted for clinical confounders of prematurity) is associated with altered cortical thickness in very preterm children at school age. 42 right-handed children born very preterm (24-32 weeks gestational age) followed longitudinally from birth underwent 3-D T1 MRI neuroimaging at mean age 7.9 yrs. Children with severe brain injury and major motor/sensory/cognitive impairment were excluded. Regional cortical thickness was calculated using custom developed software utilizing FreeSurfer segmentation data. The association between neonatal pain-related stress (defined as the number of skin-breaking procedures) accounting for clinical confounders (gestational age, illness severity, infection, mechanical ventilation, surgeries, and morphine exposure), was examined in relation to cortical thickness using constrained principal component analysis followed by generalized linear modeling. After correcting for multiple comparisons and adjusting for neonatal clinical factors, greater neonatal pain-related stress was associated with significantly thinner cortex in 21/66 cerebral regions (p-values ranged from 0.00001 to 0.014), predominately in the frontal and parietal lobes. In very preterm children without major sensory, motor or cognitive impairments, neonatal pain-related stress appears to be associated with thinner cortex in multiple

  11. Sensitivity of cortical auditory evoked potential detection for hearing-impaired infants in response to short speech sounds

    Directory of Open Access Journals (Sweden)

    Bram Van Dun

    2012-01-01

    Full Text Available

    Background: Cortical auditory evoked potentials (CAEPs are an emerging tool for hearing aid fitting evaluation in young children who cannot provide reliable behavioral feedback. It is therefore useful to determine the relationship between the sensation level of speech sounds and the detection sensitivity of CAEPs.

    Design and methods: Twenty-five sensorineurally hearing impaired infants with an age range of 8 to 30 months were tested once, 18 aided and 7 unaided. First, behavioral thresholds of speech stimuli /m/, /g/, and /t/ were determined using visual reinforcement orientation audiometry (VROA. Afterwards, the same speech stimuli were presented at 55, 65, and 75 dB SPL, and CAEP recordings were made. An automatic statistical detection paradigm was used for CAEP detection.

    Results: For sensation levels above 0, 10, and 20 dB respectively, detection sensitivities were equal to 72 ± 10, 75 ± 10, and 78 ± 12%. In 79% of the cases, automatic detection p-values became smaller when the sensation level was increased by 10 dB.

    Conclusions: The results of this study suggest that the presence or absence of CAEPs can provide some indication of the audibility of a speech sound for infants with sensorineural hearing loss. The detection of a CAEP provides confidence, to a degree commensurate with the detection probability, that the infant is detecting that sound at the level presented. When testing infants where the audibility of speech sounds has not been established behaviorally, the lack of a cortical response indicates the possibility, but by no means a certainty, that the sensation level is 10 dB or less.

  12. Puerto Rico Relative Erosion Potential (REP) - 2000

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The relative erosion potential is an indicator of sediment and pollution runoff from land based on slope, soil type, land cover (circa 2000) and (maximum monthly)...

  13. Puerto Rico Relative Erosion Potential (REP) - 1990

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The relative erosion potential is an indicator of sediment and pollution runoff from land based on slope, soil type, land cover (circa 1990) and (maximum monthly)...

  14. Cortical tremor: a variant of cortical reflex myoclonus.

    Science.gov (United States)

    Ikeda, A; Kakigi, R; Funai, N; Neshige, R; Kuroda, Y; Shibasaki, H

    1990-10-01

    Two patients with action tremor that was thought to originate in the cerebral cortex showed fine shivering-like finger twitching provoked mainly by action and posture. Surface EMG showed relatively rhythmic discharge at a rate of about 9 Hz, which resembled essential tremor. However, electrophysiologic studies revealed giant somatosensory evoked potentials (SEPs) with enhanced long-loop reflex and premovement cortical spike by the jerk-locked averaging method. Treatment with beta-blocker showed no effect, but anticonvulsants such as clonazepam, valproate, and primidone were effective to suppress the tremor and the amplitude of SEPs. We call this involuntary movement "cortical tremor," which is in fact a variant of cortical reflex myoclonus.

  15. Relations between effective potentials in different dimensions

    International Nuclear Information System (INIS)

    Bollini, C.G.; Giambiagi, J.J.

    1983-01-01

    Using dimensional regularization, the one-loop approximation for the effective potential (finite temperature) is computed as an analytic function of the number of dimensions. It is shown that a simple relation exists between potentials for different dimensions. This relation reduces to a simple derivative when these numbers differ by two units. The limit of zero temperature is calculated and also the finite temperature corrections are given. (Author) [pt

  16. Cortical evoked potential and extracellular K+ and H+ at critical levels of brain ischemia

    DEFF Research Database (Denmark)

    Astrup, J; Symon, L; Branston, N M

    1977-01-01

    + as well as evoked potential were made in the baboon neocortex. Reductions in blood flow were obtained by occlusion of the middle cerebral artery and depression beyond the ischemic threshold of electrical function achieved by a reduction of systemic blood pressure which, in the ischemic zones, changed...

  17. State and location dependence of action potential metabolic cost in cortical pyramidal neurons

    NARCIS (Netherlands)

    Hallermann, Stefan; de Kock, Christiaan P. J.; Stuart, Greg J.; Kole, Maarten H. P.

    2012-01-01

    Action potential generation and conduction requires large quantities of energy to restore Na+ and K+ ion gradients. We investigated the subcellular location and voltage dependence of this metabolic cost in rat neocortical pyramidal neurons. Using Na+/K+ charge overlap as a measure of action

  18. State and location dependence of action potential metabolic cost in cortical pyramidal neurons

    NARCIS (Netherlands)

    Hallermann, S.; de Kock, C.P.J.; Stuart, G.J.; Kole, M.H.

    2012-01-01

    Action potential generation and conduction requires large quantities of energy to restore Na + and K + ion gradients. We investigated the subcellular location and voltage dependence of this metabolic cost in rat neocortical pyramidal neurons. Using Na +K + charge overlap as a measure of action

  19. Skin denervation does not alter cortical potentials to surface concentric electrode stimulation: A comparison with laser evoked potentials and contact heat evoked potentials.

    Science.gov (United States)

    La Cesa, S; Di Stefano, G; Leone, C; Pepe, A; Galosi, E; Alu, F; Fasolino, A; Cruccu, G; Valeriani, M; Truini, A

    2018-01-01

    In the neurophysiological assessment of patients with neuropathic pain, laser evoked potentials (LEPs), contact heat evoked potentials (CHEPs) and the evoked potentials by the intraepidermal electrical stimulation via concentric needle electrode are widely agreed as nociceptive specific responses; conversely, the nociceptive specificity of evoked potentials by surface concentric electrode (SE-PREPs) is still debated. In this neurophysiological study we aimed at verifying the nociceptive specificity of SE-PREPs. We recorded LEPs, CHEPs and SE-PREPs in eleven healthy participants, before and after epidermal denervation produced by prolonged capsaicin application. We also used skin biopsy to verify the capsaicin-induced nociceptive nerve fibre loss in the epidermis. We found that whereas LEPs and CHEPs were suppressed after capsaicin-induced epidermal denervation, the surface concentric electrode stimulation of the same denervated skin area yielded unchanged SE-PREPs. The suppression of LEPs and CHEPs after nociceptive nerve fibre loss in the epidermis indicates that these techniques are selectively mediated by nociceptive system. Conversely, the lack of SE-PREP changes suggests that SE-PREPs do not provide selective information on nociceptive system function. Capsaicin-induced epidermal denervation abolishes laser evoked potentials (LEPs) and contact heat evoked potentials (CHEPs), but leaves unaffected pain-related evoked potentials by surface concentric electrode (SE-PREPs). These findings suggest that unlike LEPs and CHEPs, SE-PREPs are not selectively mediated by nociceptive system. © 2017 European Pain Federation - EFIC®.

  20. Alzheimer's-related cortical atrophy is associated with postoperative delirium severity in persons without dementia.

    Science.gov (United States)

    Racine, Annie M; Fong, Tamara G; Travison, Thomas G; Jones, Richard N; Gou, Yun; Vasunilashorn, Sarinnapha M; Marcantonio, Edward R; Alsop, David C; Inouye, Sharon K; Dickerson, Bradford C

    2017-11-01

    Patients with dementia due to Alzheimer's disease (AD) have increased risk of developing delirium. This study investigated the relationship between a magnetic resonance imaging (MRI)-derived biomarker associated with preclinical AD and postoperative delirium. Participants were older adults (≥70 years) without dementia who underwent preoperative MRI and elective surgery. Delirium incidence and severity were evaluated daily during hospitalization. Cortical thickness was averaged across a published set of a priori brain regions to derive a measure known as the "AD signature." Logistic and linear regression was used, respectively, to test whether the AD signature was associated with delirium incidence in the entire sample (N = 145) or with the severity of delirium among those who developed delirium (N = 32). Thinner cortex in the AD signature did not predict incidence of delirium (odds ratio = 1.15, p = 0.38) but was associated with greater delirium severity among those who developed delirium (b = -1.2, p = 0.014). These results suggest that thinner cortices, perhaps reflecting underlying neurodegeneration due to preclinical AD, may serve as a vulnerability factor that increases severity once delirium occurs. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. [Cortical potentials evoked to response to a signal to make a memory-guided saccade].

    Science.gov (United States)

    Slavutskaia, M V; Moiseeva, V V; Shul'govskiĭ, V V

    2010-01-01

    The difference in parameters of visually guided and memory-guided saccades was shown. Increase in the memory-guided saccade latency as compared to that of the visually guided saccades may indicate the deceleration of saccadic programming on the basis of information extraction from the memory. The comparison of parameters and topography of evoked components N1 and P1 of the evoked potential on the signal to make a memory- or visually guided saccade suggests that the early stage of the saccade programming associated with the space information processing is performed predominantly with top-down attention mechanism before the memory-guided saccade and bottom-up mechanism before the visually guided saccade. The findings show that the increase in the latency of the memory-guided saccades is connected with decision making at the central stage of the saccade programming. We proposed that wave N2, which develops in the middle of the latent period of the memory-guided saccades, is correlated with this process. Topography and spatial dynamics of components N1, P1 and N2 testify that the memory-guided saccade programming is controlled by the frontal mediothalamic system of selective attention and left-hemispheric brain mechanisms of motor attention.

  2. Age-related differences in cortical activity during a visuo-spatial working memory task with facial stimuli.

    Directory of Open Access Journals (Sweden)

    Flávia Schechtman Belham

    Full Text Available Emotion, importantly displayed by facial expressions, is one of the most significant memory modulators. The interaction between memory and the different emotional valences change across lifespan, while young adults (YA are expected to better recall negative events (Negativity Bias Hypothesis, older adults (OA tend to focus on positive stimuli (Positivity Effect Hypothesis. This research work aims at verifying whether cortical electrical activity of these two age groups would also be differently influenced by emotional valences in a visuo-spatial working memory task. 27 YA (13 males and 25 OA (14 males, all healthy volunteers, underwent electroencephalographic recordings (21 scalp electrodes montage, while performing the Spatial Delayed Recognition Span Task using a touch screen with different stimuli categories: neutral, positive and negative faces and geometric pictures. YA obtained higher scores than OA, and showed higher activation of theta and alpha bands in the frontal and midline regions, besides a more evident right-hemispheric asymmetry on alpha band when compared to OA. For both age groups, performance in the task was worse for positive faces than to negative and to neutral faces. Facial stimuli induced a better performance and higher alpha activation on the pre-frontal region for YA, and on the midline, occipital and left temporal regions for OA when compared to geometric figures. The superior performance of YA was expected due to the natural cognitive deficits connected to ageing, as was a better performance with facial stimuli due to the evolutionary importance of faces. These results were related to cortical activity on areas of importance for action-planning, decision making and sustained attention. Taken together, they are in accordance with the Negativity Bias but do not support the Positivity Effect. The methodology used was able to identify age-related differences in cortical activity during emotional mnemonic processing and

  3. Correlation between event-related potentials and MR measurements in chronic alcoholic patients

    International Nuclear Information System (INIS)

    Kaseda, Yumiko; Miyazato, Yoshikazu; Ogura, Chikara; Nakamoto, Haruo; Uema, Takeshi; Yamamoto, Kazuyoshi; Ohta, Ikuya

    1994-01-01

    Event-related potentials were recorded in 25 abstinent alcoholics, and 25 gender- and age-matched controls during a two-tone discrimination (odd ball) task. All the subjects were free from medication and dextral. MR images were examined in the alcoholics. The amplitudes of N100, N200 and P300 in the alcoholics were reduced compared with those of the controls. In order to identify morphological changes responsible for ERP abnormalities, linear regression analyses were performed between ERP measures and MRI parameters. The amplitude of N100 was inversely correlated with ventricular size. The amplitudes of P300 were inversely correlated with both ventricular size and width of cortical sulci. It was suggested that the N100 abnormality was related to subcortical structure, and P300 alteration was related to both subcortical and cortical structures in the alcoholics. (author)

  4. Translating long-term potentiation from animals to humans: a novel method for noninvasive assessment of cortical plasticity.

    Science.gov (United States)

    Clapp, Wesley C; Hamm, Jeff P; Kirk, Ian J; Teyler, Timothy J

    2012-03-15

    Long-term potentiation (LTP) is a synaptic mechanism underlying learning and memory that has been studied extensively in laboratory animals. The study of LTP recently has been extended into humans with repetitive sensory stimulation to induce cortical LTP. In this review article, we will discuss past results from our group demonstrating that repetitive sensory stimulation (visual or auditory) induces LTP within the sensory cortex (visual/auditory, respectively) and can be measured noninvasively with electroencephalography or functional magnetic resonance imaging. We will discuss a number of studies that indicate that this form of LTP shares several characteristics with the synaptic LTP described in animals: it is frequency dependent, long-lasting (> 1 hour), input-specific, depotentiates with low-frequency stimulation, and is blocked by N-methyl-D-aspartate receptor blockers in rats. In this review, we also present new data with regard to the behavioral significance of human sensory LTP. These advances will permit enquiry into the functional significance of LTP that has been hindered by the absence of a human model. The ability to elicit LTP with a natural sensory stimulus noninvasively will provide a model system allowing the detailed examination of synaptic plasticity in normal subjects and might have future clinical applications in the diagnosis and assessment of neuropsychiatric and neurocognitive disorders. Copyright © 2012 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.

  5. Cognitive event-related potentials in comatose and post-comatose states.

    Science.gov (United States)

    Vanhaudenhuyse, Audrey; Laureys, Steven; Perrin, Fabien

    2008-01-01

    We review the interest of cognitive event-related potentials (ERPs) in comatose, vegetative, or minimally conscious patients. Auditory cognitive ERPs are useful to investigate residual cognitive functions, such as echoic memory (MMN), acoustical and semantic discrimination (P300), and incongruent language detection (N400). While early ERPs (such as the absence of cortical responses on somatosensory-evoked potentials) predict bad outcome, cognitive ERPs (MMN and P300) are indicative of recovery of consciousness. In coma-survivors, cognitive potentials are more frequently obtained when using stimuli that are more ecologic or have an emotional content (such as the patient's own name) than when using classical sine tones.

  6. Therapeutic potential of cannabis-related drugs.

    Science.gov (United States)

    Alexander, Stephen P H

    2016-01-04

    In this review, I will consider the dual nature of Cannabis and cannabinoids. The duality arises from the potential and actuality of cannabinoids in the laboratory and clinic and the 'abuse' of Cannabis outside the clinic. The therapeutic areas currently best associated with exploitation of Cannabis-related medicines include pain, epilepsy, feeding disorders, multiple sclerosis and glaucoma. As with every other medicinal drug of course, the 'trick' will be to maximise the benefit and minimise the cost. After millennia of proximity and exploitation of the Cannabis plant, we are still playing catch up with an understanding of its potential influence for medicinal benefit. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Family migration and relative earnings potentials

    DEFF Research Database (Denmark)

    Foged, Mette

    2016-01-01

    of husband centered migration. Couples are more likely to migrate if household earnings potential is disproportionally due to one partner, and families react equally strongly to a male and a female relative advantage in educational earnings potential. These results are driven by households with a strong......A unitarian model of family migration in which families may discount wives’ private gains is used to derive testable predictions regarding the type of couples that select into migrating. The empirical tests show that gender neutral family migration cannot be rejected against the alternative...

  8. The enemy within: propagation of aberrant corticostriatal learning to cortical function in Parkinson's disease

    Directory of Open Access Journals (Sweden)

    Jeff A Beeler

    2013-09-01

    Full Text Available Motor dysfunction in Parkinson’s disease is believed to arise primarily from pathophysiology in the dorsal striatum and its related corticostriatal and thalamostriatal circuits during progressive dopamine denervation. One function of these circuits is to provide a filter that selectively facilitates or inhibits cortical activity to optimize cortical processing, making motor responses rapid and efficient. Corticostriatal synaptic plasticity mediates the learning that underlies this performance-optimizing filter. Under dopamine denervation, corticostriatal plasticity is altered, resulting in aberrant learning that induces inappropriate basal ganglia filtering that impedes rather than optimizes cortical processing. Human imaging suggests that increased cortical activity may compensate for striatal dysfunction in PD patients. In this Perspective article, we consider how aberrant learning at corticostriatal synapses may impair cortical processing and learning and undermine potential cortical compensatory mechanisms. Blocking or remediating aberrant corticostriatal plasticity may protect cortical function and support cortical compensatory mechanisms mitigating the functional decline associated with progressive dopamine denervation.

  9. Neurofeedback of slow cortical potentials: neural mechanisms and feasibility of a placebo-controlled design in healthy adults

    Directory of Open Access Journals (Sweden)

    Holger eGevensleben

    2014-12-01

    Full Text Available To elucidate basic mechanisms underlying neurofeedback we investigated neural mechanisms of training of slow cortical potentials by considering EEG- and fMRI. Additionally, we analyzed the feasibility of a double-blind, placebo-controlled design in NF research based on regulation performance during treatment sessions and self-assessment of the participants. Twenty healthy adults participated in 16 sessions of SCP training: 9 participants received regular SCP training, 11 participants received sham feedback. At three time points (pre, intermediate, post fMRI and EEG/ERP-measurements were conducted during a continuous performance test (CPT. Performance-data during the sessions (regulation performance in the treatment group and the placebo group were analyzed. Analysis of EEG-activity revealed in the SCP group a strong enhancement of the CNV (electrode Cz at the intermediate assessment, followed by a decrease back to baseline at the post-treatment assessment. In contrast, in the placebo group a continuous but smaller increase of the CNV could be obtained from pre to post assessment. The increase of the CNV in the SCP group at intermediate testing was superior to the enhancement in the placebo group. The changes of the CNV were accompanied by a continuous improvement in the test performance of the CPT from pre to intermediate to post assessment comparable in both groups. The change of the CNV in the SCP group is interpreted as an indicator of neural plasticity and efficiency while an increase of the CNV in the placebo group might reflect learning and improved timing due to the frequent task repetition.In the fMRI analysis evidence was obtained for neuronal plasticity. After regular SCP neurofeedback activation in the posterior parietal cortex decreased from the pre- to the intermediate measurement and increased again in the post measurement, inversely following the U-shaped increase and decrease of the tCNV EEG amplitude in the SCP-trained group

  10. Acetylcholinesterase potentiates [{sup 3}H]fluorowillardiine and [{sup 3}H]AMPA binding to rat cortical membranes

    Energy Technology Data Exchange (ETDEWEB)

    Olivera, S.; Rodriguez-Ithurralde, D. [Department of Anatomy, School of Medical Sciences, University of Bristol, University Walk, Bristol, BS8 1TD (United Kingdom); Henley, J.M. [Molecular Neuroscience Unit, Division Neuromyology, Instituto de Investigaciones Biologicas Clemente Estable, 11600 Montevideo (Uruguay)

    1999-04-01

    In addition to its action at cholinergic synapses acetylcholinesterase (AChE) has been proposed to modulate neuronal activity by mechanisms unrelated to the hydrolysis of acetylcholine. We have investigated the effects of AChE on the binding of the specific AMPA receptor agonists (S)-[{sup 3}H]5-fluorowillardiine ([{sup 3}H]FW) and [{sup 3}H]AMPA to rat cortical membranes. Pretreatment of membranes with AChE causes a dose-dependent increase in the binding of both radiolabelled agonists with a maximal increase to {approx}60% above control. This increase is completely blocked by the specific AChE inhibitors propidium, physostigmine, DFP and BW 284C51. AChE pretreatment had no effect on [{sup 3}H]kainate binding. [{sup 3}H]FW binding to membranes from young (15-day-old) rats is four orders of magnitude more sensitive to AChE modulation than membranes from adult rats (EC{sub 50} values of 4x10{sup -5} and 0.1 unit/ml, respectively) although the total percentage increase in binding is similar. Furthermore, the AChE-induced potentiation of [{sup 3}H]FW binding is Ca{sup 2+}- and temperature-dependent suggesting an enzymatic action for AChE in this system. Saturation binding experiments with [{sup 3}H]FW to adult membranes reveal high and low affinity binding sites and demonstrate that the main action of AChE is to increase the B{sub max} of both sites. These findings suggest that modulation of AMPA receptors could provide a molecular mechanism of action for the previously reported effects of AChE in synapse formation, synaptic plasticity and neurodegeneration. (Copyright (c) 1999 Elsevier Science B.V., Amsterdam. All rights reserved.)

  11. [Role of immune-related GTPase M1 in cortical neurons autophagy of mice with sepsis-induced brain injury].

    Science.gov (United States)

    Huang, Qun; Chen, Bin; Li, Yafei; Li, Xihong

    2017-12-28

    To investigate the role of immune-related GTPase M1 (IRGM1) in cortical neurons autophagy in mice with sepsis induced brain injury (SIBI).
 Methods: Sixty wild-type C57BL/6 mice and sixty IRGM1 gene knockout C57BL/6 mice were randomly divided into 4 groups: a sham-operated wild-type (SWT) group, a cecal ligation and puncture (CLP) model wild-type (MWT) group, a sham-operated knockout (SKO) group, and a CLP model knockout (MKO) group. Models of mice with sepsis were established by CLP. Six hours of after CLP, the neurobehavioral scores for mice were recorded. The mice were diagnosed with SIBI and enrolled for the studies in next step if the neurobehavioral score was less than 6 in the MWT and MKO groups. The sham operation group only opened the abdominal cavity without CLP. Pathological changes in mouse cerebral cortex were observed by HE staining. Electron microscope was used to observe the ultrastructure of autophagy in cortical neurons. The expression of IRGM1 and INF-γ mRNA in the cerebral cortex of mice were detected by Real time quantitative PCR. The protein expression of microtubule-associated protein 1 light chain 3 (LC3)-II, LC3-I, sequestosome-1 (SQSTM1) and IRGM1 were measured by Western blot. Immunofluorescence staining was used to examine the expression of IRGM1 in mouse cortical neurons.
 Results: In the MWT group, the cortical neurons showed dilated endoplasmic reticulum, swelling mitochondria, and increased number of autophagosomes after 6 or 24 h of CLP in contrast to the SWT group. At 6 h after CLP, the expression of LC3-II in the cerebral cortex began to up-regulate, and the up-regulation was maintained till 96 h after CLP; on the contrary, SQSTM1 began to decline after 6 h of CLP. Compared with SWT group, IRGM1 was strongly up-regulated in the cerebral cortex of mice at both mRNA and protein levels in the MWT group after 12 h of CLP, and the mRNA expression of IFN-γ was also increased significantly (PSIBI was 90% (27/30) in the MWT group

  12. Cortical sources of resting state EEG rhythms are related to brain hypometabolism in subjects with Alzheimer's disease: an EEG-PET study.

    Science.gov (United States)

    Babiloni, Claudio; Del Percio, Claudio; Caroli, Anna; Salvatore, Elena; Nicolai, Emanuele; Marzano, Nicola; Lizio, Roberta; Cavedo, Enrica; Landau, Susan; Chen, Kewei; Jagust, William; Reiman, Eric; Tedeschi, Gioacchino; Montella, Patrizia; De Stefano, Manuela; Gesualdo, Loreto; Frisoni, Giovanni B; Soricelli, Andrea

    2016-12-01

    Cortical sources of resting state electroencephalographic (EEG) delta (2-4 Hz) and low-frequency alpha (8-10.5 Hz) rhythms show abnormal activity (i.e., current density) in patients with dementia due to Alzheimer's disease (AD). Here, we hypothesized that abnormality of this activity is related to relevant disease processes as revealed by cortical hypometabolism typically observed in AD patients by fluorodeoxyglucose positron emission tomography. Resting state eyes-closed EEG data were recorded in 19 AD patients with dementia and 40 healthy elderly (Nold) subjects. EEG frequency bands of interest were delta and low-frequency alpha. EEG sources were estimated in these bands by low-resolution brain electromagnetic tomography (LORETA). Fluorodeoxyglucose positron emission tomography images were recorded only in the AD patients, and cortical hypometabolism was indexed by the so-called Alzheimer's discrimination analysis tool (PALZ) in the frontal association, ventromedial frontal, temporoparietal association, posterior cingulate, and precuneus areas. Results showed that compared with the Nold group, the AD group pointed to higher activity of delta sources and lower activity of low-frequency alpha sources in a cortical region of interest formed by all cortical areas of the PALZ score. In the AD patients, there was a positive correlation between the PALZ score and the activity of delta sources in the cortical region of interest (p < 0.05). These results suggest a relationship between resting state cortical hypometabolism and synchronization of cortical neurons at delta rhythms in AD patients with dementia. Copyright © 2016 Elsevier Inc. All rights reserved.

  13. Cortical volumes and atrophy rates in FTD-3 CHMP2B mutation carriers and related non-carriers

    DEFF Research Database (Denmark)

    Eskildsen, Simon F; Østergaard, Lasse R; Rodell, Anders B

    2008-01-01

    with a mean interval of 16 months and surface based cortical segmentation we measured cortical thickness and volume, and quantified atrophy rates. Cortical thickness and atrophy rates were averaged within major lobes and focal effects were determined by parametric statistical maps. The volumetric atrophy...... in the frontal and occipital lobes, and in the left temporal lobe. Results indicated that cortical thickness has a higher sensitivity for detecting small changes than whole-brain volumetric measures. Comparing mutation carriers with non-carriers revealed increased atrophy rates in mutation carriers bilaterally...

  14. Relating membrane potential to impedance spectroscopy

    Directory of Open Access Journals (Sweden)

    Eugen Gheorghiu

    2011-12-01

    Full Text Available Non-invasive, label-free assessment of membrane potential of living cells is still a challenging task. The theory linking membrane potential to the low frequency α dispersion exhibited by suspensions of spherical shelled particles (presenting a net charge distribution on the inner side of the shell has been pioneered in our previous studies with emphasis on the permittivity spectra. Whereas α dispersion is related to a rather large variation exhibited by the permittivity spectrum, we report that the related decrement presented by the impedance magnitude spectrum is either extremely small, or occurs (for large cells at very small frequencies (~mHz explaining the lack of experimental bioimpedance data on the matter. We stress that appropriate choice of the parameters (as revealed by the microscopic model may enable access to membrane potential as well as to other relevant parameters when investigating living cells and charged lipid vesicles. We analyse the effect on the low frequency of the permittivity and impedance spectra of: I. Parameters pertaining to cell membrane i.e. (i membrane potential (through the amount of the net charge on the inner side of the membrane, (ii size of the cells/vesicles, (iii conductivity of the membrane; II. Parameters of the extra cellular medium (viscosity and conductivity. The applicability of the study has far reaching implications for basic (life sciences (providing non-invasive access to the dynamics of relevant cell parameters as well as for biosensing applications, e.g. assessment of cytotoxicity of a wide range of stimuli. doi:10.5617/jeb.214 J Electr Bioimp, vol. 2, pp. 93-97, 2011

  15. Effect of relative humidity on solar potential

    International Nuclear Information System (INIS)

    Soezen, Adnan; Arcaklioglu, Erol

    2005-01-01

    In this study, the effect of relative humidity on solar potential is investigated using artificial neural-networks. Two different models are used to train the neural networks. Meteorological and geographical data (latitude, longitude, altitude, month, mean sunshine-duration, and mean temperature) are used in the input layer of the network (Model 1). But, relative humidity values are added to one network in model (Model 2). In other words, the only difference between the models is relative humidity. New formulae based on meteorological and geographical data, have been developed to determine the solar energy potential in Turkey using the networks' weights for both models. Scaled conjugate gradient (SCG) and Levenberg-Marquardt (LM) learning algorithms and a logistic sigmoid transfer-function were used in the network. The best approach was obtained by the SCG algorithm with nine neurons for both models. Meteorological data for the four years, 2000-2003, for 18 cities (Artvin, Cesme, Bozkurt, Malkara, Florya, Tosya, Kizilcahamam, Yenisehir, Edremit, Gediz, Kangal, Solhan, Ergani, Selcuk, Milas, Seydisehir, Siverek and Kilis) spread over Turkey have been used as data in order to train the neural network. Solar radiation is in output layer. One month for each city was used as test data, and these months have not been used for training. The maximum mean absolute percentage errors (MAPEs) for Tosya are 2.770394% and 2.8597% for Models 1 and 2, respectively. The minimum MAPEs for Seydisehir are 1.055205% and 1.041% with R 2 (99.9862%, 99.9842%) for Models 1 and 2, respectively, in the SCG algorithm with nine neurons. The best value of R 2 for Models 1 and 2 are for Seydisehir. The minimum value of R 2 for Model 1 is 99.8855% for Tosya, and the value for Model 2 is 99.9001% for Yenisehir. Results show that the humidity has only a negligible effect upon the prediction of solar potential using artificial neural-networks

  16. Potential protection of green tea polyphenols against 1800 MHz electromagnetic radiation-induced injury on rat cortical neurons.

    Science.gov (United States)

    Liu, Mei-Li; Wen, Jian-Qiang; Fan, Yu-Bo

    2011-10-01

    Radiofrequency electromagnetic fields (EMF) are harmful to public health, but the certain anti-irradiation mechanism is not clear yet. The present study was performed to investigate the possible protective effects of green tea polyphenols against electromagnetic radiation-induced injury in the cultured rat cortical neurons. In this study, green tea polyphenols were used in the cultured cortical neurons exposed to 1800 MHz EMFs by the mobile phone. We found that the mobile phone irradiation for 24 h induced marked neuronal cell death in the MTT (3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyl-tetrazolium bromide) and TUNEL (TdT mediated biotin-dUTP nicked-end labeling) assay, and protective effects of green tea polyphenols on the injured cortical neurons were demonstrated by testing the content of Bcl-2 Assaciated X protein (Bax) in the immunoprecipitation assay and Western blot assay. In our study results, the mobile phone irradiation-induced increases in the content of active Bax were inhibited significantly by green tea polyphenols, while the contents of total Bax had no marked changes after the treatment of green tea polyphenols. Our results suggested a neuroprotective effect of green tea polyphenols against the mobile phone irradiation-induced injury on the cultured rat cortical neurons.

  17. By Improving Regional Cortical Blood Flow, Attenuating Mitochondrial Dysfunction and Sequential Apoptosis Galangin Acts as a Potential Neuroprotective Agent after Acute Ischemic Stroke

    Directory of Open Access Journals (Sweden)

    Ming Cheng

    2012-11-01

    Full Text Available Ischemic stroke is a devastating disease with a complex pathophysiology. Galangin is a natural flavonoid isolated from the rhizome of Alpina officinarum Hance, which has been widely used as an antioxidant agent. However, its effects against ischemic stroke have not been reported and its related neuroprotective mechanism has not really been explored. In this study, neurological behavior, cerebral infarct volumes and the improvement of the regional cortical blood flow (rCBF were used to evaluate the therapeutic effect of galangin in rats impaired by middle cerebral artery occlusion (MCAO-induced focal cerebral ischemia. Furthermore, the determination of mitochondrial function and Western blot of apoptosis-related proteins were performed to interpret the neuroprotective mechanism of galangin. The results showed that galangin alleviated the neurologic impairments, reduced cerebral infarct at 24 h after MCAO and exerted a protective effect on the mitochondria with decreased production of mitochondrial reactive oxygen species (ROS. These effects were consistent with improvements in the membrane potential level (Dym, membrane fluidity, and degree of mitochondrial swelling in a dose-dependent manner. Moreover, galangin significantly improved the reduced rCBF after MCAO. Western blot analysis revealed that galangin also inhibited apoptosis in a dose-dependent manner concomitant with the up-regulation of Bcl-2 expression, down-regulation of Bax expression and the Bax/Bcl-2 ratio, a reduction in cytochrome c release from the mitochondria to the cytosol, the reduced expression of activated caspase-3 and the cleavage of poly(ADP-ribose polymerase (PARP. All these data in this study demonstrated that galangin might have therapeutic potential for ischemic stroke and play its protective role through the improvement in rCBF, mitochondrial protection and inhibiting caspase-dependent mitochondrial cell death pathway for the first time.

  18. By improving regional cortical blood flow, attenuating mitochondrial dysfunction and sequential apoptosis galangin acts as a potential neuroprotective agent after acute ischemic stroke.

    Science.gov (United States)

    Li, Shaojing; Wu, Chuanhong; Zhu, Li; Gao, Jian; Fang, Jing; Li, Defeng; Fu, Meihong; Liang, Rixin; Wang, Lan; Cheng, Ming; Yang, Hongjun

    2012-11-09

    Ischemic stroke is a devastating disease with a complex pathophysiology. Galangin is a natural flavonoid isolated from the rhizome of Alpina officinarum Hance, which has been widely used as an antioxidant agent. However, its effects against ischemic stroke have not been reported and its related neuroprotective mechanism has not really been explored. In this study, neurological behavior, cerebral infarct volumes and the improvement of the regional cortical blood flow (rCBF) were used to evaluate the therapeutic effect of galangin in rats impaired by middle cerebral artery occlusion (MCAO)-induced focal cerebral ischemia. Furthermore, the determination of mitochondrial function and Western blot of apoptosis-related proteins were performed to interpret the neuroprotective mechanism of galangin. The results showed that galangin alleviated the neurologic impairments, reduced cerebral infarct at 24 h after MCAO and exerted a protective effect on the mitochondria with decreased production of mitochondrial reactive oxygen species (ROS). These effects were consistent with improvements in the membrane potential level (Dym), membrane fluidity, and degree of mitochondrial swelling in a dose-dependent manner. Moreover, galangin significantly improved the reduced rCBF after MCAO. Western blot analysis revealed that galangin also inhibited apoptosis in a dose-dependent manner concomitant with the up-regulation of Bcl-2 expression, down-regulation of Bax expression and the Bax/Bcl-2 ratio, a reduction in cytochrome c release from the mitochondria to the cytosol, the reduced expression of activated caspase-3 and the cleavage of poly(ADP-ribose) polymerase (PARP). All these data in this study demonstrated that galangin might have therapeutic potential for ischemic stroke and play its protective role through the improvement in rCBF, mitochondrial protection and inhibiting caspase-dependent mitochondrial cell death pathway for the first time.

  19. Relation between clinical findings and progression of cerebral cortical pathology in MM1-type sporadic Creutzfeldt-Jakob disease: proposed staging of cerebral cortical pathology.

    Science.gov (United States)

    Iwasaki, Yasushi; Tatsumi, Shinsui; Mimuro, Maya; Kitamoto, Tetsuyuki; Hashizume, Yoshio; Yoshida, Mari

    2014-06-15

    In our pathologic observation of the cerebral cortex including the neocortex, hippocampus, and limbic cortex in 43 Japanese patients with MM1-type sporadic Creutzfeldt-Jakob disease, the earliest pathologic finding was spongiform change and next was gliosis. Subsequently, neuropil rarefaction appeared, followed by neuron loss. On the basis of these observations, we propose the following cortical pathologic staging: Stage I, spongiform change; Stage II, hypertrophic astrocytosis; Stage III, neuropil rarefaction; Stage IV, neuron loss; Stage V, status spongiosus; and Stage VI, large cavity formation. We also suggest a more simple staging classification: Stages I and II, mild; Stages III and IV, moderate; and Stages V and VI, severe involvement. Based on statistical analysis of the cases, strong correlation coefficients were obtained between the neocortical and limbic pathologic stage and both total disease duration and brain weight. We estimated that the first observation times of cortical hyperintensity on diffusion-weighted images of magnetic resonance imaging, myoclonus, and periodic sharp wave complexes on the electroencephalogram approximately correspond to the early phase of Stage II of the neocortex. The time to reach the akinetic mutism state approximately corresponds to the middle phase of Stage II of the neocortex. Therefore, we think that approximate clinical manifestations at death, total disease duration, and brain weight can be estimated according to the pathologic stage of the neocortex or limbic cortex. Panencephalopathic-type pathology appeared approximately 12 months after disease onset, and this time approximately corresponds to the middle phase of Stage III of the neocortex. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Relative contributions of intracortical and thalamo-cortical processes in the generation of alpha rhythms, revealed by partial coherence analysis

    NARCIS (Netherlands)

    Lopes da Silva, F.H.; Vos, J.E.; Mooibroek, J.; Rotterdam, A. van

    1980-01-01

    The thalamo-cortical relationships of alpha rhythms have been analysed in dogs using partial coherence function analysis. The objective was to clarify how far the large intracortical coherence commonly recorded between different cortical sites could depend on a common thalamic site. It was found

  1. Assessment of Cortical Visual Impairment in Infants with Periventricular Leukomalacia: a Pilot Event-Related fMRI Study

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Bing; Guo, Qiyong [Shengjing Hospital of China Medical University, Shenyang (China); Fan, Guoguang [The First Hospital of China Medical University, Shenyang (China); Liu, Na [Greater China Region of Philips, Shanghai (China)

    2011-08-15

    We wanted to investigate the usefulness of event-related (ER) functional MRI (fMRI) for the assessment of cortical visual impairment in infants with periventricular leukomalacia (PVL). FMRI data were collected from 24 infants who suffered from PVL and from 12 age-matched normal controls. Slow ER fMRI was performed using a 3.0T MR scanner while visual stimuli were being presented. Data analysis was performed using Statistical Parametric Mapping software (SPM2), the SPM toolbox MarsBar was used to analyze the region of interest data, and the time to peak (TTP) of hemodynamic response functions (HRFs) was estimated for the surviving voxels. The number of activated voxels and the TTP values of HRFs were compared. Pearson correlation analysis was performed to compare visual impairment evaluated by using Teller Acuity Cards (TAC) with the number of activated voxels in the occipital lobes in all patients. In all 12 control infants, the blood oxygenation level-dependent (BOLD) signal was negative and the maximum response was located in the anterior and superior part of the calcarine fissure, and this might correspond to the anterior region of the primary visual cortex (PVC). In contrast, for the 24 cases of PVL, there were no activated pixels in the PVC in four subjects, small and weak activations in six subjects, deviated activations in seven subjects and both small and deviated activations in three subjects. The number of active voxels in the occipital lobe was significantly correlated with the TAC-evaluated visual impairment (p < 0.001). The mean TTP of the HRFs was significantly delayed in the cases of PVL as compared with that of the normal controls. Determining the characteristics of both the BOLD response and the ER fMRI activation may play an important role in the cortical visual assessment of infants with PVL.

  2. Influência dos contrastes de fala nos potenciais evocados auditivos corticais The influence of speech stimuli contrast in cortical auditory evoked potentials

    Directory of Open Access Journals (Sweden)

    Kátia de Freitas Alvarenga

    2013-06-01

    Full Text Available Estudos voltados aos potenciais evocados auditivos com estímulos de fala em indivíduos ouvintes são importantes para compreender como a complexidade do estímulo influencia nas características do potencial cognitivo auditivo gerado. OBJETIVO: Caracterizar o potencial evocado auditivo cortical e o potencial cognitivo auditivo P3 com estímulos de contrastes vocálico e consonantal em indivíduos com audição normal. MÉTODO: Participaram deste estudo 31 indivíduos sem alterações auditivas, neurológicas e de linguagem na faixa etária de 7 a 30 anos. Os potenciais evocados auditivos corticais e cognitivo auditivo P3 foram registrados nos canais ativos Fz e Cz utilizando-se os contrastes de fala consonantal (/ba/-/da/ e vocálico (/i/-/a/. Desenho: Estudo de coorte, transversal e prospectivo. RESULTADOS: Houve diferença entre o contraste de fala utilizado e as latências dos componentes N2 (p = 0,00 e P3 (p = 0,00, assim como entre o canal ativo considerado (Fz/Cz e os valores de latência e amplitude de P3. Estas diferenças não ocorreram para os componentes exógenos N1 e P2. CONCLUSÃO: O contraste do estímulo de fala, vocálico ou consonantal, deve ser considerado na análise do potencial evocado cortical, componente N2, e do potencial cognitivo auditivo P3.Studies about cortical auditory evoked potentials using the speech stimuli in normal hearing individuals are important for understanding how the complexity of the stimulus influences the characteristics of the cortical potential generated. OBJECTIVE: To characterize the cortical auditory evoked potential and the P3 auditory cognitive potential with the vocalic and consonantal contrast stimuli in normally hearing individuals. METHOD: 31 individuals with no risk for hearing, neurologic and language alterations, in the age range between 7 and 30 years, participated in this study. The cortical auditory evoked potentials and the P3 auditory cognitive one were recorded in the Fz and Cz

  3. Profiles of cortical tissue depolarization in cat focal cerebral ischemia in relation to calcium ion homeostasis and nitric oxide production.

    Science.gov (United States)

    Ohta, K; Graf, R; Rosner, G; Heiss, W D

    1997-11-01

    Cortical depolarization was investigated in a topographic gradient of ischemic density after 1-hour transient middle cerebral artery occlusion in halothane-anesthetized cats. A laser Doppler flow probe, an ion-selective microelectrode, and a nitric oxide (NO) electrode measured regional CBF (rCBF), direct current (DC) potential, extracellular Ca2+ concentration ([Ca2+]o), and NO concentration in ectosylvian and suprasylvian gyri of nine animals. Recordings revealed 12 of 18 sites with persistent negative shifts of the DC potential, severe rCBF reduction, and a drop of [Ca2+]o characteristic for core regions of focal ischemia. Among these sites, two types were distinguished by further analysis. In Type 1 (n = 5), rapid, negative DC shifts resembled anoxic depolarization as described for complete global ischemia. In this type, ischemia was most severe (8.9 +/- 2.5% of control rCBF), [Ca2+]o dropped fast and deepest (0.48 +/- 0.20 mmol/L), and NO concentration increased transiently (36.1 +/- 24.0 nmol/L at 2.5 minutes), and decreased thereafter. In Type 2 (n = 7), the DC potential fell gradually over the first half of the ischemic episode, rCBF and [Ca2+]o reductions were smaller than in Type 1 (16.2 +/- 8.2%; 0.77 +/- 0.41 mmol/L), and NO increased continuously during ischemia (53.1 +/- 60.4 nmol/L at 60 minutes) suggesting that in this type NO most likely exerts its diverse actions on ischemia-threatened tissue. In the remaining six recording sites, a third type (Type 3) attributable to the ischemic periphery was characterized by minimal DC shifts, mild ischemia (37.2 +/- 13.3%), nonsignificant alterations of [Ca2+]o, but decreased NO concentrations during middle cerebral artery occlusion. Reperfusion returned the various parameters to baseline levels within 1 hour, the recovery of [Ca2+]o and NO concentration being delayed in Type 1. An NO synthase inhibitor (N(G)-nitro-L-arginine, 50 mg/kg intravenously; four animals) abolished NO elevation during ischemia. In

  4. Upregulation of Immunoglobulin-related Genes in Cortical Sections from Multiple Sclerosis Patients

    NARCIS (Netherlands)

    Torkildsen, O.; Stansberg, C.; Angelskar, S.M.; Kooi, E.J.; Geurts, J.J.G.; van der Valk, P.; Myhr, K.M.; Steen, V.M.; Bo, L.

    2010-01-01

    Multiple sclerosis (MS) is a demyelinating disease of the central nervous system (CNS). Microarray-based global gene expression profiling is a promising method, used to study potential genes involved in the pathogenesis of the disease. In the present study, we have examined global gene expression in

  5. Roles of N-methyl-d-aspartate receptors during the sensory stimulation-evoked field potential responses in mouse cerebellar cortical molecular layer.

    Science.gov (United States)

    Xu, Yin-Hua; Zhang, Guang-Jian; Zhao, Jing-Tong; Chu, Chun-Ping; Li, Yu-Zi; Qiu, De-Lai

    2017-11-01

    The functions of N-methyl-d-aspartate receptors (NMDARs) in cerebellar cortex have been widely studied under in vitro condition, but their roles during the sensory stimulation-evoked responses in the cerebellar cortical molecular layer in living animals are currently unclear. We here investigated the roles of NMDARs during the air-puff stimulation on ipsilateral whisker pad-evoked field potential responses in cerebellar cortical molecular layer in urethane-anesthetized mice by electrophysiological recording and pharmacological methods. Our results showed that cerebellar surface administration of NMDA induced a dose-dependent decrease in amplitude of the facial stimulation-evoked inhibitory responses (P1) in the molecular layer, accompanied with decreases in decay time, half-width and area under curve (AUC) of P1. The IC 50 of NMDA induced inhibition in amplitude of P1 was 46.5μM. In addition, application of NMDA induced significant increases in the decay time, half-width and AUC values of the facial stimulation-evoked excitatory responses (N1) in the molecular layer. Application of an NMDAR blocker, D-APV (250μM) abolished the facial stimulation-evoked P1 in the molecular layer. These results suggested that NMDARs play a critical role during the sensory information processing in cerebellar cortical molecular layer in vivo in mice. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Age- and function-related regional changes in cortical folding of the default mode network in older adults.

    Science.gov (United States)

    Jockwitz, Christiane; Caspers, Svenja; Lux, Silke; Jütten, Kerstin; Schleicher, Axel; Eickhoff, Simon B; Amunts, Katrin; Zilles, Karl

    2017-01-01

    Healthy aging is accompanied by changes in the functional architecture of the default mode network (DMN), e.g. a posterior to anterior shift (PASA) of activations. The putative structural correlate for this functional reorganization, however, is largely unknown. Changes in gyrification, i.e. decreases of cortical folding were found to be a marker of atrophy of the brain in later decades of life. Therefore, the present study assessed local gyrification indices of the DMN in relation to age and cognitive performance in 749 older adults aged 55-85 years. Age-related decreases in local gyrification indices were found in the anterior part of the DMN [particularly; medial prefrontal cortex (mPFC)] of the right hemisphere, and the medial posterior parts of the DMN [particularly; posterior cingulate cortex (PCC)/precuneus] of both hemispheres. Positive correlations between cognitive performance and local gyrification indices were found for (1) selective attention and left PCC/precuneus, (2) visual/visual-spatial working memory and bilateral PCC/precuneus and right angular gyrus (AG), and (3) semantic verbal fluency and right AG and right mPFC. The more pronounced age-related decrease in local gyrification indices of the posterior parts of the DMN supports the functionally motivated PASA theory by correlated structural changes. Surprisingly, the prominent age-related decrease in local gyrification indices in right hemispheric ROIs provides evidence for a structural underpinning of the right hemi-aging hypothesis. Noticeably, the performance-related changes in local gyrification largely involved the same parts of the DMN that were subject to age-related local gyrification decreases. Thus, the present study lends support for a combined structural and functional theory of aging, in that the functional changes in the DMN during aging are accompanied by comparably localized structural alterations.

  7. Age- and gender-related regional variations of human brain cortical thickness, complexity, and gradient in the third decade.

    Science.gov (United States)

    Creze, Maud; Versheure, Leslie; Besson, Pierre; Sauvage, Chloe; Leclerc, Xavier; Jissendi-Tchofo, Patrice

    2014-06-01

    Brain functional and cytoarchitectural maturation continue until adulthood, but little is known about the evolution of the regional pattern of cortical thickness (CT), complexity (CC), and intensity or gradient (CG) in young adults. We attempted to detect global and regional age- and gender-related variations of brain CT, CC, and CG, in 28 healthy young adults (19-33 years) using a three-dimensional T1 -weighted magnetic resonance imaging sequence and surface-based methods. Whole brain interindividual variations of CT and CG were similar to that in the literature. As a new finding, age- and gender-related variations significantly affected brain complexity (P gender), all in the right hemisphere. Regions of interest analyses showed age and gender significant interaction (P left inferior parietal. In addition, we found significant inverse correlations between CT and CC and between CT and CG over the whole brain and markedly in precentral and occipital areas. Our findings differ in details from previous reports and may correlate with late brain maturation and learning plasticity in young adults' brain in the third decade. Copyright © 2013 Wiley Periodicals, Inc.

  8. Altered cortical expression of GABA-related genes in schizophrenia: illness progression vs developmental disturbance.

    Science.gov (United States)

    Hoftman, Gil D; Volk, David W; Bazmi, H Holly; Li, Siyu; Sampson, Allan R; Lewis, David A

    2015-01-01

    Schizophrenia is a neurodevelopmental disorder with altered expression of GABA-related genes in the prefrontal cortex (PFC). However, whether these gene expression abnormalities reflect disturbances in postnatal developmental processes before clinical onset or arise as a consequence of clinical illness remains unclear. Expression levels for 7 GABA-related transcripts (vesicular GABA transporter [vGAT], GABA membrane transporter [GAT1], GABAA receptor subunit α1 [GABRA1] [novel in human and monkey cohorts], glutamic acid decarboxylase 67 [GAD67], parvalbumin, calretinin, and somatostatin [previously reported in human cohort, but not in monkey cohort]) were quantified in the PFC from 42 matched pairs of schizophrenia and comparison subjects and from 49 rhesus monkeys ranging in age from 1 week postnatal to adulthood. Levels of vGAT and GABRA1, but not of GAT1, messenger RNAs (mRNAs) were lower in the PFC of the schizophrenia subjects. As previously reported, levels of GAD67, parvalbumin, and somatostatin, but not of calretinin, mRNAs were also lower in these subjects. Neither illness duration nor age accounted for the levels of the transcripts with altered expression in schizophrenia. In monkey PFC, developmental changes in expression levels of many of these transcripts were in the opposite direction of the changes observed in schizophrenia. For example, mRNA levels for vGAT, GABRA1, GAD67, and parvalbumin all increased with age. Together with published reports, these findings support the interpretation that the altered expression of GABA-related transcripts in schizophrenia reflects a blunting of normal postnatal development changes, but they cannot exclude a decline during the early stages of clinical illness. © The Author 2013. Published by Oxford University Press on behalf of the Maryland Psychiatric Research Center. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  9. Reestablishing speech understanding through musical ear training after cochlear implantation: a study of the potential cortical plasticity in the brain

    DEFF Research Database (Denmark)

    Petersen, Bjørn; Mortensen, Malene V; Gjedde, Albert

    2009-01-01

    the behavioral and neurologic effects of musical ear training on CI users' speech and music perception. The goal is to find and work out musical methods to improve CI users' auditory capabilities and, in a longer perspective, provide an efficient strategy for improving speech understanding for both adults......Cochlear implants (CIs) provide impressive speech perception for persons with severe hearing loss, but many CI recipients fail in perceiving speech prosody and music. Successful rehabilitation depends on cortical plasticity in the brain and postoperative measures. The present study evaluates...

  10. Cortical excitability correlates with the event-related desynchronization during brain-computer interface control

    Science.gov (United States)

    Daly, Ian; Blanchard, Caroline; Holmes, Nicholas P.

    2018-04-01

    Objective. Brain-computer interfaces (BCIs) based on motor control have been suggested as tools for stroke rehabilitation. Some initial successes have been achieved with this approach, however the mechanism by which they work is not yet fully understood. One possible part of this mechanism is a, previously suggested, relationship between the strength of the event-related desynchronization (ERD), a neural correlate of motor imagination and execution, and corticospinal excitability. Additionally, a key component of BCIs used in neurorehabilitation is the provision of visual feedback to positively reinforce attempts at motor control. However, the ability of visual feedback of the ERD to modulate the activity in the motor system has not been fully explored. Approach. We investigate these relationships via transcranial magnetic stimulation delivered at different moments in the ongoing ERD related to hand contraction and relaxation during BCI control of a visual feedback bar. Main results. We identify a significant relationship between ERD strength and corticospinal excitability, and find that our visual feedback does not affect corticospinal excitability. Significance. Our results imply that efforts to promote functional recovery in stroke by targeting increases in corticospinal excitability may be aided by accounting for the time course of the ERD.

  11. Motor Cortical Networks for Skilled Movements Have Dynamic Properties That Are Related to Accurate Reaching

    Directory of Open Access Journals (Sweden)

    David F. Putrino

    2011-01-01

    Full Text Available Neurons in the Primary Motor Cortex (MI are known to form functional ensembles with one another in order to produce voluntary movement. Neural network changes during skill learning are thought to be involved in improved fluency and accuracy of motor tasks. Unforced errors during skilled tasks provide an avenue to study network connections related to motor learning. In order to investigate network activity in MI, microwires were implanted in the MI of cats trained to perform a reaching task. Spike trains from eight groups of simultaneously recorded cells (95 neurons in total were acquired. A point process generalized linear model (GLM was developed to assess simultaneously recorded cells for functional connectivity during reaching attempts where unforced errors or no errors were made. Whilst the same groups of neurons were often functionally connected regardless of trial success, functional connectivity between neurons was significantly different at fine time scales when the outcome of task performance changed. Furthermore, connections were shown to be significantly more robust across multiple latencies during successful trials of task performance. The results of this study indicate that reach-related neurons in MI form dynamic spiking dependencies whose temporal features are highly sensitive to unforced movement errors.

  12. Cortical organization of inhibition-related functions and modulation by psychopathology.

    Science.gov (United States)

    Warren, Stacie L; Crocker, Laura D; Spielberg, Jeffery M; Engels, Anna S; Banich, Marie T; Sutton, Bradley P; Miller, Gregory A; Heller, Wendy

    2013-01-01

    Individual differences in inhibition-related functions have been implicated as risk factors for a broad range of psychopathology, including anxiety and depression. Delineating neural mechanisms of distinct inhibition-related functions may clarify their role in the development and maintenance of psychopathology. The present study tested the hypothesis that activity in common and distinct brain regions would be associated with an ecologically sensitive, self-report measure of inhibition and a laboratory performance measure of prepotent response inhibition. Results indicated that sub-regions of DLPFC distinguished measures of inhibition, whereas left inferior frontal gyrus and bilateral inferior parietal cortex were associated with both types of inhibition. Additionally, co-occurring anxiety and depression modulated neural activity in select brain regions associated with response inhibition. Results imply that specific combinations of anxiety and depression dimensions are associated with failure to implement top-down attentional control as reflected in inefficient recruitment of posterior DLPFC and increased activation in regions associated with threat (MTG) and worry (BA10). Present findings elucidate possible neural mechanisms of interference that could help explain executive control deficits in psychopathology.

  13. Cortical organization of inhibition-related functions and modulation by psychopathology

    Directory of Open Access Journals (Sweden)

    Stacie L. Warren

    2013-06-01

    Full Text Available Individual differences in inhibition-related functions have been implicated as risk factors for a broad range of psychopathology, including anxiety and depression. Delineating neural mechanisms of distinct inhibition-related functions may clarify their role in the development and maintenance of psychopathology. The present study tested the hypothesis that activity in common and distinct brain regions would be associated with an ecologically sensitive, self-report measure of inhibition and a laboratory performance measure of prepotent response inhibition. Results indicated that sub-regions of DLPFC distinguished measures of inhibition, whereas left inferior frontal gyrus and bilateral inferior parietal cortex were associated with both types of inhibition. Additionally, co-occurring anxiety and depression modulated neural activity in select brain regions associated with response inhibition. Results imply that specific combinations of anxiety and depression dimensions are associated with failure to implement top-down attentional control as reflected in inefficient recruitment of posterior DLPFC and increased activation in regions associated with threat (MTG and worry (BA10. Present findings elucidate possible neural mechanisms of interference that could help explain executive control deficits in psychopathology.

  14. rTMS Induced Tinnitus Relief Is Related to an Increase in Auditory Cortical Alpha Activity

    Science.gov (United States)

    Müller, Nadia; Lorenz, Isabel; Langguth, Berthold; Weisz, Nathan

    2013-01-01

    Chronic tinnitus, the continuous perception of a phantom sound, is a highly prevalent audiological symptom. A promising approach for the treatment of tinnitus is repetitive transcranial magnetic stimulation (rTMS) as this directly affects tinnitus-related brain activity. Several studies indeed show tinnitus relief after rTMS, however effects are moderate and vary strongly across patients. This may be due to a lack of knowledge regarding how rTMS affects oscillatory activity in tinnitus sufferers and which modulations are associated with tinnitus relief. In the present study we examined the effects of five different stimulation protocols (including sham) by measuring tinnitus loudness and tinnitus-related brain activity with Magnetoencephalography before and after rTMS. Changes in oscillatory activity were analysed for the stimulated auditory cortex as well as for the entire brain regarding certain frequency bands of interest (delta, theta, alpha, gamma). In line with the literature the effects of rTMS on tinnitus loudness varied strongly across patients. This variability was also reflected in the rTMS effects on oscillatory activity. Importantly, strong reductions in tinnitus loudness were associated with increases in alpha power in the stimulated auditory cortex, while an unspecific decrease in gamma and alpha power, particularly in left frontal regions, was linked to an increase in tinnitus loudness. The identification of alpha power increase as main correlate for tinnitus reduction sheds further light on the pathophysiology of tinnitus. This will hopefully stimulate the development of more effective therapy approaches. PMID:23390539

  15. Mesenchymal stem cells can modulate longitudinal changes in cortical thickness and its related cognitive decline in patients with multiple system atrophy

    Directory of Open Access Journals (Sweden)

    Mun Kyung eSunwoo

    2014-06-01

    Full Text Available Multiple system atrophy (MSA is an adult-onset sporadic neurodegenerative disease. Because the prognosis of MSA is fatal, neuroprotective or regenerative strategies may be invaluable in MSA treatment. Previously, we obtained clinical and imaging evidence that mesenchymal stem cell (MSC treatment could have a neuroprotective role in MSA patients. In the present study, we evaluated the effects of MSC therapy on longitudinal changes in subcortical deep grey matter volumes and cortical thickness and their association with cognitive performance. Clinical and imaging data were obtained from our previous randomized trial of autologous MSC in MSA patients. During 1-year follow-up, we assessed longitudinal differences in subcortical deep grey matter volumes and cortical thickness between placebo (n=15 and MSC groups (n=11. Next, we performed correlation analysis between the changes in cortical thickness and changes in the Korean version of the Montreal Cognitive Assessment (MoCA scores and detailed cognitive performance. There were no significant differences in age, gender ratio, disease duration, clinical severity, MoCA score, or education level between the groups. The subcortical volumetric analysis revealed that the changes in deep grey matter volumes of the caudate, putamen, and thalamus did not differ significantly between the groups. The areas of cortical thinning over time in the placebo group were more extensive, including the frontal, temporal, and parietal areas, whereas these areas in the MSC group were less extensive. Correlation analysis indicated that declines in MoCA scores and phonemic fluency were significantly correlated with cortical thinning of the frontal and posterior temporal areas and anterior temporal areas in MSA patients, respectively. These results suggest that MSC treatment in patients with MSA may modulate cortical thinning over time and related cognitive performance, inferring a future therapeutic candidate for cognitive

  16. 'Visual' cortical activation induced by acupuncture at vision-related acupoint: A fMRI study

    International Nuclear Information System (INIS)

    Yan, B.; Shan, B.C.; Zhi, L.H.; Li, K.; Lu, N.; Li, L.; Liu, H.

    2005-01-01

    It has attracted attention recently that acupuncture at vision-related acupoints, which are used to treat eye diseases according to Traditional Chinese Medicine (TCM), could activate the visual cortex. Cho and colleagues have reported that acupuncture at vision-related acupoints in the foot, activate the visual cortex bilaterally. Similar results were reported by Siedentopf and coworkers using laser acupuncture. However, Gareus et al. did not get the result, In this study, manual acupuncture was used to examine the response of central nervous system (CNS) to acupuncture at Liv3, one of important acupoints used to treat eye-related disease in clinic. To avoid the non-specific factors such as pain and anxiety, a sham acupoint which is approximately 10 mm anterior to Liv3 and innervated by the same spinal segment was selected as control. The CNS response was obtained by subtracting fMRI brain images evoked by nearby 'sham' acupoint from that evoked by the 'real' acupoint. 17 healthy right handed volunteers were comprised in the study. The images were got on 1.5T MR with EPI sequence. After 62 baseline scans, a silver needle 0.30 mm in diameter and 25 mm long was inserted and twirled for 60 scans; then the needle was withdrawn while fMRI scanning continued, until a total of 402 scans were acquired. During acupuncture, the needle was twirled manually clockwise and anticlockwise at 1 Hz with 'even reinforcing and reducing' needle manipulation. The depth of needle insertion at the sham acupoint was approximately 15 mm, the same as at the real acupoint. All the points in this study were on the right foot. The data were analyzed with spm99 using random effects analysis, discrepancies in the activation areas between Liv3 and the sham acupoint were obtained at p<0.01. Acupuncture at Liv3 significantly activated Brodmann Area 19 (BA 19) bilaterally, middle temporal gyrus, cerebellum, ipsilateral posterior cingulate, parahippocampal gyrus, contralateral postcentral gyrus, and

  17. 'Visual' cortical activation induced by acupuncture at vision-related acupoint: a fMRI study

    International Nuclear Information System (INIS)

    Yan, B.; Shan, B.C.; Zhi, L.H.; Li, K.; Lu, N.; Li, L.; Liu, H.

    2005-01-01

    It has attracted attention recently that acupuncture at vision-related acupoints, which are used to treat eye diseases according to Traditional Chinese Medicine (TCM), could activate the visual cortex. Cho and colleagues have reported that acupuncture at vision-related acupoints in the foot, activate the visual cortex bilaterally. Similar results were reported by Siedentopf and coworkers using laser acupuncture. However, Gareus et al. did not get the result. In this study, manual acupuncture was used to examine the response of central nervous system (CNS) to acupuncture at Liv3, one of important acupoints used to treat eye-related disease in clinic. To avoid the non-specific factors such as pain and anxiety, a sham acupoint which is approximately 10 mm anterior to Liv3 and innervated by the same spinal segment was selected as control. The CNS response was obtained by subtracting fMRI brain images evoked by nearby 'sham' acupoint from that evoked by the 'real' acupoint. 17 healthy right handed volunteers were comprised in the study. The images were got on 1.5T MR with EPI sequence. After 62 baseline scans, a silver needle 0.30 mm in diameter and 25 mm long was inserted and twirled for 60 scans; then the needle was withdrawn while fMRI scanning continued, until a total of 402 scans were acquired. During acupuncture, the needle was twirled manually clockwise and anticlockwise at 1 Hz with 'even reinforcing and reducing' needle manipulation. The depth of needle insertion at the sham acupoint was approximately 15 mm, the same as at the real acupoint. All the points in this study were on the right foot. The data were analyzed with spm99 using random effects analysis, discrepancies in the activation areas between Liv3 and the sham acupoint were obtained at p<0.01. Acupuncture at Liv3 significantly activated Brodmann Area 19 (BA 19) bilaterally, middle temporal gyrus, cerebellum, ipsilateral posterior cingulate, parahippocampal gyrus, contralateral postcentral gyrus, and

  18. Impulse Control Disorders in Parkinson's Disease are Associated with Alterations in Reward-Related Cortical Oscillations.

    Science.gov (United States)

    Carriere, Nicolas; Bourriez, Jean-Louis; Delval, Arnaud; Derambure, Philippe; Defebvre, Luc; Dujardin, Kathy

    2016-06-28

    Impulse control disorders (ICDs) in Parkinson's disease (PD) are related to treatment with dopamine agonists, which is thought to deregulate the dopaminergic mesolimbic pathway and impair reward evaluation. EEG studies in healthy controls (HCs) have suggested that the increase in theta power observed after negative outcome is a marker of reward processing. To compare outcome-locked, event-related spectral perturbation in a gambling task in PD patients with and without ICDs and in HCs. Twelve PD patients with ICDs, 12 PD patients without ICDs and 14 HCs underwent EEG while performing a gambling task. The groups were compared in terms of (i) the peak EEG power in the theta (4-7 Hz), alpha (8-14 Hz) and beta (15-30 Hz) frequency bands between 200 and 500 ms after the outcome, and (ii) time-frequency plots at Fz, FCz and Cz. Positive outcomes were associated with greater theta power than negative outcomes in patients without ICDs and in HCs, but not in patients with ICDs. Patients with ICDs and HCs displayed greater theta power following unexpectedly high outcomes. HCs displayed greater beta power following high amplitude than low amplitude outcomes, whereas patients with ICD showed the opposite pattern. In PD, ICDs are associated with (i) weaker modulation of frontocentral theta power by reward valence, (ii) greater frontocentral theta power following unexpected, high outcomes, and (iii) a reversal of the effect of risk on beta oscillations. These observations are consistent with an impairment in prediction error computation in the medial prefrontal cortex.

  19. Unexpected effects of peripherally administered kynurenic acid on cortical spreading depression and related blood–brain barrier permeability

    Directory of Open Access Journals (Sweden)

    Oláh G

    2013-09-01

    Full Text Available Gáspár Oláh,1 Judit Herédi,1 Ákos Menyhárt,1 Zsolt Czinege,2 Dávid Nagy,1 János Fuzik,1 Kitti Kocsis,1 Levente Knapp,1 Erika Krucsó,1 Levente Gellért,1 Zsolt Kis,1 Tamás Farkas,1 Ferenc Fülöp,3 Árpád Párdutz,4 János Tajti,4 László Vécsei,4 József Toldi1 1Department of Physiology, Anatomy and Neuroscience, 2Department of Software Engineering, 3Institute of Pharmaceutical Chemistry and MTA-SZTE Research Group for Stereochemistry, 4Department of Neurology and MTA-SZTE Neuroscience Research Group, University of Szeged, Szeged, Hungary Abstract: Cortical spreading depression (CSD involves a slowly-propagating depolarization wave in the cortex, which can appear in numerous pathophysiological conditions, such as migraine with aura, stroke, and traumatic brain injury. Neurons and glial cells are also depolarized transiently during the phenomena. CSD is followed by a massive increase in glutamate release and by changes in the brain microcirculation. The aim of this study was to investigate the effects of two N-methyl-D-aspartate receptor antagonists, endogenous kynurenic acid (KYNA and dizocilpine, on CSD and the related blood–brain barrier (BBB permeability in rats. In intact animals, KYNA hardly crosses the BBB but has some positive features as compared with its precursor L-Kynurenine, which is frequently used in animal studies (KYNA cannot be metabolized to excitotoxic agents such as 3-hydroxy-L-kynurenine and quinolinic acid. We therefore investigated the possible effects of peripherally administered KYNA. Repetitive CSD waves were elicited by the application of 1 M KCl solution to the cortex. Direct current-electrocorticograms were measured for 1 hour. Four parameters of the waves were compared. Evans blue dye and fluorescent microscopy were used to study the possible changes in the permeability of the BBB. The results demonstrated that N-methyl-D-aspartate receptor antagonists can reduce the number of CSD waves and decrease

  20. Decreased prefrontal cortical dopamine transmission in alcoholism.

    Science.gov (United States)

    Narendran, Rajesh; Mason, Neale Scott; Paris, Jennifer; Himes, Michael L; Douaihy, Antoine B; Frankle, W Gordon

    2014-08-01

    Basic studies have demonstrated that optimal levels of prefrontal cortical dopamine are critical to various executive functions such as working memory, attention, inhibitory control, and risk/reward decisions, all of which are impaired in addictive disorders such as alcoholism. Based on this and imaging studies of alcoholism that have demonstrated less dopamine in the striatum, the authors hypothesized decreased dopamine transmission in the prefrontal cortex in persons with alcohol dependence. To test this hypothesis, amphetamine and [11C]FLB 457 positron emission tomography were used to measure cortical dopamine transmission in 21 recently abstinent persons with alcohol dependence and 21 matched healthy comparison subjects. [11C]FLB 457 binding potential, specific compared to nondisplaceable uptake (BPND), was measured in subjects with kinetic analysis using the arterial input function both before and after 0.5 mg kg-1 of d-amphetamine. Amphetamine-induced displacement of [11C]FLB 457 binding potential (ΔBPND) was significantly smaller in the cortical regions in the alcohol-dependent group compared with the healthy comparison group. Cortical regions that demonstrated lower dopamine transmission in the alcohol-dependent group included the dorsolateral prefrontal cortex, medial prefrontal cortex, orbital frontal cortex, temporal cortex, and medial temporal lobe. The results of this study, for the first time, unambiguously demonstrate decreased dopamine transmission in the cortex in alcoholism. Further research is necessary to understand the clinical relevance of decreased cortical dopamine as to whether it is related to impaired executive function, relapse, and outcome in alcoholism.

  1. Speaking-related changes in cortical functional connectivity associated with assisted and spontaneous recovery from developmental stuttering.

    Science.gov (United States)

    Kell, Christian A; Neumann, Katrin; Behrens, Marion; von Gudenberg, Alexander W; Giraud, Anne-Lise

    2018-03-01

    We previously reported speaking-related activity changes associated with assisted recovery induced by a fluency shaping therapy program and unassisted recovery from developmental stuttering (Kell et al., Brain 2009). While assisted recovery re-lateralized activity to the left hemisphere, unassisted recovery was specifically associated with the activation of the left BA 47/12 in the lateral orbitofrontal cortex. These findings suggested plastic changes in speaking-related functional connectivity between left hemispheric speech network nodes. We reanalyzed these data involving 13 stuttering men before and after fluency shaping, 13 men who recovered spontaneously from their stuttering, and 13 male control participants, and examined functional connectivity during overt vs. covert reading by means of psychophysiological interactions computed across left cortical regions involved in articulation control. Persistent stuttering was associated with reduced auditory-motor coupling and enhanced integration of somatosensory feedback between the supramarginal gyrus and the prefrontal cortex. Assisted recovery reduced this hyper-connectivity and increased functional connectivity between the articulatory motor cortex and the auditory feedback processing anterior superior temporal gyrus. In spontaneous recovery, both auditory-motor coupling and integration of somatosensory feedback were normalized. In addition, activity in the left orbitofrontal cortex and superior cerebellum appeared uncoupled from the rest of the speech production network. These data suggest that therapy and spontaneous recovery normalizes the left hemispheric speaking-related activity via an improvement of auditory-motor mapping. By contrast, long-lasting unassisted recovery from stuttering is additionally supported by a functional isolation of the superior cerebellum from the rest of the speech production network, through the pivotal left BA 47/12. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. Age-related changes in the plasticity and toughness of human cortical bone at multiple length-scales

    Energy Technology Data Exchange (ETDEWEB)

    Zimmermann, Elizabeth A.; Schaible, Eric; Bale, Hrishikesh; Barth, Holly D.; Tang, Simon Y.; Reichert, Peter; Busse, Bjoern; Alliston, Tamara; Ager III, Joel W.; Ritchie, Robert O.

    2011-08-10

    The structure of human cortical bone evolves over multiple length-scales from its basic constituents of collagen and hydroxyapatite at the nanoscale to osteonal structures at nearmillimeter dimensions, which all provide the basis for its mechanical properties. To resist fracture, bone’s toughness is derived intrinsically through plasticity (e.g., fibrillar sliding) at structural-scales typically below a micron and extrinsically (i.e., during crack growth) through mechanisms (e.g., crack deflection/bridging) generated at larger structural-scales. Biological factors such as aging lead to a markedly increased fracture risk, which is often associated with an age-related loss in bone mass (bone quantity). However, we find that age-related structural changes can significantly degrade the fracture resistance (bone quality) over multiple lengthscales. Using in situ small-/wide-angle x-ray scattering/diffraction to characterize sub-micron structural changes and synchrotron x-ray computed tomography and in situ fracture-toughness measurements in the scanning electron microscope to characterize effects at micron-scales, we show how these age-related structural changes at differing size-scales degrade both the intrinsic and extrinsic toughness of bone. Specifically, we attribute the loss in toughness to increased non-enzymatic collagen cross-linking which suppresses plasticity at nanoscale dimensions and to an increased osteonal density which limits the potency of crack-bridging mechanisms at micron-scales. The link between these processes is that the increased stiffness of the cross-linked collagen requires energy to be absorbed by “plastic” deformation at higher structural levels, which occurs by the process of microcracking.

  3. In Vivo Imaging of Cortical Inflammation and Subpial Pathology in Multiple Sclerosis by Combined PET and MRI

    Science.gov (United States)

    2015-09-01

    microglia to assess whether more severe structural cortical pathology in MS is related to the presence of neuroinflammation. Our initial findings...potential biomarkers of MS progression. Since cortical lesions appeared topographically related to focal meningeal inflammation in some pathological ...mm3, p=0.004 adjusting for age and total intracranial volume). In MS, cortical thinning was related with diffuse inflammation in cortex, thalamus and

  4. The cortical signature of amyotrophic lateral sclerosis.

    Directory of Open Access Journals (Sweden)

    Federica Agosta

    Full Text Available The aim of this study was to explore the pattern of regional cortical thickness in patients with non-familial amyotrophic lateral sclerosis (ALS and to investigate whether cortical thinning is associated with disease progression rate. Cortical thickness analysis was performed in 44 ALS patients and 26 healthy controls. Group differences in cortical thickness and the age-by-group effects were assessed using vertex-by-vertex and multivariate linear models. The discriminatory ability of MRI variables in distinguishing patients from controls was estimated using the Concordance Statistics (C-statistic within logistic regression analyses. Correlations between cortical thickness measures and disease progression rate were tested using the Pearson coefficient. Relative to controls, ALS patients showed a bilateral cortical thinning of the primary motor, prefrontal and ventral frontal cortices, cingulate gyrus, insula, superior and inferior temporal and parietal regions, and medial and lateral occipital areas. There was a significant age-by-group effect in the sensorimotor cortices bilaterally, suggesting a stronger association between age and cortical thinning in ALS patients compared to controls. The mean cortical thickness of the sensorimotor cortices distinguished patients with ALS from controls (C-statistic ≥ 0.74. Cortical thinning of the left sensorimotor cortices was related to a faster clinical progression (r = -0.33, p = 0.03. Cortical thickness measurements allowed the detection and quantification of motor and extramotor involvement in patients with ALS. Cortical thinning of the precentral gyrus might offer a marker of upper motor neuron involvement and disease progression.

  5. The cortical signature of amyotrophic lateral sclerosis.

    Science.gov (United States)

    Agosta, Federica; Valsasina, Paola; Riva, Nilo; Copetti, Massimiliano; Messina, Maria Josè; Prelle, Alessandro; Comi, Giancarlo; Filippi, Massimo

    2012-01-01

    The aim of this study was to explore the pattern of regional cortical thickness in patients with non-familial amyotrophic lateral sclerosis (ALS) and to investigate whether cortical thinning is associated with disease progression rate. Cortical thickness analysis was performed in 44 ALS patients and 26 healthy controls. Group differences in cortical thickness and the age-by-group effects were assessed using vertex-by-vertex and multivariate linear models. The discriminatory ability of MRI variables in distinguishing patients from controls was estimated using the Concordance Statistics (C-statistic) within logistic regression analyses. Correlations between cortical thickness measures and disease progression rate were tested using the Pearson coefficient. Relative to controls, ALS patients showed a bilateral cortical thinning of the primary motor, prefrontal and ventral frontal cortices, cingulate gyrus, insula, superior and inferior temporal and parietal regions, and medial and lateral occipital areas. There was a significant age-by-group effect in the sensorimotor cortices bilaterally, suggesting a stronger association between age and cortical thinning in ALS patients compared to controls. The mean cortical thickness of the sensorimotor cortices distinguished patients with ALS from controls (C-statistic ≥ 0.74). Cortical thinning of the left sensorimotor cortices was related to a faster clinical progression (r = -0.33, p = 0.03). Cortical thickness measurements allowed the detection and quantification of motor and extramotor involvement in patients with ALS. Cortical thinning of the precentral gyrus might offer a marker of upper motor neuron involvement and disease progression.

  6. Dynamic functional coupling of high resolution EEG potentials related to unilateral internally triggered one-digit movements.

    Science.gov (United States)

    Urbano, A; Babiloni, C; Onorati, P; Babiloni, F

    1998-06-01

    Between-electrode cross-covariances of delta (0-3 Hz)- and theta (4-7 Hz)-filtered high resolution EEG potentials related to preparation, initiation. and execution of human unilateral internally triggered one-digit movements were computed to investigate statistical dynamic coupling between these potentials. Significant (P planning, starting, and performance of unilateral movement. The involvement of these cortical areas is supported by the observation that averaged spatially enhanced delta- and theta-bandpassed potentials were computed from the scalp regions where task-related electrical activation of primary sensorimotor areas and supplementary motor area was roughly represented.

  7. Effects of traumatic brain injury on a virtual reality social problem solving task and relations to cortical thickness in adolescence.

    Science.gov (United States)

    Hanten, Gerri; Cook, Lori; Orsten, Kimberley; Chapman, Sandra B; Li, Xiaoqi; Wilde, Elisabeth A; Schnelle, Kathleen P; Levin, Harvey S

    2011-02-01

    Social problem solving was assessed in 28 youth ages 12-19 years (15 with moderate to severe traumatic brain injury (TBI), 13 uninjured) using a naturalistic, computerized virtual reality (VR) version of the Interpersonal Negotiations Strategy interview (Yeates, Schultz, & Selman, 1991). In each scenario, processing load condition was varied in terms of number of characters and amount of information. Adolescents viewed animated scenarios depicting social conflict in a virtual microworld environment from an avatar's viewpoint, and were questioned on four problem solving steps: defining the problem, generating solutions, selecting solutions, and evaluating the likely outcome. Scoring was based on a developmental scale in which responses were judged as impulsive, unilateral, reciprocal, or collaborative, in order of increasing score. Adolescents with TBI were significantly impaired on the summary VR-Social Problem Solving (VR-SPS) score in Condition A (2 speakers, no irrelevant information), p=0.005; in Condition B (2 speakers+irrelevant information), p=0.035; and Condition C (4 speakers+irrelevant information), p=0.008. Effect sizes (Cohen's D) were large (A=1.40, B=0.96, C=1.23). Significant group differences were strongest and most consistent for defining the problems and evaluating outcomes. The relation of task performance to cortical thickness of specific brain regions was also explored, with significant relations found with orbitofrontal regions, the frontal pole, the cuneus, and the temporal pole. Results are discussed in the context of specific cognitive and neural mechanisms underlying social problem solving deficits after childhood TBI. Copyright © 2010 Elsevier Ltd. All rights reserved.

  8. Direct Exploration of the Role of the Ventral Anterior Temporal Lobe in Semantic Memory: Cortical Stimulation and Local Field Potential Evidence From Subdural Grid Electrodes.

    Science.gov (United States)

    Shimotake, Akihiro; Matsumoto, Riki; Ueno, Taiji; Kunieda, Takeharu; Saito, Satoru; Hoffman, Paul; Kikuchi, Takayuki; Fukuyama, Hidenao; Miyamoto, Susumu; Takahashi, Ryosuke; Ikeda, Akio; Lambon Ralph, Matthew A

    2015-10-01

    Semantic memory is a crucial higher cortical function that codes the meaning of objects and words, and when impaired after neurological damage, patients are left with significant disability. Investigations of semantic dementia have implicated the anterior temporal lobe (ATL) region, in general, as crucial for multimodal semantic memory. The potentially crucial role of the ventral ATL subregion has been emphasized by recent functional neuroimaging studies, but the necessity of this precise area has not been selectively tested. The implantation of subdural electrode grids over this subregion, for the presurgical assessment of patients with partial epilepsy or brain tumor, offers the dual yet rare opportunities to record cortical local field potentials while participants complete semantic tasks and to stimulate the functionally identified regions in the same participants to evaluate the necessity of these areas in semantic processing. Across 6 patients, and utilizing a variety of semantic assessments, we evaluated and confirmed that the anterior fusiform/inferior temporal gyrus is crucial in multimodal, receptive, and expressive, semantic processing. © The Author 2014. Published by Oxford University Press.

  9. [Effects of anxiety and the COMT gene on cortical evoked potentials and performance effectiveness of selective attention].

    Science.gov (United States)

    Alfimova, M V; Golimbet, V E; Lebedeva, I S; Korovaĭtseva, G I; Lezheĭko, T V

    2014-01-01

    We studied influence of the anxiety-related trait Harm Avoidance and the COMT gene, which is an important modulator of prefrontal functioning, on event-related potentials in oddball paradigm and performance effectiveness of selective attention. For 50 individuals accuracy and time of searching words among letters at any desired rate and then under an instruction to perform the task as quickly and accurate as possible were measured. Scores on the Harm Avoidance scale from Cloninger's Temperament and Character Inventory, N100 and P300 parameters, and COMTVa1158Met genotypes were obtained for them as well. Searching accuracy and time were mainly related to N100 amplitude. The COMT genotype and Harm Avoidance did not affect N100 amplitude; however, the N100 amplitude modulated their effects on accuracy and time dynamics. Harm Avoidance was positively correlated with P300 latency. The results suggest that anxiety and the COMT gene effects on performance effectiveness of selective attention depend on cognitive processes reflected in N100 parameters.

  10. Cortico-cortical communication dynamics

    Directory of Open Access Journals (Sweden)

    Per E Roland

    2014-05-01

    Full Text Available IIn principle, cortico-cortical communication dynamics is simple: neurons in one cortical area communicate by sending action potentials that release glutamate and excite their target neurons in other cortical areas. In practice, knowledge about cortico-cortical communication dynamics is minute. One reason is that no current technique can capture the fast spatio-temporal cortico-cortical evolution of action potential transmission and membrane conductances with sufficient spatial resolution. A combination of optogenetics and monosynaptic tracing with virus can reveal the spatio-temporal cortico-cortical dynamics of specific neurons and their targets, but does not reveal how the dynamics evolves under natural conditions. Spontaneous ongoing action potentials also spread across cortical areas and are difficult to separate from structured evoked and intrinsic brain activity such as thinking. At a certain state of evolution, the dynamics may engage larger populations of neurons to drive the brain to decisions, percepts and behaviors. For example, successfully evolving dynamics to sensory transients can appear at the mesoscopic scale revealing how the transient is perceived. As a consequence of these methodological and conceptual difficulties, studies in this field comprise a wide range of computational models, large-scale measurements (e.g., by MEG, EEG, and a combination of invasive measurements in animal experiments. Further obstacles and challenges of studying cortico-cortical communication dynamics are outlined in this critical review.

  11. Cortico-cortical white matter motor pathway microstructure is related to psychomotor retardation in major depressive disorder.

    Directory of Open Access Journals (Sweden)

    Tobias Bracht

    Full Text Available Alterations of brain structure and function have been associated with psychomotor retardation in major depressive disorder (MDD. However, the association of motor behaviour and white matter integrity of motor pathways in MDD is unclear. The aim of the present study was to first investigate structural connectivity of white matter motor pathways in MDD. Second, we explore the relation of objectively measured motor activity and white matter integrity of motor pathways in MDD. Therefore, 21 patients with MDD and 21 healthy controls matched for age, gender, education and body mass index underwent diffusion tensor imaging and 24 hour actigraphy (measure of the activity level the same day. Applying a probabilistic fibre tracking approach we extracted connection pathways between the dorsolateral prefrontal cortex (dlPFC, the rostral anterior cingulate cortex (rACC, the pre-supplementary motor area (pre-SMA, the SMA-proper, the primary motor cortex (M1, the caudate nucleus, the putamen, the pallidum and the thalamus. Patients had lower activity levels and demonstrated increased mean diffusivity (MD in pathways linking left pre-SMA and SMA-proper, and right SMA-proper and M1. Exploratory analyses point to a positive association of activity level and mean-fractional anisotropy in the right rACC-pre-SMA connection in MDD. Only MDD patients with low activity levels had a negative linear association of activity level and mean-MD in the left dlPFC-pre-SMA connection. Our results point to structural alterations of cortico-cortical white matter motor pathways in MDD. Altered white matter organisation of rACC-pre-SMA and dlPFC-pre-SMA pathways may contribute to movement initiation in MDD.

  12. Discrepancy between perceived pain and cortical processing: A voxel-based morphometry and contact heat evoked potential study.

    Science.gov (United States)

    Kramer, J L K; Jutzeler, C R; Haefeli, J; Curt, A; Freund, P

    2016-01-01

    The purpose of this study was to determine if local gray and white matter volume variations between subjects could account for variability in responses to CHEP stimulation. Structural magnetic resonance imaging was used to perform voxel-based morphometry (VBM) of gray and white matter in 30 neurologically healthy subjects. Contact heat stimulation was performed on the dorsum of the right hand at the base of the thumb. Evoked potentials were acquired from a vertex-recording electrode referenced to linked ears. Controlling for age, total intracranial volume, and skull/scalp thickness, CHEP amplitude and pain rating were not significantly correlated between subjects. A VBM region of interest approach demonstrated a significant interaction between pain rating and N2 amplitude in the right insular cortex (ppain rating. This finding suggests that the discrepancy between pain ratings and the amplitude of evoked potentials is not solely related to measurement artifact, but rather attributable, in part, to anatomical differences between subjects. Crown Copyright © 2015. Published by Elsevier Ireland Ltd. All rights reserved.

  13. How creative potential is related to metacognition

    Directory of Open Access Journals (Sweden)

    María Luisa Sanz de Acedo Lizarraga

    2013-12-01

    Full Text Available The primary objective of this study was to investigate the possible links between metacognition and narrative (or verbal and graphic creative potential as well as the contribution of the former variable to creativity. The second objective was to study the effect of gender on these variables. This study was conducted with 360 men and women students from the Public University of Navarra enrolled in applied sociology, social work, and specialising in infant and primary education. Participants were given the Adult Creative Imagination Test and the Creative Metacognition Scale during their regular school schedule and during a single session. The results showed that the relationships between the assessed variables were significant and positive. Furthermore, metacognition moderately predicted narrative creativity; thus, cognitive processes do not operate in isolation because they affect and are affected by other factors. The findings also revealed that students obtained different results with regard to verbal and graphic creativity, and men and women differed only in narrative creative potential. The most important conclusion to be drawn from this research is that creative and metacognitive skills should be explicitly involved in higher education to stimulate the creative potential of future professionals

  14. Auditory verbal hallucinations are related to cortical thinning in the left middle temporal gyrus of patients with schizophrenia.

    Science.gov (United States)

    Cui, Y; Liu, B; Song, M; Lipnicki, D M; Li, J; Xie, S; Chen, Y; Li, P; Lu, L; Lv, L; Wang, H; Yan, H; Yan, J; Zhang, H; Zhang, D; Jiang, T

    2018-01-01

    Auditory verbal hallucinations (AVHs) are one of the most common and severe symptoms of schizophrenia, but the neuroanatomical abnormalities underlying AVHs are not well understood. The present study aims to investigate whether AVHs are associated with cortical thinning. Participants were schizophrenia patients from four centers across China, 115 with AVHs and 93 without AVHs, as well as 261 healthy controls. All received 3 T T1-weighted brain scans, and whole brain vertex-wise cortical thickness was compared across groups. Correlations between AVH severity and cortical thickness were also determined. The left middle part of the middle temporal gyrus (MTG) was significantly thinner in schizophrenia patients with AVHs than in patients without AVHs and healthy controls. Inferences were made using a false discovery rate approach with a threshold at p < 0.05. Left MTG thickness did not differ between patients without AVHs and controls. These results were replicated by a meta-analysis showing them to be consistent across the four centers. Cortical thickness of the left MTG was also found to be inversely correlated with hallucination severity across all schizophrenia patients. The results of this multi-center study suggest that an abnormally thin left MTG could be involved in the pathogenesis of AVHs in schizophrenia.

  15. Mitogen-activated protein kinase signaling pathways promote low-density lipoprotein receptor-related protein 1-mediated internalization of beta-amyloid protein in primary cortical neurons.

    Science.gov (United States)

    Yang, Wei-Na; Ma, Kai-Ge; Qian, Yi-Hua; Zhang, Jian-Shui; Feng, Gai-Feng; Shi, Li-Li; Zhang, Zhi-Chao; Liu, Zhao-Hui

    2015-07-01

    Mounting evidence suggests that the pathological hallmarks of Alzheimer's disease (AD) are caused by the intraneuronal accumulation of beta-amyloid protein (Aβ). Reuptake of extracellular Aβ is believed to contribute significantly to the intraneuronal Aβ pool in the early stages of AD. Published reports have claimed that the low-density lipoprotein receptor-related protein 1 (LRP1) mediates Aβ1-42 uptake and lysosomal trafficking in GT1-7 neuronal cells and mouse embryonic fibroblast non-neuronal cells. However, there is no direct evidence supporting the role of LRP1 in Aβ internalization in primary neurons. Our recent study indicated that p38 MAPK and ERK1/2 signaling pathways are involved in regulating α7 nicotinic acetylcholine receptor (α7nAChR)-mediated Aβ1-42 uptake in SH-SY5Y cells. This study was designed to explore the regulation of MAPK signaling pathways on LRP1-mediated Aβ internalization in neurons. We found that extracellular Aβ1-42 oligomers could be internalized into endosomes/lysosomes and mitochondria in cortical neurons. Aβ1-42 and LRP1 were also found co-localized in neurons during Aβ1-42 internalization, and they could form Aβ1-42-LRP1 complex. Knockdown of LRP1 expression significantly decreased neuronal Aβ1-42 internalization. Finally, we identified that p38 MAPK and ERK1/2 signaling pathways regulated the internalization of Aβ1-42 via LRP1. Therefore, these results demonstrated that LRP1, p38 MAPK and ERK1/2 mediated the internalization of Aβ1-42 in neurons and provided evidence that blockade of LRP1 or inhibitions of MAPK signaling pathways might be a potential approach to lowering brain Aβ levels and served a potential therapeutic target for AD. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Mesenchymal stem cells can modulate longitudinal changes in cortical thickness and its related cognitive decline in patients with multiple system atrophy

    Science.gov (United States)

    Sunwoo, Mun Kyung; Yun, Hyuk Jin; Song, Sook K.; Ham, Ji Hyun; Hong, Jin Yong; Lee, Ji E.; Lee, Hye S.; Sohn, Young H.; Lee, Jong-Min; Lee, Phil Hyu

    2014-01-01

    significant correlations were observed in the MSC group. These results suggest that MSC treatment in patients with MSA may modulate cortical thinning over time and related cognitive performance, inferring a future therapeutic candidate for cognitive disorders. PMID:24982631

  17. Brain cortical characteristics of lifetime cognitive ageing.

    Science.gov (United States)

    Cox, Simon R; Bastin, Mark E; Ritchie, Stuart J; Dickie, David Alexander; Liewald, Dave C; Muñoz Maniega, Susana; Redmond, Paul; Royle, Natalie A; Pattie, Alison; Valdés Hernández, Maria; Corley, Janie; Aribisala, Benjamin S; McIntosh, Andrew M; Wardlaw, Joanna M; Deary, Ian J

    2018-01-01

    Regional cortical brain volume is the product of surface area and thickness. These measures exhibit partially distinct trajectories of change across the brain's cortex in older age, but it is unclear which cortical characteristics at which loci are sensitive to cognitive ageing differences. We examine associations between change in intelligence from age 11 to 73 years and regional cortical volume, surface area, and thickness measured at age 73 years in 568 community-dwelling older adults, all born in 1936. A relative positive change in intelligence from 11 to 73 was associated with larger volume and surface area in selective frontal, temporal, parietal, and occipital regions (r cognitive ageing and a thinner cortex for any region. Interestingly, thickness and surface area were phenotypically independent across bilateral lateral temporal loci, whose surface area was significantly related to change in intelligence. These findings suggest that associations between regional cortical volume and cognitive ageing differences are predominantly driven by surface area rather than thickness among healthy older adults. Regional brain surface area has been relatively underexplored, and is a potentially informative biomarker for identifying determinants of cognitive ageing differences.

  18. Age-Related Differences in Cortical Activity during a Visuo-Spatial Working Memory Task with Facial Stimuli

    OpenAIRE

    Belham, Fl?via Schechtman; Satler, Corina; Garcia, Ana; Tomaz, Carlos; Gasbarri, Antonella; Rego, Artur; Tavares, Maria Clotilde H.

    2013-01-01

    Emotion, importantly displayed by facial expressions, is one of the most significant memory modulators. The interaction between memory and the different emotional valences change across lifespan, while young adults (YA) are expected to better recall negative events (Negativity Bias Hypothesis), older adults (OA) tend to focus on positive stimuli (Positivity Effect Hypothesis). This research work aims at verifying whether cortical electrical activity of these two age groups would also be diffe...

  19. Potential characteristics that relate to teachers mathematics-related beliefs

    Science.gov (United States)

    Purnomo, Y. W.; Aziz, T. A.; Pramudiani, P.; Darwis, S.; Suryadi, D.

    2018-01-01

    A characteristic of the persons was very potential to affect the beliefs they held. This study examines whether there was a significant difference between the beliefs factors with characteristics such as gender, teaching experience, certification status, and grade level assignments. There were 325 primary school teachers in East Jakarta who participated in this research. MANOVA was applied to analyze the data. The findings of this study indicate that only on teaching experience, there was a significant difference between the beliefs held by the teachers, i.e. teachers who have 11-20 years teaching experience were more likely to think absolute than constructivism. Moreover, there was no difference between each belief they held with the other characteristics.

  20. Ethanol induces cell-cycle activity and reduces stem cell diversity to alter both regenerative capacity and differentiation potential of cerebral cortical neuroepithelial precursors

    Directory of Open Access Journals (Sweden)

    Tingling Joseph D

    2005-09-01

    Full Text Available Abstract Background The fetal cortical neuroepithelium is a mosaic of distinct progenitor populations that elaborate diverse cellular fates. Ethanol induces apoptosis and interferes with the survival of differentiating neurons. However, we know little about ethanol's effects on neuronal progenitors. We therefore exposed neurosphere cultures from fetal rat cerebral cortex, to varying ethanol concentrations, to examine the impact of ethanol on stem cell fate. Results Ethanol promoted cell cycle progression, increased neurosphere number and increased diversity in neurosphere size, without inducing apoptosis. Unlike controls, dissociated cortical progenitors exposed to ethanol exhibited morphological evidence for asymmetric cell division, and cells derived from ethanol pre-treated neurospheres exhibited decreased proliferation capacity. Ethanol significantly reduced the numbers of cells expressing the stem cell markers CD117, CD133, Sca-1 and ABCG2, without decreasing nestin expression. Furthermore, ethanol-induced neurosphere proliferation was not accompanied by a commensurate increase in telomerase activity. Finally, cells derived from ethanol-pretreated neurospheres exhibited decreased differentiation in response to retinoic acid. Conclusion The reduction in stem cell number along with a transient ethanol-driven increase in cell proliferation, suggests that ethanol promotes stem to blast cell maturation, ultimately depleting the reserve proliferation capacity of neuroepithelial cells. However, the lack of a concomitant change in telomerase activity suggests that neuroepithelial maturation is accompanied by an increased potential for genomic instability. Finally, the cellular phenotype that emerges from ethanol pre-treated, stem cell depleted neurospheres is refractory to additional differentiation stimuli, suggesting that ethanol exposure ablates or delays subsequent neuronal differentiation.

  1. Changes in cortical cytoskeletal and extracellular matrix gene expression in prostate cancer are related to oncogenic ERG deregulation

    International Nuclear Information System (INIS)

    Schulz, Wolfgang A; Ingenwerth, Marc; Djuidje, Carolle E; Hader, Christiane; Rahnenführer, Jörg; Engers, Rainer

    2010-01-01

    The cortical cytoskeleton network connects the actin cytoskeleton to various membrane proteins, influencing cell adhesion, polarity, migration and response to extracellular signals. Previous studies have suggested changes in the expression of specific components in prostate cancer, especially of 4.1 proteins (encoded by EPB41 genes) which form nodes in this network. Expression of EPB41L1, EPB41L2, EPB41L3 (protein: 4.1B), EPB41L4B (EHM2), EPB41L5, EPB49 (dematin), VIL2 (ezrin), and DLG1 (summarized as „cortical cytoskeleton' genes) as well as ERG was measured by quantitative RT-PCR in a well-characterized set of 45 M0 prostate adenocarcinoma and 13 benign tissues. Hypermethylation of EPB41L3 and GSTP1 was compared in 93 cancer tissues by methylation-specific PCR. Expression of 4.1B was further studied by immunohistochemistry. EPB41L1 and EPB41L3 were significantly downregulated and EPB41L4B was upregulated in cancer tissues. Low EPB41L1 or high EPB41L4B expression were associated with earlier biochemical recurrence. None of the other cortical cytoskeleton genes displayed expression changes, in particular EPB49 and VIL2, despite hints from previous studies. EPB41L3 downregulation was significantly associated with hypermethylation of its promoter and strongly correlated with GSTP1 hypermethylation. Protein 4.1B was detected most strongly in the basal cells of normal prostate epithelia. Its expression in carcinoma cells was similar to the weaker one in normal luminal cells. EPB41L3 downregulation and EPB41L4B upregulation were essentially restricted to the 22 cases with ERG overexpression. Expression changes in EPB41L3 and EPB41L4B closely paralleled those previously observed for the extracellular matrix genes FBLN1 and SPOCK1, respectively. Specific changes in the cortical cytoskeleton were observed during prostate cancer progression. They parallel changes in the expression of extracellular matrix components and all together appear to be associated with

  2. Effect of porosity, tissue density, and mechanical properties on radial sound speed in human cortical bone

    Energy Technology Data Exchange (ETDEWEB)

    Eneh, C. T. M., E-mail: chibuzor.eneh@uef.fi, E-mail: markus.malo@uef.fi, E-mail: janne.karjalainen@boneindex.fi, E-mail: jukka.liukkonen@gmail.com, E-mail: juha.toyras@uef.fi; Töyräs, J., E-mail: chibuzor.eneh@uef.fi, E-mail: markus.malo@uef.fi, E-mail: janne.karjalainen@boneindex.fi, E-mail: jukka.liukkonen@gmail.com, E-mail: juha.toyras@uef.fi; Jurvelin, J. S., E-mail: jukka.jurvelin@uef.fi [Department of Applied Physics, University of Eastern Finland, P.O. Box 1627, Kuopio FI-70211, Finland and Diagnostic Imaging Center, Kuopio University Hospital, P.O. Box 100, Kuopio FI-70029 (Finland); Malo, M. K. H., E-mail: chibuzor.eneh@uef.fi, E-mail: markus.malo@uef.fi, E-mail: janne.karjalainen@boneindex.fi, E-mail: jukka.liukkonen@gmail.com, E-mail: juha.toyras@uef.fi; Liukkonen, J., E-mail: chibuzor.eneh@uef.fi, E-mail: markus.malo@uef.fi, E-mail: janne.karjalainen@boneindex.fi, E-mail: jukka.liukkonen@gmail.com, E-mail: juha.toyras@uef.fi [Department of Applied Physics, University of Eastern Finland, P.O. Box 1627, Kuopio FI-70211 (Finland); Karjalainen, J. P., E-mail: chibuzor.eneh@uef.fi, E-mail: markus.malo@uef.fi, E-mail: janne.karjalainen@boneindex.fi, E-mail: jukka.liukkonen@gmail.com, E-mail: juha.toyras@uef.fi [Bone Index Finland Ltd., P.O. Box 1188, Kuopio FI-70211 (Finland)

    2016-05-15

    Purpose: The purpose of this study was to investigate the effect of simultaneous changes in cortical porosity, tissue mineral density, and elastic properties on radial speed of sound (SOS) in cortical bone. The authors applied quantitative pulse-echo (PE) ultrasound techniques that hold much potential especially for screening of osteoporosis at primary healthcare facilities. Currently, most PE measurements of cortical thickness, a well-known indicator of fracture risk, use a predefined estimate for SOS in bone to calculate thickness. Due to variation of cortical bone porosity, the use of a constant SOS value propagates to an unknown error in cortical thickness assessment by PE ultrasound. Methods: The authors conducted 2.25 and 5.00 MHz focused PE ultrasound time of flight measurements on femoral diaphyses of 18 cadavers in vitro. Cortical porosities of the samples were determined using microcomputed tomography and related to SOS in the samples. Additionally, the effect of cortical bone porosity and mechanical properties of the calcified matrix on SOS was investigated using numerical finite difference time domain simulations. Results: Both experimental measurements and simulations demonstrated significant negative correlation between radial SOS and cortical porosity (R{sup 2} ≥ 0.493, p < 0.01 and R{sup 2} ≥ 0.989, p < 0.01, respectively). When a constant SOS was assumed for cortical bone, the error due to variation of cortical bone porosity (4.9%–16.4%) was about 6% in the cortical thickness assessment in vitro. Conclusions: Use of a predefined, constant value for radial SOS in cortical bone, i.e., neglecting the effect of measured variation in cortical porosity, propagated to an error of 6% in cortical thickness. This error can be critical as characteristic cortical thinning of 1.10% ± 1.06% per yr decreases bending strength of the distal radius and results in increased fragility in postmenopausal women. Provided that the cortical porosity can be estimated

  3. Effect of porosity, tissue density, and mechanical properties on radial sound speed in human cortical bone

    International Nuclear Information System (INIS)

    Eneh, C. T. M.; Töyräs, J.; Jurvelin, J. S.; Malo, M. K. H.; Liukkonen, J.; Karjalainen, J. P.

    2016-01-01

    Purpose: The purpose of this study was to investigate the effect of simultaneous changes in cortical porosity, tissue mineral density, and elastic properties on radial speed of sound (SOS) in cortical bone. The authors applied quantitative pulse-echo (PE) ultrasound techniques that hold much potential especially for screening of osteoporosis at primary healthcare facilities. Currently, most PE measurements of cortical thickness, a well-known indicator of fracture risk, use a predefined estimate for SOS in bone to calculate thickness. Due to variation of cortical bone porosity, the use of a constant SOS value propagates to an unknown error in cortical thickness assessment by PE ultrasound. Methods: The authors conducted 2.25 and 5.00 MHz focused PE ultrasound time of flight measurements on femoral diaphyses of 18 cadavers in vitro. Cortical porosities of the samples were determined using microcomputed tomography and related to SOS in the samples. Additionally, the effect of cortical bone porosity and mechanical properties of the calcified matrix on SOS was investigated using numerical finite difference time domain simulations. Results: Both experimental measurements and simulations demonstrated significant negative correlation between radial SOS and cortical porosity (R"2 ≥ 0.493, p < 0.01 and R"2 ≥ 0.989, p < 0.01, respectively). When a constant SOS was assumed for cortical bone, the error due to variation of cortical bone porosity (4.9%–16.4%) was about 6% in the cortical thickness assessment in vitro. Conclusions: Use of a predefined, constant value for radial SOS in cortical bone, i.e., neglecting the effect of measured variation in cortical porosity, propagated to an error of 6% in cortical thickness. This error can be critical as characteristic cortical thinning of 1.10% ± 1.06% per yr decreases bending strength of the distal radius and results in increased fragility in postmenopausal women. Provided that the cortical porosity can be estimated in vivo

  4. Extensive Tonotopic Mapping across Auditory Cortex Is Recapitulated by Spectrally Directed Attention and Systematically Related to Cortical Myeloarchitecture.

    Science.gov (United States)

    Dick, Frederic K; Lehet, Matt I; Callaghan, Martina F; Keller, Tim A; Sereno, Martin I; Holt, Lori L

    2017-12-13

    diverse pathologies reduce quality of life by impacting such spectrally directed auditory attention, its neurobiological bases are unclear. We demonstrate that human primary and nonprimary auditory cortical activation is modulated by spectrally directed attention in a manner that recapitulates its tonotopic sensory organization. Further, the graded activation profiles evoked by single-frequency bands are correlated with attentionally driven activation when these bands are presented in complex soundscapes. Finally, we observe a strong concordance in the degree of cortical myelination and the strength of tonotopic activation across several auditory cortical regions. Copyright © 2017 Dick et al.

  5. Relating derived relations as a model of analogical reasoning: reaction times and event-related potentials.

    Science.gov (United States)

    Barnes-Holmes, Dermot; Regan, Donal; Barnes-Holmes, Yvonne; Commins, Sean; Walsh, Derek; Stewart, Ian; Smeets, Paul M; Whelan, Robert; Dymond, Simon

    2005-11-01

    The current study aimed to test a Relational Frame Theory (RFT) model of analogical reasoning based on the relating of derived same and derived difference relations. Experiment 1 recorded reaction time measures of similar-similar (e.g., "apple is to orange as dog is to cat") versus different-different (e.g., "he is to his brother as chalk is to cheese") derived relational responding, in both speed-contingent and speed-noncontingent conditions. Experiment 2 examined the event-related potentials (ERPs) associated with these two response patterns. Both experiments showed similar-similar responding to be significantly faster than different-different responding. Experiment 2 revealed significant differences between the waveforms of the two response patterns in the left-hemispheric prefrontal regions; different-different waveforms were significantly more negative than similar-similar waveforms. The behavioral and neurophysiological data support the RFT prediction that, all things being equal, similar-similar responding is relationally "simpler" than, and functionally distinct from, different-different analogical responding. The ERP data were fully consistent with findings in the neurocognitive literature on analogy. These findings strengthen the validity of the RFT model of analogical reasoning and supplement the behavior-analytic approach to analogy based on the relating of derived relations.

  6. The association between poor sleep quality and global cortical atrophy is related to age. Results from the Atahualpa Project

    Directory of Open Access Journals (Sweden)

    Oscar H. Del Brutto

    2016-07-01

    Full Text Available Community-dwellers aged ≥60 years enrolled in the Atahualpa Project underwent brain MRI and were interviewed with the Pittsburgh Sleep Quality Index. Of 290 participants, 94 (32% had poor sleep quality and 143 (49% had global cortical atrophy (GCA. In a logistic regression model (adjusted for demographics, cardiovascular risk factor, severe edentulism, symptoms of depression, the MoCA score, and neuroimaging signatures of cerebrovascular damage, poor sleep quality was associated with GCA (p=0.004. A multivariate probability model showed that the probability of moderate-to-severe GCA significantly increased in individuals with poor sleep quality aged ≥67 years. This study provides evidence for an association between poor sleep quality and GCA in older adults and the important interaction of age in this association.

  7. Automatic temporal expectancy: a high-density event-related potential study.

    Directory of Open Access Journals (Sweden)

    Giovanni Mento

    Full Text Available How we compute time is not fully understood. Questions include whether an automatic brain mechanism is engaged in temporally regular environmental structure in order to anticipate events, and whether this can be dissociated from task-related processes, including response preparation, selection and execution. To investigate these issues, a passive temporal oddball task requiring neither time-based motor response nor explicit decision was specifically designed and delivered to participants during high-density, event-related potentials recording. Participants were presented with pairs of audiovisual stimuli (S1 and S2 interspersed with an Inter-Stimulus Interval (ISI that was manipulated according to an oddball probabilistic distribution. In the standard condition (70% of trials, the ISI lasted 1,500 ms, while in the two alternative, deviant conditions (15% each, it lasted 2,500 and 3,000 ms. The passive over-exposition to the standard ISI drove participants to automatically and progressively create an implicit temporal expectation of S2 onset, reflected by the time course of the Contingent Negative Variation response, which always peaked in correspondence to the point of S2 maximum expectation and afterwards inverted in polarity towards the baseline. Brain source analysis of S1- and ISI-related ERP activity revealed activation of sensorial cortical areas and the supplementary motor area (SMA, respectively. In particular, since the SMA time course synchronised with standard ISI, we suggest that this area is the major cortical generator of the temporal CNV reflecting an automatic, action-independent mechanism underlying temporal expectancy.

  8. Simultaneous evaluation of substrate-dependent oxygen consumption rates and mitochondrial membrane potential by TMRM and safranin in cortical mitochondria.

    Science.gov (United States)

    Chowdhury, Subir Roy; Djordjevic, Jelena; Albensi, Benedict C; Fernyhough, Paul

    2015-12-08

    Mitochondrial membrane potential (mtMP) is critical for maintaining the physiological function of the respiratory chain to generate ATP. The present study characterized the inter-relationship between mtMP, using safranin and tetramethyl rhodamine methyl ester (TMRM), and mitochondrial respiratory activity and established a protocol for functional analysis of mitochondrial bioenergetics in a multi-sensor system. Coupled respiration was decreased by 27 and 30-35% in the presence of TMRM and safranin respectively. Maximal respiration was higher than coupled with Complex I- and II-linked substrates in the presence of both dyes. Safranin showed decreased maximal respiration at a higher concentration of carbonyl cyanide-4-(trifluoromethoxy)phenylhydrazone (FCCP) compared with TMRM. FCCP titration revealed that maximal respiration in the presence of glutamate and malate was not sustainable at higher FCCP concentrations as compared with pyruvate and malate. Oxygen consumption rate (OCR) and mtMP in response to mitochondrial substrates were higher in isolated mitochondria compared with tissue homogenates. Safranin exhibited higher sensitivity to changes in mtMP than TMRM. This multi-sensor system measured mitochondrial parameters in the brain of transgenic mice that model Alzheimer's disease (AD), because mitochondrial dysfunction is believed to be a primary event in the pathogenesis of AD. The coupled and maximal respiration of electron transport chain were decreased in the cortex of AD mice along with the mtMP compared with age-matched controls. Overall, these data demonstrate that safranin and TMRM are suitable for the simultaneous evaluation of mtMP and respiratory chain activity using isolated mitochondria and tissue homogenate. However, certain care should be taken concerning the selection of appropriate substrates and dyes for specific experimental circumstances. © 2016 Authors.

  9. Magnetic fields, special relativity and potential theory elementary electromagnetic theory

    CERN Document Server

    Chirgwin, B H; Kilmister, C W

    1972-01-01

    Magnetic Fields, Special Relativity and Potential Theory is an introduction to electromagnetism, special relativity, and potential theory, with emphasis on the magnetic field of steady currents (magnetostatics). Topics covered range from the origin of the magnetic field and the magnetostatic scalar potential to magnetization, electromagnetic induction and magnetic energy, and the displacement current and Maxwell's equations. This volume is comprised of five chapters and begins with an overview of magnetostatics, followed by a chapter on the methods of solving potential problems drawn from elec

  10. Potential gray matter unpruned in adolescents and young adults dependent on dextromethorphan-containing cough syrups: evidence from cortical and subcortical study.

    Science.gov (United States)

    Qiu, Ying-Wei; Lv, Xiao-Fei; Jiang, Gui-Hua; Su, Huan-Huan; Ma, Xiao-Fen; Tian, Jun-Zhang; Zhuo, Fu-Zhen

    2017-10-01

    Adolescence is a unique period in neurodevelopment. Dextromethorphan (DXM)-containing cough syrups are new addictive drugs used by adolescents and young adults. The effects of chronic DXM abuse on neurodevelopment in adolescents and young adults are still unknown. The aim of this study was to investigate the differences in cortical thickness and subcortical gray matter volumes between DXM-dependent adolescents and young adults and healthy controls, and to explore relationships between alternations in cortical thickness/subcortical volume and DXM duration, initial age of DXM use, as well as impulsive behavior in DXM-dependent adolescents and young adults. Thirty-eight DXM-dependent adolescents and young adults and 18 healthy controls underwent magnetic resonance imaging scanning, and cortical thickness across the continuous cortical surface was compared between the groups. Subcortical volumes were compared on a structure-by-structure basis. DXM-dependent adolescents and young adults exhibited significantly increased cortical thickness in the bilateral precuneus (PreC), left dorsal lateral prefrontal cortex (DLPFC. L), left inferior parietal lobe (IPL. L), right precentral gyrus (PreCG. R), right lateral occipital cortex (LOC. R), right inferior temporal cortex (ITC. R), right lateral orbitofrontal cortex (lOFC. R) and right transverse temporal gyrus (TTG. R) (all p < 0.05, multiple comparison corrected) and increased subcortical volumes of the right thalamus and right pallidum. There was a significant correlation between initial age of DXM use and cortical thickness of the DLPFC. L and PreCG. R. A significant correlation was also found between cortical thickness of the DLPFC. L and impulsive behavior in patients. This was the first study to explore relationships between cortical thickness/subcortical volume and impulsive behavior in adolescents dependent on DXM. These structural changes might explain the neurobiological mechanism of impulsive behavior in

  11. Cortical plasticity as a new endpoint measurement for chronic pain

    Directory of Open Access Journals (Sweden)

    Zhuo Min

    2011-07-01

    Full Text Available Abstract Animal models of chronic pain are widely used to investigate basic mechanisms of chronic pain and to evaluate potential novel drugs for treating chronic pain. Among the different criteria used to measure chronic pain, behavioral responses are commonly used as the end point measurements. However, not all chronic pain conditions can be easily measured by behavioral responses such as the headache, phantom pain and pain related to spinal cord injury. Here I propose that cortical indexes, that indicate neuronal plastic changes in pain-related cortical areas, can be used as endpoint measurements for chronic pain. Such cortical indexes are not only useful for those chronic pain conditions where a suitable animal model is lacking, but also serve as additional screening methods for potential drugs to treat chronic pain in humans. These cortical indexes are activity-dependent immediate early genes, electrophysiological identified plastic changes and biochemical assays of signaling proteins. It can be used to evaluate novel analgesic compounds that may act at peripheral or spinal sites. I hope that these new cortical endpoint measurements will facilitate our search for new, and more effective, pain medicines, and help to reduce false lead drug targets.

  12. Neurophysiological Effects of Meditation Based on Evoked and Event Related Potential Recordings.

    Science.gov (United States)

    Singh, Nilkamal; Telles, Shirley

    2015-01-01

    Evoked potentials (EPs) are a relatively noninvasive method to assess the integrity of sensory pathways. As the neural generators for most of the components are relatively well worked out, EPs have been used to understand the changes occurring during meditation. Event-related potentials (ERPs) yield useful information about the response to tasks, usually assessing attention. A brief review of the literature yielded eleven studies on EPs and seventeen on ERPs from 1978 to 2014. The EP studies covered short, mid, and long latency EPs, using both auditory and visual modalities. ERP studies reported the effects of meditation on tasks such as the auditory oddball paradigm, the attentional blink task, mismatched negativity, and affective picture viewing among others. Both EP and ERPs were recorded in several meditations detailed in the review. Maximum changes occurred in mid latency (auditory) EPs suggesting that maximum changes occur in the corresponding neural generators in the thalamus, thalamic radiations, and primary auditory cortical areas. ERP studies showed meditation can increase attention and enhance efficiency of brain resource allocation with greater emotional control.

  13. Neurophysiological Effects of Meditation Based on Evoked and Event Related Potential Recordings

    Science.gov (United States)

    Singh, Nilkamal; Telles, Shirley

    2015-01-01

    Evoked potentials (EPs) are a relatively noninvasive method to assess the integrity of sensory pathways. As the neural generators for most of the components are relatively well worked out, EPs have been used to understand the changes occurring during meditation. Event-related potentials (ERPs) yield useful information about the response to tasks, usually assessing attention. A brief review of the literature yielded eleven studies on EPs and seventeen on ERPs from 1978 to 2014. The EP studies covered short, mid, and long latency EPs, using both auditory and visual modalities. ERP studies reported the effects of meditation on tasks such as the auditory oddball paradigm, the attentional blink task, mismatched negativity, and affective picture viewing among others. Both EP and ERPs were recorded in several meditations detailed in the review. Maximum changes occurred in mid latency (auditory) EPs suggesting that maximum changes occur in the corresponding neural generators in the thalamus, thalamic radiations, and primary auditory cortical areas. ERP studies showed meditation can increase attention and enhance efficiency of brain resource allocation with greater emotional control. PMID:26137479

  14. U.S.V.I. Relative Erosion Potential - 2000

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The relative erosion potential is an indicator of sediment and pollution runoff from land based on slope, soil type, land cover (circa 2000) and (maximum monthly)...

  15. U.S.V.I. Relative Erosion Potential - 1990

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The relative erosion potential is an indicator of sediment and pollution runoff from land based on slope, soil type, land cover (circa 1990) and (maximum monthly)...

  16. Cortical visual impairment

    OpenAIRE

    Koželj, Urša

    2013-01-01

    In this thesis we discuss cortical visual impairment, diagnosis that is in the developed world in first place, since 20 percent of children with blindness or low vision are diagnosed with it. The objectives of the thesis are to define cortical visual impairment and the definition of characters suggestive of the cortical visual impairment as well as to search for causes that affect the growing diagnosis of cortical visual impairment. There are a lot of signs of cortical visual impairment. ...

  17. Proprioceptive event related potentials: gating and task effects

    DEFF Research Database (Denmark)

    Arnfred, Sidse M

    2005-01-01

    The integration of proprioception with vision, touch or audition is considered basic to the developmental formation of perceptions, conceptual objects and the creation of cognitive schemes. Thus, mapping of proprioceptive information processing is important in cognitive research. A stimulus...... of a brisk change of weight on a hand held load elicit a proprioceptive evoked potential (PEP). Here this is used to examine early and late information processing related to weight discrimination by event related potentials (ERP)....

  18. Recapitulating cortical development with organoid culture in vitro and modeling abnormal spindle-like (ASPM related primary) microcephaly disease

    Institute of Scientific and Technical Information of China (English)

    Rui Li; Le Sun; Ai Fang; Peng Li; Qian Wu; Xiaoqun Wang

    2017-01-01

    The development of a cerebral organoid culture in vitro offers an opportunity to generate human brain-like organs to investigate mechanisms of human disease that are specific to the neurogenesis of radial glial (RG) and outer radial glial (oRG) cells in the ventricular zone (VZ) and subventricular zone (SVZ) of the developing neocortex.Modeling neuronal progenitors and the organization that produces mature subcortical neuron subtypes during early stages of development is essential for studying human brain developmental diseases.Several previous efforts have shown to grow neural organoid in culture dishes successfully,however we demonstrate a new paradigm that recapitulates neocortical development process with VZ,OSVZ formation and the lamination organization of cortical layer structure.In addition,using patient-specific induced pluripotent stem cells (iPSCs) with dysfunction of the Aspm gene from a primary microcephaly patient,we demonstrate neurogenesis defects result in defective neuronal activity in patient organoids,suggesting a new strategy to study human developmental diseases in central nerve system.

  19. Using modern human cortical bone distribution to test the systemic robusticity hypothesis.

    Science.gov (United States)

    Baab, Karen L; Copes, Lynn E; Ward, Devin L; Wells, Nora; Grine, Frederick E

    2018-06-01

    The systemic robusticity hypothesis links the thickness of cortical bone in both the cranium and limb bones. This hypothesis posits that thick cortical bone is in part a systemic response to circulating hormones, such as growth hormone and thyroid hormone, possibly related to physical activity or cold climates. Although this hypothesis has gained popular traction, only rarely has robusticity of the cranium and postcranial skeleton been considered jointly. We acquired computed tomographic scans from associated crania, femora and humeri from single individuals representing 11 populations in Africa and North America (n = 228). Cortical thickness in the parietal, frontal and occipital bones and cortical bone area in limb bone diaphyses were analyzed using correlation, multiple regression and general linear models to test the hypothesis. Absolute thickness values from the crania were not correlated with cortical bone area of the femur or humerus, which is at odds with the systemic robusticity hypothesis. However, measures of cortical bone scaled by total vault thickness and limb cross-sectional area were positively correlated between the cranium and postcranium. When accounting for a range of potential confounding variables, including sex, age and body mass, variation in relative postcranial cortical bone area explained ∼20% of variation in the proportion of cortical cranial bone thickness. While these findings provide limited support for the systemic robusticity hypothesis, cranial cortical thickness did not track climate or physical activity across populations. Thus, some of the variation in cranial cortical bone thickness in modern humans is attributable to systemic effects, but the driving force behind this effect remains obscure. Moreover, neither absolute nor proportional measures of cranial cortical bone thickness are positively correlated with total cranial bone thickness, complicating the extrapolation of these findings to extinct species where only cranial

  20. Cortical fMRI activation to opponents' body kinematics in sport-related anticipation: expert-novice differences with normal and point-light video.

    Science.gov (United States)

    Wright, M J; Bishop, D T; Jackson, R C; Abernethy, B

    2011-08-18

    Badminton players of varying skill levels viewed normal and point-light video clips of opponents striking the shuttle towards the viewer; their task was to predict in which quadrant of the court the shuttle would land. In a whole-brain fMRI analysis we identified bilateral cortical networks sensitive to the anticipation task relative to control stimuli. This network is more extensive and localised than previously reported. Voxel clusters responding more strongly in experts than novices were associated with all task-sensitive areas, whereas voxels responding more strongly in novices were found outside these areas. Task-sensitive areas for normal and point-light video were very similar, whereas early visual areas responded differentially, indicating the primacy of kinematic information for sport-related anticipation. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  1. The Coulomb potential in quantum mechanics and related topics

    International Nuclear Information System (INIS)

    Haeringen, H. van.

    1978-01-01

    This dissertation consists of an analytic study of the Coulomb interaction in nonrelativistic quantum mechanics and some related topics. The author investigates in a number of self-contained articles various interesting and important properties of the Coulomb potential. Some of these properties are shared by other potentials which also play a role in quantum mechanics. For such related interactions a comparative study is made. The principal difficulties in the description of proton-deuteron scattering and break-up reactions, due to the Coulomb interaction, are studied by working out a simple model. The bound states are studied for the Coulomb plus Yamaguchi potential, for the symmetric shifted Coulomb potential, and for local potentials with an inverse-distance-squared asymptotic behaviour. (Auth.)

  2. A frontal cortex event-related potential driven by the basal forebrain

    Science.gov (United States)

    Nguyen, David P; Lin, Shih-Chieh

    2014-01-01

    Event-related potentials (ERPs) are widely used in both healthy and neuropsychiatric conditions as physiological indices of cognitive functions. Contrary to the common belief that cognitive ERPs are generated by local activity within the cerebral cortex, here we show that an attention-related ERP in the frontal cortex is correlated with, and likely generated by, subcortical inputs from the basal forebrain (BF). In rats performing an auditory oddball task, both the amplitude and timing of the frontal ERP were coupled with BF neuronal activity in single trials. The local field potentials (LFPs) associated with the frontal ERP, concentrated in deep cortical layers corresponding to the zone of BF input, were similarly coupled with BF activity and consistently triggered by BF electrical stimulation within 5–10 msec. These results highlight the important and previously unrecognized role of long-range subcortical inputs from the BF in the generation of cognitive ERPs. DOI: http://dx.doi.org/10.7554/eLife.02148.001 PMID:24714497

  3. Event-related potentials and secondary task performance during simulated driving.

    Science.gov (United States)

    Wester, A E; Böcker, K B E; Volkerts, E R; Verster, J C; Kenemans, J L

    2008-01-01

    Inattention and distraction account for a substantial number of traffic accidents. Therefore, we examined the impact of secondary task performance (an auditory oddball task) on a primary driving task (lane keeping). Twenty healthy participants performed two 20-min tests in the Divided Attention Steering Simulator (DASS). The visual secondary task of the DASS was replaced by an auditory oddball task to allow recording of brain activity. The driving task and the secondary (distracting) oddball task were presented in isolation and simultaneously, to assess their mutual interference. In addition to performance measures (lane keeping in the primary driving task and reaction speed in the secondary oddball task), brain activity, i.e. event-related potentials (ERPs), was recorded. Performance parameters on the driving test and the secondary oddball task did not differ between performance in isolation and simultaneous performance. However, when both tasks were performed simultaneously, reaction time variability increased in the secondary oddball task. Analysis of brain activity indicated that ERP amplitude (P3a amplitude) related to the secondary task, was significantly reduced when the task was performed simultaneously with the driving test. This study shows that when performing a simple secondary task during driving, performance of the driving task and this secondary task are both unaffected. However, analysis of brain activity shows reduced cortical processing of irrelevant, potentially distracting stimuli from the secondary task during driving.

  4. Contextual control of audiovisual integration in low-level sensory cortices

    NARCIS (Netherlands)

    Van Atteveldt, N.; Peterson, Bradley S; Schroeder, Charles E

    Potential sources of multisensory influences on low-level sensory cortices include direct projections from sensory cortices of different modalities, as well as more indirect feedback inputs from higher order multisensory cortical regions. These multiple architectures may be functionally

  5. An automatic algorithm for blink-artifact suppression based on iterative template matching: application to single channel recording of cortical auditory evoked potentials

    Science.gov (United States)

    Valderrama, Joaquin T.; de la Torre, Angel; Van Dun, Bram

    2018-02-01

    Objective. Artifact reduction in electroencephalogram (EEG) signals is usually necessary to carry out data analysis appropriately. Despite the large amount of denoising techniques available with a multichannel setup, there is a lack of efficient algorithms that remove (not only detect) blink-artifacts from a single channel EEG, which is of interest in many clinical and research applications. This paper describes and evaluates the iterative template matching and suppression (ITMS), a new method proposed for detecting and suppressing the artifact associated with the blink activity from a single channel EEG. Approach. The approach of ITMS consists of (a) an iterative process in which blink-events are detected and the blink-artifact waveform of the analyzed subject is estimated, (b) generation of a signal modeling the blink-artifact, and (c) suppression of this signal from the raw EEG. The performance of ITMS is compared with the multi-window summation of derivatives within a window (MSDW) technique using both synthesized and real EEG data. Main results. Results suggest that ITMS presents an adequate performance in detecting and suppressing blink-artifacts from a single channel EEG. When applied to the analysis of cortical auditory evoked potentials (CAEPs), ITMS provides a significant quality improvement in the resulting responses, i.e. in a cohort of 30 adults, the mean correlation coefficient improved from 0.37 to 0.65 when the blink-artifacts were detected and suppressed by ITMS. Significance. ITMS is an efficient solution to the problem of denoising blink-artifacts in single-channel EEG applications, both in clinical and research fields. The proposed ITMS algorithm is stable; automatic, since it does not require human intervention; low-invasive, because the EEG segments not contaminated by blink-artifacts remain unaltered; and easy to implement, as can be observed in the Matlab script implemeting the algorithm provided as supporting material.

  6. Slow cortical potential Neurofeedback and self-management training in outpatient care for children with ADHD: study protocol and first preliminary results of a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Hanna eChristiansen

    2014-11-01

    Full Text Available Background: Treatment for children with attention deficit/hyperactivity disorder (ADHD today is predominantly pharmacological. While it is the most common treatment, it might not always be the most appropriate one. Moreover, long term effects remain unclear. Behavior therapy and non-pharmacological treatments such as neurofeedback (NF are promising alternatives, though there are no routine outpatient care/effectiveness studies yet that have included children with medication or changes in medication.Methods/design: This paper presents the protocol of a randomized controlled trial to compare the effectiveness of a Slow Cortical Potential (SCP NF protocol with self-management (SM in a high frequent outpatient care setting. Both groups (NF/SM receive a total of 30 high frequent therapy sessions. Additionally, 6 sessions are reserved for comorbid problems. The primary outcome measure is the reduction of ADHD core symptoms according to parent and teacher ratings.Preliminary Results: Untill now 58 children were included in the study (48 males, with a mean age of 8.42 (1.34 years, and a mean IQ of 110 (13.37. Conners-3 parent and teacher ratings were used to estimate core symptom change. Since the study is still ongoing, and children are in different study stages, pre-post and follow-up results are not yet available for all children included. Preliminary results suggest overall good pre-post effects, though. For parent and teacher ratings an ANOVA with repeated measures yielded overall satisfying pre-post effects (η2 .175 to .513. Differences between groups (NF vs. SM could not yet be established (p = .81.Discussion: This is the first randomized controlled trial to test the effectiveness of a NF protocol in a high frequent outpatient care setting that does not exclude children on or with changes in medication. First preliminary results show positive effects. The rationale for the trial, the design, and the strengths and limitations of the study are

  7. Effects of external trigeminal nerve stimulation (eTNS) on laser evoked cortical potentials (LEP): A pilot study in migraine patients and controls.

    Science.gov (United States)

    Vecchio, Eleonora; Gentile, Eleonora; Franco, Giovanni; Ricci, Katia; de Tommaso, Marina

    2017-01-01

    Background Transcutaneous external supraorbital nerve stimulation has emerged as a treatment option for primary headache disorders, though its action mechanism is still unclear. Study aim In this randomized, sham-controlled pilot study we aimed to test the effects of a single external transcutaneous nerve stimulation session on pain perception and cortical responses induced by painful laser stimuli delivered to the right forehead and the right hand in a cohort of migraine without aura patients and healthy controls. Methods Seventeen migraine without aura patients and 21 age- and sex-matched controls were selected and randomly assigned to a real or sham external transcutaneous nerve stimulation single stimulation session. The external transcutaneous nerve stimulation was delivered with a self-adhesive electrode placed on the forehead and generating a 60 Hz pulse at 16 mA intensity for 20 minutes. For sham stimulation, we used 2 mA intensity. Laser evoked responses were recorded from 21 scalp electrodes in basal condition (T0), during external transcutaneous nerve stimulation and sham stimulation (T1), and immediately after these (T2). The laser evoked responses were analyzed by LORETA software. Results The real external transcutaneous nerve stimulation reduced the trigeminal N2P2 amplitude in migraine and control groups significantly in respect to placebo. The real stimulation was associated with lower activity in the anterior cingulate cortex under trigeminal laser stimuli. The pattern of LEP-reduced habituation was reverted by real and sham transcutaneous stimulation in migraine patients. Conclusions The present results could suggest that the external transcutaneous nerve stimulation may interfere with the threshold and the extent of trigeminal system activation, with a mechanism of potential utility in the resolution and prevention of migraine attacks.

  8. Novel assessment of cortical response to somatosensory stimuli in children with hemiparetic cerebral palsy.

    Science.gov (United States)

    Maitre, Nathalie L; Barnett, Zachary P; Key, Alexandra P F

    2012-10-01

    The brain's response to somatosensory stimuli is essential to experience-driven learning in children. It was hypothesized that advances in event-related potential technology could quantify the response to touch in somatosensory cortices and characterize the responses of hemiparetic children. In this prospective study of 8 children (5-8 years old) with hemiparetic cerebral palsy, both event-related potential responses to sham or air puff trials and standard functional assessments were used. Event-related potential technology consistently measured signals reflecting activity in the primary and secondary somatosensory cortices as well as complex cognitive processing of touch. Participants showed typical early responses but less efficient perceptual processes. Significant differences between affected and unaffected extremities correlated with sensorimotor testing, stereognosis, and 2-point discrimination (r > 0.800 and P = .001 for all). For the first time, a novel event-related potential paradigm shows that hemiparetic children have slower and less efficient tactile cortical perception in their affected extremities.

  9. Brain Signals of Face Processing as Revealed by Event-Related Potentials

    Directory of Open Access Journals (Sweden)

    Ela I. Olivares

    2015-01-01

    Full Text Available We analyze the functional significance of different event-related potentials (ERPs as electrophysiological indices of face perception and face recognition, according to cognitive and neurofunctional models of face processing. Initially, the processing of faces seems to be supported by early extrastriate occipital cortices and revealed by modulations of the occipital P1. This early response is thought to reflect the detection of certain primary structural aspects indicating the presence grosso modo of a face within the visual field. The posterior-temporal N170 is more sensitive to the detection of faces as complex-structured stimuli and, therefore, to the presence of its distinctive organizational characteristics prior to within-category identification. In turn, the relatively late and probably more rostrally generated N250r and N400-like responses might respectively indicate processes of access and retrieval of face-related information, which is stored in long-term memory (LTM. New methods of analysis of electrophysiological and neuroanatomical data, namely, dynamic causal modeling, single-trial and time-frequency analyses, are highly recommended to advance in the knowledge of those brain mechanisms concerning face processing.

  10. Emotion and attention : Event-related brain potential studies

    OpenAIRE

    Schupp, Harald Thomas; Flaisch, Tobias; Stockburger, Jessica; Junghöfer, Markus

    2006-01-01

    Emotional pictures guide selective visual attention. A series of event-related brain potential (ERP) studies is reviewed demonstrating the consistent and robust modulation of specific ERP components by emotional images. Specifically, pictures depicting natural pleasant and unpleasant scenes are associated with an increased early posterior negativity, late positive potential, and sustained positive slow wave compared with neutral contents. These modulations are considered to index different st...

  11. Toward FRP-Based Brain-Machine Interfaces-Single-Trial Classification of Fixation-Related Potentials.

    Directory of Open Access Journals (Sweden)

    Andrea Finke

    Full Text Available The co-registration of eye tracking and electroencephalography provides a holistic measure of ongoing cognitive processes. Recently, fixation-related potentials have been introduced to quantify the neural activity in such bi-modal recordings. Fixation-related potentials are time-locked to fixation onsets, just like event-related potentials are locked to stimulus onsets. Compared to existing electroencephalography-based brain-machine interfaces that depend on visual stimuli, fixation-related potentials have the advantages that they can be used in free, unconstrained viewing conditions and can also be classified on a single-trial level. Thus, fixation-related potentials have the potential to allow for conceptually different brain-machine interfaces that directly interpret cortical activity related to the visual processing of specific objects. However, existing research has investigated fixation-related potentials only with very restricted and highly unnatural stimuli in simple search tasks while participant's body movements were restricted. We present a study where we relieved many of these restrictions while retaining some control by using a gaze-contingent visual search task. In our study, participants had to find a target object out of 12 complex and everyday objects presented on a screen while the electrical activity of the brain and eye movements were recorded simultaneously. Our results show that our proposed method for the classification of fixation-related potentials can clearly discriminate between fixations on relevant, non-relevant and background areas. Furthermore, we show that our classification approach generalizes not only to different test sets from the same participant, but also across participants. These results promise to open novel avenues for exploiting fixation-related potentials in electroencephalography-based brain-machine interfaces and thus providing a novel means for intuitive human-machine interaction.

  12. Relativistic gravitational potential and its relation to mass-energy

    International Nuclear Information System (INIS)

    Voracek, P.

    1979-01-01

    From the general theory of relativity a relation is deduced between the mass of a particle and the gravitational field at the position of the particle. For this purpose the fall of a particle of negligible mass in the gravitational field of a massive body is used. After establishing the relativistic potential and its relationship to the rest mass of the particle, we show, assuming conservation of mass-energy, that the difference between two potential-levels depends upon the value of the radial metric coefficient at the position of an observer. Further, it is proved that the relativistic potential is compatible with the general concept of the potential also from the standpoint of kinematics. In the third section it is shown that, although the mass-energy of a body is a function of the distance from it, this does not influence the relativistic potential of the body itself. From this conclusion it follows that the mass-energy of a particle in a gravitational field is anisotropic; isotropic is the mass only. Further, the possibility of an incidental feed-back between two masses is ruled out, and the law of the composition of the relativistic gravitational potentials is deduced. Finally, it is shown, by means of a simple model, that local inhomogeneities in the ideal fluid filling the Universe have negligible influence on the total potential in large regions. (orig.)

  13. Neurophysiological traces of interpersonal pain: How emotional autobiographical memories affect event-related potentials.

    Science.gov (United States)

    Rohde, Kristina B; Caspar, Franz; Koenig, Thomas; Pascual-Leone, Antonio; Stein, Maria

    2018-03-01

    The automatic, involuntary reactivation of disturbing emotional memories, for example, of interpersonal pain, causes psychological discomfort and is central to many psychopathologies. This study aimed at elucidating the automatic brain processes underlying emotional autobiographical memories by investigating the neurophysiological dynamics within the first second after memory reactivation. Pictures of different individualized familiar faces served as cues for different specific emotional autobiographical memories, for example, for memories of interpersonal pain and grievances or for memories of appreciation in interpersonal relationships. Nineteen subjects participated in a passive face-viewing task while multichannel electroencephalogram was recorded. Analyses of event-related potentials demonstrated that emotional memories elicited an early posterior negativity and a stronger late positive potential, which tended to be particularly enhanced for painful memories. Source estimations attributed this stronger activation to networks including the posterior cingulate and ventrolateral prefrontal cortices. The findings suggest that the reactivation of emotional autobiographical memories involves privileged automatic attention at perceptual processing stages, and an enhanced recruitment of neural network activity at a postperceptual stage sensitive to emotional-motivational processing. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  14. Olfactory short-term memory encoding and maintenance - an event-related potential study.

    Science.gov (United States)

    Lenk, Steffen; Bluschke, Annet; Beste, Christian; Iannilli, Emilia; Rößner, Veit; Hummel, Thomas; Bender, Stephan

    2014-09-01

    This study examined whether the memory encoding and short term maintenance of olfactory stimuli is associated with neurophysiological activation patterns which parallel those described for sensory modalities such as vision and auditory. We examined olfactory event-related potentials in an olfactory change detection task in twenty-four healthy adults and compared the measured activation to that found during passive olfactory stimulation. During the early olfactory post-processing phase, we found a sustained negativity over bilateral frontotemporal areas in the passive perception condition which was enhanced in the active memory task. There was no significant lateralization in either experimental condition. During the maintenance interval at the end of the delay period, we still found sustained activation over bilateral frontotemporal areas which was more negative in trials with correct - as compared to incorrect - behavioural responses. This was complemented by a general significantly stronger frontocentral activation. Summarizing, we were able to show that olfactory short term memory involves a parallel sequence of activation as found in other sensory modalities. In addition to olfactory-specific frontotemporal activations in the memory encoding phase, we found slow cortical potentials over frontocentral areas during the memory maintenance phase indicating the activation of a supramodal memory maintenance system. These findings could represent the neurophysiological underpinning of the 'olfactory flacon', the olfactory counter-part to the visual sketchpad and phonological loop embedded in Baddeley's working memory model. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Cognitive processing in non-communicative patients: what can event-related potentials tell us?

    Directory of Open Access Journals (Sweden)

    Zulay Rosario Lugo

    2016-11-01

    Full Text Available Event-related potentials (ERP have been proposed to improve the differential diagnosis of non-responsive patients. We investigated the potential of the P300 as a reliable marker of conscious processing in patients with locked-in syndrome (LIS. Eleven chronic LIS patients and ten healthy subjects (HS listened to a complex-tone auditory oddball paradigm, first in a passive condition (listen to the sounds and then in an active condition (counting the deviant tones. Seven out of nine HS displayed a P300 waveform in the passive condition and all in the active condition. HS showed statistically significant changes in peak and area amplitude between conditions. Three out of seven LIS patients showed the P3 waveform in the passive condition and 5 of 7 in the active condition. No changes in peak amplitude and only a significant difference at one electrode in area amplitude were observed in this group between conditions. We conclude that, in spite of keeping full consciousness and intact or nearly intact cortical functions, compared to HS, LIS patients present less reliable results when testing with ERP, specifically in the passive condition. We thus strongly recommend applying ERP paradigms in an active condition when evaluating consciousness in non-responsive patients.

  16. Cortical Visual Impairment

    Science.gov (United States)

    ... resolves by one year of life. Is “cortical blindness” the same thing as CVI? Cortical blindness is ... What visual characteristics are associated with CVI? • Distinct color preferences • Variable level of vision loss, often demonstrating ...

  17. Potential capabilities of lunar laser ranging for geodesy and relativity

    Science.gov (United States)

    Muller, Jurgen; Williams, James G.; Turshev, Slava G.; Shelus, Peter J.

    2005-01-01

    Here, we review the LLR technique focusing on its impact on Geodesy and Relativity. We discuss the modem observational accuracy and the level of existing LLR modeling. We present the near-term objectives and emphasize improvements needed to fully utilize the scientific potential of LLR.

  18. Relations between the density matrix and thermodynamic potential

    International Nuclear Information System (INIS)

    Pitanga, P.; Mundim, K.C.

    1988-01-01

    We propose to study the stability of a polyatomic molecular system in terms of the thermodynamic potential G. This enables us to establish a relation between the bond index and susceptibility tensor ∂ 2 G/∂μ i ∂ j . (author) [pt

  19. Intracerebral Event-related Potentials to Subthreshold Target Stimuli

    Czech Academy of Sciences Publication Activity Database

    Brázdil, M.; Rektor, I.; Daniel, P.; Dufek, M.; Jurák, Pavel

    2001-01-01

    Roč. 112, č. 4 (2001), s. 650-661 ISSN 1388-2457 R&D Projects: GA ČR GA309/98/0490 Institutional research plan: CEZ:AV0Z2065902 Keywords : event-related potentials * intracerebral recordings * oddball paradigm Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 1.922, year: 2001

  20. Dimensions of Teacher Burnout: Relations with Potential Stressors at School

    Science.gov (United States)

    Skaalvik, Einar M.; Skaalvik, Sidsel

    2017-01-01

    The purpose of this study was to analyze how four potential stressors in the school environment (discipline problems, time pressure, low student motivation, and value dissonance) were related to dimensions of teacher burnout (emotional exhaustion, depersonalization, and reduced personal accomplishment). Participants were 1145 teachers from grade 1…

  1. Modulation of long-term potentiation-like cortical plasticity in the healthy brain with low frequency-pulsed electromagnetic fields.

    Science.gov (United States)

    Premi, Enrico; Benussi, Alberto; La Gatta, Antonio; Visconti, Stefano; Costa, Angelo; Gilberti, Nicola; Cantoni, Valentina; Padovani, Alessandro; Borroni, Barbara; Magoni, Mauro

    2018-06-13

    Non-depolarizing magnetic fields, like low frequency-pulsed electromagnetic fields (LF-PEMFs) have shown the ability to modulate living structures, principally by influencing synaptic activity and ion channels on cellular membranes. Recently, the CTU Mega 20 device was presented as a molecular accelerator, using energy up to 200 J and providing high-power (2 Tesla) pulsating fields with a water-repulsive (diamagnetic) action and tissue biostimulation. We tested the hypothesis that LF-PEMFs could modulate long-term corticospinal excitability in healthy brains by applying CTU Mega 20 ® . Ten healthy subjects without known neurological and/or psychiatric diseases entered the study. A randomized double-blind sham-controlled crossover design was employed, recording TMS parameters (amplitude variation of the motor evoked potential as index of cortical excitability perturbations of the motor system) before (pre) and after (post + 0, + 15, + 30 min) a single CTU Mega 20 session on the corresponding primary right-hand motor area, using a real (magnetic field = 2 Tesla; intensity = 90 J; impulse frequency = 7 Hz; duration = 15 min) or sham device. A two-way repeated measures ANOVA with TIME (pre, post + 0, + 15, + 30 min) and TREATMENT (real vs. sham stimulation) as within-subjects factor was applied. A significant TIME × TREATMENT interaction was found (p < 0.001). Post hoc comparisons showed a significant effect of TIME, with significant differences at + 0, + 15 and + 30 min compared to baseline after real stimulation (all p < 0.05) but not after sham stimulation (all p < 0.05) and significant effects of TREATMENT, with significant differences at + 0, + 15 and + 30 min for real stimulation compared to sham stimulation (all p < 0.005). No significant depolarizing effects were detected throughout the (real) stimulation. Our proof-of-concept study in healthy subjects supports the idea that non-ionizing LF

  2. Communication and Wiring in the Cortical Connectome

    Directory of Open Access Journals (Sweden)

    Julian eBudd

    2012-10-01

    Full Text Available In cerebral cortex, the huge mass of axonal wiring that carries information between near and distant neurons is thought to provide the neural substrate for cognitive and perceptual function. The goal of mapping the connectivity of cortical axons at different spatial scales, the cortical connectome, is to trace the paths of information flow in cerebral cortex. To appreciate the relationship between the connectome and cortical function, we need to discover the nature and purpose of the wiring principles underlying cortical connectivity. A popular explanation has been that axonal length is strictly minimized both within and between cortical regions. In contrast, we have hypothesized the existence of a multi-scale principle of cortical wiring where to optimise communication there is a trade-off between spatial (construction and temporal (routing costs. Here, using recent evidence concerning cortical spatial networks we critically evaluate this hypothesis at neuron, local circuit, and pathway scales. We report three main conclusions. First, the axonal and dendritic arbor morphology of single neocortical neurons may be governed by a similar wiring principle, one that balances the conservation of cellular material and conduction delay. Second, the same principle may be observed for fibre tracts connecting cortical regions. Third, the absence of sufficient local circuit data currently prohibits any meaningful assessment of the hypothesis at this scale of cortical organization. To avoid neglecting neuron and microcircuit levels of cortical organization, the connectome framework should incorporate more morphological description. In addition, structural analyses of temporal cost for cortical circuits should take account of both axonal conduction and neuronal integration delays, which appear mostly of the same order of magnitude. We conclude the hypothesized trade-off between spatial and temporal costs may potentially offer a powerful explanation for

  3. Neurodevelopment of Conflict Adaptation: Evidence From Event-Related Potentials

    DEFF Research Database (Denmark)

    Liu, Xiuying; Liu, Tongran; Shangguan, Fangfang

    2018-01-01

    Conflict adaptation is key in how children self-regulate and assert cognitive control in a given situation compared with a previous experience. In the current study, we analyzed event-related potentials (ERPs) to identify age-related differences in conflict adaptation. Participants of different a...... to better assimilate and accommodate potential environmental conflicts. The results may also indicate that the development of conflict adaption is affected by the specific characteristic of the different types of conflict.......Conflict adaptation is key in how children self-regulate and assert cognitive control in a given situation compared with a previous experience. In the current study, we analyzed event-related potentials (ERPs) to identify age-related differences in conflict adaptation. Participants of different...... ages (5-year-old children, 10-year-old children, and adults) were subjected to a stimulus-stimulus (S-S) conflict control task (the flanker task) and a stimulus-response (S-R) conflict control task (the Simon task). The behavioral results revealed that all age groups had reliable conflict adaptation...

  4. Quantifying cortical surface harmonic deformation with stereovision during open cranial neurosurgery

    Science.gov (United States)

    Ji, Songbai; Fan, Xiaoyao; Roberts, David W.; Paulsen, Keith D.

    2012-02-01

    Cortical surface harmonic motion during open cranial neurosurgery is well observed in image-guided neurosurgery. Recently, we quantified cortical surface deformation noninvasively with synchronized blood pressure pulsation (BPP) from a sequence of stereo image pairs using optical flow motion tracking. With three subjects, we found the average cortical surface displacement can reach more than 1 mm and in-plane principal strains of up to 7% relative to the first image pair. In addition, the temporal changes in deformation and strain were in concert with BPP and patient respiration [1]. However, because deformation was essentially computed relative to an arbitrary reference, comparing cortical surface deformation at different times was not possible. In this study, we extend the technique developed earlier by establishing a more reliable reference profile of the cortical surface for each sequence of stereo image acquisitions. Specifically, fast Fourier transform (FFT) was applied to the dynamic cortical surface deformation, and the fundamental frequencies corresponding to patient respiration and BPP were identified, which were used to determine the number of image acquisitions for use in averaging cortical surface images. This technique is important because it potentially allows in vivo characterization of soft tissue biomechanical properties using intraoperative stereovision and motion tracking.

  5. Cortical gyrification is abnormal in children with prenatal alcohol exposure

    Directory of Open Access Journals (Sweden)

    Timothy J. Hendrickson

    2017-01-01

    Conclusions: Abnormalities in cortical development were seen across the brain in children with PAE compared to controls. Cortical gyrification and IQ were strongly correlated, suggesting that examining mechanisms by which alcohol disrupts cortical formation may yield clinically relevant insights and potential directions for early intervention.

  6. Measurement of event-related potentials and placebo

    Directory of Open Access Journals (Sweden)

    Sovilj Platon

    2014-01-01

    Full Text Available ERP is common abbreviation for event-related brain potentials, which are measured and used in clinical practice as well as in research practice. Contemporary studies of placebo effect are often based on functional neuromagnetic resonance (fMRI, positron emission tomography (PET, and event related potentials (ERP. This paper considers an ERP instrumentation system used in experimental researches of placebo effect. This instrumentation system can be divided into four modules: electrodes and cables, conditioning module, digital measurement module, and PC module for stimulations, presentations, acquisition and data processing. The experimental oddball paradigm is supported by the software of the instrumentation. [Projekat Ministarstva nauke Republike Srbije, br. TR32019 and Provincial Secretariat for Science and Technological Development of Autonomous Province of Vojvodina (Republic of Serbia under research grant No. 114-451-2723

  7. Relating Derived Relations as a Model of Analogical Reasoning: Reaction Times and Event-Related Potentials

    Science.gov (United States)

    Barnes-Holmes, Dermot; Regan, Donal; Barnes-Holmes, Yvonne; Commins, Sean; Walsh, Derek; Stewart, Ian; Smeets, Paul M.; Whelan, Robert; Dymond, Simon

    2005-01-01

    The current study aimed to test a Relational Frame Theory (RFT) model of analogical reasoning based on the relating of derived same and derived difference relations. Experiment 1 recorded reaction time measures of similar-similar (e.g., "apple is to orange as dog is to cat") versus different-different (e.g., "he is to his brother as…

  8. Sleep spindle-related reactivation of category-specific cortical regions after learning face-scene associations

    DEFF Research Database (Denmark)

    Bergmann, Til O; Mölle, Matthias; Diedrichs, Jens

    2012-01-01

    Newly acquired declarative memory traces are believed to be reactivated during NonREM sleep to promote their hippocampo-neocortical transfer for long-term storage. Yet it remains a major challenge to unravel the underlying neuronal mechanisms. Using simultaneous electroencephalography (EEG......-coupled reactivation of brain regions representing the specific task stimuli was traced during subsequent NonREM sleep with EEG-informed fMRI. Relative to the control task, learning face-scene associations triggered a stronger combined activation of neocortical and hippocampal regions during subsequent sleep. Notably......) and functional magnetic resonance imaging (fMRI) recordings in humans, we show that sleep spindles play a key role in the reactivation of memory-related neocortical representations. On separate days, participants either learned face-scene associations or performed a visuomotor control task. Spindle...

  9. The parietal cortices participate in encoding, short-term memory, and decision-making related to tactile shape.

    Science.gov (United States)

    Rojas-Hortelano, Eduardo; Concha, Luis; de Lafuente, Victor

    2014-10-15

    We routinely identify objects with our hands, and the physical attributes of touched objects are often held in short-term memory to aid future decisions. However, the brain structures that selectively process tactile information to encode object shape are not fully identified. In this article we describe the areas within the human cerebral cortex that specialize in encoding, short-term memory, and decision-making related to the shape of objects explored with the hand. We performed event-related functional magnetic resonance imaging in subjects performing a shape discrimination task in which two sequentially presented objects had to be explored to determine whether they had the same shape or not. To control for low-level and nonspecific brain activations, subjects performed a temperature discrimination task in which they compared the temperature of two spheres. Our results show that although a large network of brain structures is engaged in somatosensory processing, it is the areas lining the intraparietal sulcus that selectively participate in encoding, maintaining, and deciding on tactile information related to the shape of objects. Copyright © 2014 the American Physiological Society.

  10. Single-Trial Event-Related Potential Based Rapid Image Triage System

    Directory of Open Access Journals (Sweden)

    Ke Yu

    2011-06-01

    Full Text Available Searching for points of interest (POI in large-volume imagery is a challenging problem with few good solutions. In this work, a neural engineering approach called rapid image triage (RIT which could offer about a ten-fold speed up in POI searching is developed. It is essentially a cortically-coupled computer vision technique, whereby the user is presented bursts of images at a speed of 6–15 images per second and then neural signals called event-related potential (ERP is used as the ‘cue’ for user seeing images of high relevance likelihood. Compared to past efforts, the implemented system has several unique features: (1 it applies overlapping frames in image chip preparation, to ensure rapid image triage performance; (2 a novel common spatial-temporal pattern (CSTP algorithm that makes use of both spatial and temporal patterns of ERP topography is proposed for high-accuracy single-trial ERP detection; (3 a weighted version of probabilistic support-vector-machine (SVM is used to address the inherent unbalanced nature of single-trial ERP detection for RIT. High accuracy, fast learning, and real-time capability of the developed system shown on 20 subjects demonstrate the feasibility of a brainmachine integrated rapid image triage system for fast detection of POI from large-volume imagery.

  11. Visual event-related potentials to biological motion stimuli in autism spectrum disorders

    Science.gov (United States)

    Bletsch, Anke; Krick, Christoph; Siniatchkin, Michael; Jarczok, Tomasz A.; Freitag, Christine M.; Bender, Stephan

    2014-01-01

    Atypical visual processing of biological motion contributes to social impairments in autism spectrum disorders (ASD). However, the exact temporal sequence of deficits of cortical biological motion processing in ASD has not been studied to date. We used 64-channel electroencephalography to study event-related potentials associated with human motion perception in 17 children and adolescents with ASD and 21 typical controls. A spatio-temporal source analysis was performed to assess the brain structures involved in these processes. We expected altered activity already during early stimulus processing and reduced activity during subsequent biological motion specific processes in ASD. In response to both, random and biological motion, the P100 amplitude was decreased suggesting unspecific deficits in visual processing, and the occipito-temporal N200 showed atypical lateralization in ASD suggesting altered hemispheric specialization. A slow positive deflection after 400 ms, reflecting top-down processes, and human motion-specific dipole activation differed slightly between groups, with reduced and more diffuse activation in the ASD-group. The latter could be an indicator of a disrupted neuronal network for biological motion processing in ADS. Furthermore, early visual processing (P100) seems to be correlated to biological motion-specific activation. This emphasizes the relevance of early sensory processing for higher order processing deficits in ASD. PMID:23887808

  12. Auditory event-related potentials in children with benign epilepsy with centro-temporal spikes.

    Science.gov (United States)

    Tomé, David; Sampaio, Mafalda; Mendes-Ribeiro, José; Barbosa, Fernando; Marques-Teixeira, João

    2014-12-01

    Benign focal epilepsy in childhood with centro-temporal spikes (BECTS) is one of the most common forms of idiopathic epilepsy, with onset from age 3 to 14 years. Although the prognosis for children with BECTS is excellent, some studies have revealed neuropsychological deficits in many domains, including language. Auditory event-related potentials (AERPs) reflect activation of different neuronal populations and are suggested to contribute to the evaluation of auditory discrimination (N1), attention allocation and phonological categorization (N2), and echoic memory (mismatch negativity--MMN). The scarce existing literature about this theme motivated the present study, which aims to investigate and document the existing AERP changes in a group of children with BECTS. AERPs were recorded, during the day, to pure and vocal tones and in a conventional auditory oddball paradigm in five children with BECTS (aged 8-12; mean=10 years; male=5) and in six gender and age-matched controls. Results revealed high amplitude of AERPs for the group of children with BECTS with a slight latency delay more pronounced in fronto-central electrodes. Children with BECTS may have abnormal central auditory processing, reflected by electrophysiological measures such as AERPs. In advance, AERPs seem a good tool to detect and reliably reveal cortical excitability in children with typical BECTS. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Event-related potential correlates of suspicious thoughts in individuals with schizotypal personality features.

    Science.gov (United States)

    Li, Xue-bing; Huang, Jia; Cheung, Eric F C; Gong, Qi-yong; Chan, Raymond C K

    2011-01-01

    Suspiciousness is a common feature of schizophrenia. However, suspicious thoughts are also commonly experienced by the general population. This study aimed to examine the underlying neural mechanism of suspicious thoughts in individuals with and without schizotypal personality disorder (SPD)-proneness, using an event-related potential (ERP) paradigm. Electroencephalography (EEG) was recorded when the "feeling of being seen through" was evoked in the participants. The findings showed a prominent positive deflection of the difference wave within the time window 250-400 ms after stimuli presentation in both SPD-prone and non-SPD-prone groups. Furthermore, the P3 amplitude was significantly reduced in the SPD-prone group compared to the non-SPD-prone group. The current density analysis also indicated hypoactivity in both frontal and temporal regions in the SPD-prone group, suggesting that the frontotemporal cortical network may play a role in the onset of suspicious thoughts. The P3 of difference wave was inversely correlated with the cognitive-perception factor and the suspiciousness/paranoid ideation trait, which provided preliminary electrophysiological evidence for the association of suspiciousness with SPD features.

  14. A hierarchy of event-related potential markers of auditory processing in disorders of consciousness

    Directory of Open Access Journals (Sweden)

    Steve Beukema

    2016-01-01

    Full Text Available Functional neuroimaging of covert perceptual and cognitive processes can inform the diagnoses and prognoses of patients with disorders of consciousness, such as the vegetative and minimally conscious states (VS;MCS. Here we report an event-related potential (ERP paradigm for detecting a hierarchy of auditory processes in a group of healthy individuals and patients with disorders of consciousness. Simple cortical responses to sounds were observed in all 16 patients; 7/16 (44% patients exhibited markers of the differential processing of speech and noise; and 1 patient produced evidence of the semantic processing of speech (i.e. the N400 effect. In several patients, the level of auditory processing that was evident from ERPs was higher than the abilities that were evident from behavioural assessment, indicating a greater sensitivity of ERPs in some cases. However, there were no differences in auditory processing between VS and MCS patient groups, indicating a lack of diagnostic specificity for this paradigm. Reliably detecting semantic processing by means of the N400 effect in passively listening single-subjects is a challenge. Multiple assessment methods are needed in order to fully characterise the abilities of patients with disorders of consciousness.

  15. Event-Related Potentials in Parkinson’s Disease: A Review

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    E. Růžička

    1993-01-01

    Full Text Available This article reviews the findings of event-related potentials (ERP in Parkinson's disease (PD published during the last 10 years. Basic principles and methods of ERP are briefly presented with particular regard to the auditory “odd-ball” paradigm almost uniquely employed for the ERP assessment in PD to date. The results of respective studies are overviewed and discussed with respect to three main axes: (1 The slowing down of cognitive processing in PD is reflected by the delays of N2 and P3 components of ERP which are more important in demented than in non-demented patients. The Nl component is delayed in demented patients with PD as well as in other dementias of presumed subcortical origin. (2 Various neuropsychological deficits observed in PD correlate with the delays of ERP evoking the implication of common subcortico-cortical cerebral mechanisms. (3 The variations of ERP under dopaminergic manipulation suggest conflicting effects of levodopa treatment on cognition, at least in certain categories of PD patients. These findings are discussed in the light of current knowledge on neurotransmitter brain systems and some hypothetic explanations are proposed. Finally, an attempt is made to outline further perspectives of clinical and research utilization of ERP in Parkinson's disease.

  16. Detection of movement intention from single-trial movement-related cortical potentials using random and non-random paradigms

    DEFF Research Database (Denmark)

    Aliakbaryhosseinabadi, Susan; Jiang, Ning; Vuckovic, Aleksandra

    2015-01-01

    Detection of motor intention with short latency from scalp electroencephalography (EEG) is essential for the development of brain-computer interface (BCI) systems for neuromodulation. This latency determines the temporal association between motor intention and the triggered afferent neurofeedback...

  17. Reduced cortical thickness associated with visceral fat and BMI

    Directory of Open Access Journals (Sweden)

    Ralf Veit

    2014-01-01

    Full Text Available Structural brain imaging studies have shown that obesity is associated with widespread reductions in gray matter (GM volume. Although the body mass index (BMI is an easily accessible anthropometric measure, substantial health problems are more related to specific body fat compartments, like visceral adipose tissue (VAT. We investigated cortical thickness measures in a group of 72 healthy subjects (BMI range 20–35 kg/m2, age range 19–50 years. Multiple regression analyses were performed using VAT and BMI as predictors and age, gender, total surface area and education as confounds. BMI and VAT were independently associated with reductions in cortical thickness in clusters comprising the left lateral occipital area, the left inferior temporal cortex, and the left precentral and inferior parietal area, while the right insula, the left fusiform gyrus and the right inferior temporal area showed a negative correlation with VAT only. In addition, we could show significant reductions in cortical thickness with increasing VAT adjusted for BMI in the left temporal cortex. We were able to detect widespread cortical thinning in a young to middle-aged population related to BMI and VAT; these findings show close resemblance to studies focusing on GM volume differences in diabetic patients. This may point to the influence of VAT related adverse effects, like low-grade inflammation, as a potentially harmful factor on brain integrity already in individuals at risk of developing diabetes, metabolic syndromes and arteriosclerosis.

  18. Limbic-thalamo-cortical projections and reward-related circuitry integrity affects eating behavior: A longitudinal DTI study in adolescents with restrictive eating disorders.

    Directory of Open Access Journals (Sweden)

    Gaia Olivo

    Full Text Available Few studies have used diffusion tensor imaging (DTI to investigate the micro-structural alterations of WM in patients with restrictive eating disorders (rED, and longitudinal data are lacking. Twelve patients with rED were scanned at diagnosis and after one year of family-based treatment, and compared to twenty-four healthy controls (HCs through DTI analysis. A tract-based spatial statistics procedure was used to investigate diffusivity parameters: fractional anisotropy (FA and mean, radial and axial diffusivities (MD, RD and AD, respectively. Reduced FA and increased RD were found in patients at baseline in the corpus callosum, corona radiata and posterior thalamic radiation compared with controls. However, no differences were found between follow-up patients and controls, suggesting a partial normalization of the diffusivity parameters. In patients, trends for a negative correlation were found between the baseline FA of the right anterior corona radiata and the Eating Disorder Examination Questionnaire total score, while a positive trend was found between the baseline FA in the splenium of corpus callosum and the weight loss occurred between maximal documented weight and time of admission. A positive trend for correlation was also found between baseline FA in the right anterior corona radiata and the decrease in the Obsessive-Compulsive Inventory Revised total score over time. Our results suggest that the integrity of the limbic-thalamo-cortical projections and the reward-related circuitry are important for cognitive control processes and reward responsiveness in regulating eating behavior.

  19. Multi-scale radiomic analysis of sub-cortical regions in MRI related to autism, gender and age

    Science.gov (United States)

    Chaddad, Ahmad; Desrosiers, Christian; Toews, Matthew

    2017-03-01

    We propose using multi-scale image textures to investigate links between neuroanatomical regions and clinical variables in MRI. Texture features are derived at multiple scales of resolution based on the Laplacian-of-Gaussian (LoG) filter. Three quantifier functions (Average, Standard Deviation and Entropy) are used to summarize texture statistics within standard, automatically segmented neuroanatomical regions. Significance tests are performed to identify regional texture differences between ASD vs. TDC and male vs. female groups, as well as correlations with age (corrected p brain imaging data exchange (ABIDE) brain MRI dataset is used to evaluate texture features derived from 31 brain regions from 1112 subjects including 573 typically developing control (TDC, 99 females, 474 males) and 539 Autism spectrum disorder (ASD, 65 female and 474 male) subjects. Statistically significant texture differences between ASD vs. TDC groups are identified asymmetrically in the right hippocampus, left choroid-plexus and corpus callosum (CC), and symmetrically in the cerebellar white matter. Sex-related texture differences in TDC subjects are found in primarily in the left amygdala, left cerebellar white matter, and brain stem. Correlations between age and texture in TDC subjects are found in the thalamus-proper, caudate and pallidum, most exhibiting bilateral symmetry.

  20. Chilling-related cell damage of apple (Malus × domestica Borkh.) fruit cortical tissue impacts antioxidant, lipid and phenolic metabolism.

    Science.gov (United States)

    Leisso, Rachel S; Buchanan, David A; Lee, Jinwook; Mattheis, James P; Sater, Chris; Hanrahan, Ines; Watkins, Christopher B; Gapper, Nigel; Johnston, Jason W; Schaffer, Robert J; Hertog, Maarten L A T M; Nicolaï, Bart M; Rudell, David R

    2015-02-01

    'Soggy breakdown' (SB) is an internal flesh disorder of 'Honeycrisp' apple (Malus × domestica Borkh.) fruit that occurs during low temperature storage. The disorder is a chilling injury (CI) in which visible symptoms typically appear after several weeks of storage, but information about the underlying metabolism associated with its induction and development is lacking. The metabolic profile of flesh tissue from wholly healthy fruit and brown and healthy tissues from fruit with SB was characterized using gas chromatography-mass spectrometry (GC-MS) and liquid chromatograph-mass spectrometry (LC-MS). Partial least squares discriminant analysis (PLS-DA) and correlation networks revealed correlation among ester volatile compounds by composition and differences in phytosterol, phenolic and putative triacylglycerides (TAGs) metabolism among the tissues. anova-simultaneous component analysis (ASCA) was used to test the significance of metabolic changes linked with tissue health status. ASCA-significant components included antioxidant compounds, TAGs, and phytosterol conjugates. Relative to entirely healthy tissues, elevated metabolite levels in symptomatic tissue included γ-amino butyric acid, glycerol, sitosteryl (6'-O-palmitoyl) β-d-glucoside and sitosteryl (6'-O-stearate) β-d-glucoside, and TAGs containing combinations of 16:0, 18:3, 18:2 and 18:1 fatty acids. Reduced metabolite levels in SB tissue included 5-caffeoyl quinate, β-carotene, catechin, epicatechin, α-tocopherol, violaxanthin and sitosteryl β-d glucoside. Pathway analysis indicated aspects of primary metabolism differed according to tissue condition, although differences in metabolites involved were more subtle than those of some secondary metabolites. The results implicate oxidative stress and membrane disruption processes in SB development and constitute a diagnostic metabolic profile for the disorder. © 2014 Scandinavian Plant Physiology Society.

  1. Agonist contraction during intermittent theta burst stimulation enhances motor cortical plasticity of the wrist flexors.

    Science.gov (United States)

    Mirdamadi, J L; Suzuki, L Y; Meehan, S K

    2015-03-30

    Differences in cortical control across the different muscles of the upper limb may mitigate the efficacy of TMS interventions targeting a specific muscle. The current study sought to determine whether weak concurrent contraction during TMS could enhance the efficacy of intermittent theta burst stimulation (iTBS) in the forearm flexors. Motor evoked potentials (MEP) were elicited from the flexor (FCR) and extensor carpi radialis (ECR) motor cortical hotspots before and after iTBS over the FCR cortical hotspot. During iTBS the FCR was either relaxed (iTBS-Relax) or tonically contracted to 10% of maximum voluntary force (iTBS-Contract). iTBS-Relax failed to produce consistent potentiation of MEPFCR amplitude. Individuals with a relatively lower RMTFCR compared RMTECR demonstrated MEPFCR facilitation post-iTBS-Relax. Individuals with relatively higher RMTFCR demonstrated less facilitation and even suppression of MEPFCR amplitude. iTBS-Contract facilitated MEPFCR amplitude but only for MEPFCR evoked from the ECR hotspot. Interactions between overlapping cortical representations determine the efficacy of iTBS. Tonic contraction increases the efficacy of iTBS by enhancing the volume of the cortical representation. However, metaplastic effects may attenuate the enhancement of MEP gain at the motor cortical hotspot. The use of TMS as an adjunct to physical therapy should account for inter-muscle interactions when targeting muscles of the forearm. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  2. Analysis of Amygdalar-Cortical Network Covariance During Pre- versus Post-menopausal Estrogen Levels: Potential Relevance to Resting State Networks, Mood, and Cognition

    Science.gov (United States)

    Ottowitz, William E.; Derro, David; Dougherty, Darin D.; Lindquist, Martin A.; Fischman, Alan J.; Hall, Janet E.

    2014-01-01

    Objectives 1.) Expand the scope of neuroendocrine applications of functional neuroimaging techniques. 2.) Compare the covariance of amygdalar activity with that of the rest of the brain during pre- and post-menopausal levels of estrogen (E2). Based on the distribution of cortical E2 receptors and the neocortical regions where E2 has been shown to preferentially accumulate, we predict that E2 infusion will increase covariance of amygdalar activity with that of the temporal and frontal cortices. Design This basic physiology study employed a within-subject design. All participants were post-menopausal women (n =7). Analysis of covariance between whole brain and amygdalar regional cerebral glucose consumption (CMRglc) was conducted in a voxel-wise manner by means of the basic regression option in SPM2 and was applied to FDG-PET scans acquired at baseline and after a 24 hour graded E2 infusion. Setting an academic medical center; Massachusetts General Hospital, Boston, Massachusetts. Results E2 levels (mean ± sem) were significantly greater at 24 hours (257.9 pg/mL ± 29.7) than at 0 hours (28.1 pg/mL ± 3.4). Right amygdalar CMRglc showed a significant covariance with activity of three different regions of the temporal cortex during E2 infusion, but none at baseline. In addition, right amygdalar CMRglc covaried with that of the right medial and superior frontal gyri only during E2 infusion. Conclusions In addition to suggesting changes in amygdalar-cortical network connectivity as a result of short-term E2 exposure, these analyses provide evidence that basic neuroendocrine research may benefit from further use of FDG-PET and other functional neuroimaging modalities for network level analyses. PMID:18766152

  3. Multiple-choice pretesting potentiates learning of related information.

    Science.gov (United States)

    Little, Jeri L; Bjork, Elizabeth Ligon

    2016-10-01

    Although the testing effect has received a substantial amount of empirical attention, such research has largely focused on the effects of tests given after study. The present research examines the effect of using tests prior to study (i.e., as pretests), focusing particularly on how pretesting influences the subsequent learning of information that is not itself pretested but that is related to the pretested information. In Experiment 1, we found that multiple-choice pretesting was better for the learning of such related information than was cued-recall pretesting or a pre-fact-study control condition. In Experiment 2, we found that the increased learning of non-pretested related information following multiple-choice testing could not be attributed to increased time allocated to that information during subsequent study. Last, in Experiment 3, we showed that the benefits of multiple-choice pretesting over cued-recall pretesting for the learning of related information persist over 48 hours, thus demonstrating the promise of multiple-choice pretesting to potentiate learning in educational contexts. A possible explanation for the observed benefits of multiple-choice pretesting for enhancing the effectiveness with which related nontested information is learned during subsequent study is discussed.

  4. The potential of social learning in relation to leadership training

    DEFF Research Database (Denmark)

    Moesby-Jensen, Cecilie K.

    in the healthcare sector in Denmark. The findings presented in the paper are based on participant observations, interviews, surveys and documentary material collected from 12 managers and the 160 staff members they supervise. Analyses of the data lead to recommendations for further integration of social learning......This paper discusses the potential of social learning in relation to leadership training courses, by presenting an empirical case study of the intended and unintended consequences of learning that occurred as a result of a specific leadership training course for public middle managers...

  5. Neural correlates of economic value and valuation context: an event-related potential study.

    Science.gov (United States)

    Tyson-Carr, John; Kokmotou, Katerina; Soto, Vicente; Cook, Stephanie; Fallon, Nicholas; Giesbrecht, Timo; Stancak, Andrej

    2018-05-01

    The value of environmental cues and internal states is continuously evaluated by the human brain, and it is this subjective value that largely guides decision making. The present study aimed to investigate the initial value attribution process, specifically the spatiotemporal activation patterns associated with values and valuation context, using electroencephalographic event-related potentials (ERPs). Participants completed a stimulus rating task in which everyday household items marketed up to a price of £4 were evaluated with respect to their desirability or material properties. The subjective values of items were evaluated as willingness to pay (WTP) in a Becker-DeGroot-Marschak auction. On the basis of the individual's subjective WTP values, the stimuli were divided into high- and low-value items. Source dipole modeling was applied to estimate the cortical sources underlying ERP components modulated by subjective values (high vs. low WTP) and the evaluation condition (value-relevant vs. value-irrelevant judgments). Low-WTP items and value-relevant judgments both led to a more pronounced N2 visual evoked potential at right frontal scalp electrodes. Source activity in right anterior insula and left orbitofrontal cortex was larger for low vs. high WTP at ∼200 ms. At a similar latency, source activity in right anterior insula and right parahippocampal gyrus was larger for value-relevant vs. value-irrelevant judgments. A stronger response for low- than high-value items in anterior insula and orbitofrontal cortex appears to reflect aversion to low-valued item acquisition, which in an auction experiment would be perceived as a relative loss. This initial low-value bias occurs automatically irrespective of the valuation context. NEW & NOTEWORTHY We demonstrate the spatiotemporal characteristics of the brain valuation process using event-related potentials and willingness to pay as a measure of subjective value. The N2 component resolves values of objects with a

  6. [Mechanoelectric potentials in synthetic hydrogels: possible relation to cytoskeleton].

    Science.gov (United States)

    Shkliar, T F; Safronov, A P; Toropova, O A; Pollack, G N; Bliakhman, F A

    2010-01-01

    Mechanical and electrical properties of a synthetic polyelectrolyte hydrogel considered as a model of the cytoskeletal gel were studied. Hydrogels were synthesized from polymethacrylic acid by radical polymerization in aqueous solution. The electrical charge was introduced into the gel network by partial neutralization of monomer acids with magnesium (hydro)oxides. Through the use of a motor, triangular longitudinal (axial) deformations were applied to gel samples. Simultaneously, the electrochemical (Donnan) potential of the gel was measured using conventional microelectrodes. We found that: (1) the Young modulus of the gel was 0.53 kPa; (2) at a given deformation velocity, the extent of gel deformation closely correlates with the gel potential; and (3) at the same level of gel deformation, the lower the deformation velocity, the higher the relative change of gel potential. These findings show a striking similarity to the data obtained in living cells, particularly in cardiac myocytes. A hypothesis involving the deformation-induced solvent migration from the gel to the surrounding solution is considered. It is concluded that the physicochemical features of the cytoskeletal gel may play a role in determining the mechanoelectric properties of excited cells.

  7. Event-related potential evidence for the processing efficiency theory.

    Science.gov (United States)

    Murray, N P; Janelle, C M

    2007-01-15

    The purpose of this study was to examine the central tenets of the processing efficiency theory using psychophysiological measures of attention and effort. Twenty-eight participants were divided equally into either a high or low trait anxiety group. They were then required to perform a simulated driving task while responding to one of four target light-emitting diodes. Cortical activity and dual task performance were recorded under two conditions -- baseline and competition -- with cognitive anxiety being elevated in the competitive session by an instructional set. Although driving speed was similar across sessions, a reduction in P3 amplitude to cue onset in the light detection task occurred for both groups during the competitive session, suggesting a reduction in processing efficiency as participants became more state anxious. Our findings provide more comprehensive and mechanistic evidence for processing efficiency theory, and confirm that increases in cognitive anxiety can result in a reduction of processing efficiency with little change in performance effectiveness.

  8. Attention-dependent sound offset-related brain potentials.

    Science.gov (United States)

    Horváth, János

    2016-05-01

    When performing sensory tasks, knowing the potentially occurring goal-relevant and irrelevant stimulus events allows the establishment of selective attention sets, which result in enhanced sensory processing of goal-relevant events. In the auditory modality, such enhancements are reflected in the increased amplitude of the N1 ERP elicited by the onsets of task-relevant sounds. It has been recently suggested that ERPs to task-relevant sound offsets are similarly enhanced in a tone-focused state in comparison to a distracted one. The goal of the present study was to explore the influence of attention on ERPs elicited by sound offsets. ERPs elicited by tones in a duration-discrimination task were compared to ERPs elicited by the same tones in not-tone-focused attentional setting. Tone offsets elicited a consistent, attention-dependent biphasic (positive-negative--P1-N1) ERP waveform for tone durations ranging from 150 to 450 ms. The evidence, however, did not support the notion that the offset-related ERPs reflected an offset-specific attention set: The offset-related ERPs elicited in a duration-discrimination condition (in which offsets were task relevant) did not significantly differ from those elicited in a pitch-discrimination condition (in which the offsets were task irrelevant). Although an N2 reflecting the processing of offsets in task-related terms contributed to the observed waveform, this contribution was separable from the offset-related P1 and N1. The results demonstrate that when tones are attended, offset-related ERPs may substantially overlap endogenous ERP activity in the postoffset interval irrespective of tone duration, and attention differences may cause ERP differences in such postoffset intervals. © 2016 Society for Psychophysiological Research.

  9. Event-related potentials dissociate perceptual from response-related age effects in visual search

    DEFF Research Database (Denmark)

    Wiegand, Iris; Müller, Hermann J.; Finke, Kathrin

    2013-01-01

    measures with lateralized event-related potentials of younger and older adults performing a compound-search task, in which the target-defining dimension of a pop-out target (color/shape) and the response-critical target feature (vertical/horizontal stripes) varied independently across trials. Slower...... responses in older participants were associated with age differences in all analyzed event-related potentials from perception to response, indicating that behavioral slowing originates from multiple stages within the information-processing stream. Furthermore, analyses of carry-over effects from one trial...

  10. Qur’an-related Intertextuality: Textual Potentiation in Translation

    Directory of Open Access Journals (Sweden)

    Aladdin Al-Kharabsheh

    2017-09-01

    Full Text Available Qur’an-related intertextuality, envisaged as an enriching communicative act both monolingually and interlingually, represents a case of semantic complexity that is wired to present inconceivable translation challenges. Drawing on Derrida’s (1977 dichotomy iterability/citationality, Kristeva’s (1980 vertical intertextuality, Fairclough’s (1992a; 1992b; 1995 & 2011 manifest intertextuality, and Bakhtin’s (1986 double voicing or re-accentuation, the study argues that Qur’an-related intertextuality is conducive of conceptual densities, the ‘harnessing’ of which requires ‘mobilizing’ those translation strategies that should exceed the lexicographical equivalence (Venuti 2009 to establish intertextual relations relevant to the form and theme of the foreign text. To resolve the arising translation problems, the study basically proposes two synthetic approaches: the gist-paratextual and the gist-exegetical. Translation skopos has been found to be central to the production and reception of intertextuality and to determining which of the two proposed synthetic approaches to operationalize. Finally, analysis shows that Qur’an proved to be a virtual breeding ground for textual dynamism and potentiation.

  11. Attentional Modulation of Somatosensory Processing During the Anticipation of Movements Accompanying Pain: An Event-Related Potential Study.

    Science.gov (United States)

    Clauwaert, Amanda; Torta, Diana M; Danneels, Lieven; Van Damme, Stefaan

    2018-02-01

    Attending to pain-relevant information is crucial to protect us from physical harm. Behavioral studies have already suggested that during anticipation of pain somatosensory input at the body location under threat is prioritized. However, research using daily life cues for pain, especially movements, is lacking. Furthermore, to our knowledge, no studies have investigated cortical processing associated with somatosensory processing during threatened movements. The current study aims to investigate whether movements accompanying pain automatically steer attention toward somatosensory input at the threatened location, affecting somatosensory evoked potentials (SEPs). Healthy volunteers were cued to perform movements with the left or the right hand, and one of these movements could be accompanied by pain on the moving hand. During movement anticipation, a task-irrelevant tactile stimulus was presented to the threatened or pain-free hand to evoke SEPs. During anticipation of movements accompanying pain, the N120 component was increased for tactile stimuli at the threatened relative to the hand without pain. Moreover, the P200 SEP was enhanced during anticipation of movements accompanying pain relative to movements without pain, irrespective of which hand was stimulated. These findings show that the anticipation of pain-accompanying movements may affect the processing of somatosensory input, and that this is likely to be driven by attentional processes. This study shows that the anticipation of pain-related movements automatically biases attention toward stimuli at a pain-related location, measured according to SEPs. The present study provides important new insights in the interplay between pain and attention, and its consequences at the cortical level. Copyright © 2017 The American Pain Society. Published by Elsevier Inc. All rights reserved.

  12. Intracerebral recording of cortical activity related to self-paced voluntary movements: a Bereitschaftspotential and event-related desynchronization/synchronization. SEEG study

    Czech Academy of Sciences Publication Activity Database

    Sochůrková, D.; Rektor, I.; Jurák, Pavel; Stančák, A.

    2006-01-01

    Roč. 173, č. 4 (2006), s. 637-649 ISSN 0014-4819 R&D Projects: GA ČR(CZ) GA102/05/0402 Institutional research plan: CEZ:AV0Z20650511 Keywords : SEEG * Bereitschaftspotential * Event-related desynchronization * Event-related synchronization Subject RIV: FS - Medical Facilities ; Equipment Impact factor: 1.959, year: 2006

  13. Prepulse Inhibition of Auditory Cortical Responses in the Caudolateral Superior Temporal Gyrus in Macaca mulatta.

    Science.gov (United States)

    Chen, Zuyue; Parkkonen, Lauri; Wei, Jingkuan; Dong, Jin-Run; Ma, Yuanye; Carlson, Synnöve

    2018-04-01

    Prepulse inhibition (PPI) refers to a decreased response to a startling stimulus when another weaker stimulus precedes it. Most PPI studies have focused on the physiological startle reflex and fewer have reported the PPI of cortical responses. We recorded local field potentials (LFPs) in four monkeys and investigated whether the PPI of auditory cortical responses (alpha, beta, and gamma oscillations and evoked potentials) can be demonstrated in the caudolateral belt of the superior temporal gyrus (STGcb). We also investigated whether the presence of a conspecific, which draws attention away from the auditory stimuli, affects the PPI of auditory cortical responses. The PPI paradigm consisted of Pulse-only and Prepulse + Pulse trials that were presented randomly while the monkey was alone (ALONE) and while another monkey was present in the same room (ACCOMP). The LFPs to the Pulse were significantly suppressed by the Prepulse thus, demonstrating PPI of cortical responses in the STGcb. The PPI-related inhibition of the N1 amplitude of the evoked responses and cortical oscillations to the Pulse were not affected by the presence of a conspecific. In contrast, gamma oscillations and the amplitude of the N1 response to Pulse-only were suppressed in the ACCOMP condition compared to the ALONE condition. These findings demonstrate PPI in the monkey STGcb and suggest that the PPI of auditory cortical responses in the monkey STGcb is a pre-attentive inhibitory process that is independent of attentional modulation.

  14. Stem cells: Potential therapy for age-related diseases

    DEFF Research Database (Denmark)

    Kassem, Moustapha

    2006-01-01

    Aging is associated with a progressive failing of tissues and organs of the human body leading to a large number of age-related diseases. Regenerative medicine is an emerging clinical discipline that aims to employ cellular medicines (normal cells, ex vivo expanded cells, or tissue......-engineered organs) to restore the functions of damaged or defective tissues and organs and thus to "rejuvenate" the failing aging body. One of the most important sources for cellular medicine is embryonic and adult (somatic) stem cells (SSCs). One example of SCCs with enormous clinical potential is the mesenchymal...... and organs in tissue-engineering protocols. However, several challenges confront the use of these cells in the clinic, ranging from biological challenges (e.g., how to isolate a homogenous populations of the cells with specific criteria from the bone marrow and how to expand them ex vivo without affecting...

  15. Event-Related Potentials and Emotion Processing in Child Psychopathology

    Directory of Open Access Journals (Sweden)

    Georgia eChronaki

    2016-04-01

    Full Text Available In recent years there has been increasing interest in the neural mechanisms underlying altered emotional processes in children and adolescents with psychopathology. This review provides a brief overview of the most up-to-date findings in the field of Event-Related Potentials (ERPs to facial and vocal emotional expressions in the most common child psychopathological conditions. In regards to externalising behaviour (i.e. ADHD, CD, ERP studies show enhanced early components to anger, reflecting enhanced sensory processing, followed by reductions in later components to anger, reflecting reduced cognitive-evaluative processing. In regards to internalising behaviour, research supports models of increased processing of threat stimuli especially at later more elaborate and effortful stages. Finally, in autism spectrum disorders abnormalities have been observed at early visual-perceptual stages of processing. An affective neuroscience framework for understanding child psychopathology can be valuable in elucidating underlying mechanisms and inform preventive intervention.

  16. Comparison of event related potentials with and without hypnagogic imagery.

    Science.gov (United States)

    Michida, N; Hayashi, M; Hori, T

    1998-04-01

    It is hypothesized that when hypnagogic imagery occurs, an appropriate attention may allocate to the imagery, resulting in the allocation of attention to the external tone stimuli being diminished. N3 amplitude of event related potentials (ERP) obtained a significant difference between the conditions with and without imagery. Arousal level of behavior and electroencephalography were not different between the conditions, therefore it is interpreted that the decrease of the N3 amplitude during imagining reflects the diminution of the allocation of attention to the external tone stimuli. Another late component of ERP, P3, did not make clear peaks in this study despite a large time constant (tau=3.2 s) used for EEG records.

  17. Is cortical bone hip? What determines cortical bone properties?

    Science.gov (United States)

    Epstein, Sol

    2007-07-01

    Increased bone turnover may produce a disturbance in bone structure which may result in fracture. In cortical bone, both reduction in turnover and increase in hip bone mineral density (BMD) may be necessary to decrease hip fracture risk and may require relatively greater proportionate changes than for trabecular bone. It should also be noted that increased porosity produces disproportionate reduction in bone strength, and studies have shown that increased cortical porosity and decreased cortical thickness are associated with hip fracture. Continued studies for determining the causes of bone strength and deterioration show distinct promise. Osteocyte viability has been observed to be an indicator of bone strength, with viability as the result of maintaining physiological levels of loading and osteocyte apoptosis as the result of a decrease in loading. Osteocyte apoptosis and decrease are major factors in the bone loss and fracture associated with aging. Both the osteocyte and periosteal cell layer are assuming greater importance in the process of maintaining skeletal integrity as our knowledge of these cells expand, as well being a target for pharmacological agents to reduce fracture especially in cortical bone. The bisphosphonate alendronate has been seen to have a positive effect on cortical bone by allowing customary periosteal growth, while reducing the rate of endocortical bone remodeling and slowing bone loss from the endocortical surface. Risedronate treatment effects were attributed to decrease in bone resorption and thus a decrease in fracture risk. Ibandronate has been seen to increase BMD as the spine and femur as well as a reduced incidence of new vertebral fractures and non vertebral on subset post hoc analysis. And treatment with the anabolic agent PTH(1-34) documented modeling and remodelling of quiescent and active bone surfaces. Receptor activator of nuclear factor kappa B ligand (RANKL) plays a key role in bone destruction, and the human monoclonal

  18. The role of auditory cortices in the retrieval of single-trial auditory-visual object memories.

    OpenAIRE

    Matusz, P.J.; Thelen, A.; Amrein, S.; Geiser, E.; Anken, J.; Murray, M.M.

    2015-01-01

    Single-trial encounters with multisensory stimuli affect both memory performance and early-latency brain responses to visual stimuli. Whether and how auditory cortices support memory processes based on single-trial multisensory learning is unknown and may differ qualitatively and quantitatively from comparable processes within visual cortices due to purported differences in memory capacities across the senses. We recorded event-related potentials (ERPs) as healthy adults (n = 18) performed a ...

  19. Event-related potential correlates of mindfulness meditation competence.

    Science.gov (United States)

    Atchley, R; Klee, D; Memmott, T; Goodrich, E; Wahbeh, H; Oken, B

    2016-04-21

    This cross-sectional study evaluated event-related potentials (ERPs) across three groups: naïve, novice, and experienced meditators as potential physiological markers of mindfulness meditation competence. Electroencephalographic (EEG) data were collected during a target tone detection task and a Breath Counting task. The Breath Counting task served as the mindfulness meditation condition for the novice and experienced meditator groups. Participants were instructed to respond to target tones with a button press in the first task (Tones), and then ignore the primed tones while Breath Counting. The primary outcomes were ERP responses to target tones, namely the N2 and P3, as markers of stimulus discrimination and attention, respectively. As expected, P3 amplitudes elicited by target tones were attenuated within groups during the Breath Counting task in comparison to the Tones task (pmeditator groups displayed greater change in peak-to-trough P3 amplitudes, with higher amplitudes during the Tones condition and more pronounced reductions in P3 amplitudes during the Breath Counting meditation task in comparison to the naïve group. Meditators had stronger P3 amplitude responses to target tones when instructed to attend to the tones, and a greater attenuation of P3 amplitudes when instructed to ignore the same tones during the Breath Counting task. This study introduces the idea of identifying ERP markers as a means of measuring mindfulness meditation competence, and results suggest this may be a valid approach. This information has the potential to improve mindfulness meditation interventions by allowing objective assessment of mindfulness meditation quality. Published by Elsevier Ltd.

  20. Emotion and attention: event-related brain potential studies.

    Science.gov (United States)

    Schupp, Harald T; Flaisch, Tobias; Stockburger, Jessica; Junghöfer, Markus

    2006-01-01

    Emotional pictures guide selective visual attention. A series of event-related brain potential (ERP) studies is reviewed demonstrating the consistent and robust modulation of specific ERP components by emotional images. Specifically, pictures depicting natural pleasant and unpleasant scenes are associated with an increased early posterior negativity, late positive potential, and sustained positive slow wave compared with neutral contents. These modulations are considered to index different stages of stimulus processing including perceptual encoding, stimulus representation in working memory, and elaborate stimulus evaluation. Furthermore, the review includes a discussion of studies exploring the interaction of motivated attention with passive and active forms of attentional control. Recent research is reviewed exploring the selective processing of emotional cues as a function of stimulus novelty, emotional prime pictures, learned stimulus significance, and in the context of explicit attention tasks. It is concluded that ERP measures are useful to assess the emotion-attention interface at the level of distinct processing stages. Results are discussed within the context of two-stage models of stimulus perception brought out by studies of attention, orienting, and learning.

  1. Probabilistic delay differential equation modeling of event-related potentials.

    Science.gov (United States)

    Ostwald, Dirk; Starke, Ludger

    2016-08-01

    "Dynamic causal models" (DCMs) are a promising approach in the analysis of functional neuroimaging data due to their biophysical interpretability and their consolidation of functional-segregative and functional-integrative propositions. In this theoretical note we are concerned with the DCM framework for electroencephalographically recorded event-related potentials (ERP-DCM). Intuitively, ERP-DCM combines deterministic dynamical neural mass models with dipole-based EEG forward models to describe the event-related scalp potential time-series over the entire electrode space. Since its inception, ERP-DCM has been successfully employed to capture the neural underpinnings of a wide range of neurocognitive phenomena. However, in spite of its empirical popularity, the technical literature on ERP-DCM remains somewhat patchy. A number of previous communications have detailed certain aspects of the approach, but no unified and coherent documentation exists. With this technical note, we aim to close this gap and to increase the technical accessibility of ERP-DCM. Specifically, this note makes the following novel contributions: firstly, we provide a unified and coherent review of the mathematical machinery of the latent and forward models constituting ERP-DCM by formulating the approach as a probabilistic latent delay differential equation model. Secondly, we emphasize the probabilistic nature of the model and its variational Bayesian inversion scheme by explicitly deriving the variational free energy function in terms of both the likelihood expectation and variance parameters. Thirdly, we detail and validate the estimation of the model with a special focus on the explicit form of the variational free energy function and introduce a conventional nonlinear optimization scheme for its maximization. Finally, we identify and discuss a number of computational issues which may be addressed in the future development of the approach. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Hostile attribution biases for relationally provocative situations and event-related potentials.

    Science.gov (United States)

    Godleski, Stephanie A; Ostrov, Jamie M; Houston, Rebecca J; Schlienz, Nicolas J

    2010-04-01

    This exploratory study investigates how hostile attribution biases for relationally provocative situations may be related to neurocognitive processing using the P300 event-related potential. Participants were 112 (45 women) emerging adults enrolled in a large, public university in upstate New York. Participants completed self-report measures on relational aggression and hostile attribution biases and performed an auditory perseveration task to elicit the P300. It was found that hostile attribution biases for relational provocation situations was associated with a larger P300 amplitude above and beyond the role of hostile attribution biases for instrumental situations, relational aggression, and gender. Larger P300 amplitude is interpreted to reflect greater allocation of cognitive resources or enhanced "attending" to salient stimuli. Implications for methodological approaches to studying aggression and hostile attribution biases and for theory are discussed, as well as implications for the fields of developmental psychology and psychopathology. Copyright 2010 Elsevier B.V. All rights reserved.

  3. Diagnostic study on the relation between ozone and vorticity potential

    Energy Technology Data Exchange (ETDEWEB)

    Abdel Basset, H. [Department of Astronomy and Meteorology, Faculty of Science, Al Azhar University, Nasr City, Cairo (Egypt); Gahein, A. [Egyptian Meteorological Authority, Cairo (Egypt)

    2003-04-01

    A diagnostic analysis of a Mediterranean system and the associated tropopause folding for the period 27 February to 10 March, 1987 is presented. Geopotential height, potential vorticity (PV) and relative humidity distributions were diagnosed. The analysis indicates clear correlation between the development of the cut-off low and the tropopause folding. A series of vertical cross-sections at the ends of the jet streaks demonstrated that a fold could be captured using potential vorticity and relative humidity. Q-vectors were employed to investigate vertical motion in the vicinity of the fold and showed the exact positions of descent corresponding to the fold along the entire length of the jet streak. The analysis also shows that the strong correlation between total ozone and column integrated vorticity potential holds well for all levels. As both quantities are integrals through the atmosphere, this result is consistent with, but does not prove, a high independent linear dependence between ozone and PV. More case studies are needed to assure the high linear dependence between ozone and PV. The maximum transport of ozone from the stratosphere to the troposphere is coinciding with the maximum developing system, and also with the maximum values of PV. [Spanish] Se presenta un analisis diagnostico de un Sistema mediterraneo y del pliegue de la tropopausa asociado durante el periodo del 27 de febrero al 10 de marzo de 1987. Se diagnosticaron la altitud neopotencial, el potencial de vorticidad y la distribucion de la humedad relativa. El analisis indica una correlacion clara entre el desarrollo de la baja segregada y el pliegue de la tropopausa. Una serie de cortes verticales en los extremos de las trazas del chorro demostraron que el pliegue puede ser capturado utilizando el potencial de vorticidad y la humedad relativa. Para investigar la movilidad vertical en la vecindad del pliegue se utilizaron vectores Q, y se demostraron las posiciones exactas de descenso

  4. Extent of cortical involvement in amyotrophic lateral sclerosis--an analysis based on cortical thickness.

    Science.gov (United States)

    Thorns, Johannes; Jansma, Henk; Peschel, Thomas; Grosskreutz, Julian; Mohammadi, Bahram; Dengler, Reinhard; Münte, Thomas F

    2013-10-18

    Besides the defining involvement of upper and lower motor neurons, the involvement of extramotor structures has been increasingly acknowledged in amyotrophic lateral sclerosis (ALS). Here we investigated a group of 14 mildly to moderately affected ALS patients and 14 age-matched healthy control participants using cortical thickness analysis. Cortical thickness was determined from high resolution 3D T1 magnetic resonance images and involved semiautomatic segmentation in grey and white matter, cortical alignment and determination of thickness using the Laplace method. In addition to a whole-cortex analysis a region of interest approach was applied. ALS patients showed regions of significant cortical thinning in the pre- and postcentral gyri bilaterally. Further regions of cortical thinning included superior and inferior parietal lobule, angular and supramarginal gyrus, insula, superior frontal, temporal and occipital regions, thus further substantiating extramotor involvement in ALS. A relationship between cortical thickness of the right superior frontal cortex and clinical severity (assessed by the ALS functional rating scale) was also demonstrated. Cortical thickness is reduced in ALS not only in motor areas but in widespread non-motor cortical areas. Cortical thickness is related to clinical severity.

  5. Agency attribution: event-related potentials and outcome monitoring.

    Science.gov (United States)

    Bednark, Jeffery G; Franz, Elizabeth A

    2014-04-01

    Knowledge about the effects of our actions is an underlying feature of voluntary behavior. Given the importance of identifying the outcomes of our actions, it has been proposed that the sensory outcomes of self-made actions are inherently different from those of externally caused outcomes. Thus, the outcomes of self-made actions are likely to be more motivationally significant for an agent. We used event-related potentials to investigate the relationship between the perceived motivational significance of an outcome and the attribution of agency in the presence of others. In our experiment, we assessed agency attribution in the presence of another agent by varying the degree of contiguity between participants' self-made actions and the sensory outcome. Specifically, we assessed the feedback correct-related positivity (fCRP) and the novelty P3 measures of an outcome's motivational significance and unexpectedness, respectively. Results revealed that both the fCRP and participants' agency attributions were significantly influenced by action-outcome contiguity. However, when action-outcome contiguity was ambiguous, novelty P3 amplitude was a reliable indicator of agency attribution. Prior agency attributions were also found to influence attribution in trials with ambiguous and low action-outcome contiguity. Participants' use of multiple cues to determine agency is consistent with the cue integration theory of agency. In addition to these novel findings, this study supports growing evidence suggesting that reinforcement processes play a significant role in the sense of agency.

  6. Bisphosphonate-Related Osteonecrosis of the Jaw Bone: Radiological Pattern and the Potential Role of CBCT in Early Diagnosis

    Directory of Open Access Journals (Sweden)

    James Olutayo

    2010-04-01

    Full Text Available Objectives: To systematize the clinico-radiological symptoms and course of bisphosphonate-related osteonecrosis of jaw bone and to evaluate the diagnostic potential of various radiological techniques to detect mild osteonecrosis in each stage of the disease.Material and Methods: The sample consisted of 22 patients previously diagnosed with extraoral malignant disease. Diagnosis was based on a clinical examination in conjunction to digital panoramic radiography and cone beam computed tomography (CBCT. Two dentomaxillofacial radiologists reviewed all images.Results: Twenty patients showed mandibular involvement clinically, while two others had a maxillary involvement. Four stages of the disease were proposed based on the clinico-radiological findings. Subclinical cortical and lamina dura thickening was detected with only three-dimensional CBCT and periapical images, while ulceration and cortical bone thickening was detected only by three-dimensional CBCT. Mixed sclerotic, lytic bone destruction involving alveolar and basal bone with or without encroachment on the mandibular canal, pathological mandibular fractures were detected by two-dimensional panoramic and three-dimensional CBCT images. Other findings are non healing extraction sockets, periapical radiolucencies, osteolysis, sequestra, oroantral fistula, and periosteal new bone formation.Conclusions: The present study showed that bisphosphonate-related osteonecrosis of jaw bone occurs in four distinct clinico-radiological stages. For mild cases, panoramic image diagnosis was much less obvious, whereas cone beam computed tomography was able to fully characterise the bony lesions and describe their extent and involvement of neighbouring structures in all cases. Thus cone beam computed tomography might better contribute to the prevention of bisphosphonate-related osteonecrosis of jaw bone as well to the disease management.

  7. Combined effects of type 2 diabetes and hypertension associated with cortical thinning and impaired cerebrovascular reactivity relative to hypertension alone in older adults

    Directory of Open Access Journals (Sweden)

    Ekaterina Tchistiakova

    2014-01-01

    Conclusions: Individuals with T2DM and HTN showed decreased CVR and CThk compared to age-matched HTN controls. This study identifies brain regions that are impacted by the combined effects of comorbid T2DM and HTN conditions, with new evidence that the corresponding cortical thinning may contribute to cognitive decline.

  8. Explicit Relations of Physical Potentials Through Generalized Hypervirial and Kramers' Recurrence Relations

    Science.gov (United States)

    Sun, Guo-Hua; Dong, Shi-Hai

    2015-06-01

    Based on a Hamiltonian identity, we study one-dimensional generalized hypervirial theorem, Blanchard-like (non-diagonal case) and Kramers' (diagonal case) recurrence relations for arbitrary xκ which is independent of the central potential V(x). Some significant results in diagonal case are obtained for special κ in xκ (κ ≥ 2). In particular, we find the orthogonal relation = δn1n2 (κ = 0), = (En1 - En2)2 (κ = 1), En = + (κ = 2) and -4En + + 4 = 0 (κ = 3). The latter two formulas can be used directly to calculate the energy levels. We present useful explicit relations for some well known physical potentials without requiring the energy spectra of quantum system. Supported in part by Project 20150964-SIP-IPN, COFAA-IPN, Mexico

  9. Dynamics of large-scale cortical interactions at high gamma frequencies during word production: event related causality (ERC) analysis of human electrocorticography (ECoG).

    Science.gov (United States)

    Korzeniewska, Anna; Franaszczuk, Piotr J; Crainiceanu, Ciprian M; Kuś, Rafał; Crone, Nathan E

    2011-06-15

    Intracranial EEG studies in humans have shown that functional brain activation in a variety of functional-anatomic domains of human cortex is associated with an increase in power at a broad range of high gamma (>60Hz) frequencies. Although these electrophysiological responses are highly specific for the location and timing of cortical processing and in animal recordings are highly correlated with increased population firing rates, there has been little direct empirical evidence for causal interactions between different recording sites at high gamma frequencies. Such causal interactions are hypothesized to occur during cognitive tasks that activate multiple brain regions. To determine whether such causal interactions occur at high gamma frequencies and to investigate their functional significance, we used event-related causality (ERC) analysis to estimate the dynamics, directionality, and magnitude of event-related causal interactions using subdural electrocorticography (ECoG) recorded during two word production tasks: picture naming and auditory word repetition. A clinical subject who had normal hearing but was skilled in American Signed Language (ASL) provided a unique opportunity to test our hypothesis with reference to a predictable pattern of causal interactions, i.e. that language cortex interacts with different areas of sensorimotor cortex during spoken vs. signed responses. Our ERC analyses confirmed this prediction. During word production with spoken responses, perisylvian language sites had prominent causal interactions with mouth/tongue areas of motor cortex, and when responses were gestured in sign language, the most prominent interactions involved hand and arm areas of motor cortex. Furthermore, we found that the sites from which the most numerous and prominent causal interactions originated, i.e. sites with a pattern of ERC "divergence", were also sites where high gamma power increases were most prominent and where electrocortical stimulation mapping

  10. BoNT-A related changes of cortical activity in patients suffering from severe hand paralysis with arm spasticity following ischemic stroke.

    Science.gov (United States)

    Veverka, Tomáš; Hluštík, Petr; Tomášová, Zuzana; Hok, Pavel; Otruba, Pavel; Král, Michal; Tüdös, Zbyněk; Zapletalová, Jana; Herzig, Roman; Krobot, Alois; Kaňovský, Petr

    2012-08-15

    Investigations were performed to localize and analyze the botulinum toxin (BoNT-A) related changes of cerebral cortex activation in chronic stroke patients suffering from severe hand paralysis with arm spasticity. Effects on task- related cerebral activation were evaluated by functional magnetic resonance imaging (fMRI). 14 patients (5 males, 9 females, mean age 55.3 years) suffering from upper limb post-stroke spasticity were investigated. The change of arm spasticity was assessed by using the modified Ashworth scale (MAS). FMRI sessions were performed before (W0), four weeks (W4) and 11 weeks (W11) after BoNT-A application. Patients were scanned while performing imaginary movement with the impaired hand. Group fMRI analysis included patient age as a covariate. BoNT-A treatment was effective in alleviation of arm spasticity. Mean MAS was at Week 0: 2.5 (SD 0.53), at Week 4: 1.45 (SD 0.38), at Week 11: 2.32 (SD 0.44). Task-related fMRI prior to the treatment showed extensive activation of bilateral frontoparietal sensorimotor cortical areas, anterior cingulate gyrus, pallidum, thalamus and cerebellum. Effective BoNT-A treatment (W4) resulted in partial reduction of active network volume in most of the observed areas, whereas BoNT-free data (W11) revealed further volume reduction in the sensorimotor network. On direct comparison, significant activation decreases associated with BoNT-A treatment were located in areas outside the classical sensorimotor system, namely, ipsilesional lateral occipital cortex, supramarginal gyrus and precuneus cortex. On comparison of W4 and W11, no activation increases were found, instead, activation further decreased in ipsilesional insular cortex, contralesional superior frontal gyrus and bilateral frontal pole. Whole brain activation patterns during BoNT-A treatment of post-stroke arm spasticity and further follow up document predominantly gradual changes both within and outside the classical sensorimotor system. Copyright © 2012

  11. Alterations of cortical GABA neurons and network oscillations in schizophrenia.

    Science.gov (United States)

    Gonzalez-Burgos, Guillermo; Hashimoto, Takanori; Lewis, David A

    2010-08-01

    The hypothesis that alterations of cortical inhibitory gamma-aminobutyric acid (GABA) neurons are a central element in the pathology of schizophrenia has emerged from a series of postmortem studies. How such abnormalities may contribute to the clinical features of schizophrenia has been substantially informed by a convergence with basic neuroscience studies revealing complex details of GABA neuron function in the healthy brain. Importantly, activity of the parvalbumin-containing class of GABA neurons has been linked to the production of cortical network oscillations. Furthermore, growing knowledge supports the concept that gamma band oscillations (30-80 Hz) are an essential mechanism for cortical information transmission and processing. Herein we review recent studies further indicating that inhibition from parvalbumin-positive GABA neurons is necessary to produce gamma oscillations in cortical circuits; provide an update on postmortem studies documenting that deficits in the expression of glutamic acid decarboxylase67, which accounts for most GABA synthesis in the cortex, are widely observed in schizophrenia; and describe studies using novel, noninvasive approaches directly assessing potential relations between alterations in GABA, oscillations, and cognitive function in schizophrenia.

  12. Hemispheric Lateralization of Event-Related Brain Potentials in Different Processing Phases during Unimanual Finger Movements

    Directory of Open Access Journals (Sweden)

    Yi-Wen Li

    2008-04-01

    Full Text Available Previous functional MRI and brain electrophysiology studies have studied the left-right differences during the tapping tasks and found that the activation of left hemisphere was more significant than that of right hemisphere. In this study, we wanted to delineate this lateralization phenomenon not only in the execution phase but also in other processing phases, such as early visual, pre-executive and post-executive phases. We have designed a finger-tapping task to delineate the left-right differences of event related potentials (ERPs to right finger movement in sixteen right handed college students. The mean amplitudes of ERPs were analyzed to examine the left-right dominance of cortical activity in the phase of early visual process (75-120ms, pre-execution (175-260ms, execution (310-420ms and post-execution (420-620ms. In the execution phase, ERPs at the left electrodes were significantly more pronounced than those at the right electrodes (F3 > F4, C3 > C4, P3 > P4, O1 > O2 under the situation without comparing the central electrodes (Fz, Cz, Pz, and Oz. No difference was found between left and right electrodes in other three phases except the C3 electrode still showed more dominant than C4 in the pre- and post-execution phase. In conclusion, the phenomenon of brain lateralization occur major in the execution phase. The central area also showed the lateralization in the pre- and post-execution to demonstrate its unique lateralized contributions to unilateral simple finger movements.

  13. Cognitive deficits following exposure to pneumococcal meningitis: an event-related potential study

    Directory of Open Access Journals (Sweden)

    Kihara Michael

    2012-03-01

    Full Text Available Abstract Background Pneumococcal meningitis (PM is a severe and life-threatening disease that is associated with cognitive impairment including learning difficulties, cognitive slowness, short-term memory deficits and poor academic performance. There are limited data on cognitive outcomes following exposure to PM from Africa mainly due to lack of culturally appropriate tools. We report cognitive processes of exposed children as measured by auditory and visual event-related potentials. Methods Sixty-five children (32 male, mean 8.4 years, SD 3.0 years aged between 4-15 years with a history of PM and an age-matched control group of 93 children (46 male; mean 8.4 years, SD 2.7 years were recruited from a well-demarcated study area in Kilifi. In the present study, both baseline to peak and peak-to-peak amplitude differences are reported. Results Children with a history of pneumococcal meningitis had significantly longer auditory P1 and P3a latencies and smaller P1 amplitudes compared to unexposed children. In the visual paradigm, children with PM seemingly lacked a novelty P3a component around 350 ms where control children had a maximum, and showed a lack of stimulus differentiation at Nc. Further, children with exposure to PM had smaller peak to peak amplitude (N2-P1 compared to unexposed children. Conclusion The results suggest that children with a history of PM process novelty differently than do unexposed children, with slower latencies and reduced or absent components. This pattern suggests poorer auditory attention and/or cognitive slowness and poorer visual attention orienting, possibly due to disruption in the functions of the lateral prefrontal and superior temporal cortices. ERPs may be useful for assessment of the development of perceptual-cognitive functions in post brain-injury in African children by providing an alternate way of assessing cognitive development in patient groups for whom more typical standardized neuropsychological

  14. Investigation of potential fire-related damage to safety-related equipment in nuclear power plants

    International Nuclear Information System (INIS)

    Wanless, J.

    1985-11-01

    Based on a review of vendor information, fire damage reports, equipment qualification and hydrogen burn test results, and material properties, thirty-three types of equipment found in nuclear power plants were ranked in terms of their potential sensitivity to fire environments. The ranking considered both the functional requirements and damage proneness of each component. A further review of the seven top-ranked components was performed, considering the relative prevalence and potential safety significance of each. From this, relays and hand switches dominate as first choices for fire damage testing with logic equipment, power supplies, transmitters, and motor control centers as future candidates

  15. Simultaneous odour-face presentation strengthens hedonic evaluations and event-related potential responses influenced by unpleasant odour.

    Science.gov (United States)

    Cook, Stephanie; Kokmotou, Katerina; Soto, Vicente; Wright, Hazel; Fallon, Nicholas; Thomas, Anna; Giesbrecht, Timo; Field, Matt; Stancak, Andrej

    2018-04-13

    Odours alter evaluations of concurrently presented visual stimuli, such as faces. Stimulus onset asynchrony (SOA) is known to affect evaluative priming in various sensory modalities. However, effects of SOA on odour priming of visual stimuli are not known. The present study aimed to analyse whether subjective and cortical activation changes during odour priming would vary as a function of SOA between odours and faces. Twenty-eight participants rated faces under pleasant, unpleasant, and no-odour conditions using visual analogue scales. In half of trials, faces appeared one-second after odour offset (SOA 1). In the other half of trials, faces appeared during the odour pulse (SOA 2). EEG was recorded continuously using a 128-channel system, and event-related potentials (ERPs) to face stimuli were evaluated using statistical parametric mapping (SPM). Faces presented during unpleasant-odour stimulation were rated significantly less pleasant than the same faces presented one-second after offset of the unpleasant odour. Scalp-time clusters in the late-positive-potential (LPP) time-range showed an interaction between odour and SOA effects, whereby activation was stronger for faces presented simultaneously with the unpleasant odour, compared to the same faces presented after odour offset. Our results highlight stronger unpleasant odour priming with simultaneous, compared to delayed, odour-face presentation. Such effects were represented in both behavioural and neural data. A greater cortical and subjective response during simultaneous presentation of faces and unpleasant odour may have an adaptive role, allowing for a prompt and focused behavioural reaction to a concurrent stimulus if an aversive odour would signal danger, or unwanted social interaction. Copyright © 2018 Elsevier B.V. All rights reserved.

  16. Cortical bone metastases

    International Nuclear Information System (INIS)

    Davis, T.M. Jr.; Rogers, L.F.; Hendrix, R.W.

    1986-01-01

    Twenty-five cases of bone metastases involving the cortex alone are reviewed. Seven patients had primary lung carcinoma, while 18 had primary tumors not previously reported to produce cortical bone metastases (tumors of the breast, kidney, pancreas, adenocarcinoma of unknown origin, multiple myeloma). Radiographically, these cortical lesions were well circumscribed, osteolytic, and produced soft-tissue swelling and occasional periosteal reaction. A recurrent pattern of metadiaphyseal involvement of the long bones of the lower extremity (particularly the femur) was noted, and is discussed. Findings reported in the literature, review, pathophysiology, and the role of skeletal radiographs, bone scans, and CT scans in evaluating cortical bone metastases are addressed

  17. Attention in essential tremor: evidence from event-related potentials.

    Science.gov (United States)

    Pauletti, C; Mannarelli, D; Locuratolo, N; Vanacore, N; De Lucia, M C; Mina, C; Fattapposta, F

    2013-07-01

    Clinically subtle executive dysfunctions have recently been described in essential tremor (ET), though the presence of attentional deficits is still unclear. We investigated the psychophysiological aspects of attention in ET, using event-related potentials (ERPs). Twenty-one non-demented patients with ET and 21 age- and sex-matched healthy controls underwent a psychophysiological evaluation. P300 components and the Contingent Negative Variation (CNV) were recorded. The latencies and amplitudes of the P3a and P3b subcomponents and CNV areas were evaluated. Possible correlations between clinical parameters and ERP data were investigated. P3a latency was significantly longer in the ET group (p attentive circuits, while the memory context-updating process appears to be spared. This selective cognitive dysfunction does not appear to interfere with the attentional set linked to the expectancy evaluated during a complex choice-reaction time task, which is preserved in ET. This multitask psychophysiological approach reveals the presence of a peculiar attentional deficit in patients with ET, thus expanding the clinical features of this disease.

  18. Non-invasive modulation of somatosensory evoked potentials by the application of static magnetic fields over the primary and supplementary motor cortices.

    Science.gov (United States)

    Kirimoto, Hikari; Asao, Akihiko; Tamaki, Hiroyuki; Onishi, Hideaki

    2016-10-04

    This study was performed to investigate the possibility of non-invasive modulation of SEPs by the application of transcranial static magnetic field stimulation (tSMS) over the primary motor cortex (M1) and supplementary motor cortex (SMA), and to measure the strength of the NdFeB magnetic field by using a gaussmeter. An NdFeB magnet or a non-magnetic stainless steel cylinder (for sham stimulation) was settled on the scalp over M1 and SMA of 14 subjects for periods of 15 min. SEPs following right median nerve stimulation were recorded before and immediately after, 5 min after, and 10 min after tSMS from sites C3' and F3. Amplitudes of the N33 component of SEPs at C3' significantly decreased immediately after tSMS over M1 by up to 20%. However, tSMS over the SMA did not affect the amplitude of any of the SEP components. At a distance of 2-3 cm (rough depth of the cortex), magnetic field strength was in the range of 110-190 mT. Our results that tSMS over M1 can reduce the amplitude of SEPs are consistent with those of low-frequency repeated TMS and cathodal tDCS studies. Therefore, tSMS could be a useful tool for modulating cortical somatosensory processing.

  19. Event-related potential correlates of emergent inference in human arbitrary relational learning.

    Science.gov (United States)

    Wang, Ting; Dymond, Simon

    2013-01-01

    Two experiments investigated the functional-anatomical correlates of cognition supporting untrained, emergent relational inference in a stimulus equivalence task. In Experiment 1, after learning a series of conditional relations involving words and pseudowords, participants performed a relatedness task during which EEG was recorded. Behavioural performance was faster and more accurate on untrained, indirectly related symmetry (i.e., learn AB and infer BA) and equivalence trials (i.e., learn AB and AC and infer CB) than on unrelated trials, regardless of whether or not a formal test for stimulus equivalence relations had been conducted. Consistent with previous results, event related potentials (ERPs) evoked by trained and emergent trials at parietal and occipital sites differed only for those participants who had not received a prior equivalence test. Experiment 2 further replicated and extended these behavioural and ERP findings using arbitrary symbols as stimuli and demonstrated time and frequency differences for trained and untrained relatedness trials. Overall, the findings demonstrate convincingly the ERP correlates of intra-experimentally established stimulus equivalence relations consisting entirely of arbitrary symbols and offer support for a contemporary cognitive-behavioural model of symbolic categorisation and relational inference. Copyright © 2012 Elsevier B.V. All rights reserved.

  20. Iconic Meaning in Music: An Event-Related Potential Study

    Science.gov (United States)

    Luo, Qiuling; Huang, Hong; Mo, Lei

    2015-01-01

    Although there has been extensive research on the processing of the emotional meaning of music, little is known about other aspects of listeners’ experience of music. The present study investigated the neural correlates of the iconic meaning of music. Event-related potentials (ERP) were recorded while a group of 20 music majors and a group of 20 non-music majors performed a lexical decision task in the context of implicit musical iconic meaning priming. ERP analysis revealed a significant N400 effect of congruency in time window 260-510 ms following the onset of the target word only in the group of music majors. Time-course analysis using 50 ms windows indicated significant N400 effects both within the time window 410-460 ms and 460-510 ms for music majors, whereas only a partial N400 effect during time window 410-460 ms was observed for non-music majors. There was also a trend for the N400 effects in the music major group to be stronger than those in the non-major group in the sub-windows of 310-360ms and 410-460ms. Especially in the sub-window of 410-460 ms, the topographical map of the difference waveforms between congruent and incongruent conditions revealed different N400 distribution between groups; the effect was concentrated in bilateral frontal areas for music majors, but in central-parietal areas for non-music majors. These results imply probable neural mechanism differences underlying automatic iconic meaning priming of music. Our findings suggest that processing of the iconic meaning of music can be accomplished automatically and that musical training may facilitate the understanding of the iconic meaning of music. PMID:26161561

  1. Iconic Meaning in Music: An Event-Related Potential Study.

    Science.gov (United States)

    Cai, Liman; Huang, Ping; Luo, Qiuling; Huang, Hong; Mo, Lei

    2015-01-01

    Although there has been extensive research on the processing of the emotional meaning of music, little is known about other aspects of listeners' experience of music. The present study investigated the neural correlates of the iconic meaning of music. Event-related potentials (ERP) were recorded while a group of 20 music majors and a group of 20 non-music majors performed a lexical decision task in the context of implicit musical iconic meaning priming. ERP analysis revealed a significant N400 effect of congruency in time window 260-510 ms following the onset of the target word only in the group of music majors. Time-course analysis using 50 ms windows indicated significant N400 effects both within the time window 410-460 ms and 460-510 ms for music majors, whereas only a partial N400 effect during time window 410-460 ms was observed for non-music majors. There was also a trend for the N400 effects in the music major group to be stronger than those in the non-major group in the sub-windows of 310-360 ms and 410-460 ms. Especially in the sub-window of 410-460 ms, the topographical map of the difference waveforms between congruent and incongruent conditions revealed different N400 distribution between groups; the effect was concentrated in bilateral frontal areas for music majors, but in central-parietal areas for non-music majors. These results imply probable neural mechanism differences underlying automatic iconic meaning priming of music. Our findings suggest that processing of the iconic meaning of music can be accomplished automatically and that musical training may facilitate the understanding of the iconic meaning of music.

  2. Robust estimation of event-related potentials via particle filter.

    Science.gov (United States)

    Fukami, Tadanori; Watanabe, Jun; Ishikawa, Fumito

    2016-03-01

    In clinical examinations and brain-computer interface (BCI) research, a short electroencephalogram (EEG) measurement time is ideal. The use of event-related potentials (ERPs) relies on both estimation accuracy and processing time. We tested a particle filter that uses a large number of particles to construct a probability distribution. We constructed a simple model for recording EEG comprising three components: ERPs approximated via a trend model, background waves constructed via an autoregressive model, and noise. We evaluated the performance of the particle filter based on mean squared error (MSE), P300 peak amplitude, and latency. We then compared our filter with the Kalman filter and a conventional simple averaging method. To confirm the efficacy of the filter, we used it to estimate ERP elicited by a P300 BCI speller. A 400-particle filter produced the best MSE. We found that the merit of the filter increased when the original waveform already had a low signal-to-noise ratio (SNR) (i.e., the power ratio between ERP and background EEG). We calculated the amount of averaging necessary after applying a particle filter that produced a result equivalent to that associated with conventional averaging, and determined that the particle filter yielded a maximum 42.8% reduction in measurement time. The particle filter performed better than both the Kalman filter and conventional averaging for a low SNR in terms of both MSE and P300 peak amplitude and latency. For EEG data produced by the P300 speller, we were able to use our filter to obtain ERP waveforms that were stable compared with averages produced by a conventional averaging method, irrespective of the amount of averaging. We confirmed that particle filters are efficacious in reducing the measurement time required during simulations with a low SNR. Additionally, particle filters can perform robust ERP estimation for EEG data produced via a P300 speller. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  3. Decoding 3D reach and grasp from hybrid signals in motor and premotor cortices: spikes, multiunit activity, and local field potentials.

    Science.gov (United States)

    Bansal, Arjun K; Truccolo, Wilson; Vargas-Irwin, Carlos E; Donoghue, John P

    2012-03-01

    Neural activity in motor cortex during reach and grasp movements shows modulations in a broad range of signals from single-neuron spiking activity (SA) to various frequency bands in broadband local field potentials (LFPs). In particular, spatiotemporal patterns in multiband LFPs are thought to reflect dendritic integration of local and interareal synaptic inputs, attentional and preparatory processes, and multiunit activity (MUA) related to movement representation in the local motor area. Nevertheless, the relationship between multiband LFPs and SA, and their relationship to movement parameters and their relative value as brain-computer interface (BCI) control signals, remain poorly understood. Also, although this broad range of signals may provide complementary information channels in primary (MI) and ventral premotor (PMv) areas, areal differences in information have not been systematically examined. Here, for the first time, the amount of information in SA and multiband LFPs was compared for MI and PMv by recording from dual 96-multielectrode arrays while monkeys made naturalistic reach and grasp actions. Information was assessed as decoding accuracy for 3D arm end point and grip aperture kinematics based on SA or LFPs in MI and PMv, or combinations of signal types across areas. In contrast with previous studies with ≤16 simultaneous electrodes, here ensembles of >16 units (on average) carried more information than multiband, multichannel LFPs. Furthermore, reach and grasp information added by various LFP frequency bands was not independent from that in SA ensembles but rather typically less than and primarily contained within the latter. Notably, MI and PMv did not show a particular bias toward reach or grasp for this task or for a broad range of signal types. For BCIs, our results indicate that neuronal ensemble spiking is the preferred signal for decoding, while LFPs and combined signals from PMv and MI can add robustness to BCI control.

  4. The neuromechanism underlying verbal analogical reasoning of metaphorical relations: an event-related potentials study.

    Science.gov (United States)

    Zhao, Ming; Meng, Huishan; Xu, Zhiyuan; Du, Fenglei; Liu, Tao; Li, Yongxin; Chen, Feiyan

    2011-11-24

    Using event-related potentials (ERPs), this study investigated the neuromechanism underlying verbal analogical reasoning of two different metaphorical relations: attributive metaphor and relational metaphor. The analogical reasoning of attributive metaphor (AM-AR) involves a superficial similarity between analogues, while the analogical reasoning of relational metaphor (RM-AR) requires a structural similarity. Subjects were asked to judge whether one word pair was semantically analogous to another word pair. Results showed that the schema induction stage elicited a greater N400 component at the right anterior scalp for the AM-AR and RM-AR tasks, possibly attributable to semantic processing of metaphorical word pairs. The N400 was then followed by a widely distributed P300 and a late negative component (LNC1) at the left anterior scalp. The P300 was possibly related to the formation of a relational category, while the LNC1 was possibly related to the maintenance of a reasoning cue in working memory. The analogy mapping stage elicited broadly distributed N400 and LNC2, which might indicate the presence of semantic retrieval and analogical transfer. In the answer production stage, all conditions elicited the P2 component due to early stimulus encoding. The largest P2 amplitude was in the RM-AR task. The RM-AR elicited a larger LPC than did the AM-AR, even though the baseline correction was taken as a control for the differential P2 effect. The LPC effect might suggest that relational metaphors involved more integration processing than attributive metaphors. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. Application of the P300 Event-Related Potential in the Diagnosis of Epilepsy Disorder: A Review

    Directory of Open Access Journals (Sweden)

    Kandhasamy Sowndhararajan

    2018-03-01

    Full Text Available Epilepsy is one of the most serious chronical neurological disorders, affecting more than 50 million people worldwide. It can be defined as a spectrum disorder, and patients with epilepsy possess abnormalities in cognitive functions. A number of factors can cause cognitive dysfunctions in epileptic syndromes, including etiology, the age of onset, type of seizure and severity, duration, and antiepileptic drugs. Event-related potentials (ERPs are very useful clinical and research instruments to evaluate cognitive function in patients with neuropsychiatry disorders. Event-related potentials directly reflect cortical neuronal activity and provide a particular level of temporal resolution. Among various ERP components, the P300 is the most important component for assessing cognitive processes such as attention, working memory, and concentration. Numerous studies have reported the abnormalities in amplitude or latency of P300 component of ERP in epileptic patients, and these abnormalities are indicative of cognitive dysfunction. Therefore, the purpose of this review is to consolidate the existing literature in connection with the use of P300 in epileptic patients.

  6. Cortical network during deception detection by functional neuroimaging

    International Nuclear Information System (INIS)

    Saito, Keiichi

    2008-01-01

    We examined the coherence of cortical network during deception detection. First, we performed combined EEG-MRI experiments during the Guilty Knowledge Test (GKT) using number cards which has been used to model deception and 5 right-handed healthy participants performed the experiment. The superior frontal gyrus, the anterior cingulate cortex and the inferior parietal lobule were activated and the P 300 event-related brain potential (300-450 ms) was detected at only 'Lie' card. Secondary, we measured magnetoencephalography (MEG) data during GKT and the other 5 right-handed healthy subjects participated in the next experiment. The coherence between the superior frontal gyrus and the inferior parietal lobule showed significant differences between 'Lie' card and 'truth' cards during P 300 emerging. This results indicates that the coherence of cortical network is useful for GKT. (author)

  7. Event-related oscillations (EROs) and event-related potentials (ERPs) comparison in facial expression recognition.

    Science.gov (United States)

    Balconi, Michela; Pozzoli, Uberto

    2007-09-01

    The study aims to explore the significance of event-related potentials (ERPs) and event-related brain oscillations (EROs) (delta, theta, alpha, beta, gamma power) in response to emotional (fear, happiness, sadness) when compared with neutral faces during 180-250 post-stimulus time interval. The ERP results demonstrated that the emotional face elicited a negative peak at approximately 230 ms (N2). Moreover, EEG measures showed that motivational significance of face (emotional vs. neutral) could modulate the amplitude of EROs, but only for some frequency bands (i.e. theta and gamma bands). In a second phase, we considered the resemblance of the two EEG measures by a regression analysis. It revealed that theta and gamma oscillations mainly effect as oscillation activity at the N2 latency. Finally, a posterior increased power of theta was found for emotional faces.

  8. Minor and unsystematic cortical topographic changes of attention correlates between modalities.

    Directory of Open Access Journals (Sweden)

    Luis F H Basile

    2010-12-01

    Full Text Available In this study we analyzed the topography of induced cortical oscillations in 20 healthy individuals performing simple attention tasks. We were interested in qualitatively replicating our recent findings on the localization of attention-induced beta bands during a visual task [1], and verifying whether significant topographic changes would follow the change of attention to the auditory modality. We computed corrected latency averaging of each induced frequency bands, and modeled their generators by current density reconstruction with Lp-norm minimization. We quantified topographic similarity between conditions by an analysis of correlations, whereas the inter-modality significant differences in attention correlates were illustrated in each individual case. We replicated the qualitative result of highly idiosyncratic topography of attention-related activity to individuals, manifested both in the beta bands, and previously studied slow potential distributions [2]. Visual inspection of both scalp potentials and distribution of cortical currents showed minor changes in attention-related bands with respect to modality, as compared to the theta and delta bands, known to be major contributors to the sensory-related potentials. Quantitative results agreed with visual inspection, supporting to the conclusion that attention-related activity does not change much between modalities, and whatever individual changes do occur, they are not systematic in cortical localization across subjects. We discuss our results, combined with results from other studies that present individual data, with respect to the function of cortical association areas.

  9. State-dependent intrinsic predictability of cortical network dynamics.

    Directory of Open Access Journals (Sweden)

    Leila Fakhraei

    Full Text Available The information encoded in cortical circuit dynamics is fleeting, changing from moment to moment as new input arrives and ongoing intracortical interactions progress. A combination of deterministic and stochastic biophysical mechanisms governs how cortical dynamics at one moment evolve from cortical dynamics in recently preceding moments. Such temporal continuity of cortical dynamics is fundamental to many aspects of cortex function but is not well understood. Here we study temporal continuity by attempting to predict cortical population dynamics (multisite local field potential based on its own recent history in somatosensory cortex of anesthetized rats and in a computational network-level model. We found that the intrinsic predictability of cortical dynamics was dependent on multiple factors including cortical state, synaptic inhibition, and how far into the future the prediction extends. By pharmacologically tuning synaptic inhibition, we obtained a continuum of cortical states with asynchronous population activity at one extreme and stronger, spatially extended synchrony at the other extreme. Intermediate between these extremes we observed evidence for a special regime of population dynamics called criticality. Predictability of the near future (10-100 ms increased as the cortical state was tuned from asynchronous to synchronous. Predictability of the more distant future (>1 s was generally poor, but, surprisingly, was higher for asynchronous states compared to synchronous states. These experimental results were confirmed in a computational network model of spiking excitatory and inhibitory neurons. Our findings demonstrate that determinism and predictability of network dynamics depend on cortical state and the time-scale of the dynamics.

  10. Review Article Therapeutic Potential of Statins in Age-related ...

    African Journals Online (AJOL)

    2011-08-09

    Aug 9, 2011 ... Keywords: Age-related macular, Non-invasive treatment, Pleiotropic effects, Prevention, Statins. Received 14 June ... two types: non-exudative or “dry', characterised by .... Dam Eye Study in Wisconsin, statin use at the 10-.

  11. Age-related differences in event-related potentials for early visual processing of emotional faces.

    Science.gov (United States)

    Hilimire, Matthew R; Mienaltowski, Andrew; Blanchard-Fields, Fredda; Corballis, Paul M

    2014-07-01

    With advancing age, processing resources are shifted away from negative emotional stimuli and toward positive ones. Here, we explored this 'positivity effect' using event-related potentials (ERPs). Participants identified the presence or absence of a visual probe that appeared over photographs of emotional faces. The ERPs elicited by the onsets of angry, sad, happy and neutral faces were recorded. We examined the frontocentral emotional positivity (FcEP), which is defined as a positive deflection in the waveforms elicited by emotional expressions relative to neutral faces early on in the time course of the ERP. The FcEP is thought to reflect enhanced early processing of emotional expressions. The results show that within the first 130 ms young adults show an FcEP to negative emotional expressions, whereas older adults show an FcEP to positive emotional expressions. These findings provide additional evidence that the age-related positivity effect in emotion processing can be traced to automatic processes that are evident very early in the processing of emotional facial expressions. © The Author (2013). Published by Oxford University Press. For Permissions, please email: journals.permissions@oup.com.

  12. Event-related potentials reveal the relations between feature representations at different levels of abstraction.

    Science.gov (United States)

    Hannah, Samuel D; Shedden, Judith M; Brooks, Lee R; Grundy, John G

    2016-11-01

    In this paper, we use behavioural methods and event-related potentials (ERPs) to explore the relations between informational and instantiated features, as well as the relation between feature abstraction and rule type. Participants are trained to categorize two species of fictitious animals and then identify perceptually novel exemplars. Critically, two groups are given a perfectly predictive counting rule that, according to Hannah and Brooks (2009. Featuring familiarity: How a familiar feature instantiation influences categorization. Canadian Journal of Experimental Psychology/Revue Canadienne de Psychologie Expérimentale, 63, 263-275. Retrieved from http://doi.org/10.1037/a0017919), should orient them to using abstract informational features when categorizing the novel transfer items. A third group is taught a feature list rule, which should orient them to using detailed instantiated features. One counting-rule group were taught their rule before any exposure to the actual stimuli, and the other immediately after training, having learned the instantiations first. The feature-list group were also taught their rule after training. The ERP results suggest that at test, the two counting-rule groups processed items differently, despite their identical rule. This not only supports the distinction that informational and instantiated features are qualitatively different feature representations, but also implies that rules can readily operate over concrete inputs, in contradiction to traditional approaches that assume that rules necessarily act on abstract inputs.

  13. Nicotine enhances an auditory Event-Related Potential component which is inversely related to habituation.

    Science.gov (United States)

    Veltri, Theresa; Taroyan, Naira; Overton, Paul G

    2017-07-01

    Nicotine is a psychoactive substance that is commonly consumed in the context of music. However, the reason why music and nicotine are co-consumed is uncertain. One possibility is that nicotine affects cognitive processes relevant to aspects of music appreciation in a beneficial way. Here we investigated this possibility using Event-Related Potentials. Participants underwent a simple decision-making task (to maintain attentional focus), responses to which were signalled by auditory stimuli. Unlike previous research looking at the effects of nicotine on auditory processing, we used complex tones that varied in pitch, a fundamental element of music. In addition, unlike most other studies, we tested non-smoking subjects to avoid withdrawal-related complications. We found that nicotine (4.0 mg, administered as gum) increased P2 amplitude in the frontal region. Since a decrease in P2 amplitude and latency is related to habituation processes, and an enhanced ability to disengage from irrelevant stimuli, our findings suggest that nicotine may cause a reduction in habituation, resulting in non-smokers being less able to adapt to repeated stimuli. A corollary of that decrease in adaptation may be that nicotine extends the temporal window during which a listener is able and willing to engage with a piece of music.

  14. Potential SSP Perfluorooctanoic Acid Related Fluoropolymer Materials Obsolescence

    Science.gov (United States)

    Segars, Matt G.

    2006-01-01

    The Shuttle Environmental Assurance Initiative (SEA) has identified a potential for the Space Shuttle Program (SSP) to incur materials obsolescence issues due to agreements between the fluoro-chemical industry and the United States Environmental Protection Agency (USEPA) to participate in a Global Stewardship Program for perfluorooctanoic acid (PFOA). This presentation will include discussions of the chemistry, regulatory drivers, affected types of fluoropolymer and fluoroelastomer products, timeline for reformulations, and methodology for addressing the issue. It will cover the coordination of assessment efforts with the International Space Station and Head Quarters Air Force Space Command, along with some examples of impacted materials. The presentation is directed at all members of the international aerospace community concerned with identifying potential environmentally driven materials obsolescence issues.

  15. Consumer-Related Food Waste: Causes and Potential for Action

    DEFF Research Database (Denmark)

    Aschemann-Witzel, Jessica; Hooge, Ilona de; Amani, Pegah

    2015-01-01

    behaviors. We identify actions that governments, societal stakeholders and retailers can undertake to reduce consumer-related food waste, highlighting that synergistic actions between all parties are most promising. Further research should focus on exploring specific food waste contexts and interactions......In the past decade, food waste has received increased attention on both academic and societal levels. As a cause of negative economic, environmental and social effects, food waste is considered to be one of the sustainability issues that needs to be addressed. In developed countries, consumers...... are one of the biggest sources of food waste. To successfully reduce consumer-related food waste, it is necessary to have a clear understanding of the factors influencing food waste-related consumer perceptions and behaviors. The present paper presents the results of a literature review and expert...

  16. Longitudinal data on cortical thickness before and after working memory training

    Directory of Open Access Journals (Sweden)

    Claudia Metzler-Baddeley

    2016-06-01

    Full Text Available The data and supplementary information provided in this article relate to our research article “Task complexity and location specific changes of cortical thickness in executive and salience networks after working memory training” (Metzler-Baddeley et al., 2016 [1]. We provide cortical thickness and subcortical volume data derived from parieto-frontal cortical regions and the basal ganglia with the FreeSurfer longitudinal analyses stream (http://surfer.nmr.mgh.harvard.edu [2] before and after Cogmed working memory training (Cogmed and Cogmed Working Memory Training, 2012 [3]. This article also provides supplementary information to the research article, i.e., within-group comparisons between baseline and outcome cortical thickness and subcortical volume measures, between-group tests of performance changes in cognitive benchmark tests (www.cambridgebrainsciences.com [4], correlation analyses between performance changes in benchmark tests and training-related structural changes, correlation analyses between the time spent training and structural changes, a scatterplot of the relationship between cortical thickness measures derived from the occipital lobe as control region and the chronological order of the MRI sessions to assess potential scanner drift effects and a post-hoc vertex-wise whole brain analysis with FreeSurfer Qdec (https://surfer.nmr.mgh.harvard.edu/fswiki/Qdec [5].

  17. Longitudinal data on cortical thickness before and after working memory training.

    Science.gov (United States)

    Metzler-Baddeley, Claudia; Caeyenberghs, Karen; Foley, Sonya; Jones, Derek K

    2016-06-01

    The data and supplementary information provided in this article relate to our research article "Task complexity and location specific changes of cortical thickness in executive and salience networks after working memory training" (Metzler-Baddeley et al., 2016) [1]. We provide cortical thickness and subcortical volume data derived from parieto-frontal cortical regions and the basal ganglia with the FreeSurfer longitudinal analyses stream (http://surfer.nmr.mgh.harvard.edu [2]) before and after Cogmed working memory training (Cogmed and Cogmed Working Memory Training, 2012) [3]. This article also provides supplementary information to the research article, i.e., within-group comparisons between baseline and outcome cortical thickness and subcortical volume measures, between-group tests of performance changes in cognitive benchmark tests (www.cambridgebrainsciences.com [4]), correlation analyses between performance changes in benchmark tests and training-related structural changes, correlation analyses between the time spent training and structural changes, a scatterplot of the relationship between cortical thickness measures derived from the occipital lobe as control region and the chronological order of the MRI sessions to assess potential scanner drift effects and a post-hoc vertex-wise whole brain analysis with FreeSurfer Qdec (https://surfer.nmr.mgh.harvard.edu/fswiki/Qdec [5]).

  18. Mapping cortical mesoscopic networks of single spiking cortical or sub-cortical neurons.

    Science.gov (United States)

    Xiao, Dongsheng; Vanni, Matthieu P; Mitelut, Catalin C; Chan, Allen W; LeDue, Jeffrey M; Xie, Yicheng; Chen, Andrew Cn; Swindale, Nicholas V; Murphy, Timothy H

    2017-02-04

    Understanding the basis of brain function requires knowledge of cortical operations over wide-spatial scales, but also within the context of single neurons. In vivo, wide-field GCaMP imaging and sub-cortical/cortical cellular electrophysiology were used in mice to investigate relationships between spontaneous single neuron spiking and mesoscopic cortical activity. We make use of a rich set of cortical activity motifs that are present in spontaneous activity in anesthetized and awake animals. A mesoscale spike-triggered averaging procedure allowed the identification of motifs that are preferentially linked to individual spiking neurons by employing genetically targeted indicators of neuronal activity. Thalamic neurons predicted and reported specific cycles of wide-scale cortical inhibition/excitation. In contrast, spike-triggered maps derived from single cortical neurons yielded spatio-temporal maps expected for regional cortical consensus function. This approach can define network relationships between any point source of neuronal spiking and mesoscale cortical maps.

  19. [Schizophrenia and cortical GABA neurotransmission].

    Science.gov (United States)

    Hashimoto, Takanori; Matsubara, Takuro; Lewis, David A

    2010-01-01

    Individuals with schizophrenia show disturbances in a number of brain functions that regulate cognitive, affective, motor, and sensory processing. The cognitive deficits associated with dysfunction of the dorsolateral prefrontal cortex result, at least in part, from abnormalities in GABA neurotransmission, as reflected in a specific pattern of altered expression of GABA-related molecules. First, mRNA levels for the 67-kilodalton isoform of glutamic acid decarboxylase (GAD67), an enzyme principally responsible for GABA synthesis, and the GABA membrane transporter GAT1, which regulates the reuptake of synaptically released GABA, are decreased in a subset of GABA neurons. Second, affected GABA neurons include those that express the calcium-binding protein parvalbumin (PV), because PV mRNA levels are decreased in the prefrontal cortex of subjects with schizophrenia and GAD67 mRNA is undetectable in almost half of PV-containing neurons. These changes are accompanied by decreased GAT1 expression in the presynaptic terminals of PV-containing neurons and by increased postsynaptic GABA-A receptor alpha2 subunit expression at the axon initial segments of pyramidal neurons. These findings indicate decreased GABA synthesis/release by PV-containing GABA neurons and compensatory changes at synapses formed by these neurons. Third, another subset of GABA neurons that express the neuropeptide somatostatin (SST) also appear to be affected because their specific markers, SST and neuropeptide Y mRNAs, are decreased in a manner highly correlated with the decreases in GAD67 mRNA. Finally, mRNA levels for GABA-A receptor subunits for synaptic (alpha1 and gamma2) and extra-synaptic (delta) receptors are decreased, indicating alterations in both synaptic and extra-synaptic GABA neurotransmission. Together, this pattern of changes indicates that the altered GABA neurotransmission is specific to PV-containing and SST-containing GABA neuron subsets and involves both synaptic and extra

  20. Neurocalcin-delta: a potential memory-related factor in ...

    African Journals Online (AJOL)

    switched back to a NF diet and were designated as con- trols (CON). ..... cium sensor (NCS) family of calcium-binding proteins, .... Ikeda Y, Eagle KA, Elisaf M, Bhatt DL, Steg PG. Car- diovascular risk in relation to body mass index and use.

  1. Consumer-Related Food Waste: Causes and Potential for Action

    Directory of Open Access Journals (Sweden)

    Jessica Aschemann-Witzel

    2015-05-01

    Full Text Available In the past decade, food waste has received increased attention on both academic and societal levels. As a cause of negative economic, environmental and social effects, food waste is considered to be one of the sustainability issues that needs to be addressed. In developed countries, consumers are one of the biggest sources of food waste. To successfully reduce consumer-related food waste, it is necessary to have a clear understanding of the factors influencing food waste-related consumer perceptions and behaviors. The present paper presents the results of a literature review and expert interviews on factors causing consumer-related food waste in households and supply chains. Results show that consumers’ motivation to avoid food waste, their management skills of food provisioning and food handling and their trade-offs between priorities have an extensive influence on their food waste behaviors. We identify actions that governments, societal stakeholders and retailers can undertake to reduce consumer-related food waste, highlighting that synergistic actions between all parties are most promising. Further research should focus on exploring specific food waste contexts and interactions more in-depth. Experiments and interventions in particular can contribute to a shift from analysis to solutions.

  2. Characteristics of potential drug-related problems among oncology patients

    NARCIS (Netherlands)

    Bulsink, Arjan; Imholz, Alex L. T.; Brouwers, Jacobus R. B. J.; Jansman, Frank G. A.

    Background Oncology patients are more at risk for drug related problems because of treatment with (combinations of) anticancer drugs, as they have a higher risk for organ failure or altered metabolism with progression of their disease. Objective The aim of this study was to characterize and to

  3. Age Effects on Cortical Thickness in Cognitively Normal Elderly Individuals

    Directory of Open Access Journals (Sweden)

    Sona Hurtz

    2014-07-01

    Full Text Available Background/Aims: Atrophy in both grey and white matter is found in normal aging. The prefrontal cortex and the frontal lobe white matter are thought to be the most affected regions. Our aim was to examine the effects of normal aging on cortical grey matter using a 3D quantitative cortical mapping method. Methods: We analyzed 1.5-tesla brain magnetic resonance imaging data from 44 cognitively normal elderly subjects using cortical pattern matching and cortical thickness analyses. Linear regression analysis was used to study the effect of age on cortical thickness. 3D map-wide correction for multiple comparisons was conducted with permutation analyses using a threshold of p Results: We found a significant negative association between age and cortical thickness in the right hemisphere (pcorrected = 0.009 and a trend level association in the left hemisphere (pcorrected = 0.081. Age-related changes were greatest in the sensorimotor, bilateral dorsal anterior cingulate and supplementary motor cortices, and the right posterior middle and inferior frontal gyri. Age effects greater in the medial than lateral visual association cortices were also seen bilaterally. Conclusion: Our novel method further validates that normal aging results in diffuse cortical thinning that is most pronounced in the frontal and visual association cortices.

  4. Dynamic Causal Modeling of the Cortical Responses to Wrist Perturbations

    Directory of Open Access Journals (Sweden)

    Yuan Yang

    2017-09-01

    Full Text Available Mechanical perturbations applied to the wrist joint typically evoke a stereotypical sequence of cortical and muscle responses. The early cortical responses (<100 ms are thought be involved in the “rapid” transcortical reaction to the perturbation while the late cortical responses (>100 ms are related to the “slow” transcortical reaction. Although previous studies indicated that both responses involve the primary motor cortex, it remains unclear if both responses are engaged by the same effective connectivity in the cortical network. To answer this question, we investigated the effective connectivity cortical network after a “ramp-and-hold” mechanical perturbation, in both the early (<100 ms and late (>100 ms periods, using dynamic causal modeling. Ramp-and-hold perturbations were applied to the wrist joint while the subject maintained an isometric wrist flexion. Cortical activity was recorded using a 128-channel electroencephalogram (EEG. We investigated how the perturbation modulated the effective connectivity for the early and late periods. Bayesian model comparisons suggested that different effective connectivity networks are engaged in these two periods. For the early period, we found that only a few cortico-cortical connections were modulated, while more complicated connectivity was identified in the cortical network during the late period with multiple modulated cortico-cortical connections. The limited early cortical network likely allows for a rapid muscle response without involving high-level cognitive processes, while the complexity of the late network may facilitate coordinated responses.

  5. Regenerative Potential of Mesenchymal Stromal Cells: Age-Related Changes

    Directory of Open Access Journals (Sweden)

    Flavia Bruna

    2016-01-01

    Full Text Available Preclinical and clinical studies have shown that a therapeutic effect results from mesenchymal stromal cells (MSCs transplant. No systematic information is currently available regarding whether donor age modifies MSC regenerative potential on cutaneous wound healing. Here, we evaluate whether donor age influences this potential. Two different doses of bone marrow MSCs (BM-MSCs from young, adult, or old mouse donors or two doses of their acellular derivatives mesenchymal stromal cells (acd-MSCs were intradermally injected around wounds in the midline of C57BL/6 mice. Every two days, wound healing was macroscopically assessed (wound closure and microscopically assessed (reepithelialization, dermal-epidermal junction, skin appendage regeneration, granulation tissue, leukocyte infiltration, and density dermal collagen fibers after 12 days from MSC transplant. Significant differences in the wound closure kinetic, quality, and healing of skin regenerated were observed in lesions which received BM-MSCs from different ages or their acd-MSCs compared to lesions which received vehicle. Nevertheless, our data shows that adult’s BM-MSCs or their acd-MSCs were the most efficient for recovery of most parameters analyzed. Our data suggest that MSC efficacy was negatively affected by donor age, where the treatment with adult’s BM-MSCs or their acd-MSCs in cutaneous wound promotes a better tissue repair/regeneration. This is due to their paracrine factors secretion.

  6. Mean cortical curvature reflects cytoarchitecture restructuring in mild traumatic brain injury

    Directory of Open Access Journals (Sweden)

    Jace B. King

    2016-01-01

    Full Text Available In the United States alone, the number of persons living with the enduring consequences of traumatic brain injuries is estimated to be between 3.2 and 5 million. This number does not include individuals serving in the United States military or seeking care at Veterans Affairs hospitals. The importance of understanding the neurobiological consequences of mild traumatic brain injury (mTBI has increased with the return of veterans from conflicts overseas, many of who have suffered this type of brain injury. However, identifying the neuroanatomical regions most affected by mTBI continues to prove challenging. The aim of this study was to assess the use of mean cortical curvature as a potential indicator of progressive tissue loss in a cross-sectional sample of 54 veterans with mTBI compared to 31 controls evaluated with MRI. It was hypothesized that mean cortical curvature would be increased in veterans with mTBI, relative to controls, due in part to cortical restructuring related to tissue volume loss. Mean cortical curvature was assessed in 60 bilateral regions (31 sulcal, 29 gyral. Of the 120 regions investigated, nearly 50% demonstrated significantly increased mean cortical curvature in mTBI relative to controls with 25% remaining significant following multiple comparison correction (all, pFDR < .05. These differences were most prominent in deep gray matter regions of the cortex. Additionally, significant relationships were found between mean cortical curvature and gray and white matter volumes (all, p < .05. These findings suggest potentially unique patterns of atrophy by region and indicate that changes in brain microstructure due to mTBI are sensitive to measures of mean curvature.

  7. Pre-attentive processing of spectrally complex sounds with asynchronous onsets: an event-related potential study with human subjects.

    Science.gov (United States)

    Tervaniemi, M; Schröger, E; Näätänen, R

    1997-05-23

    Neuronal mechanisms involved in the processing of complex sounds with asynchronous onsets were studied in reading subjects. The sound onset asynchrony (SOA) between the leading partial and the remaining complex tone was varied between 0 and 360 ms. Infrequently occurring deviant sounds (in which one out of 10 harmonics was different in pitch relative to the frequently occurring standard sound) elicited the mismatch negativity (MMN), a change-specific cortical event-related potential (ERP) component. This indicates that the pitch of standard stimuli had been pre-attentively coded by sensory-memory traces. Moreover, when the complex-tone onset fell within temporal integration window initiated by the leading-partial onset, the deviants elicited the N2b component. This indexes that involuntary attention switch towards the sound change occurred. In summary, the present results support the existence of pre-perceptual integration mechanism of 100-200 ms duration and emphasize its importance in switching attention towards the stimulus change.

  8. Combined effects of alcohol and caffeine on the late components of the event-related potential and on reaction time.

    Science.gov (United States)

    Martin, Frances Heritage; Garfield, Joshua

    2006-01-01

    The effects of .7 ml/kg alcohol and 200 mg caffeine on the P200, N200, P300 and N500 difference wave components of the event-related potential and on reaction time (RT) were examined in 16 females who performed both simple and choice RT tasks. Alcohol slowed the decision time (DT) component of reaction time, lengthened the latency of the P200 and P300 components, reduced N200 amplitude, increased P300 amplitude at parietal sites, and modified the effect of sagittal site on N500 difference wave peak amplitude. Caffeine shortened DT in the choice RT task, shortened N200 latency at right hemisphere sites, and shortened N200 latency in the choice RT task in combination with alcohol compared to when alcohol was administered alone. Caffeine also increased P300 amplitude in the choice RT task and reduced the integral of the N500 difference wave at most sites when combined with alcohol. It was concluded that whereas alcohol slows attention allocation and impairs working memory, caffeine accelerated response-related decisions and enhanced cortical arousal.

  9. Literature-Related Discovery: Potential Treatments and Preventives for SARS

    Science.gov (United States)

    2010-01-01

    We recently demonstrated that kefir modulates the immune response in mice, increasing the number of IgA+ cells in the intestinal and bronchial...retrieval and analysis of the core SARS literature and literatures related directly to the core SARS literature (e.g., immune system component literatures...According to recent reviews of the pandemic, none of the drugs worked. Those who recovered did so by natural means; their immune systems were

  10. Cortical myoclonus and cerebellar pathology

    NARCIS (Netherlands)

    Tijssen, MAJ; Thom, M; Ellison, DW; Wilkins, P; Barnes, D; Thompson, PD; Brown, P

    2000-01-01

    Objective To study the electrophysiologic and pathologic findings in three patients with cortical myoclonus. In two patients the myoclonic ataxic syndrome was associated with proven celiac disease. Background: The pathologic findings in conditions associated with cortical myoclonus commonly involve

  11. Cortical myoclonus and cerebellar pathology

    NARCIS (Netherlands)

    Tijssen, M. A.; Thom, M.; Ellison, D. W.; Wilkins, P.; Barnes, D.; Thompson, P. D.; Brown, P.

    2000-01-01

    OBJECTIVE: To study the electrophysiologic and pathologic findings in three patients with cortical myoclonus. In two patients the myoclonic ataxic syndrome was associated with proven celiac disease. BACKGROUND: The pathologic findings in conditions associated with cortical myoclonus commonly involve

  12. Geometric objects related to the potential of electric charges

    International Nuclear Information System (INIS)

    Mozrzymas, J.

    1995-01-01

    We derive explicit formulas for curvature and torsion of a line of the field of n electric charges. These formulas show that in general the torsion of a field line is not zero if n≥3. We also propose a geometric interpretation of the derived formulas. In the second part of the paper we present an outline of a new description of equipotential surfaces of two and three electric charges. In this description the golden section appears in a natural way when two electric charges are equal. This approach also relates an equipotential surface of three charges to the classic surface containing twenty seven straight lines. (author)

  13. Evaluation of cortical bone mass, thickness and density by z-scores in osteopenic conditions and in relation to menopause and estrogen treatment

    International Nuclear Information System (INIS)

    Meema, S.; Meema, H.E.

    1982-01-01

    Z-scores express, differences from normals in standard deviation units, and are particularly useful for comparison of changes where normal values are age- and sex-dependent. We determined z-scores for bone mineral mass, cortical thickness, and bone mineral density in the radius in various conditions and diseases in both sexes. In the males, z-scores were calculated for age, but in the females z-scores for menopausal status (years postmenopausal exclusive of years on estrogen treatment) were found to be more appropriate. With few exceptions, changes in a disease were of a similar order in both sexes. For bone minerals mass few mean z-scores were significantly increased, but diseases with significantly decreased mean z-scores were numerous. The usefulness of z-scores in diagnosis and study of metabolic bone disease is discussed. (orig.)

  14. Women with Premenstrual Dysphoria Lack the Seemingly Normal Premenstrual Right-Sided Relative Dominance of 5-HTP-Derived Serotonergic Activity in the Dorsolateral Prefrontal Cortices - A Possible Cause of Disabling Mood Symptoms.

    Directory of Open Access Journals (Sweden)

    Olle Eriksson

    Full Text Available To investigate potential quantitative and qualitative differences in brain serotonergic activity between women with Premenstrual Dysphoria (PMD and asymptomatic controls.Serotonin-augmenting drugs alleviate premenstrual mood symptoms in the majority of women with PMD while serotonin-depleting diets worsen PMD symptoms, both indicating intrinsic differences in brain serotonergic activity in women with PMD compared to asymptomatic women.Positron-emission tomography with the immediate precursor of serotonin, 5-hydroxytryptophan (5-HTP, radiolabelled by 11C in the beta-3 position, was performed in the follicular and luteal phases for 12 women with PMD and 8 control women. Brain radioactivity-a proxy for serotonin precursor uptake and synthesis-was measured in 9 regions of interest (ROIs: the right and left sides of the medial prefrontal cortex, dorsolateral prefrontal cortex, putamen and caudate nucleus, and the single "whole brain".There were no significant quantitative differences in brain 5-HTP-derived activity between the groups in either of the menstrual phases for any of the 9 ROIs. However, multivariate analysis revealed a significant quantitative and qualitative difference between the groups. Asymptomatic control women showed a premenstrual right sided relative increase in dorsolateral prefrontal cortex 5-HTP derived activity, whereas PMD women displayed the opposite (p = 0.0001. Menstrual phase changes in this asymmetry (premenstrual-follicular correlated with changes in self ratings of 'irritability' for the entire group (rs = -0.595, p = 0.006. The PMD group showed a strong inverse correlation between phase changes (premenstrual-follicular in plasma levels of estradiol and phase changes in the laterality (dx/sin of radiotracer activity in the dorsolateral prefrontal ROI (rs = -0.635; 0.027. The control group showed no such correlation.Absence of increased premenstrual right-sided relative 5-HTP-derived activity of the dorsolateral

  15. Reduced cortical thickness in gambling disorder

    DEFF Research Database (Denmark)

    Grant, Jon E; Odlaug, Brian Lawrence; Chamberlain, Samuel R

    2015-01-01

    with significant reductions (average 15.8-19.9 %) in cortical thickness, versus controls, predominantly in right frontal cortical regions. Pronounced right frontal morphometric brain abnormalities occur in gambling disorder, supporting neurobiological overlap with substance disorders and its recent......Gambling disorder has recently been recognized as a prototype 'behavioral addiction' by virtue of its inclusion in the DSM-5 category of 'Substance-Related and Addictive Disorders.' Despite its newly acquired status and prevalence rate of 1-3 % globally, relatively little is known regarding...... the neurobiology of this disorder. The aim of this study was to explore cortical morphometry in untreated gambling disorder, for the first time. Subjects with gambling disorder (N = 16) free from current psychotropic medication or psychiatric comorbidities, and healthy controls (N = 17), were entered...

  16. Single-trial event-related potentials to significant stimuli.

    Science.gov (United States)

    Rushby, Jacqueline A; Barry, Robert J

    2009-11-01

    The stimulus-response pattern of the skin conductance response (SCR) was used as a model of the Orienting Reflex (OR) to assess the P1, N1, P2, N2 and late positive complex (LPC/P300) components of the ERP in a simple habituation paradigm, in which a single series of 12 innocuous tones were presented at a very long interstimulus interval (2 min). To maintain their waking state during this boring task, participants were instructed to alternately close or open their eyes to each stimulus. None of the baseline-to-peak ERP measures showed trials effects comparable with the marked habituation over trials shown by the SCRs. Principal Components Analysis was used to decompose the ERP, yielding factors identified as the N1, N2, P3a, P3b and Novelty P3 components. An additional factor represented later eye-movement activity. No trial effects were apparent for the N1, N2, P3a or P3b components. The Novelty P3 showed marked response decrement over trials. These results are discussed in relation to current conceptualisations of the OR.

  17. Developmental changes in visuo-spatial working memory in normally developing children: event-related potentials study.

    Science.gov (United States)

    Myatchin, Ivan; Lagae, Lieven

    2013-10-01

    Working memory (WM) is very important for normal development. The fronto-parietal neuronal network supporting WM has already been well-studied. Less is known about the cortical activity changes during development of WM. We evaluated the maturation of visual WM network at the electrophysiological level in a group of normally developing children. Multichannel (n=31) event-related potentials (ERP) were measured during a visuo-spatial backmatching task in 69 childrens (6-16 years old). One-backmatching (BM1) and two-backmatching (BM2) tasks were performed. Age-related changes in behavioral parameters (commission and omission errors and reaction times) and ERP parameters (peak amplitudes and latencies) were analyzed between different ages. Clear improvement in performance from young childhood toward adolescence was seen at the behavioral level: decrease of errors and fastening of reaction times. At the electrophysiological level age-related changes were seen in peak latencies and especially in amplitudes. Different peaks have different dynamics in amplitudes and latencies: early peak amplitude decreased and latency shortened with age, which was not always seen in late peaks. This reflects developmental changes in intensity and speed of WM processing. Later peaks were more clearly seen over the right hemisphere in older children, illustrating hemispheric lateralization in visuo-spatial working memory. Our results indicate that not only at the behavioral but also at the electrophysiological level clear age-related dynamics in WM processing can be seen. Furthermore, with ERP we showed that different WM components follow different developmental trajectories. Our work demonstrates that age-related dynamics in intensity and speed of information processing during WM task is reflected in developmental changes in different ERP components. It also states that fronto-parietal visual WM network can be functional even before all its nodes are fully mature. Copyright © 2012 The

  18. Alternaria Toxins: Potential Virulence Factors and Genes Related to Pathogenesis

    Directory of Open Access Journals (Sweden)

    Mukesh Meena

    2017-08-01

    Full Text Available Alternaria is an important fungus to study due to their different life style from saprophytes to endophytes and a very successful fungal pathogen that causes diseases to a number of economically important crops. Alternaria species have been well-characterized for the production of different host-specific toxins (HSTs and non-host specific toxins (nHSTs which depend upon their physiological and morphological stages. The pathogenicity of Alternaria species depends on host susceptibility or resistance as well as quantitative production of HSTs and nHSTs. These toxins are chemically low molecular weight secondary metabolites (SMs. The effects of toxins are mainly on different parts of cells like mitochondria, chloroplast, plasma membrane, Golgi complex, nucleus, etc. Alternaria species produce several nHSTs such as brefeldin A, tenuazonic acid, tentoxin, and zinniol. HSTs that act in very low concentrations affect only certain plant varieties or genotype and play a role in determining the host range of specificity of plant pathogens. The commonly known HSTs are AAL-, AK-, AM-, AF-, ACR-, and ACT-toxins which are named by their host specificity and these toxins are classified into different family groups. The HSTs are differentiated on the basis of bio-statistical and other molecular analyses. All these toxins have different mode of action, biochemical reactions and signaling mechanisms to cause diseases. Different species of Alternaria produced toxins which reveal its biochemical and genetic effects on itself as well as on its host cells tissues. The genes responsible for the production of HSTs are found on the conditionally dispensable chromosomes (CDCs which have been well characterized. Different bio-statistical methods like basic local alignment search tool (BLAST data analysis used for the annotation of gene prediction, pathogenicity-related genes may provide surprising knowledge in present and future.

  19. Right temporal cortical hypertrophy in resilience to trauma: an MRI study.

    Science.gov (United States)

    Nilsen, André Sevenius; Hilland, Eva; Kogstad, Norunn; Heir, Trond; Hauff, Edvard; Lien, Lars; Endestad, Tor

    2016-01-01

    In studies employing physiological measures such as magnetic resonance imaging (MRI), it is often hard to distinguish what constitutes risk-resilience factors to posttraumatic stress disorder (PTSD) following trauma exposure and what the effects of trauma exposure and PTSD are. We aimed to investigate whether there were observable morphological differences in cortical and sub-cortical regions of the brain, 7-8 years after a single potentially traumatic event. Twenty-four participants, who all directly experienced the 2004 Indian Ocean Tsunami, and 25 controls, underwent structural MRI using a 3T scanner. We generated cortical thickness maps and parcellated sub-cortical volumes for analysis. We observed greater cortical thickness for the trauma-exposed participants relative to controls, in a right lateralized temporal lobe region including anterior fusiform gyrus, and superior, middle, and inferior temporal gyrus. We observed greater thickness in the right temporal lobe which might indicate that the region could be implicated in resilience to the long-term effects of a traumatic event. We hypothesize this is due to altered emotional semantic memory processing. However, several methodological and confounding issues warrant caution in interpretation of the results.

  20. Cortical interneurons from human pluripotent stem cells: prospects for neurological and psychiatric disease

    Directory of Open Access Journals (Sweden)

    Charles Edward Arber

    2013-03-01

    Full Text Available Cortical interneurons represent 20% of the cells in the cortex. These cells are local inhibitory neurons whose function is to modulate the firing activities of the excitatory projection neurons. Cortical interneuron dysfunction is believed to lead to runaway excitation underlying (or implicated in seizure-based diseases, such as epilepsy, autism and schizophrenia. The complex development of this cell type and the intricacies involved in defining the relative subtypes are being increasingly well defined. This has led to exciting experimental cell therapy in model organisms, whereby fetal-derived interneuron precursors can reverse seizure severity and reduce mortality in adult epileptic rodents. These proof-of-principle studies raise hope for potential interneuron-based transplantation therapies for treating epilepsy. On the other hand, cortical neurons generated from patient iPSCs serve as a valuable tool to explore genetic influences of interneuron development and function. This is a fundamental step in enhancing our understanding of the molecular basis of neuropsychiatric illnesses and the development of targeted treatments. Protocols are currently being developed for inducing cortical interneuron subtypes from mouse and human pluripotent stem cells. This review sets out to summarize the progress made in cortical interneuron development, fetal tissue transplantation and the recent advance in stem cell differentiation towards interneurons.

  1. Right temporal cortical hypertrophy in resilience to trauma: an MRI study

    Directory of Open Access Journals (Sweden)

    André Sevenius Nilsen

    2016-07-01

    Full Text Available Background: In studies employing physiological measures such as magnetic resonance imaging (MRI, it is often hard to distinguish what constitutes risk-resilience factors to posttraumatic stress disorder (PTSD following trauma exposure and what the effects of trauma exposure and PTSD are. Objective: We aimed to investigate whether there were observable morphological differences in cortical and sub-cortical regions of the brain, 7–8 years after a single potentially traumatic event. Methods: Twenty-four participants, who all directly experienced the 2004 Indian Ocean Tsunami, and 25 controls, underwent structural MRI using a 3T scanner. We generated cortical thickness maps and parcellated sub-cortical volumes for analysis. Results: We observed greater cortical thickness for the trauma-exposed participants relative to controls, in a right lateralized temporal lobe region including anterior fusiform gyrus, and superior, middle, and inferior temporal gyrus. Conclusions: We observed greater thickness in the right temporal lobe which might indicate that the region could be implicated in resilience to the long-term effects of a traumatic event. We hypothesize this is due to altered emotional semantic memory processing. However, several methodological and confounding issues warrant caution in interpretation of the results.

  2. Effects of Aging on Cortical Neural Dynamics and Local Sleep Homeostasis in Mice.

    Science.gov (United States)

    McKillop, Laura E; Fisher, Simon P; Cui, Nanyi; Peirson, Stuart N; Foster, Russell G; Wafford, Keith A; Vyazovskiy, Vladyslav V

    2018-04-18

    Healthy aging is associated with marked effects on sleep, including its daily amount and architecture, as well as the specific EEG oscillations. Neither the neurophysiological underpinnings nor the biological significance of these changes are understood, and crucially the question remains whether aging is associated with reduced sleep need or a diminished capacity to generate sufficient sleep. Here we tested the hypothesis that aging may affect local cortical networks, disrupting the capacity to generate and sustain sleep oscillations, and with it the local homeostatic response to sleep loss. We performed chronic recordings of cortical neural activity and local field potentials from the motor cortex in young and older male C57BL/6J mice, during spontaneous waking and sleep, as well as during sleep after sleep deprivation. In older animals, we observed an increase in the incidence of non-rapid eye movement sleep local field potential slow waves and their associated neuronal silent (OFF) periods, whereas the overall pattern of state-dependent cortical neuronal firing was generally similar between ages. Furthermore, we observed that the response to sleep deprivation at the level of local cortical network activity was not affected by aging. Our data thus suggest that the local cortical neural dynamics and local sleep homeostatic mechanisms, at least in the motor cortex, are not impaired during healthy senescence in mice. This indicates that powerful protective or compensatory mechanisms may exist to maintain neuronal function stable across the life span, counteracting global changes in sleep amount and architecture. SIGNIFICANCE STATEMENT The biological significance of age-dependent changes in sleep is unknown but may reflect either a diminished sleep need or a reduced capacity to generate deep sleep stages. As aging has been linked to profound disruptions in cortical sleep oscillations and because sleep need is reflected in specific patterns of cortical activity, we

  3. Auditory cortical and hippocampal-system mismatch responses to duration deviants in urethane-anesthetized rats.

    Directory of Open Access Journals (Sweden)

    Timo Ruusuvirta

    Full Text Available Any change in the invariant aspects of the auditory environment is of potential importance. The human brain preattentively or automatically detects such changes. The mismatch negativity (MMN of event-related potentials (ERPs reflects this initial stage of auditory change detection. The origin of MMN is held to be cortical. The hippocampus is associated with a later generated P3a of ERPs reflecting involuntarily attention switches towards auditory changes that are high in magnitude. The evidence for this cortico-hippocampal dichotomy is scarce, however. To shed further light on this issue, auditory cortical and hippocampal-system (CA1, dentate gyrus, subiculum local-field potentials were recorded in urethane-anesthetized rats. A rare tone in duration (deviant was interspersed with a repeated tone (standard. Two standard-to-standard (SSI and standard-to-deviant (SDI intervals (200 ms vs. 500 ms were applied in different combinations to vary the observability of responses resembling MMN (mismatch responses. Mismatch responses were observed at 51.5-89 ms with the 500-ms SSI coupled with the 200-ms SDI but not with the three remaining combinations. Most importantly, the responses appeared in both the auditory-cortical and hippocampal locations. The findings suggest that the hippocampus may play a role in (cortical manifestation of MMN.

  4. Electrophysiological Data and the Biophysical Modelling of Local Cortical Circuits

    Directory of Open Access Journals (Sweden)

    Dimitris Pinotsis

    2014-03-01

    activity – using a field model that incorporates canonical cortical microcircuitry, where each population or layer has a receptor complement based on findings in cellular neuroscience. In the second part of this paper, we follow a different route, and use neural fields quantitatively – that is to fit empirical data recorded during visual stimulation, see e.g. [9–12]. We focus on neuromodulatory effects and discuss particular applications of DCMs with neural fields to explain invasive and non-invasive data. We present two studies of spectral responses obtained from the visual cortex during visual perception experiments: in the first study, MEG data were acquired during a task designed to show how activity in the gamma band is related to visual perception. This experiment tried to determine the spectral properties of an individual's gamma response, and how this relates to underlying visual cortex microcircuitry. In the second study, we exploited high density – spatially resolved – data from multi-electrode electrocorticographic (ECoG arrays to study the effect of varying stimulus contrast on cortical excitability and gamma peak frequency. These data were acquired at the Ernst Strüngmann Institute for Neuroscience, in collaboration with the Max Planck Society in Frankfurt. We will consider neural field models in the light of a Bayesian framework for evaluating model evidence and obtaining parameter estimates using invasive and non-invasive recordings of gamma oscillations. We will first focus on model predictions of conductance and convolution based field models and showed that these can yield spectral responses that are sensitive to biophysical properties of local cortical circuits like cortical excitability and synaptic filtering; we will also consider two different mechanisms for this filtering: a nonlinear mechanism involving specific conductances and a linear convolution of afferent firing rates producing post synaptic potentials. We will then turn to

  5. Cortical representations of communication sounds.

    Science.gov (United States)

    Heiser, Marc A; Cheung, Steven W

    2008-10-01

    This review summarizes recent research into cortical processing of vocalizations in animals and humans. There has been a resurgent interest in this topic accompanied by an increased number of studies using animal models with complex vocalizations and new methods in human brain imaging. Recent results from such studies are discussed. Experiments have begun to reveal the bilateral cortical fields involved in communication sound processing and the transformations of neural representations that occur among those fields. Advances have also been made in understanding the neuronal basis of interaction between developmental exposures and behavioral experiences with vocalization perception. Exposure to sounds during the developmental period produces large effects on brain responses, as do a variety of specific trained tasks in adults. Studies have also uncovered a neural link between the motor production of vocalizations and the representation of vocalizations in cortex. Parallel experiments in humans and animals are answering important questions about vocalization processing in the central nervous system. This dual approach promises to reveal microscopic, mesoscopic, and macroscopic principles of large-scale dynamic interactions between brain regions that underlie the complex phenomenon of vocalization perception. Such advances will yield a greater understanding of the causes, consequences, and treatment of disorders related to speech processing.

  6. Women in the midluteal phase of the menstrual cycle have difficulty suppressing the processing of negative emotional stimuli: An event-related potential study.

    Science.gov (United States)

    Lusk, Bethany R; Carr, Andrea R; Ranson, Valerie A; Felmingham, Kim L

    2017-08-01

    Emotion regulation deficits have been implicated in anxiety and depressive disorders, and these internalising disorders are more prevalent in women than men. Few electrophysiological studies have investigated sex differences in emotional reactivity and emotion regulation controlling for menstrual phase. Event-related potentials (ERPs) were recorded from 28 early follicular women, 29 midluteal women, and 27 men who completed an emotion regulation task. A novel finding of increased N2 amplitude during suppression was found for midluteal women compared with men. These findings suggest midluteal women may be significantly less able to suppress cortical processing of negative stimuli compared to men. This ERP finding was complemented by behavioral ratings data which revealed that while both early follicular and midluteal women reported more distress than men, midluteal women also reported greater effort when suppressing their responses than men. P1 and N1 components were increased in midluteal women compared to men regardless of instructional set, suggesting greater early attentional processing. No sex or menstrual phase differences were apparent in P3 or LPP. This study underscores the importance of considering menstrual phase when examining sex differences in the cortical processing of emotion regulation and demonstrates that midluteal women may have deficits in down-regulating their neural and behavioural responses.

  7. Changing relations between intelligence and brain activity in late childhood: A longitudinal event-related potential study.

    NARCIS (Netherlands)

    Stauder, J.E.A.; van der Molen, M.W.; Molenaar, P.C.M.

    1998-01-01

    In studying the relationship between Raven intelligence and event-related brain potentials to a visual oddball task in the same children, at respectively 9, 10 and 11 years of age, dramatic changes were observed with age. The event-related amplitude data suggest a shift in relation between

  8. Morphometric Changes in the Cortical Microvascular Network in Alzheimer's Disease

    NARCIS (Netherlands)

    Richard, E.; van Gool, W.A.; Hoozemans, J.J.M.; van Haastert, E.S.; Eikelenboom, P.; Rozemuller, A.J.M.; van de Berg, W.D.J.

    2010-01-01

    Alzheimer's disease (AD) pathology is accompanied by abnormalities of the microvasculature. Despite the potential importance of morphometric changes in the cortical capillary network on neuronal dysfunction and cognitive impairment, few autopsy studies have addressed this issue. In the present

  9. Cortical thickness patterns as state biomarker of anorexia nervosa.

    Science.gov (United States)

    Lavagnino, Luca; Mwangi, Benson; Cao, Bo; Shott, Megan E; Soares, Jair C; Frank, Guido K W

    2018-03-01

    Only few studies have investigated cortical thickness in anorexia nervosa (AN), and it is unclear whether patterns of altered cortical thickness can be identified as biomarkers for AN. Cortical thickness was measured in 19 adult women with restricting-type AN, 24 individuals recovered from restricting-type AN (REC-AN) and 24 healthy controls. Those individuals with current or recovered from AN had previously shown altered regional cortical volumes across orbitofrontal cortex and insula. A linear relevance vector machine-learning algorithm estimated patterns of regional thickness across 24 subdivisions of those regions. Region-based analysis showed higher cortical thickness in AN and REC-AN, compared to controls, in the right medial orbital (olfactory) sulcus, and greater cortical thickness for short insular gyri in REC-AN versus controls bilaterally. The machine-learning algorithm identified a pattern of relatively higher right orbital, right insular and left middle frontal cortical thickness, but lower left orbital, right middle and inferior frontal, and bilateral superior frontal cortical thickness specific to AN versus controls (74% specificity and 74% sensitivity, χ 2 p < .004); predicted probabilities differed significantly between AN and controls (p < .023). No pattern significantly distinguished the REC-AN group from controls. Higher cortical thickness in medial orbitofrontal cortex and insula probably contributes to higher gray matter volume in AN in those regions. The machine-learning algorithm identified a mixed pattern of mostly higher orbital and insular, but relatively lower superior frontal cortical thickness in individuals with current AN. These novel results suggest that regional cortical thickness patterns could be state markers for AN. © 2018 Wiley Periodicals, Inc.

  10. Low-frequency repetitive transcranial magnetic stimulation (rTMS) affects event-related potential measures of novelty processing in autism.

    Science.gov (United States)

    Sokhadze, Estate; Baruth, Joshua; Tasman, Allan; Mansoor, Mehreen; Ramaswamy, Rajesh; Sears, Lonnie; Mathai, Grace; El-Baz, Ayman; Casanova, Manuel F

    2010-06-01

    In our previous study on individuals with autism spectrum disorder (ASD) (Sokhadze et al., Appl Psychophysiol Biofeedback 34:37-51, 2009a) we reported abnormalities in the attention-orienting frontal event-related potentials (ERP) and the sustained-attention centro-parietal ERPs in a visual oddball experiment. These results suggest that individuals with autism over-process information needed for the successful differentiation of target and novel stimuli. In the present study we examine the effects of low-frequency, repetitive Transcranial Magnetic Stimulation (rTMS) on novelty processing as well as behavior and social functioning in 13 individuals with ASD. Our hypothesis was that low-frequency rTMS application to dorsolateral prefrontal cortex (DLFPC) would result in an alteration of the cortical excitatory/inhibitory balance through the activation of inhibitory GABAergic double bouquet interneurons. We expected to find post-TMS differences in amplitude and latency of early and late ERP components. The results of our current study validate the use of low-frequency rTMS as a modulatory tool that altered the disrupted ratio of cortical excitation to inhibition in autism. After rTMS the parieto-occipital P50 amplitude decreased to novel distracters but not to targets; also the amplitude and latency to targets increased for the frontal P50 while decreasing to non-target stimuli. Low-frequency rTMS minimized early cortical responses to irrelevant stimuli and increased responses to relevant stimuli. Improved selectivity in early cortical responses lead to better stimulus differentiation at later-stage responses as was made evident by our P3b and P3a component findings. These results indicate a significant change in early, middle-latency and late ERP components at the frontal, centro-parietal, and parieto-occipital regions of interest in response to target and distracter stimuli as a result of rTMS treatment. Overall, our preliminary results show that rTMS may prove to

  11. Cortical drive to breathe in amyotrophic lateral sclerosis: a dyspnoea-worsening defence?

    Science.gov (United States)

    Georges, Marjolaine; Morawiec, Elise; Raux, Mathieu; Gonzalez-Bermejo, Jésus; Pradat, Pierre-François; Similowski, Thomas; Morélot-Panzini, Capucine

    2016-06-01

    Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease causing diaphragm weakness that can be partially compensated by inspiratory neck muscle recruitment. This disappears during sleep, which is compatible with a cortical contribution to the drive to breathe. We hypothesised that ALS patients with respiratory failure exhibit respiratory-related cortical activity, relieved by noninvasive ventilation (NIV) and related to dyspnoea.We studied 14 ALS patients with respiratory failure. Electroencephalographic recordings (EEGs) and electromyographic recordings of inspiratory neck muscles were performed during spontaneous breathing and NIV. Dyspnoea was evaluated using the Multidimensional Dyspnea Profile.Eight patients exhibited slow EEG negativities preceding inspiration (pre-inspiratory potentials) during spontaneous breathing. Pre-inspiratory potentials were attenuated during NIV (p=0.04). Patients without pre-inspiratory potentials presented more advanced forms of ALS and more severe respiratory impairment, but less severe dyspnoea. Patients with pre-inspiratory potentials had stronger inspiratory neck muscle activation and more severe dyspnoea during spontaneous breathing.ALS-related diaphragm weakness can engage cortical resources to augment the neural drive to breathe. This might reflect a compensatory mechanism, with the intensity of dyspnoea a negative consequence. Disease progression and the corresponding neural loss could abolish this phenomenon. A putative cognitive cost should be investigated. Copyright ©ERS 2016.

  12. Widespread cortical morphologic changes in juvenile myoclonic epilepsy: evidence from structural MRI.

    LENUS (Irish Health Repository)

    Ronan, Lisa

    2012-04-01

    Atypical morphology of the surface of the cerebral cortex may be related to abnormal cortical folding (gyrification) and therefore may indicate underlying malformations of cortical development (MCDs). Using magnetic resonance imaging (MRI)-based analysis, we examined cortical morphology in patients with juvenile myoclonic epilepsy (JME).

  13. Cortical associates of emotional reactivity and regulation in childhood stuttering.

    Science.gov (United States)

    Zengin-Bolatkale, Hatun; Conture, Edward G; Key, Alexandra P; Walden, Tedra A; Jones, Robin M

    2018-06-01

    This study sought to determine the cortical associates of emotional reactivity and emotion regulation (as indexed by the amplitude of evoked response potentials [ERP]) in young children who do and do not stutter during passive viewing of pleasant, unpleasant and neutral pictures. Participants were 17 young children who stutter and 22 young children who do not stutter (between 4 years 0 months to 6 years 11 months). The dependent measures were (1) mean amplitude of late positive potential (LPP, an ERP sensitive to emotional stimuli) during passive (i.e., no response required) picture viewing and directed reappraisal tasks and (2) emotional reactivity and regulation related scores on caregiver reports of young children's temperament (Children's Behavior Questionnaire, CBQ). Young CWS, when compared to CWNS, exhibited significantly greater LPP amplitudes when viewing unpleasant pictures, but no significant between-group difference when viewing pleasant pictures and during the emotion regulation condition. There were, however, for CWS, but not CWNS, significant correlations between temperament-related measures of emotion and cortical measures of emotional reactivity and regulation. Findings provide further empirical support for the notion that emotional processes are associated with childhood stuttering, and that CWS's inherent temperamental proclivities need to be taken into account when empirically studying or theorizing about this association. Copyright © 2018 Elsevier Inc. All rights reserved.

  14. Altered cortical communication in amyotrophic lateral sclerosis.

    Science.gov (United States)

    Blain-Moraes, Stefanie; Mashour, George A; Lee, Heonsoo; Huggins, Jane E; Lee, Uncheol

    2013-05-24

    Amyotrophic lateral sclerosis (ALS) is a disorder associated primarily with the degeneration of the motor system. More recently, functional connectivity studies have demonstrated potentially adaptive changes in ALS brain organization, but disease-related changes in cortical communication remain unknown. We recruited individuals with ALS and age-matched controls to operate a brain-computer interface while electroencephalography was recorded over three sessions. Using normalized symbolic transfer entropy, we measured directed functional connectivity from frontal to parietal (feedback connectivity) and parietal to frontal (feedforward connectivity) regions. Feedback connectivity was not significantly different between groups, but feedforward connectivity was significantly higher in individuals with ALS. This result was consistent across a broad electroencephalographic spectrum (4-35 Hz), and in theta, alpha and beta frequency bands. Feedback connectivity has been associated with conscious state and was found to be independent of ALS symptom severity in this study, which may have significant implications for the detection of consciousness in individuals with advanced ALS. We suggest that increases in feedforward connectivity represent a compensatory response to the ALS-related loss of input such that sensory stimuli have sufficient strength to cross the threshold necessary for conscious processing in the global neuronal workspace. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  15. A Mechanistic Link from GABA to Cortical Architecture and Perception.

    Science.gov (United States)

    Kolasinski, James; Logan, John P; Hinson, Emily L; Manners, Daniel; Divanbeighi Zand, Amir P; Makin, Tamar R; Emir, Uzay E; Stagg, Charlotte J

    2017-06-05

    Understanding both the organization of the human cortex and its relation to the performance of distinct functions is fundamental in neuroscience. The primary sensory cortices display topographic organization, whereby receptive fields follow a characteristic pattern, from tonotopy to retinotopy to somatotopy [1]. GABAergic signaling is vital to the maintenance of cortical receptive fields [2]; however, it is unclear how this fine-grain inhibition relates to measurable patterns of perception [3, 4]. Based on perceptual changes following perturbation of the GABAergic system, it is conceivable that the resting level of cortical GABAergic tone directly relates to the spatial specificity of activation in response to a given input [5-7]. The specificity of cortical activation can be considered in terms of cortical tuning: greater cortical tuning yields more localized recruitment of cortical territory in response to a given input. We applied a combination of fMRI, MR spectroscopy, and psychophysics to substantiate the link between the cortical neurochemical milieu, the tuning of cortical activity, and variability in perceptual acuity, using human somatosensory cortex as a model. We provide data that explain human perceptual acuity in terms of both the underlying cellular and metabolic processes. Specifically, higher concentrations of sensorimotor GABA are associated with more selective cortical tuning, which in turn is associated with enhanced perception. These results show anatomical and neurochemical specificity and are replicated in an independent cohort. The mechanistic link from neurochemistry to perception provides a vital step in understanding population variability in sensory behavior, informing metabolic therapeutic interventions to restore perceptual abilities clinically. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  16. Influence of Concussion History and Genetics on Event-Related Potentials in Athletes: Potential Use in Concussion Management

    Directory of Open Access Journals (Sweden)

    Taylor Guth

    2018-01-01

    Full Text Available Sports-related concussions are an increasing public health issue with much concern about the possible long-term decrements in cognitive function and quality of life that may occur in athletes. The measurement of cognitive function is a common component of concussion management protocols due to cognitive impairments that occur after sustaining a concussion; however, the tools that are often used may not be sensitive enough to expose long term problems with cognitive function. The current paper is a brief review, which suggests that measuring cognitive processing through the use of event related potentials (ERPs may provide a more sensitive assessment of cognitive function, as shown through recent research showing concussion history to influence ERPs components. The potential influence of genetics on cognitive function and ERPs components will also be discussed in relation to future concussion management.

  17. Stroke rehabilitation using noninvasive cortical stimulation: aphasia.

    Science.gov (United States)

    Mylius, Veit; Zouari, Hela G; Ayache, Samar S; Farhat, Wassim H; Lefaucheur, Jean-Pascal

    2012-08-01

    Poststroke aphasia results from the lesion of cortical areas involved in the motor production of speech (Broca's aphasia) or in the semantic aspects of language comprehension (Wernicke's aphasia). Such lesions produce an important reorganization of speech/language-specific brain networks due to an imbalance between cortical facilitation and inhibition. In fact, functional recovery is associated with changes in the excitability of the damaged neural structures and their connections. Two main mechanisms are involved in poststroke aphasia recovery: the recruitment of perilesional regions of the left hemisphere in case of small lesion and the acquisition of language processing ability in homotopic areas of the nondominant right hemisphere when left hemispheric language abilities are permanently lost. There is some evidence that noninvasive cortical stimulation, especially when combined with language therapy or other therapeutic approaches, can promote aphasia recovery. Cortical stimulation was mainly used to either increase perilesional excitability or reduce contralesional activity based on the concept of reciprocal inhibition and maladaptive plasticity. However, recent studies also showed some positive effects of the reinforcement of neural activities in the contralateral right hemisphere, based on the potential compensatory role of the nondominant hemisphere in stroke recovery.

  18. The use of dispersion relations to construct unified nucleon optical potentials

    International Nuclear Information System (INIS)

    Hodgson, P.E.

    1991-01-01

    The dispersion relations provide a simple and accurate way of parametrizing the optical potential for a particular nucleus over a range of energies. A method is proposed for obtaining a global nucleon optical potential incorporating the dispersion relations. (author). 9 refs, 3 figs

  19. Toward relating the subthalamic nucleus spiking activity to the local field potentials acquired intranuclearly

    International Nuclear Information System (INIS)

    Michmizos, K P; Nikita, K S; Sakas, D

    2011-01-01

    Studies on neurophysiological correlates of the functional magnetic resonance imaging (fMRI) signals reveal a strong relationship between the local field potential (LFP) acquired invasively and metabolic signal changes in fMRI experiments. Most of these studies failed to reveal an analogous relationship between metabolic signals and the spiking activity. That would allow for the prediction of the neural activity exclusively from the fMRI signals. However, the relationship between fMRI signals and spiking activity can be inferred indirectly provided that the LFPs can be used to predict the spiking activity of the area. Until now, only the LFP–spike relationship in cortical areas has been examined. Herein, we show that the spiking activity can be predicted by the LFPs acquired in a deep nucleus, namely the subthalamic nucleus (STN), using a nonlinear cascade model. The model can reproduce the spike patterns inside the motor area of the STN that represent information about the motor plans. Our findings expand the possibility of further recruiting non-invasive neuroimaging techniques to understand the activity of the STN and predict or even control movement

  20. Cerebellar cortical infarct cavities and vertebral artery disease

    Energy Technology Data Exchange (ETDEWEB)

    Cocker, Laurens J.L. de [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands); Kliniek Sint-Jan Radiologie, Brussels (Belgium); Compter, A.; Kappelle, L.J.; Worp, H.B. van der [University Medical Center Utrecht, Department of Neurology and Neurosurgery, Brain Center Rudolf Magnus, Utrecht (Netherlands); Luijten, P.R.; Hendrikse, J. [University Medical Center Utrecht, Department of Radiology, Utrecht (Netherlands)

    2016-09-15

    Cerebellar cortical infarct cavities are a newly recognised entity associated with atherothromboembolic cerebrovascular disease and worse physical functioning. We aimed to investigate the relationship of cerebellar cortical infarct cavities with symptomatic vertebrobasilar ischaemia and with vascular risk factors. We evaluated the MR images of 46 patients with a recent vertebrobasilar TIA or stroke and a symptomatic vertebral artery stenosis ≥50 % from the Vertebral Artery Stenting Trial (VAST) for the presence of cerebellar cortical infarct cavities ≤1.5 cm. At inclusion in VAST, data were obtained on age, sex, history of vertebrobasilar TIA or stroke, and vascular risk factors. Adjusted risk ratios were calculated with Poisson regression analyses for the relation between cerebellar cortical infarct cavities and vascular risk factors. Sixteen out of 46 (35 %) patients showed cerebellar cortical infarct cavities on the initial MRI, and only one of these 16 patients was known with a previous vertebrobasilar TIA or stroke. In patients with symptomatic vertebrobasilar ischaemia, risk factor profiles of patients with cerebellar cortical infarct cavities were not different from patients without these cavities. Cerebellar cortical infarct cavities are seen on MRI in as much as one third of patients with recently symptomatic vertebral artery stenosis. Since patients usually have no prior history of vertebrobasilar TIA or stroke, cerebellar cortical infarct cavities should be added to the spectrum of common incidental brain infarcts visible on routine MRI. (orig.)

  1. Bilateral Cerebellar Cortical Dysplasia without Other Malformations: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Jung Seok; Ahn Kook Jin; Kim, Jee Young; Lee, Sun Jin; Park, Jeong Mi [Catholic University Yeouido St. Mary' s Hospital, College of Medicine, Seoul (Korea, Republic of)

    2010-06-15

    Recent advances in MRI have revealed congenital brain malformations and subtle developmental abnormalities of the cerebral and cerebellar cortical architecture. Typical cerebellar cortical dysplasia as a newly categorized cerebellar malformation, has been seen in patients with Fukuyama congenital muscular dystrophy. Cerebellar cortical dysplasia occurs at the embryonic stage and is often observed in healthy newborns. It is also incidentally and initially detected in adults without symptoms. To the best of our knowledge, cerebellar dysplasia without any related disorders is very rare. We describe the MRI findings in one patient with disorganized foliation of both cerebellar hemispheres without a related disorder or syndrome

  2. TAAR1 Modulates Cortical Glutamate NMDA Receptor Function

    Science.gov (United States)

    Espinoza, Stefano; Lignani, Gabriele; Caffino, Lucia; Maggi, Silvia; Sukhanov, Ilya; Leo, Damiana; Mus, Liudmila; Emanuele, Marco; Ronzitti, Giuseppe; Harmeier, Anja; Medrihan, Lucian; Sotnikova, Tatyana D; Chieregatti, Evelina; Hoener, Marius C; Benfenati, Fabio; Tucci, Valter; Fumagalli, Fabio; Gainetdinov, Raul R

    2015-01-01

    Trace Amine-Associated Receptor 1 (TAAR1) is a G protein-coupled receptor expressed in the mammalian brain and known to influence subcortical monoaminergic transmission. Monoamines, such as dopamine, also play an important role within the prefrontal cortex (PFC) circuitry, which is critically involved in high-o5rder cognitive processes. TAAR1-selective ligands have shown potential antipsychotic, antidepressant, and pro-cognitive effects in experimental animal models; however, it remains unclear whether TAAR1 can affect PFC-related processes and functions. In this study, we document a distinct pattern of expression of TAAR1 in the PFC, as well as altered subunit composition and deficient functionality of the glutamate N-methyl-D-aspartate (NMDA) receptors in the pyramidal neurons of layer V of PFC in mice lacking TAAR1. The dysregulated cortical glutamate transmission in TAAR1-KO mice was associated with aberrant behaviors in several tests, indicating a perseverative and impulsive phenotype of mutants. Conversely, pharmacological activation of TAAR1 with selective agonists reduced premature impulsive responses observed in the fixed-interval conditioning schedule in normal mice. Our study indicates that TAAR1 plays an important role in the modulation of NMDA receptor-mediated glutamate transmission in the PFC and related functions. Furthermore, these data suggest that the development of TAAR1-based drugs could provide a novel therapeutic approach for the treatment of disorders related to aberrant cortical functions. PMID:25749299

  3. Electrocorticography reveals beta desynchronization in the basal ganglia-cortical loop during rest tremor in Parkinson's disease.

    Science.gov (United States)

    Qasim, Salman E; de Hemptinne, Coralie; Swann, Nicole C; Miocinovic, Svjetlana; Ostrem, Jill L; Starr, Philip A

    2016-02-01

    The pathophysiology of rest tremor in Parkinson's disease (PD) is not well understood, and its severity does not correlate with the severity of other cardinal signs of PD. We hypothesized that tremor-related oscillatory activity in the basal-ganglia-thalamocortical loop might serve as a compensatory mechanism for the excessive beta band synchronization associated with the parkinsonian state. We recorded electrocorticography (ECoG) from the sensorimotor cortex and local field potentials (LFP) from the subthalamic nucleus (STN) in patients undergoing lead implantation for deep brain stimulation (DBS). We analyzed differences in measures of network synchronization during epochs of spontaneous rest tremor, versus epochs without rest tremor, occurring in the same subjects. The presence of tremor was associated with reduced beta power in the cortex and STN. Cortico-cortical coherence and phase-amplitude coupling (PAC) decreased during rest tremor, as did basal ganglia-cortical coherence in the same frequency band. Cortical broadband gamma power was not increased by tremor onset, in contrast to the movement-related gamma increase typically observed at the onset of voluntary movement. These findings suggest that the cortical representation of rest tremor is distinct from that of voluntary movement, and support a model in which tremor acts to decrease beta band synchronization within the basal ganglia-cortical loop. Copyright © 2015 Elsevier Inc. All rights reserved.

  4. Electrocorticographic discharge patterns in glioneuronal tumors and focal cortical dysplasia

    NARCIS (Netherlands)

    Ferrier, Cyrille H.; Aronica, Eleanora; Leijten, Frans S. S.; Spliet, Wim G. M.; van Huffelen, Alexander C.; van Rijen, Peter C.; Binnie, Colin D.

    2006-01-01

    PURPOSE: To determine whether highly epileptiform electrocorticographical discharge patterns occur in patients with glioneuronal tumors (GNTs) and focal cortical dysplasia (FCD) and whether specific histopathological features are related to such patterns. METHODS: The series consists of operated

  5. Cortical enhancement in chronic subdural hematoma

    International Nuclear Information System (INIS)

    Taguchi, Yoshio; Sato, Jun; Makita, Tadatoshi; Hayashi, Shigetoshi; Nakamura, Norio.

    1981-01-01

    In the CT findings of chronic subdural hematoma, brain enhancement adjacent to a subdural hematoma was seen occasionally after the injection of a contrast material. The authors called this finding ''cortical enhancement'', and 35 cases of chronic subdural hematoma were studied concerning cortical enhancement in relation to age, clinical signs and symptoms, hematoma density, and volume of the hematoma. Eight cases out of the 35 were subjected to measurements of the regional cerebral blood flow preoperatively by the method of the carotid injection of Xe-133. Cortical enhancement was apt to be seen in the cases which revealed intracranial hypertension or disturbance of consciousness, in isodensity or mixed-density hematomas, and in huge subdural hematomas. There was no specific correlation with age distribution. The pathogenesis of cortical enhancement seemed to be the result of cerebral compression with an increase in the contrast material per unit of volume and a prolonged venous outflow from the hemisphere, but no characteristic feature was detected in the average regional cerebral blood flow in our cases. (author)

  6. A Brain–Computer Interface for Potential Nonverbal Facial Communication Based on EEG Signals Related to Specific Emotions

    Directory of Open Access Journals (Sweden)

    Koji eKashihara

    2014-08-01

    Full Text Available Unlike assistive technology for verbal communication, the brain–machine or brain–computer interface (BMI/BCI has not been established as a nonverbal communication tool for amyotrophic lateral sclerosis (ALS patients. Face-to-face communication enables access to rich emotional information, but individuals suffering from neurological disorders, such as ALS and autism, may not express their emotions or communicate their negative feelings. Although emotions may be inferred by looking at facial expressions, emotional prediction for neutral faces necessitates advanced judgment. The process that underlies brain neuronal responses to neutral faces and causes emotional changes remains unknown. To address this problem, therefore, this study attempted to decode conditioned emotional reactions to neutral face stimuli. This direction was motivated by the assumption that if electroencephalogram (EEG signals can be used to detect patients’ emotional responses to specific inexpressive faces, the results could be incorporated into the design and development of BMI/BCI-based nonverbal communication tools. To these ends, this study investigated how a neutral face associated with a negative emotion modulates rapid central responses in face processing and then identified cortical activities. The conditioned neutral face-triggered event-related potentials that originated from the posterior temporal lobe statistically significantly changed during late face processing (600–700 ms after stimulus, rather than in early face processing activities, such as P1 and N170 responses. Source localization revealed that the conditioned neutral faces increased activity in the right fusiform gyrus. This study also developed an efficient method for detecting implicit negative emotional responses to specific faces by using EEG signals.

  7. A brain-computer interface for potential non-verbal facial communication based on EEG signals related to specific emotions.

    Science.gov (United States)

    Kashihara, Koji

    2014-01-01

    Unlike assistive technology for verbal communication, the brain-machine or brain-computer interface (BMI/BCI) has not been established as a non-verbal communication tool for amyotrophic lateral sclerosis (ALS) patients. Face-to-face communication enables access to rich emotional information, but individuals suffering from neurological disorders, such as ALS and autism, may not express their emotions or communicate their negative feelings. Although emotions may be inferred by looking at facial expressions, emotional prediction for neutral faces necessitates advanced judgment. The process that underlies brain neuronal responses to neutral faces and causes emotional changes remains unknown. To address this problem, therefore, this study attempted to decode conditioned emotional reactions to neutral face stimuli. This direction was motivated by the assumption that if electroencephalogram (EEG) signals can be used to detect patients' emotional responses to specific inexpressive faces, the results could be incorporated into the design and development of BMI/BCI-based non-verbal communication tools. To these ends, this study investigated how a neutral face associated with a negative emotion modulates rapid central responses in face processing and then identified cortical activities. The conditioned neutral face-triggered event-related potentials that originated from the posterior temporal lobe statistically significantly changed during late face processing (600-700 ms) after stimulus, rather than in early face processing activities, such as P1 and N170 responses. Source localization revealed that the conditioned neutral faces increased activity in the right fusiform gyrus (FG). This study also developed an efficient method for detecting implicit negative emotional responses to specific faces by using EEG signals. A classification method based on a support vector machine enables the easy classification of neutral faces that trigger specific individual emotions. In

  8. Progressive posterior cortical dysfunction

    Directory of Open Access Journals (Sweden)

    Fábio Henrique de Gobbi Porto

    Full Text Available Abstract Progressive posterior cortical dysfunction (PPCD is an insidious syndrome characterized by prominent disorders of higher visual processing. It affects both dorsal (occipito-parietal and ventral (occipito-temporal pathways, disturbing visuospatial processing and visual recognition, respectively. We report a case of a 67-year-old woman presenting with progressive impairment of visual functions. Neurologic examination showed agraphia, alexia, hemispatial neglect (left side visual extinction, complete Balint's syndrome and visual agnosia. Magnetic resonance imaging showed circumscribed atrophy involving the bilateral parieto-occipital regions, slightly more predominant to the right . Our aim was to describe a case of this syndrome, to present a video showing the main abnormalities, and to discuss this unusual presentation of dementia. We believe this article can contribute by improving the recognition of PPCD.

  9. Progressive posterior cortical dysfunction

    Science.gov (United States)

    Porto, Fábio Henrique de Gobbi; Machado, Gislaine Cristina Lopes; Morillo, Lilian Schafirovits; Brucki, Sonia Maria Dozzi

    2010-01-01

    Progressive posterior cortical dysfunction (PPCD) is an insidious syndrome characterized by prominent disorders of higher visual processing. It affects both dorsal (occipito-parietal) and ventral (occipito-temporal) pathways, disturbing visuospatial processing and visual recognition, respectively. We report a case of a 67-year-old woman presenting with progressive impairment of visual functions. Neurologic examination showed agraphia, alexia, hemispatial neglect (left side visual extinction), complete Balint’s syndrome and visual agnosia. Magnetic resonance imaging showed circumscribed atrophy involving the bilateral parieto-occipital regions, slightly more predominant to the right. Our aim was to describe a case of this syndrome, to present a video showing the main abnormalities, and to discuss this unusual presentation of dementia. We believe this article can contribute by improving the recognition of PPCD. PMID:29213665

  10. Modeling cortical circuits.

    Energy Technology Data Exchange (ETDEWEB)

    Rohrer, Brandon Robinson; Rothganger, Fredrick H.; Verzi, Stephen J.; Xavier, Patrick Gordon

    2010-09-01

    The neocortex is perhaps the highest region of the human brain, where audio and visual perception takes place along with many important cognitive functions. An important research goal is to describe the mechanisms implemented by the neocortex. There is an apparent regularity in the structure of the neocortex [Brodmann 1909, Mountcastle 1957] which may help simplify this task. The work reported here addresses the problem of how to describe the putative repeated units ('cortical circuits') in a manner that is easily understood and manipulated, with the long-term goal of developing a mathematical and algorithmic description of their function. The approach is to reduce each algorithm to an enhanced perceptron-like structure and describe its computation using difference equations. We organize this algorithmic processing into larger structures based on physiological observations, and implement key modeling concepts in software which runs on parallel computing hardware.

  11. Learning in AN Oscillatory Cortical Model

    Science.gov (United States)

    Scarpetta, Silvia; Li, Zhaoping; Hertz, John

    We study a model of generalized-Hebbian learning in asymmetric oscillatory neural networks modeling cortical areas such as hippocampus and olfactory cortex. The learning rule is based on the synaptic plasticity observed experimentally, in particular long-term potentiation and long-term depression of the synaptic efficacies depending on the relative timing of the pre- and postsynaptic activities during learning. The learned memory or representational states can be encoded by both the amplitude and the phase patterns of the oscillating neural populations, enabling more efficient and robust information coding than in conventional models of associative memory or input representation. Depending on the class of nonlinearity of the activation function, the model can function as an associative memory for oscillatory patterns (nonlinearity of class II) or can generalize from or interpolate between the learned states, appropriate for the function of input representation (nonlinearity of class I). In the former case, simulations of the model exhibits a first order transition between the "disordered state" and the "ordered" memory state.

  12. Minimally conscious state or cortically mediated state?

    Science.gov (United States)

    Naccache, Lionel

    2018-04-01

    Durable impairments of consciousness are currently classified in three main neurological categories: comatose state, vegetative state (also recently coined unresponsive wakefulness syndrome) and minimally conscious state. While the introduction of minimally conscious state, in 2002, was a major progress to help clinicians recognize complex non-reflexive behaviours in the absence of functional communication, it raises several problems. The most important issue related to minimally conscious state lies in its criteria: while behavioural definition of minimally conscious state lacks any direct evidence of patient's conscious content or conscious state, it includes the adjective 'conscious'. I discuss this major problem in this review and propose a novel interpretation of minimally conscious state: its criteria do not inform us about the potential residual consciousness of patients, but they do inform us with certainty about the presence of a cortically mediated state. Based on this constructive criticism review, I suggest three proposals aiming at improving the way we describe the subjective and cognitive state of non-communicating patients. In particular, I present a tentative new classification of impairments of consciousness that combines behavioural evidence with functional brain imaging data, in order to probe directly and univocally residual conscious processes.

  13. Altered Regional Brain Cortical Thickness in Pediatric Obstructive Sleep Apnea

    Directory of Open Access Journals (Sweden)

    Paul M. Macey

    2018-01-01

    Full Text Available RationaleObstructive sleep apnea (OSA affects 2–5% of all children and is associated with cognitive and behavioral deficits, resulting in poor school performance. These psychological deficits may arise from brain injury, as seen in preliminary findings of lower gray matter volume among pediatric OSA patients. However, the psychological deficits in OSA are closely related to functions in the cortex, and such brain areas have not been specifically assessed. The objective was to determine whether cortical thickness, a marker of possible brain injury, is altered in children with OSA.MethodsWe examined regional brain cortical thicknesses using high-resolution T1-weighted magnetic resonance images in 16 pediatric OSA patients (8 males; mean age ± SD = 8.4 ± 1.2 years; mean apnea/hypopnea index ± SD = 11 ± 6 events/h and 138 controls (8.3 ± 1.1 years; 62 male; 138 subjects from the NIH Pediatric MRI database to identify cortical thickness differences in pediatric OSA subjects.ResultsCortical thinning occurred in multiple regions including the superior frontal, ventral medial prefrontal, and superior parietal cortices. The left side showed greater thinning in the superior frontal cortex. Cortical thickening was observed in bilateral precentral gyrus, mid-to-posterior insular cortices, and left central gyrus, as well as right anterior insula cortex.ConclusionChanges in cortical thickness are present in children with OSA and likely indicate disruption to neural developmental processes, including maturational patterns of cortical volume increases and synaptic pruning. Regions with thicker cortices may reflect inflammation or astrocyte activation. Both the thinning and thickening associated with OSA in children may contribute to the cognitive and behavioral dysfunction frequently found in the condition.

  14. Altered Cortical Swallowing Processing in Patients with Functional Dysphagia: A Preliminary Study

    Science.gov (United States)

    Wollbrink, Andreas; Warnecke, Tobias; Winkels, Martin; Pantev, Christo; Dziewas, Rainer

    2014-01-01

    Objective Current neuroimaging research on functional disturbances provides growing evidence for objective neuronal correlates of allegedly psychogenic symptoms, thereby shifting the disease concept from a psychological towards a neurobiological model. Functional dysphagia is such a rare condition, whose pathogenetic mechanism is largely unknown. In the absence of any organic reason for a patient's persistent swallowing complaints, sensorimotor processing abnormalities involving central neural pathways constitute a potential etiology. Methods In this pilot study we measured cortical swallow-related activation in 5 patients diagnosed with functional dysphagia and a matched group of healthy subjects applying magnetoencephalography. Source localization of cortical activation was done with synthetic aperture magnetometry. To test for significant differences in cortical swallowing processing between groups, a non-parametric permutation test was afterwards performed on individual source localization maps. Results Swallowing task performance was comparable between groups. In relation to control subjects, in whom activation was symmetrically distributed in rostro-medial parts of the sensorimotor cortices of both hemispheres, patients showed prominent activation of the right insula, dorsolateral prefrontal cortex and lateral premotor, motor as well as inferolateral parietal cortex. Furthermore, activation was markedly reduced in the left medial primary sensory cortex as well as right medial sensorimotor cortex and adjacent supplementary motor area (pdysphagia - a condition with assumed normal brain function - seems to be associated with distinctive changes of the swallow-related cortical activation pattern. Alterations may reflect exaggerated activation of a widely distributed vigilance, self-monitoring and salience rating network that interferes with down-stream deglutition sensorimotor control. PMID:24586948

  15. Age, intelligence, and event-related brain potentials during late childhood: A longitudinal study.

    NARCIS (Netherlands)

    Molenaar, P.C.M.; Molen, M.W.; Stauder, J.E.A.

    2003-01-01

    he relation between event-related brain activity, age, and intelligence was studied using a visual oddball task presented longitudinally to girls at 9, 10, and 11 years of age. The event-related brain potential (ERP) components showed typical gradual decrements in latency and amplitude with

  16. Dose-Related Modulation of Event-Related Potentials to Novel and Target Stimuli by Intravenous Δ9-THC in Humans

    Science.gov (United States)

    D'Souza, Deepak Cyril; Fridberg, Daniel J; Skosnik, Patrick D; Williams, Ashley; Roach, Brian; Singh, Nagendra; Carbuto, Michelle; Elander, Jacqueline; Schnakenberg, Ashley; Pittman, Brian; Sewell, R Andrew; Ranganathan, Mohini; Mathalon, Daniel

    2012-01-01

    Cannabinoids induce a host of perceptual alterations and cognitive deficits in humans. However, the neural correlates of these deficits have remained elusive. The current study examined the acute, dose-related effects of delta-9-tetrahydrocannabinol (Δ9-THC) on psychophysiological indices of information processing in humans. Healthy subjects (n=26) completed three test days during which they received intravenous Δ9-THC (placebo, 0.015 and 0.03 mg/kg) in a within-subject, double-blind, randomized, cross-over, and counterbalanced design. Psychophysiological data (electroencephalography) were collected before and after drug administration while subjects engaged in an event-related potential (ERP) task known to be a valid index of attention and cognition (a three-stimulus auditory ‘oddball' P300 task). Δ9-THC dose-dependently reduced the amplitude of both the target P300b and the novelty P300a. Δ9-THC did not have any effect on the latency of either the P300a or P300b, or on early sensory-evoked ERP components preceding the P300 (the N100). Concomitantly, Δ9-THC induced psychotomimetic effects, perceptual alterations, and subjective ‘high' in a dose-dependent manner. Δ9-THC -induced reductions in P3b amplitude correlated with Δ9-THC-induced perceptual alterations. Lastly, exploratory analyses examining cannabis use status showed that whereas recent cannabis users had blunted behavioral effects to Δ9-THC, there were no dose-related effects of Δ9-THC on P300a/b amplitude between cannabis-free and recent cannabis users. Overall, these data suggest that at doses that produce behavioral and subjective effects consistent with the known properties of cannabis, Δ9-THC reduced P300a and P300b amplitudes without altering the latency of these ERPs. Cannabinoid agonists may therefore disrupt cortical processes responsible for context updating and the automatic orientation of attention, while leaving processing speed and earlier sensory ERP components intact

  17. Ventral Striatum, but Not Cortical Volume Loss, Is Related to Cognitive Dysfunction in Type 1 Diabetic Patients With and Without Microangiopathy

    NARCIS (Netherlands)

    van Duinkerken, E.; Schoonheim, M.M.; Steenwijk, M.D.; Klein, M.; IJzerman, R.G.; Moll, A.C.; Heymans, M.W.; Snoek, F.J.; Barkhof, F.; Diamant, M.

    2014-01-01

    Objective: Patients with longstanding type 1 diabetes may develop microangiopathy due to high cumulative glucose exposure. Also, chronic hyperglycemia is related to cerebral alterations and cognitive dysfunction. Whether the presence of microangiopathy is conditional to the development of

  18. Dynamics of Ionic Shifts in Cortical Spreading Depression.

    Science.gov (United States)

    Enger, Rune; Tang, Wannan; Vindedal, Gry Fluge; Jensen, Vidar; Johannes Helm, P; Sprengel, Rolf; Looger, Loren L; Nagelhus, Erlend A

    2015-11-01

    Cortical spreading depression is a slowly propagating wave of near-complete depolarization of brain cells followed by temporary suppression of neuronal activity. Accumulating evidence indicates that cortical spreading depression underlies the migraine aura and that similar waves promote tissue damage in stroke, trauma, and hemorrhage. Cortical spreading depression is characterized by neuronal swelling, profound elevation of extracellular potassium and glutamate, multiphasic blood flow changes, and drop in tissue oxygen tension. The slow speed of the cortical spreading depression wave implies that it is mediated by diffusion of a chemical substance, yet the identity of this substance and the pathway it follows are unknown. Intercellular spread between gap junction-coupled neurons or glial cells and interstitial diffusion of K(+) or glutamate have been proposed. Here we use extracellular direct current potential recordings, K(+)-sensitive microelectrodes, and 2-photon imaging with ultrasensitive Ca(2+) and glutamate fluorescent probes to elucidate the spatiotemporal dynamics of ionic shifts associated with the propagation of cortical spreading depression in the visual cortex of adult living mice. Our data argue against intercellular spread of Ca(2+) carrying the cortical spreading depression wavefront and are in favor of interstitial K(+) diffusion, rather than glutamate diffusion, as the leading event in cortical spreading depression. © The Author 2015. Published by Oxford University Press.

  19. Basal Forebrain Gating by Somatostatin Neurons Drives Prefrontal Cortical Activity.

    Science.gov (United States)

    Espinosa, Nelson; Alonso, Alejandra; Morales, Cristian; Espinosa, Pedro; Chávez, Andrés E; Fuentealba, Pablo

    2017-11-17

    The basal forebrain provides modulatory input to the cortex regulating brain states and cognitive processing. Somatostatin-expressing neurons constitute a heterogeneous GABAergic population known to functionally inhibit basal forebrain cortically projecting cells thus favoring sleep and cortical synchronization. However, it remains unclear if somatostatin cells can regulate population activity patterns in the basal forebrain and modulate cortical dynamics. Here, we demonstrate that somatostatin neurons regulate the corticopetal synaptic output of the basal forebrain impinging on cortical activity and behavior. Optogenetic inactivation of somatostatin neurons in vivo rapidly modified neural activity in the basal forebrain, with the consequent enhancement and desynchronization of activity in the prefrontal cortex, reflected in both neuronal spiking and network oscillations. Cortical activation was partially dependent on cholinergic transmission, suppressing slow waves and potentiating gamma oscillations. In addition, recruitment dynamics was cell type-specific, with interneurons showing similar temporal profiles, but stronger responses than pyramidal cells. Finally, optogenetic stimulation of quiescent animals during resting periods prompted locomotor activity, suggesting generalized cortical activation and increased arousal. Altogether, we provide physiological and behavioral evidence indicating that somatostatin neurons are pivotal in gating the synaptic output of the basal forebrain, thus indirectly controlling cortical operations via both cholinergic and non-cholinergic mechanisms. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

  20. Cortical surface area reduction in identification of subjects at high risk for post-traumatic stress disorder: A pilot study.

    Science.gov (United States)

    Hu, Hao; Sun, Yawen; Su, Shanshan; Wang, Yao; Qiu, Yongming; Yang, Xi; Zhou, Yan; Xiao, Zeping; Wang, Zhen

    2018-01-01

    Victims of motor vehicle accidents often develop post-traumatic stress disorder, which causes significant social function loss. For the difficulty in treating post-traumatic stress disorder, identification of subjects at high risk for post-traumatic stress disorder is essential for providing possible intervention. This paper aims to examine the cortical structural traits related to susceptibility to post-traumatic stress disorder. To address this issue, we performed structural magnetic resonance imaging study in motor vehicle accident victims within 48 hours from the accidents. A total of 70 victims, available for both clinical and magnetic resonance imaging data, enrolled in our study. Upon completion of 6-month follow-up, 29 of them developed post-traumatic stress disorder, while 41 of them didn't. At baseline, voxelwise comparisons of cortical thickness, cortical area and cortical volume were conducted between post-traumatic stress disorder group and trauma control group. As expected, several reduced cortical volume within frontal-temporal loop were observed in post-traumatic stress disorder. For cortical thickness, no between-group differences were observed. There were three clusters in left hemisphere and one cluster in right hemisphere showing decreased cortical area in post-traumatic stress disorder patients, compared with trauma controls. Peak voxels of the three clusters in left hemisphere were separately located in superior parietal cortex, insula and rostral anterior cingulate cortex. The finding of reduced surface area of left insula and left rostral anterior cingulate cortex suggests that shrinked surface area in motor vehicle accident victims could act as potential biomarker of subjects at high risk for post-traumatic stress disorder.

  1. MRI study on the cortical thickness of occipital lobe in children with ametropic amblyopia

    International Nuclear Information System (INIS)

    Du Hanjian; Wang Jian; Li Chuan; Zhang Jiuquan; Chen Li; Liu Bo

    2008-01-01

    Objective: To study cortical thickness of the occipital lobe in children with ametropic amblyopia by using MRI technique and the FreeSurfer software. Methods: Nine children with ametropic amblyopia were included in the amblyopic group and 8 normal children were included in the control group. All the children underwent brain MRI on the Siemens Avanto 1.5 T scanner. For the cortical thickness analysis, 3-demensional MPRAGE images were collected and analyzed with FreeSurfer software package. Cortical thickness of related regions in the occipital lobe (including the cuneus, later occipital, lingual, and pericalcarine gyri) were recorded and compared. Results: The cortical thickness of the lingual, pericalcarine gyri on the left hemisphere and the cuneus, lateraloccipital, lingual gyri on the right hemisphere in amblyopic group were lower than the control group (P<0.05). Conclusion: Morphological changes existed in the occipital lobe in ametropic amblyopic children. The analysis technique with the FreeSurfer package has a potential value in the clinical application. (authors)

  2. Topology and graph theory applied to cortical anatomy may help explain working memory capacity for three or four simultaneous items.

    Science.gov (United States)

    Glassman, Robert B

    2003-04-15

    Cognitive experimentation suggests that at any single instant only three or four items ("chunks") are simultaneously prominent as a working memory (WM) trace, if we disregard the rehearsal component of WM. The reason for small WM capacity may concern combinatorial manageability. How might the neural representations of these few coactive chunks occupy a spatially distributed set of areas of the sheet-like cortex, while providing both order and flexibility to associate items in WM? Each attribute of each simultaneously active WM item must have broad access to the representational facilities of the cortical sheet, comprising tens of thousands of modular "cortical columns." The two hypothesized neural levels of WM during any moment of cognition comprise (a) "binding" together of many distributed attribute representations within each respective WM chunk, and (b) combinatorial play among three or four WM chunk-representations. Anatomical and functional evidence of cortical unity through its depth suggests that cortex may be viewed as essentially planar in its distribution of activations. Thus, a moment's WM is hypothesized here to reside in myriad activated cortical planar "patches," each subdivided into up to four amoeboid "subpatches." Two different lines of topological reasoning suggest orderly associations of such representations. (1) The four-color principle of map topology, and the related K(4) is planar theorem of graph theory, imply that if a small cortical area is dynamically subdivided into no more than four, discretely bounded planar subareas, then each such segment has ample free access to each of the others. (2) A hypothetical alternative to such associative adjacency of simultaneously active cortical representations of chunk-attributes is associative overlap, whereby, in dense cortical neuropil, activated subpatches behave like Venn diagrams of intersecting sets. As the number of Venn-like coactive subpatches within a patch increases, maintaining ad hoc

  3. Kinetic determinations of accurate relative oxidation potentials of amines with reactive radical cations.

    Science.gov (United States)

    Gould, Ian R; Wosinska, Zofia M; Farid, Samir

    2006-01-01

    Accurate oxidation potentials for organic compounds are critical for the evaluation of thermodynamic and kinetic properties of their radical cations. Except when using a specialized apparatus, electrochemical oxidation of molecules with reactive radical cations is usually an irreversible process, providing peak potentials, E(p), rather than thermodynamically meaningful oxidation potentials, E(ox). In a previous study on amines with radical cations that underwent rapid decarboxylation, we estimated E(ox) by correcting the E(p) from cyclic voltammetry with rate constants for decarboxylation obtained using laser flash photolysis. Here we use redox equilibration experiments to determine accurate relative oxidation potentials for the same amines. We also describe an extension of these experiments to show how relative oxidation potentials can be obtained in the absence of equilibrium, from a complete kinetic analysis of the reversible redox kinetics. The results provide support for the previous cyclic voltammetry/laser flash photolysis method for determining oxidation potentials.

  4. Shining a light on posterior cortical atrophy.

    Science.gov (United States)

    Crutch, Sebastian J; Schott, Jonathan M; Rabinovici, Gil D; Boeve, Bradley F; Cappa, Stefano F; Dickerson, Bradford C; Dubois, Bruno; Graff-Radford, Neill R; Krolak-Salmon, Pierre; Lehmann, Manja; Mendez, Mario F; Pijnenburg, Yolande; Ryan, Natalie S; Scheltens, Philip; Shakespeare, Tim; Tang-Wai, David F; van der Flier, Wiesje M; Bain, Lisa; Carrillo, Maria C; Fox, Nick C

    2013-07-01

    Posterior cortical atrophy (PCA) is a clinicoradiologic syndrome characterized by progressive decline in visual processing skills, relatively intact memory and language in the early stages, and atrophy of posterior brain regions. Misdiagnosis of PCA is common, owing not only to its relative rarity and unusual and variable presentation, but also because patients frequently first seek the opinion of an ophthalmologist, who may note normal eye examinations by their usual tests but may not appreciate cortical brain dysfunction. Seeking to raise awareness of the disease, stimulate research, and promote collaboration, a multidisciplinary group of PCA research clinicians formed an international working party, which had its first face-to-face meeting on July 13, 2012 in Vancouver, Canada, prior to the Alzheimer's Association International Conference. Copyright © 2013 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.

  5. Functionally Independent Components of the Late Positive Event-Related Potential During Visual Spatial Attention

    National Research Council Canada - National Science Library

    Makeig, Scott; Westeifleld, Marissa; Jung, Tzyy-Ping; Covington, James; Townsend, Jeanne; Sejnowski, Terrence J; Courchesne, Eric

    1999-01-01

    Human event-related potentials (ERPs) were recorded from 10 subjects presented with visual target and nontarget stimuli at five screen locations and responding to targets presented at one of the locations...

  6. Ionization Potentials of Chemical Warfare Agents and Related Compounds Determined with Density Functional Theory

    National Research Council Canada - National Science Library

    Wright, J

    2000-01-01

    ...) agents at contaminated sites. Reported herein are theoretical ionization potentials for CW agents and their related compounds calculated using density functional theory at the B3LYP/6-311+G(2d,p) level of theory...

  7. The Relative Importance of Spatial Versus Temporal Structure in the Perception of Biological Motion: An Event-Related Potential Study

    Science.gov (United States)

    Hirai, Masahiro; Hiraki, Kazuo

    2006-01-01

    We investigated how the spatiotemporal structure of animations of biological motion (BM) affects brain activity. We measured event-related potentials (ERPs) during the perception of BM under four conditions: normal spatial and temporal structure; scrambled spatial and normal temporal structure; normal spatial and scrambled temporal structure; and…

  8. Selective chronic stress-induced in vivo ERK1/2 hyperphosphorylation in medial prefrontocortical dendrites : implications for stress-related cortical pathology?

    NARCIS (Netherlands)

    Trentani, A; Kuipers, SD; Ter Horst, GJ; Den Boer, JA

    Stress has been shown to affect brain structural plasticity, promote long-term changes in multiple neurotransmitter systems and cause neuronal atrophy. However, the mechanisms involved in these stress-related neural alterations are still poorly understood. Mitogen-activated protein kinase (MAPK)

  9. SKA2 Methylation is associated with Decreased Prefrontal Cortical Thickness and Greater PTSD Severity among Trauma-Exposed Veterans

    Science.gov (United States)

    Sadeh, Naomi; Spielberg, Jeffrey M.; Logue, Mark W.; Wolf, Erika J.; Smith, Alicia K.; Lusk, Joanna; Hayes, Jasmeet P.; Sperbeck, Emily; Milberg, William P.; McGlinchey, Regina E.; Salat, David H.; Carter, Weleetka C.; Stone, Annjanette; Schichman, Steven A.; Humphries, Donald E.; Miller, Mark W.

    2015-01-01

    Methylation of the SKA2 gene has recently been identified as a promising biomarker of suicide risk. Based on this finding, we examined associations between SKA2 methylation, cortical thickness, and psychiatric phenotypes linked to suicide in trauma-exposed veterans. 200 trauma-exposed white non-Hispanic veterans of the recent conflicts in Iraq and Afghanistan (91% male) underwent clinical assessment and had blood drawn for genotyping and methylation analysis. 145 participants also had neuroimaging data available. Based on previous research, we examined DNA methylation at the CpG locus cg13989295 as well as DNA methylation adjusted for genotype at the methylation-associated SNP (rs7208505) in relationship to whole-brain cortical thickness, posttraumatic stress disorder symptoms (PTSD), and depression symptoms. Whole-brain vertex-wise analyses identified three clusters in prefrontal cortex that were associated with genotype-adjusted SKA2 DNA methylation (methylationadj). Specifically, DNA methylationadj was associated with bilateral reductions of cortical thickness in frontal pole and superior frontal gyrus, and similar effects were found in the right orbitofrontal cortex and right inferior frontal gyrus. PTSD symptom severity was positively correlated with SKA2 DNA methylationadj and negatively correlated with cortical thickness in these regions. Mediation analyses showed a significant indirect effect of PTSD on cortical thickness via SKA2 methylation status. Results suggest that DNA methylationadj of SKA2 in blood indexes stress-related psychiatric phenotypes and neurobiology, pointing to its potential value as a biomarker of stress exposure and susceptibility. PMID:26324104

  10. An event-related potential study on memory search for color

    OpenAIRE

    Miyatani, Makoto; Nakao, Takasi; Ohkawa, Kaori; Sanderson, Nicholas S. R.; Takumi, Ken

    2002-01-01

    The present study focused on memory search processes in nonverbal working memory. Event-related potentials (ERPs) were recorded while subjects engaged in two memory search tasks. Effects of memory set size on event-related potentials were compared between when memory sets consisted of one or four alphabets and when one to three unvocable color patches composed memory sets. In a letter search task, increase of memory set size caused the enlargement of negativities of ERPs between 250 and 450 m...

  11. The changing roles of neurons in the cortical subplate

    Directory of Open Access Journals (Sweden)

    Michael J Friedlander

    2009-08-01

    Full Text Available Neurons may serve different functions over the course of an organism’s life. Recent evidence suggests that cortical subplate neurons including those that reside in the white matter may perform longitudinal multi-tasking at different stages of development. These cells play a key role in early cortical development in coordinating thalamocortical reciprocal innervation. At later stages of development, they become integrated within the cortical microcircuitry. This type of longitudinal multi-tasking can enhance the capacity for information processing by populations of cells serving different functions over the lifespan. Subplate cells are initially derived when cells from the ventricular zone underlying the cortex migrate to the cortical preplate that is subsequently split by the differentiating neurons of the cortical plate with some neurons locating in the marginal zone and others settling below in the subplate (SP. While the cortical plate neurons form most of the cortical layers (layers 2-6, the marginal zone neurons form layer 1 and the SP neurons become interstitial cells of the white matter as well as forming a compact sublayer along the bottom of layer 6. After serving as transient innervation targets for thalamocortical axons, most of these cells die and layer 4 neurons become innervated by thalamic axons. However, 10-20% survives, remaining into adulthood along the bottom of layer 6 and as a scattered population of interstitial neurons in the white matter. Surviving subplate cells’ axons project throughout the overlying laminae, reaching layer 1 and issuing axon collaterals within white matter and in lower layer 6. This suggests that they participate in local synaptic networks, as well. Moreover, they receive excitatory and inhibitory synaptic inputs, potentially monitoring outputs from axon collaterals of cortical efferents, from cortical afferents and/or from each other. We explore our understanding of the functional connectivity of

  12. Interactive effects of dehydroepiandrosterone and testosterone on cortical thickness during early brain development.

    Science.gov (United States)

    Nguyen, Tuong-Vi; McCracken, James T; Ducharme, Simon; Cropp, Brett F; Botteron, Kelly N; Evans, Alan C; Karama, Sherif

    2013-06-26

    Humans and the great apes are the only species demonstrated to exhibit adrenarche, a key endocrine event associated with prepubertal increases in the adrenal production of androgens, most significantly dehydroepiandrosterone (DHEA) and to a certain degree testosterone. Adrenarche also coincides with the emergence of the prosocial and neurobehavioral skills of middle childhood and may therefore represent a human-specific stage of development. Both DHEA and testosterone have been reported in animal and in vitro studies to enhance neuronal survival and programmed cell death depending on the timing, dose, and hormonal context involved, and to potentially compete for the same signaling pathways. Yet no extant brain-hormone studies have examined the interaction between DHEA- and testosterone-related cortical maturation in humans. Here, we used linear mixed models to examine changes in cortical thickness associated with salivary DHEA and testosterone levels in a longitudinal sample of developmentally healthy children and adolescents 4-22 years old. DHEA levels were associated with increases in cortical thickness of the left dorsolateral prefrontal cortex, right temporoparietal junction, right premotor and right entorhinal cortex between the ages of 4-13 years, a period marked by the androgenic changes of adrenarche. There was also an interaction between DHEA and testosterone on cortical thickness of the right cingulate cortex and occipital pole that was most significant in prepubertal subjects. DHEA and testosterone appear to interact and modulate the complex process of cortical maturation during middle childhood, consistent with evidence at the molecular level of fast/nongenomic and slow/genomic or conversion-based mechanisms underlying androgen-related brain development.

  13. Abnormalities of fixation, saccade and pursuit in posterior cortical atrophy.

    Science.gov (United States)

    Shakespeare, Timothy J; Kaski, Diego; Yong, Keir X X; Paterson, Ross W; Slattery, Catherine F; Ryan, Natalie S; Schott, Jonathan M; Crutch, Sebastian J

    2015-07-01

    whose frequency correlated significantly with generalized reductions in cortical thickness. Patients with both posterior cortical atrophy and typical Alzheimer's disease showed lower gain in smooth pursuit compared to controls. The current study establishes that eye movement abnormalities are near-ubiquitous in posterior cortical atrophy, and highlights multiple aspects of saccadic performance which distinguish posterior cortical atrophy from typical Alzheimer's disease. We suggest the posterior cortical atrophy oculomotor profile (e.g. exacerbation of the saccadic gap/overlap effect, preserved saccadic velocity) reflects weak input from degraded occipito-parietal spatial representations of stimulus location into a superior collicular spatial map for eye movement regulation. This may indicate greater impairment of identification of oculomotor targets rather than generation of oculomotor movements. The results highlight the critical role of spatial attention and object identification but also precise stimulus localization in explaining the complex real world perception deficits observed in posterior cortical atrophy and many other patients with dementia-related visual impairment. © The Author (2015). Published by Oxford University Press on behalf of the Guarantors of Brain.

  14. Motor cortical plasticity in Parkinson's disease.

    Science.gov (United States)

    Udupa, Kaviraja; Chen, Robert

    2013-09-04

    In Parkinson's disease (PD), there are alterations of the basal ganglia (BG) thalamocortical networks, primarily due to degeneration of nigrostriatal dopaminergic neurons. These changes in subcortical networks lead to plastic changes in primary motor cortex (M1), which mediates cortical motor output and is a potential target for treatment of PD. Studies investigating the motor cortical plasticity using non-invasive transcranial magnetic stimulation (TMS) have found altered plasticity in PD, but there are inconsistencies among these studies. This is likely because plasticity depends on many factors such as the extent of dopaminergic loss and disease severity, response to dopaminergic replacement therapies, development of l-DOPA-induced dyskinesias (LID), the plasticity protocol used, medication, and stimulation status in patients treated with deep brain stimulation (DBS). The influences of LID and DBS on BG and M1 plasticity have been explored in animal models and in PD patients. In addition, many other factors such age, genetic factors (e.g., brain derived neurotropic factor and other neurotransmitters or receptors polymorphism), emotional state, time of the day, physical fitness have been documented to play role in the extent of plasticity induced by TMS in human studies. In this review, we summarize the studies that investigated M1 plasticity in PD and demonstrate how these afore-mentioned factors affect motor cortical plasticity in PD. We conclude that it is important to consider the clinical, demographic, and technical factors that influence various plasticity protocols while developing these protocols as diagnostic or prognostic tools in PD. We also discuss how the modulation of cortical excitability and the plasticity with these non-invasive brain stimulation techniques facilitate the understanding of the pathophysiology of PD and help design potential therapeutic possibilities in this disorder.

  15. Event-Related Potentials during a Gambling Task in Young Adults with Attention-Deficit/Hyperactivity Disorder

    Science.gov (United States)

    Mesrobian, Sarah K.; Villa, Alessandro E. P.; Bader, Michel; Götte, Lorenz; Lintas, Alessandra

    2018-01-01

    Attention-deficit hyperactivity disorder (ADHD) is characterized by deficits in executive functions and decision making during childhood and adolescence. Contradictory results exist whether altered event-related potentials (ERPs) in adults are associated with the tendency of ADHD patients toward risky behavior. Clinically diagnosed ADHD patients (n = 18) and healthy controls (n = 18), aged between 18 and 29 (median 22 Yo), were screened with the Conners' Adult ADHD Rating Scales and assessed by the Mini-International Neuropsychiatric Interview, adult ADHD Self-Report Scale, and by the 60-item HEXACO Personality Inventory. The characteristic personality traits of ADHD patients were the high level of impulsiveness associated with lower values of agreeableness. All participants performed a probability gambling task (PGT) with two frequencies of the feedback information of the outcome. For each trial, ERPs were triggered by the self-paced trial onset and by the gamble selection. After trial onset, N2-P3a ERP component associated with the attentional load peaked earlier in the ADHD group than in controls. An N500 component related to the feedback frequency condition after trial onset and an N400-like component after gamble selection suggest a large affective stake of the decision making and an emphasized post-decisional evaluation of the choice made by the ADHD participants. By combining ERPs, related to the emotions associated with the feedback frequency condition, and behavioral analyses during completion of PGT, this study provides new findings on the neural dynamics that differentiate controls and young ADHD adults. In the patients' group, we raise the hypothesis that the activity of frontocentral and centroparietal neural circuits drive the decision-making processes dictated by an impaired cognitive workload followed by the build-up of large emotional feelings generated by the conflict toward the outcome of the gambling choice. Our results can be used for new

  16. Event-Related Potentials during a Gambling Task in Young Adults with Attention-Deficit/Hyperactivity Disorder

    Directory of Open Access Journals (Sweden)

    Sarah K. Mesrobian

    2018-02-01

    Full Text Available Attention-deficit hyperactivity disorder (ADHD is characterized by deficits in executive functions and decision making during childhood and adolescence. Contradictory results exist whether altered event-related potentials (ERPs in adults are associated with the tendency of ADHD patients toward risky behavior. Clinically diagnosed ADHD patients (n = 18 and healthy controls (n = 18, aged between 18 and 29 (median 22 Yo, were screened with the Conners' Adult ADHD Rating Scales and assessed by the Mini-International Neuropsychiatric Interview, adult ADHD Self-Report Scale, and by the 60-item HEXACO Personality Inventory. The characteristic personality traits of ADHD patients were the high level of impulsiveness associated with lower values of agreeableness. All participants performed a probability gambling task (PGT with two frequencies of the feedback information of the outcome. For each trial, ERPs were triggered by the self-paced trial onset and by the gamble selection. After trial onset, N2-P3a ERP component associated with the attentional load peaked earlier in the ADHD group than in controls. An N500 component related to the feedback frequency condition after trial onset and an N400-like component after gamble selection suggest a large affective stake of the decision making and an emphasized post-decisional evaluation of the choice made by the ADHD participants. By combining ERPs, related to the emotions associated with the feedback frequency condition, and behavioral analyses during completion of PGT, this study provides new findings on the neural dynamics that differentiate controls and young ADHD adults. In the patients' group, we raise the hypothesis that the activity of frontocentral and centroparietal neural circuits drive the decision-making processes dictated by an impaired cognitive workload followed by the build-up of large emotional feelings generated by the conflict toward the outcome of the gambling choice. Our results can be used

  17. Influences of brain development and ageing on cortical interactive networks.

    Science.gov (United States)

    Zhu, Chengyu; Guo, Xiaoli; Jin, Zheng; Sun, Junfeng; Qiu, Yihong; Zhu, Yisheng; Tong, Shanbao

    2011-02-01

    To study the effect of brain development and ageing on the pattern of cortical interactive networks. By causality analysis of multichannel electroencephalograph (EEG) with partial directed coherence (PDC), we investigated the different neural networks involved in the whole cortex as well as the anterior and posterior areas in three age groups, i.e., children (0-10 years), mid-aged adults (26-38 years) and the elderly (56-80 years). By comparing the cortical interactive networks in different age groups, the following findings were concluded: (1) the cortical interactive network in the right hemisphere develops earlier than its left counterpart in the development stage; (2) the cortical interactive network of anterior cortex, especially at C3 and F3, is demonstrated to undergo far more extensive changes, compared with the posterior area during brain development and ageing; (3) the asymmetry of the cortical interactive networks declines during ageing with more loss of connectivity in the left frontal and central areas. The age-related variation of cortical interactive networks from resting EEG provides new insights into brain development and ageing. Our findings demonstrated that the PDC analysis of EEG is a powerful approach for characterizing the cortical functional connectivity during brain development and ageing. Copyright © 2010 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  18. Potential of mediation for resolving environmental disputes related to energy facilities

    Energy Technology Data Exchange (ETDEWEB)

    None

    1979-12-01

    This study assesses the potential of mediation as a tool for resolving disputes related to the environmental regulation of new energy facilities and identifies possible roles the Federal government might play in promoting the use of mediation. These disputes result when parties challenge an energy project on the basis of its potential environmental impacts. The paper reviews the basic theory of mediation, evaluates specific applications of mediation to recent environmental disputes, discusses the views of environmental public-interest groups towards mediation, and identifies types of energy facility-related disputes where mediation could have a significant impact. Finally, potential avenues for the Federal government to encourage use of this tool are identified.

  19. The cortical representation of sensory inputs arising from bone.

    Science.gov (United States)

    Ivanusic, Jason J; Sahai, Vineet; Mahns, David A

    2009-05-07

    In the present study, we show that sensory information from bone reaches the discriminative areas of the somatosensory cortices by electrically stimulating the nerve to the cat humerus and recording evoked potentials on the surface of the primary (SI) and secondary (SII) somatosensory cortex. The SI focus was located over the rostral part of the postcruciate cortex, caudal to the lateral aspect of the cruciate sulcus. The SII focus was identified on the anterior ectosylvian gyrus, lateral to the suprasylvian sulcus. These foci were located adjacent to, or within areas that responded to stimulation of the median, ulnar and/or musculocutaneous nerves. The latency (6-11 ms) to onset of cortical responses in SI and SII were indistinguishable (unpaired t-test; P>0.05), and were consistent with activation of A delta fibers in the peripheral nerve. The amplitudes of the cortical responses were graded as a function of stimulus intensity, and may reflect a mechanism for intensity coding. We did not observe long latency cortical responses (50-300 ms) that would be consistent with C fiber activation in the peripheral nerve, and provide evidence that this may be attributable to inhibition of cortical responsiveness following the initial A delta response. Our finding of discrete, short latency evoked potentials (presumably of A delta origin) in the primary and secondary somatosensory cortices, following stimulation of a nerve innervating bone, may reflect a mechanism for the discriminative component of bone pain.

  20. Cognitive Demands during Quiet Standing Elicit Truncal Tremor in Two Frequency Bands: Differential Relations to Tissue Integrity of Corticospinal Tracts and Cortical Targets

    Directory of Open Access Journals (Sweden)

    Edith V Sullivan

    2015-04-01

    Full Text Available The ability to stand quietly is disturbed by degradation of cerebellar systems. Given the complexity of sensorimotor integration invoked to maintain upright posture, the integrity of supratentorial brain structures may also contribute to quiet standing and consequently be vulnerable to interference from cognitive challenges. As cerebellar system disruption is a common concomitant of alcoholism, we examined 46 alcoholics and 43 controls with a force platform to derive physiological indices of quiet standing during cognitive (solving simple, mental arithmetic problems and visual (eyes closed challenges. Also tested were relations between tremor velocity and regional gray matter and white matter tissue quality measured with the diffusion tensor imaging (DTI metric of mean diffusivity (MD, indexing disorganized microstructure. Spectral analysis of sway revealed greater tremor in alcoholic men than alcoholic women or controls. Cognitive dual-tasking elicited excessive tremor in two frequency bands, each related to DTI signs of degradation in separate brain systems: tremor velocity at a low power (2-5 Hz/0-2 Hz correlated with higher MD in the cerebellar hemispheres and superior cingulate bundles, whereas tremor velocity at a higher power (5-7 Hz correlated with higher MD in the motor cortex and internal capsule. These brain sites may represent tremorgenic networks that when disturbed by disease and exacerbated by cognitive dual-tasking contribute to postural instability, putting affected individuals at heightened risk for falling.

  1. Conceptual Integration of Arithmetic Operations with Real-World Knowledge: Evidence from Event-Related Potentials

    Science.gov (United States)

    Guthormsen, Amy M.; Fisher, Kristie J.; Bassok, Miriam; Osterhout, Lee; DeWolf, Melissa; Holyoak, Keith J.

    2016-01-01

    Research on language processing has shown that the disruption of conceptual integration gives rise to specific patterns of event-related brain potentials (ERPs)--N400 and P600 effects. Here, we report similar ERP effects when adults performed cross-domain conceptual integration of analogous semantic and mathematical relations. In a problem-solving…

  2. Scalp topography of event-related brain potentials and cognitive transitions during childhood.

    NARCIS (Netherlands)

    Molenaar, P.C.M.; van der Molen, M.W.; Stauder, J.E.A.

    1993-01-01

    Examined the relation between cognitive development (CGD) and the ontogenesis of event-related brain potentials (ERPs) during childhood among 48 girls (aged 5-7 yrs). The level of CGD was assessed with a standard Piagetian conservation kit. Ss performed a visual selective attention (oddball) task

  3. Brain activity and cognitive transition during childhood: A longitudinal event-related brain potential study.

    NARCIS (Netherlands)

    Stauder, J.E.A.; Molenaar, P.C.M.; van der Molen, M.W.

    1998-01-01

    Examined the relation between brain activation and cognitive development using event-related brain potentials (ERPs) and a longitudinal design. 5 yr old females performed a visual recognition ('oddball') task and an experimental analogue of the Piagetian conservation of liquid quantity task At three

  4. Classification of Cortical Brain Malformations

    Directory of Open Access Journals (Sweden)

    J Gordon Millichap

    2008-03-01

    Full Text Available Clinical, radiological, and genetic classifications of 113 cases of malformations of cortical development (MCD were evaluated at the Erasmus Medical Center-Sophia Children's Hospital, Rotterdam, the Netherlands.

  5. Focal cortical dysplasia – review

    International Nuclear Information System (INIS)

    Kabat, Joanna; Król, Przemysław

    2012-01-01

    Focal cortical dysplasia is a malformation of cortical development, which is the most common cause of medically refractory epilepsy in the pediatric population and the second/third most common etiology of medically intractable seizures in adults. Both genetic and acquired factors are involved in the pathogenesis of cortical dysplasia. Numerous classifications of the complex structural abnormalities of focal cortical dysplasia have been proposed – from Taylor et al. in 1971 to the last modification of Palmini classification made by Blumcke in 2011. In general, three types of cortical dysplasia are recognized. Type I focal cortical dysplasia with mild symptomatic expression and late onset, is more often seen in adults, with changes present in the temporal lobe. Clinical symptoms are more severe in type II of cortical dysplasia usually seen in children. In this type, more extensive changes occur outside the temporal lobe with predilection for the frontal lobes. New type III is one of the above dysplasias with associated another principal lesion as hippocampal sclerosis, tumor, vascular malformation or acquired pathology during early life. Brain MRI imaging shows abnormalities in the majority of type II dysplasias and in only some of type I cortical dysplasias. The most common findings on MRI imaging include: focal cortical thickening or thinning, areas of focal brain atrophy, blurring of the gray-white junction, increased signal on T2- and FLAIR-weighted images in the gray and subcortical white matter often tapering toward the ventricle. On the basis of the MRI findings, it is possible to differentiate between type I and type II cortical dysplasia. A complete resection of the epileptogenic zone is required for seizure-free life. MRI imaging is very helpful to identify those patients who are likely to benefit from surgical treatment in a group of patients with drug-resistant epilepsy. However, in type I cortical dysplasia, MR imaging is often normal, and also in both

  6. Sleep/wake dependent changes in cortical glucose concentrations.

    Science.gov (United States)

    Dash, Michael B; Bellesi, Michele; Tononi, Giulio; Cirelli, Chiara

    2013-01-01

    Most of the energy in the brain comes from glucose and supports glutamatergic activity. The firing rate of cortical glutamatergic neurons, as well as cortical extracellular glutamate levels, increase with time spent awake and decline throughout non rapid eye movement sleep, raising the question whether glucose levels reflect behavioral state and sleep/wake history. Here chronic (2-3 days) electroencephalographic recordings in the rat cerebral cortex were coupled with fixed-potential amperometry to monitor the extracellular concentration of glucose ([gluc]) on a second-by-second basis across the spontaneous sleep-wake cycle and in response to 3 h of sleep deprivation. [Gluc] progressively increased during non rapid eye movement sleep and declined during rapid eye movement sleep, while during wake an early decline in [gluc] was followed by an increase 8-15 min after awakening. There was a significant time of day effect during the dark phase, when rats are mostly awake, with [gluc] being significantly lower during the last 3-4 h of the night relative to the first 3-4 h. Moreover, the duration of the early phase of [gluc] decline during wake was longer after prolonged wake than after consolidated sleep. Thus, the sleep/wake history may affect the levels of glucose available to the brain upon awakening. © 2012 The Authors Journal of Neurochemistry © 2012 International Society for Neurochemistry.

  7. CORTICAL RESPONSES TO SALIENT NOCICEPTIVE AND NOT NOCICEPTIVE STIMULI IN VEGETATIVE AND MINIMAL CONSCIOUS STATE

    Directory of Open Access Journals (Sweden)

    MARINA eDE TOMMASO

    2015-01-01

    Full Text Available Aims Questions regarding perception of pain in non-communicating patients and the management of pain continue to raise controversy both at a clinical and ethical level. The aim of this study was to examine the cortical response to salient multimodal visual, acoustic, somatosensory electric non nociceptive and nociceptive laser stimuli and their correlation with the clinical evaluation.Methods: Five Vegetative State (VS, 4 Minimally Conscious State (MCS patients and 11 age- and sex-matched controls were examined. Evoked responses were obtained by 64 scalp electrodes, while delivering auditory, visual, non-noxious electrical and noxious laser stimulation, which were randomly presented every 10 sec. Laser, somatosensory, auditory and visual evoked responses were identified as a negative-positive (N2-P2 vertex complex in the 500 msec post-stimulus time. We used Nociception Coma Scale-Revised (NCS-R and Coma Recovery Scale (CRS-R for clinical evaluation of pain perception and consciousness impairment.Results: The laser evoked potentials (LEPs were recognizable in all cases. Only one MCS patient showed a reliable cortical response to all the employed stimulus modalities. One VS patient did not present cortical responses to any other stimulus modality. In the remaining participants, auditory, visual and electrical related potentials were inconstantly present. Significant N2 and P2 latency prolongation occurred in both VS and MCS patients. The presence of a reliable cortical response to auditory, visual and electric stimuli was able to correctly classify VS and MCS patients with 90% accuracy. Laser P2 and N2 amplitudes were not correlated with the CRS-R and NCS-R scores, while auditory and electric related potentials amplitude were associated with the motor response to pain and consciousness recovery. Discussion: pain arousal may be a primary function also in vegetative state patients while the relevance of other stimulus modalities may indicate the

  8. Spatial integration and cortical dynamics.

    Science.gov (United States)

    Gilbert, C D; Das, A; Ito, M; Kapadia, M; Westheimer, G

    1996-01-23

    Cells in adult primary visual cortex are capable of integrating information over much larger portions of the visual field than was originally thought. Moreover, their receptive field properties can be altered by the context within which local features are presented and by changes in visual experience. The substrate for both spatial integration and cortical plasticity is likely to be found in a plexus of long-range horizontal connections, formed by cortical pyramidal cells, which link cells within each cortical area over distances of 6-8 mm. The relationship between horizontal connections and cortical functional architecture suggests a role in visual segmentation and spatial integration. The distribution of lateral interactions within striate cortex was visualized with optical recording, and their functional consequences were explored by using comparable stimuli in human psychophysical experiments and in recordings from alert monkeys. They may represent the substrate for perceptual phenomena such as illusory contours, surface fill-in, and contour saliency. The dynamic nature of receptive field properties and cortical architecture has been seen over time scales ranging from seconds to months. One can induce a remapping of the topography of visual cortex by making focal binocular retinal lesions. Shorter-term plasticity of cortical receptive fields was observed following brief periods of visual stimulation. The mechanisms involved entailed, for the short-term changes, altering the effectiveness of existing cortical connections, and for the long-term changes, sprouting of axon collaterals and synaptogenesis. The mutability of cortical function implies a continual process of calibration and normalization of the perception of visual attributes that is dependent on sensory experience throughout adulthood and might further represent the mechanism of perceptual learning.

  9. Spatial integration and cortical dynamics.

    OpenAIRE

    Gilbert, C D; Das, A; Ito, M; Kapadia, M; Westheimer, G

    1996-01-01

    Cells in adult primary visual cortex are capable of integrating information over much larger portions of the visual field than was originally thought. Moreover, their receptive field properties can be altered by the context within which local features are presented and by changes in visual experience. The substrate for both spatial integration and cortical plasticity is likely to be found in a plexus of long-range horizontal connections, formed by cortical pyramidal cells, which link cells wi...

  10. Connections underlying the synthesis of cognition, memory, and emotion in primate prefrontal cortices.

    Science.gov (United States)

    Barbas, H

    2000-07-15

    Distinct domains of the prefrontal cortex in primates have a set of connections suggesting that they have different roles in cognition, memory, and emotion. Caudal lateral prefrontal areas (areas 8 and 46) receive projections from cortices representing early stages in visual or auditory processing, and from intraparietal and posterior cingulate areas associated with oculomotor guidance and attentional processes. Cortical input to areas 46 and 8 is complemented by projections from the thalamic multiform and parvicellular sectors of the mediodorsal nucleus associated with oculomotor functions and working memory. In contrast, caudal orbitofrontal areas receive diverse input from cortices representing late stages of processing within every unimodal sensory cortical system. In addition, orbitofrontal and caudal medial (limbic) prefrontal cortices receive robust projections from the amygdala, associated with emotional memory, and from medial temporal and thalamic structures associated with long-term memory. Prefrontal cortices are linked with motor control structures related to their specific roles in central executive functions. Caudal lateral prefrontal areas project to brainstem oculomotor structures, and are connected with premotor cortices effecting head, limb and body movements. In contrast, medial prefrontal and orbitofrontal limbic cortices project to hypothalamic visceromotor centers for the expression of emotions. Lateral, orbitofrontal, and medial prefrontal cortices are robustly interconnected, suggesting that they participate in concert in central executive functions. Prefrontal limbic cortices issue widespread projections through their deep layers and terminate in the upper layers of lateral (eulaminate) cortices, suggesting a predominant role in feedback communication. In contrast, when lateral prefrontal cortices communicate with limbic areas they issue projections from their upper layers and their axons terminate in the deep layers, suggesting a role in

  11. On how the motor cortices resolve an inter-hemispheric response conflict: an event-related EEG potential-guided TMS study of the flankers task

    DEFF Research Database (Denmark)

    Verleger, Rolf; Kuniecki, Michal; Möller, Friderike

    2009-01-01

    in the contralateral first dorsal interosseus muscle was taken as an index of corticospinal excitability. Guided by the previous LRP measurement, magnetic stimuli were applied 0-90 ms after the individual LRP peak, to cover the epoch of conflict resolution. When flankers were incompatible with the target, excitability......An important aspect of human motor control is the ability to resolve conflicting response tendencies. Here we used single-pulse transcranial magnetic stimulation (TMS) to track the time course of excitability changes in the primary motor hand areas (M1(HAND)) while the motor system resolved...... response conflicts. Healthy volunteers had to respond fast with their right and left index fingers to right- and left-pointing arrows. These central target stimuli were preceded by flanking arrows, inducing premature response tendencies which competed with correct response activation. The time point...

  12. Visual Dysfunction in Posterior Cortical Atrophy

    Science.gov (United States)

    Maia da Silva, Mari N.; Millington, Rebecca S.; Bridge, Holly; James-Galton, Merle; Plant, Gordon T.

    2017-01-01

    Posterior cortical atrophy (PCA) is a syndromic diagnosis. It is characterized by progressive impairment of higher (cortical) visual function with imaging evidence of degeneration affecting the occipital, parietal, and posterior temporal lobes bilaterally. Most cases will prove to have Alzheimer pathology. The aim of this review is to summarize the development of the concept of this disorder since it was first introduced. A critical discussion of the evolving diagnostic criteria is presented and the differential diagnosis with regard to the underlying pathology is reviewed. Emphasis is given to the visual dysfunction that defines the disorder, and the classical deficits, such as simultanagnosia and visual agnosia, as well as the more recently recognized visual field defects, are reviewed, along with the evidence on their neural correlates. The latest developments on the imaging of PCA are summarized, with special attention to its role on the differential diagnosis with related conditions. PMID:28861031

  13. Visual Dysfunction in Posterior Cortical Atrophy

    Directory of Open Access Journals (Sweden)

    Mari N. Maia da Silva

    2017-08-01

    Full Text Available Posterior cortical atrophy (PCA is a syndromic diagnosis. It is characterized by progressive impairment of higher (cortical visual function with imaging evidence of degeneration affecting the occipital, parietal, and posterior temporal lobes bilaterally. Most cases will prove to have Alzheimer pathology. The aim of this review is to summarize the development of the concept of this disorder since it was first introduced. A critical discussion of the evolving diagnostic criteria is presented and the differential diagnosis with regard to the underlying pathology is reviewed. Emphasis is given to the visual dysfunction that defines the disorder, and the classical deficits, such as simultanagnosia and visual agnosia, as well as the more recently recognized visual field defects, are reviewed, along with the evidence on their neural correlates. The latest developments on the imaging of PCA are summarized, with special attention to its role on the differential diagnosis with related conditions.

  14. Source-reconstruction of event-related fields reveals hyperfunction and hypofunction of cortical circuits in antipsychotic-naive, first-episode schizophrenia patients during Mooney face processing.

    Science.gov (United States)

    Rivolta, Davide; Castellanos, Nazareth P; Stawowsky, Cerisa; Helbling, Saskia; Wibral, Michael; Grützner, Christine; Koethe, Dagmar; Birkner, Katharina; Kranaster, Laura; Enning, Frank; Singer, Wolf; Leweke, F Markus; Uhlhaas, Peter J

    2014-04-23

    Schizophrenia is characterized by dysfunctions in neural circuits that can be investigated with electrophysiological methods, such as EEG and MEG. In the present human study, we examined event-related fields (ERFs), in a sample of medication-naive, first-episode schizophrenia (FE-ScZ) patients (n = 14) and healthy control participants (n = 17) during perception of Mooney faces to investigate the integrity of neuromagnetic responses and their experience-dependent modification. ERF responses were analyzed for M100, M170, and M250 components at the sensor and source levels. In addition, we analyzed peak latency and adaptation effects due to stimulus repetition. FE-ScZ patients were characterized by significantly impaired sensory processing, as indicated by a reduced discrimination index (A'). At the sensor level, M100 and M170 responses in FE-ScZ were within the normal range, whereas the M250 response was impaired. However, source localization revealed widespread elevated activity for M100 and M170 in FE-ScZ and delayed peak latencies for the M100 and M250 responses. In addition, M170 source activity in FE-ScZ was not modulated by stimulus repetitions. The present findings suggest that neural circuits in FE-ScZ may be characterized by a disturbed balance between excitation and inhibition that could lead to a failure to gate information flow and abnormal spreading of activity, which is compatible with dysfunctional glutamatergic neurotransmission.

  15. Sustained attention in skilled and novice martial arts athletes: a study of event-related potentials and current sources.

    Science.gov (United States)

    Sanchez-Lopez, Javier; Silva-Pereyra, Juan; Fernandez, Thalia

    2016-01-01

    Background. Research on sports has revealed that behavioral responses and event-related brain potentials (ERP) are better in expert than in novice athletes for sport-related tasks. Focused attention is essential for optimal athletic performance across different sports but mainly in combat disciplines. During combat, long periods of focused attention (i.e., sustained attention) are required for a good performance. Few investigations have reported effects of expertise on brain electrical activity and its neural generators during sport-unrelated attention tasks. The aim of the present study was to assess the effect of expertise (i.e., skilled and novice martial arts athletes) analyzing the ERP during a sustained attention task (Continuous Performance Task; CPT) and the cortical three-dimensional distribution of current density, using the sLORETA technique. Methods. CPT consisted in an oddball-type paradigm presentation of five stimuli (different pointing arrows) where only one of them (an arrow pointing up right) required a motor response (i.e., target). CPT was administered to skilled and novice martial arts athletes while EEG were recorded. Amplitude ERP data from target and non-target stimuli were compared between groups. Subsequently, current source analysis for each ERP component was performed on each subject. sLORETA images were compared by condition and group using Statistical Non-Parametric Mapping analysis. Results. Skilled athletes showed significant amplitude differences between target and non-target conditions in early ERP components (P100 and P200) as opposed to the novice group; however, skilled athletes showed no significant effect of condition in N200 but novices did show a significant effect. Current source analysis showed greater differences in activations in skilled compared with novice athletes between conditions in the frontal (mainly in the Superior Frontal Gyrus and Medial Frontal Gyrus) and limbic (mainly in the Anterior Cingulate Gyrus) lobes

  16. Frontal cortical control of posterior sensory and association cortices through the claustrum.

    Science.gov (United States)

    White, Michael G; Mathur, Brian N

    2018-04-06

    The claustrum is a telencephalic gray matter nucleus that is richly interconnected with the neocortex. This structure subserves top-down executive functions that require frontal cortical control of posterior cortical regions. However, functional anatomical support for the claustrum allowing for long-range intercortical communication is lacking. To test this, we performed a channelrhodopsin-assisted long-circuit mapping strategy in mouse brain slices. We find that anterior cingulate cortex input to the claustrum is transiently amplified by claustrum neurons that, in turn, project to parietal association cortex or to primary and secondary visual cortices. Additionally, we observe that claustrum drive of cortical neurons in parietal association cortex is layer-specific, eliciting action potential generation briefly in layers II/III, IV, and VI but not V. These data are the first to provide a functional anatomical substrate through claustrum that may underlie top-down functions, such as executive attention or working memory, providing critical insight to this most interconnected and enigmatic nucleus.

  17. Extensive cortical rewiring after brain injury.

    Science.gov (United States)

    Dancause, Numa; Barbay, Scott; Frost, Shawn B; Plautz, Erik J; Chen, Daofen; Zoubina, Elena V; Stowe, Ann M; Nudo, Randolph J

    2005-11-02

    Previously, we showed that the ventral premotor cortex (PMv) underwent neurophysiological remodeling after injury to the primary motor cortex (M1). In the present study, we examined cortical connections of PMv after such lesions. The neuroanatomical tract tracer biotinylated dextran amine was injected into the PMv hand area at least 5 months after ischemic injury to the M1 hand area. Comparison of labeling patterns between experimental and control animals demonstrated extensive proliferation of novel PMv terminal fields and the appearance of retrogradely labeled cell bodies within area 1/2 of the primary somatosensory cortex after M1 injury. Furthermore, evidence was found for alterations in the trajectory of PMv intracortical axons near the site of the lesion. The results suggest that M1 injury results in axonal sprouting near the ischemic injury and the establishment of novel connections within a distant target. These results support the hypothesis that, after a cortical injury, such as occurs after stroke, cortical areas distant from the injury undergo major neuroanatomical reorganization. Our results reveal an extraordinary anatomical rewiring capacity in the adult CNS after injury that may potentially play a role in recovery.

  18. Hiperostosis cortical infantil

    Directory of Open Access Journals (Sweden)

    Salvador Javier Santos Medina

    2015-04-01

    Full Text Available La enfermedad de Caffey, o hiperostosis cortical infantil, es una rara enfermedad ósea autolimitada, que aparece de preferencia en lactantes con signos inespecíficos sistémicos; el más relevante es la reacción subperióstica e hiperostosis en varios huesos del cuerpo, con predilección en el 75-80 % de los casos por la mandíbula. Su pronóstico es bueno, la mayoría no deja secuelas. El propósito del presente trabajo es describir las características clínicas, presentes en un lactante de cinco meses de edad, atendido en el Hospital Pediátrico Provincial “Mártires de Las Tunas” con este diagnóstico, quien ingresó en el servicio de miscelánea B por una celulitis facial. Presentaba aumento de volumen en la región geniana izquierda, febrícola e inapetencia. Se impuso tratamiento con cefazolina y se egresó a los siete días. Acudió nuevamente con tumefacción blanda y difusa de ambas hemicaras, irritabilidad y fiebre. Se interconsultó con cirugía maxilofacial, se indicaron estudios sanguíneos y radiológicos. Se diagnosticó como enfermedad de Caffey, basado en la edad del niño, tumefacción facial sin signos inflamatorios agudos e hiperostosis en ambas corticales mandibulares a la radiografía AP mandíbula; unido a anemia ligera, leucocitosis y eritrosedimentación acelerada. El paciente se trató sintomáticamente y con antinflamatorios no esteroideos. Esta rara entidad se debe tener presente en casos de niños y lactantes con irritabilidad y fiebre inespecífica

  19. Plasma Soluble Prion Protein, a Potential Biomarker for Sport-Related Concussions: A Pilot Study

    OpenAIRE

    Pham, Nam; Akonasu, Hungbo; Shishkin, Rhonda; Taghibiglou, Changiz

    2015-01-01

    Sport-related mild traumatic brain injury (mTBI) or concussion is a significant health concern to athletes with potential long-term consequences. The diagnosis of sport concussion and return to sport decision making is one of the greatest challenges facing health care clinicians working in sports. Blood biomarkers have recently demonstrated their potential in assisting the detection of brain injury particularly, in those cases with no obvious physical injury. We have recently discovered plasm...

  20. Event-related potentials reveal increased distraction by salient global objects in older adults

    DEFF Research Database (Denmark)

    Wiegand, Iris; Finke, Kathrin; Töllner, Thomas

    Age-related changes in visual functions influence how older individuals perceive and react upon objects in their environment. In particular, older individuals might be more distracted by highly salient, irrelevant information. Kanizsa figures induce a ‘global precedence’ effect, which reflects...... a processing advantage for salient whole-object representations relative to configurations of local elements not inducing a global form. We investigated event-related potential (ERP) correlates of age-related decline in visual abilities, and specifically, distractibility by salient global objects in visual...

  1. Concomitant Human Herpes Virus 6 and nivolumab-related pneumonitis: Potential pathogenetic insights

    Directory of Open Access Journals (Sweden)

    Periklis G. Foukas

    2018-01-01

    Full Text Available The development of immune system modulating agents, such as immune checkpoint inhibitors (ICIs, has revolutionized cancer treatment. Nivolumab, a human monoclonal antibody against PD-1, has emerged as an efficient treatment for various malignancies, including non-small cell lung cancer (NSCLC; however, it is associated with important immune related side-effects, attributed to organ-specific inflammation, such as immune-mediated pneumonitis, a relatively uncommon, albeit potentially fatal adverse event. We herein present the unique case of severe interstitial pneumonitis with concomitant detection of Human Herpes Virus 6 (HHV-6 in a nivolumab treated patient with NSCLC. Potential pathogenetic mechanisms are discussed.

  2. [Event-related EEG potentials associated with error detection in psychiatric disorder: literature review].

    Science.gov (United States)

    Balogh, Lívia; Czobor, Pál

    2010-01-01

    Error-related bioelectric signals constitute a special subgroup of event-related potentials. Researchers have identified two evoked potential components to be closely related to error processing, namely error-related negativity (ERN) and error-positivity (Pe), and they linked these to specific cognitive functions. In our article first we give a brief description of these components, then based on the available literature, we review differences in error-related evoked potentials observed in patients across psychiatric disorders. The PubMed and Medline search engines were used in order to identify all relevant articles, published between 2000 and 2009. For the purpose of the current paper we reviewed publications summarizing results of clinical trials. Patients suffering from schizophrenia, anorexia nervosa or borderline personality disorder exhibited a decrease in the amplitude of error-negativity when compared with healthy controls, while in cases of depression and anxiety an increase in the amplitude has been observed. Some of the articles suggest specific personality variables, such as impulsivity, perfectionism, negative emotions or sensitivity to punishment to underlie these electrophysiological differences. Research in the field of error-related electric activity has come to the focus of psychiatry research only recently, thus the amount of available data is significantly limited. However, since this is a relatively new field of research, the results available at present are noteworthy and promising for future electrophysiological investigations in psychiatric disorders.

  3. Reconfiguration of Cortical Networks in MDD Uncovered by Multiscale Community Detection with fMRI.

    Science.gov (United States)

    He, Ye; Lim, Sol; Fortunato, Santo; Sporns, Olaf; Zhang, Lei; Qiu, Jiang; Xie, Peng; Zuo, Xi-Nian

    2018-04-01

    Major depressive disorder (MDD) is known to be associated with altered interactions between distributed brain regions. How these regional changes relate to the reorganization of cortical functional systems, and their modulation by antidepressant medication, is relatively unexplored. To identify changes in the community structure of cortical functional networks in MDD, we performed a multiscale community detection algorithm on resting-state functional connectivity networks of unmedicated MDD (uMDD) patients (n = 46), medicated MDD (mMDD) patients (n = 38), and healthy controls (n = 50), which yielded a spectrum of multiscale community partitions. we selected an optimal resolution level by identifying the most stable community partition for each group. uMDD and mMDD groups exhibited a similar reconfiguration of the community structure of the visual association and the default mode systems but showed different reconfiguration profiles in the frontoparietal control (FPC) subsystems. Furthermore, the central system (somatomotor/salience) and 3 frontoparietal subsystems showed strengthened connectivity with other communities in uMDD but, with the exception of 1 frontoparietal subsystem, returned to control levels in mMDD. These findings provide evidence for reconfiguration of specific cortical functional systems associated with MDD, as well as potential effects of medication in restoring disease-related network alterations, especially those of the FPC system.

  4. Preferential processing of task-irrelevant beloved-related information and task performance: Two event-related potential studies.

    Science.gov (United States)

    Langeslag, Sandra J E; van Strien, Jan W

    2017-09-18

    People who are in love have better attention for beloved-related information, but report having trouble focusing on other tasks, such as (home)work. So, romantic love can both improve and hurt cognition. Emotional information is preferentially processed, which improves task performance when the information is task-relevant, but hurts task performance when it is task-irrelevant. Because beloved-related information is highly emotional, the effects of romantic love on cognition may resemble these effects of emotion on cognition. We examined whether beloved-related information is preferentially processed even when it is task-irrelevant and whether this hurts task performance. In two event-related potential studies, participants who had recently fallen in love performed a visuospatial short-term memory task. Task-irrelevant beloved, friend, and stranger faces were presented during maintenance (Study 1), or encoding (Study 2). The Early Posterior Negativity (EPN) reflecting early automatic attentional capturing and the Late Positive Potential (LPP) reflecting sustained motivated attention were largest for beloved pictures. Thus, beloved pictures are preferentially processed even when they are task-irrelevant. Task performance and reaction times did not differ between beloved, friend, and stranger conditions. Nevertheless, self-reported obsessive thinking about the beloved tended to correlate negatively with task performance, and positively with reaction times, across conditions. So, although task-irrelevant beloved-related information does not impact task performance, more obsessive thinking about the beloved might relate to poorer and slower overall task performance. More research is needed to clarify why people experience trouble focusing on beloved-unrelated tasks and how this negative effect of love on cognition could be reduced. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Curved planar reconstruction of MR images in focal cortical dysplasia of the brain

    International Nuclear Information System (INIS)

    Chung, Gyung Ho; Lee, Sang Yong; Kim, Chong So; Kim, Young Kon; Lee, Young Hwan; Jeong, Su Hyun

    2002-01-01

    To describe curved planar reconstruction imaging (CPR) and determine its usefulness in the evaluation of focal cortical dysplasia of the brain. In 17 cases of focal cortical dysplasia (cortical dysplasia (n=9), schizencephaly (n=5), and heterotopia (n=3), CPR images were created using a multiplanar reconstruction program and imaging data obtained during T1 magnetization prepared rapid acquisition gradient-echo MR imaging. We assessed the precise configuration of abnormalities and their relation to adjacent gyri and sulci. CPRI showed the brain cortex as a 2D panoramic image, demonstrating the precise configurations and locations of dysplasia-associated abnormalities and their relation to adjacent gyri and sulci, and the precise shape of the gray-white matter interface. CPRI can provide important radiological information about the extension and configuration of focal cortical dysplasia, and its relation to neighboring cortical structures. We believe that CPRI should form an essential part of the routine investigation os suspected cases of focal cortical dysplasia

  6. Methylation of NR3C1 is related to maternal PTSD, parenting stress and maternal medial prefrontal cortical activity in response to child separation among mothers with histories of violence exposure

    Science.gov (United States)

    Schechter, Daniel S.; Moser, Dominik A.; Paoloni-Giacobino, Ariane; Stenz, Ludwig; Gex-Fabry, Marianne; Aue, Tatjana; Adouan, Wafae; Cordero, María I.; Suardi, Francesca; Manini, Aurelia; Sancho Rossignol, Ana; Merminod, Gaëlle; Ansermet, Francois; Dayer, Alexandre G.; Rusconi Serpa, Sandra

    2015-01-01

    Prior research has shown that mothers with Interpersonal violence-related posttraumatic stress disorder (IPV-PTSD) report greater difficulty in parenting their toddlers. Relative to their frequent early exposure to violence and maltreatment, these mothers display dysregulation of their hypothalamic pituitary adrenal axis (HPA-axis), characterized by hypocortisolism. Considering methylation of the promoter region of the glucocorticoid receptor gene NR3C1 as a marker for HPA-axis functioning, with less methylation likely being associated with less circulating cortisol, the present study tested the hypothesis that the degree of methylation of this gene would be negatively correlated with maternal IPV-PTSD severity and parenting stress, and positively correlated with medial prefrontal cortical (mPFC) activity in response to video-stimuli of stressful versus non-stressful mother–child interactions. Following a mental health assessment, 45 mothers and their children (ages 12–42 months) participated in a behavioral protocol involving free-play and laboratory stressors such as mother–child separation. Maternal DNA was extracted from saliva. Interactive behavior was rated on the CARE-Index. During subsequent fMRI scanning, mothers were shown films of free-play and separation drawn from this protocol. Maternal PTSD severity and parenting stress were negatively correlated with the mean percentage of methylation of NR3C1. Maternal mPFC activity in response to video-stimuli of mother–child separation versus play correlated positively to NR3C1 methylation, and negatively to maternal IPV-PTSD and parenting stress. Among interactive behavior variables, child cooperativeness in play was positively correlated with NR3C1 methylation. Thus, the present study is the first published report to our knowledge, suggesting convergence of behavioral, epigenetic, and neuroimaging data that form a psychobiological signature of parenting-risk in the context of early life stress and PTSD

  7. Methylation of NR3C1 is related to maternal PTSD, parenting stress and maternal medial prefrontal cortical activity in response to child separation among mothers with histories of violence exposure

    Directory of Open Access Journals (Sweden)

    Daniel Scott Schechter

    2015-05-01

    Full Text Available Prior research has shown that mothers with Interpersonal Violence-related Posttraumatic Stress Disorder (IPV-PTSD report greater difficulty in parenting their toddlers. Relative to their frequent early exposure to violence and maltreatment, these mothers display dysregulation of their hypothalamic pituitary adrenal axis (HPA-axis, characterized by hypocortisolism. Considering methylation of the promoter region of the glucocorticoid receptor gene NR3C1 as a marker for HPA-axis functioning, with less methylation likely being associated with less circulating cortisol, the present study tested the hypothesis that the degree of methylation of this gene would be negatively correlated with maternal IPV-PTSD severity and parenting stress, and positively correlated with medial prefrontal cortical (mPFC activity in response to video-stimuli of stressful versus non-stressful mother-child interactions. Following a mental health assessment, 45 mothers and their children (ages 12-42 months participated in a behavioral protocol involving free-play and laboratory stressors such as mother-child separation. Maternal DNA was extracted from saliva. Interactive behavior was rated on the CARE-Index. During subsequent fMRI scanning, mothers were shown films of free-play and separation drawn from this protocol. Maternal PTSD severity and parenting stress were negatively correlated with the mean percentage of methylation of NR3C1. Maternal mPFC activity in response to video-stimuli of mother-child separation versus play correlated positively to NR3C1 methylation, and negatively to maternal IPV-PTSD and parenting stress. Among interactive behavior variables, child cooperativeness in play was positively correlated with NR3C1 methylation. Thus, the present study is the first published report to our knowledge, suggesting convergence of behavioral, epigenetic, and neuroimaging data that form a psychobiological signature of parenting-risk in the context of early life stress

  8. Effects of nicotine on visuo-spatial selective attention as indexed by event-related potentials.

    Science.gov (United States)

    Meinke, A; Thiel, C M; Fink, G R

    2006-08-11

    Nicotine has been shown to specifically reduce reaction times to invalidly cued targets in spatial cueing paradigms. In two experiments, we used event-related potentials to test whether the facilitative effect of nicotine upon the detection of invalidly cued targets is due to a modulation of perceptual processing, as indexed by early attention-related event-related potential components. Furthermore, we assessed whether the effect of nicotine on such unattended stimuli depends upon the use of exogenous or endogenous cues. In both experiments, the electroencephalogram was recorded while non-smokers completed discrimination tasks in Posner-type paradigms after chewing a nicotine polacrilex gum (Nicorette 2 mg) in one session and a placebo gum in another session. Nicotine reduced reaction times to invalidly cued targets when cueing was endogenous. In contrast, no differential effect of nicotine on reaction times was observed when exogenous cues were used. Electrophysiologically, we found a similar attentional modulation of the P1 and N1 components under placebo and nicotine but a differential modulation of later event-related potential components at a frontocentral site. The lack of a drug-dependent modulation of P1 and N1 in the presence of a behavioral effect suggests that the effect of nicotine in endogenous visuo-spatial cueing tasks is not due to an alteration of perceptual processes. Rather, the differential modulation of frontocentral event-related potentials suggests that nicotine acts at later stages of target processing.

  9. Changes in event-related potential functional networks predict traumatic brain injury in piglets.

    Science.gov (United States)

    Atlan, Lorre S; Lan, Ingrid S; Smith, Colin; Margulies, Susan S

    2018-06-01

    Traumatic brain injury is a leading cause of cognitive and behavioral deficits in children in the US each year. None of the current diagnostic tools, such as quantitative cognitive and balance tests, have been validated to identify mild traumatic brain injury in infants, adults and animals. In this preliminary study, we report a novel, quantitative tool that has the potential to quickly and reliably diagnose traumatic brain injury and which can track the state of the brain during recovery across multiple ages and species. Using 32 scalp electrodes, we recorded involuntary auditory event-related potentials from 22 awake four-week-old piglets one day before and one, four, and seven days after two different injury types (diffuse and focal) or sham. From these recordings, we generated event-related potential functional networks and assessed whether the patterns of the observed changes in these networks could distinguish brain-injured piglets from non-injured. Piglet brains exhibited significant changes after injury, as evaluated by five network metrics. The injury prediction algorithm developed from our analysis of the changes in the event-related potentials functional networks ultimately produced a tool with 82% predictive accuracy. This novel approach is the first application of auditory event-related potential functional networks to the prediction of traumatic brain injury. The resulting tool is a robust, objective and predictive method that offers promise for detecting mild traumatic brain injury, in particular because collecting event-related potentials data is noninvasive and inexpensive. Copyright © 2018 The Authors. Published by Elsevier Ltd.. All rights reserved.

  10. Mean field methods for cortical network dynamics

    DEFF Research Database (Denmark)

    Hertz, J.; Lerchner, Alexander; Ahmadi, M.

    2004-01-01

    We review the use of mean field theory for describing the dynamics of dense, randomly connected cortical circuits. For a simple network of excitatory and inhibitory leaky integrate- and-fire neurons, we can show how the firing irregularity, as measured by the Fano factor, increases...... with the strength of the synapses in the network and with the value to which the membrane potential is reset after a spike. Generalizing the model to include conductance-based synapses gives insight into the connection between the firing statistics and the high- conductance state observed experimentally in visual...

  11. Effects of Grammatical Categories on Children's Visual Language Processing: Evidence from Event-Related Brain Potentials

    Science.gov (United States)

    Weber-Fox, Christine; Hart, Laura J.; Spruill, John E., III

    2006-01-01

    This study examined how school-aged children process different grammatical categories. Event-related brain potentials elicited by words in visually presented sentences were analyzed according to seven grammatical categories with naturally varying characteristics of linguistic functions, semantic features, and quantitative attributes of length and…

  12. Spoken sentence comprehension in aphasia: Event-related potential evidence for a lexical integration deficit

    NARCIS (Netherlands)

    Swaab, T.Y.; Brown, C.; Hagoort, P.

    1997-01-01

    In this study the N400 component of the event-related potential was used to investigate spoken sentence understanding in Broca's and Wernicke's aphasics. The aim of the study was to determine whether spoken sentence comprehension problems in these patients might result from a deficit in the on-line

  13. Cognitive Association Formation in Episodic Memory: Evidence from Event-Related Potentials

    Science.gov (United States)

    Kim, Alice S. N.; Vallesi, Antonino; Picton, Terence W.; Tulving, Endel

    2009-01-01

    The present study focused on the processes underlying cognitive association formation by investigating subsequent memory effects. Event-related potentials were recorded as participants studied pairs of words, presented one word at a time, for later recall. The findings showed that a frontal-positive late wave (LW), which occurred 1-1.6 s after the…

  14. Children's Performance on Pseudoword Repetition Depends on Auditory Trace Quality: Evidence from Event-Related Potentials.

    Science.gov (United States)

    Ceponiene, Rita; Service, Elisabet; Kurjenluoma, Sanna; Cheour, Marie; Naatanen, Risto

    1999-01-01

    Compared the mismatch-negativity (MMN) component of auditory event-related brain potentials to explore the relationship between phonological short-term memory and auditory-sensory processing in 7- to 9-year olds scoring the highest and lowest on a pseudoword repetition test. Found that high and low repeaters differed in MMN amplitude to speech…

  15. The effects of cortisol administration on approach-avoidance behavior: An event-related potential study

    NARCIS (Netherlands)

    Peer, J.M. van; Roelofs, K.; Rotteveel, M.; Dijk, J.G. van; Spinhoven, P.; Ridderinkhof, K.R.

    2007-01-01

    We investigated the effects of cortisol administration (50 mg) on approach and avoidance tendencies in low and high trait avoidant healthy young men. Event-related brain potentials (ERPs) were measured during a reaction time task, in which participants evaluated the emotional expression of

  16. Introducing GaLA: Serious Game potentials, challenges and TEL-related issues

    NARCIS (Netherlands)

    Earp, Jeffrey; Klemke, Roland

    2011-01-01

    Earp, J., & Klemke, R. (2011, 21 September). Introducing GaLA: Serious Game potentials, challenges and TEL-related issues. Presented at TEL-Think-Tank Workshop at the 6th European conference on Technology enhanced learning: towards ubiquitous learning (EC-TEL 2011), Palermo, Italy.

  17. Event-related Potentials Reflecting the Processing of Phonological Constraint Violations

    NARCIS (Netherlands)

    Domahs, Ulrike; Kehrein, Wolfgang; Knaus, Johannes; Wiese, Richard; Schlesewsky, Matthias

    2009-01-01

    Flow are violations of phonological constraints processed in word comprehension? The present article reports the results of ail event-related potentials (ERP) Study oil a phonological constraint of German that disallows identical segments within it syllable or word (CC(i)VC(i)). We examined three

  18. Event-related potentials reflecting the processing of phonological constraint violations

    NARCIS (Netherlands)

    Domahs, U.; Kehrein, W.; Knaus, J.; Wiese, R.; Schlesewsky, M.

    2009-01-01

    How are violations of phonological constraints processed in word comprehension? The present article reports the results of an event-related potentials (ERP) study on a phonological constraint of German that disallows identical segments within a syllable or word (CC iVCi). We examined three types of

  19. Snake scales, partial exposure, and the Snake Detection Theory: A human event-related potentials study

    NARCIS (Netherlands)

    J.W. van Strien (Jan); L.A. Isbell (Lynne A.)

    2017-01-01

    textabstractStudies of event-related potentials in humans have established larger early posterior negativity (EPN) in response to pictures depicting snakes than to pictures depicting other creatures. Ethological research has recently shown that macaques and wild vervet monkeys respond strongly to

  20. An event-related brain potential correlate of visual short-term memory

    NARCIS (Netherlands)

    Klaver, Peter; Talsma, D.; Wijers, Albertus; Heinze, Hans-Jochen; Mulder, Gijsbertus

    1999-01-01

    EVENT-RELATED potentials (ERPs) were recorded as 12 subjects performed a delayed matching to sample task. We presented two bilateral abstract shapes and cued spatially which had to be memorized for a subsequent matching task: left, right or both. During memorization a posterior slow negative ERP

  1. Adapting to Changing Memory Retrieval Demands: Evidence from Event-Related Potentials

    Science.gov (United States)

    Benoit, Roland G.; Werkle-Bergner, Markus; Mecklinger, Axel; Kray, Jutta

    2009-01-01

    This study investigated preparatory processes involved in adapting to changing episodic memory retrieval demands. Event-related potentials (ERPs) were recorded while participants performed a general old/new recognition task and a specific task that also required retrieval of perceptual details. The relevant task remained either constant or changed…

  2. Attentional Mechanisms in Sports via Brain-Electrical Event-Related Potentials

    Science.gov (United States)

    Hack, Johannes; Memmert, Daniel; Rup, Andre

    2009-01-01

    In this study, we examined attention processes in complex, sport-specific decision-making tasks without interdependencies from anticipation. Psychophysiological and performance data recorded from advanced and intermediate level basketball referees were compared. Event-related potentials obtained while judging game situations in foul recognition…

  3. Complement Set Reference after Implicitly Small Quantities: An Event-Related Potentials Study

    Science.gov (United States)

    Ingram, Joanne; Ferguson, Heather J.

    2018-01-01

    An anaphoric reference to the complement-set is a reference to the set that does not fulfil the predicate of the preceding sentence. Preferred reference to the complement-set has been found in eye movements when a character's implicit desire for a high amount has been denied using a negative emotion. We recorded event-related potentials to examine…

  4. Event-related potentials during visual selective attention in children of alcoholics.

    NARCIS (Netherlands)

    van der Stelt, O.; Gunning, W.B.; Snel, J.; Kok, A.

    1998-01-01

    Event-related potentials (ERPs) were recorded from 50 7-18 yr old children of alcoholics (COAs) and 50 age- and sex-matched control children while they performed a visual selective attention task. The task was to attend selectively to stimuli with a specified color (red or blue) in an attempt to

  5. MODULATION OF EVENT-RELATED POTENTIALS BY WORD REPETITION - THE ROLE OF VISUAL SELECTIVE ATTENTION

    NARCIS (Netherlands)

    OTTEN, LJ; RUGG, MD; DOYLE, MC

    1993-01-01

    Event-related potentials (ERPs) were recorded while subjects viewed visually presented words, some of which occurred twice. Each trial consisted of two colored letter strings, the requirement being to attend to and make a word/nonword discrimination for one of the strings. Attention was manipulated

  6. Declarative memory formation in hippocampal sclerosis: an intracranial event-related potentials study.

    NARCIS (Netherlands)

    Mormann, F.; Fernandez, G.S.E.; Klaver, P.; Weber, B.; Elger, C.E.; Fell, J.

    2007-01-01

    The functional deficits associated with hippocampal sclerosis during declarative memory formation are largely unknown. In this study, we analyzed intracranial event-related potentials recorded from the medial temporal lobes of nine epilepsy patients performing a word memorization task. We used

  7. Decision making on organ donation: the dilemmas of relatives of potential brain dead donors

    NARCIS (Netherlands)

    Groot, J.J.A.M. de; Hoek, M.; Hoedemaekers, C.W.E.; Hoitsma, A.J.; Smeets, W.; Vernooij-Dassen, M.J.F.J.; Leeuwen, E. van

    2015-01-01

    BACKGROUND: This article is part of a study to gain insight into the decision-making process by looking at the views of the relatives of potential brain dead donors. Alongside a literature review, focus interviews were held with healthcare professionals about their role in the request and

  8. Early referential context effects in sentence processing: Evidence from event-related brain potentials

    NARCIS (Netherlands)

    Berkum, J.J.A. van; Brown, C.M.; Hagoort, P.

    1999-01-01

    An event-related brain potentials experiment was carried out to examine the interplay of referential and structural factors during sentence processing in discourse. Subjects read (Dutch) sentences beginning like “David told the girl that … ” in short story contexts that had introduced either one or

  9. Opening the Learning Process: The Potential Role of Feature Film in Teaching Employment Relations

    Science.gov (United States)

    Lafferty, George

    2016-01-01

    This paper explores the potential of feature film to encourage more inclusive, participatory and open learning in the area of employment relations. Evaluations of student responses in a single postgraduate course over a five-year period revealed how feature film could encourage participatory learning processes in which students reexamined their…

  10. Changes in time and frequency related aspects of motor unit action potentials during fatigue

    NARCIS (Netherlands)

    Wallinga, W.; Bouwens, Jeroen S.; Baten, Christian T.M.

    1996-01-01

    During fatigue the shape of motor unit action potentials (MUAPs) change. Characteristics of the MUAPs described before concern several time related aspects. No attention has been given to the frequency spectrum changes of MUAPS. The median frequency of MUAPS has now been determined for motor units

  11. Do U Txt? Event-Related Potentials to Semantic Anomalies in Standard and Texted English

    Science.gov (United States)

    Berger, Natalie I.; Coch, Donna

    2010-01-01

    Texted English is a hybrid, technology-based language derived from standard English modified to facilitate ease of communication via instant and text messaging. We compared semantic processing of texted and standard English sentences by recording event-related potentials in a classic semantic incongruity paradigm designed to elicit an N400 effect.…

  12. Suicide-Related Experiences Among Blacks: An Empirical Test of a Suicide Potential Scale

    Science.gov (United States)

    Wenz, Friedrich V.

    1978-01-01

    Developing a Suicide Potential Scale for a number of socially differentiated, stratified census tract populations in a northern city, this paper argues that scores on this scale are related to actual suicidal behavior. These data support the position that variation in suicide among blacks is mainly determined by economic status. (Author)

  13. Temporal Dynamics of Late Second Language Acquisition: Evidence from Event-Related Brain Potentials

    Science.gov (United States)

    Steinhauer, Karsten; White, Erin J.; Drury, John E.

    2009-01-01

    The ways in which age of acquisition (AoA) may affect (morpho)syntax in second language acquisition (SLA) are discussed. We suggest that event-related brain potentials (ERPs) provide an appropriate online measure to test some such effects. ERP findings of the past decade are reviewed with a focus on recent and ongoing research. It is concluded…

  14. Implicit Phonological and Semantic Processing in Children with Developmental Dyslexia: Evidence from Event-Related Potentials

    Science.gov (United States)

    Jednorog, K.; Marchewka, A.; Tacikowski, P.; Grabowska, A.

    2010-01-01

    Dyslexia is characterized by a core phonological deficit, although recent studies indicate that semantic impairment also contributes to this condition. In this study, event-related potentials (ERP) were used to examine whether the N400 wave in dyslexic children is modulated by phonological or semantic priming, similarly to age-matched controls.…

  15. Representations in human visual short-term memory : an event-related brain potential study

    NARCIS (Netherlands)

    Klaver, P; Smid, HGOM; Heinze, HJ

    1999-01-01

    Behavioral measures and event-related potentials (ERPs) were recorded from 12 subjects while performing three delayed matching-to-sample tasks. The task instructions indicated whether stimulus locations, shapes or conjunctions of locations and shapes had to be memorized and matched against a probe.

  16. Contingent Attentional Capture by Top-Down Control Settings: Converging Evidence from Event-Related Potentials

    Science.gov (United States)

    Lien, Mei-Ching; Ruthruff, Eric; Goodin, Zachary; Remington, Roger W.

    2008-01-01

    Theories of attentional control are divided over whether the capture of spatial attention depends primarily on stimulus salience or is contingent on attentional control settings induced by task demands. The authors addressed this issue using the N2-posterior-contralateral (N2pc) effect, a component of the event-related brain potential thought to…

  17. Potential Mediating Pathways through Which Sports Participation Relates to Reduced Risk of Suicidal Ideation

    Science.gov (United States)

    Taliaferro, Lindsay A.; Rienzo, Barbara A.; Miller, M. David; Pigg, R. Morgan; Dodd, Virginia J.

    2010-01-01

    Suicide ranks as the third leading cause of death for American youth. Researchers examining sport participation and suicidal behavior have regularly found inverse relationships. This study represents the first effort to test a model depicting potential mechanisms through which sport participation relates to reduced risk of suicidal ideation. The…

  18. Working memory processes show different degrees of lateralization : Evidence from event-related potentials

    NARCIS (Netherlands)

    Talsma, D; Wijers, A.A.; Klaver, P; Mulder, G.

    This study aimed to identify different processes in working memory, using event-related potentials (ERPs) and response times. Abstract polygons were presented for memorization and subsequent recall in a delayed matching-to-sample paradigm. Two polygons were presented bilaterally for memorization and

  19. On the relation between fields and potentials in non abelian Gauge Theories

    International Nuclear Information System (INIS)

    Bollini, C.G.; Giambiagi, J.J.

    1979-01-01

    Some examples have been given in the literature of ambiguous gauge fields, i.e. those not having a unique potential (up to a gauge transformation). An example given by Deser and Wilczek is examined and found the condition (for any gauge group) that the group element generating the potentials must satisfy in order for the potentials not to be related by any gauge transformation. In three dimensions (for Su 2 ) there are other families of ambiguous fields characterized by arbitrary unit vector fields n vector (n vector) (n 2 vector =1). The example given by Wu and Yang belongs to a particular family with n vector = n vector. r vector / r vector. The sources of these fields and some interesting relations between them are also found [pt

  20. Cortical thinning and clinical heterogeneity in amyotrophic lateral sclerosis.

    Science.gov (United States)

    Mezzapesa, Domenico Maria; D'Errico, Eustachio; Tortelli, Rosanna; Distaso, Eugenio; Cortese, Rosa; Tursi, Marianna; Federico, Francesco; Zoccolella, Stefano; Logroscino, Giancarlo; Dicuonzo, Franca; Simone, Isabella Laura

    2013-01-01

    Amyotrophic lateral sclerosis (ALS) has heterogeneous clinical features that could be translated into specific patterns of brain atrophy. In the current study we have evaluated the relationship between different clinical expressions of classical ALS and measurements of brain cortical thickness. Cortical thickness analysis was conducted from 3D-MRI using FreeSurfer software in 29 ALS patients and 20 healthy controls. We explored three clinical traits of the disease, subdividing the patients into two groups for each of them: the bulbar or spinal onset, the higher or lower upper motor neuron burden, the faster or slower disease progression. We used both a whole brain vertex-wise analysis and a ROI analysis on primary motor areas. ALS patients showed cortical thinning in bilateral precentral gyrus, bilateral middle frontal gyrus, right superior temporal gyrus and right occipital cortex. ALS patients with higher upper motor neuron burden showed a significant cortical thinning in the right precentral gyrus and in other frontal extra-motor areas, compared to healthy controls. ALS patients with spinal onset showed a significant cortical thinning in the right precentral gyrus and paracentral lobule, compared to healthy controls. ALS patients with faster progressive disease showed a significant cortical thinning in widespread bilateral frontal and temporal areas, including the bilateral precentral gyrus, compared to healthy controls. Focusing on the primary motor areas, the ROI analysis revealed that the mean cortical thickness values were significantly reduced in ALS patients with higher upper motor neuron burden, spinal onset and faster disease progression related to healthy controls. In conclusion, the thickness of primary motor cortex could be a useful surrogate marker of upper motor neuron involvement in ALS; also our results suggest that cortical thinning in motor and non motor areas seem to reflect the clinical heterogeneity of the disease.

  1. Cortical thinning and clinical heterogeneity in amyotrophic lateral sclerosis.

    Directory of Open Access Journals (Sweden)

    Domenico Maria Mezzapesa

    Full Text Available Amyotrophic lateral sclerosis (ALS has heterogeneous clinical features that could be translated into specific patterns of brain atrophy. In the current study we have evaluated the relationship between different clinical expressions of classical ALS and measurements of brain cortical thickness. Cortical thickness analysis was conducted from 3D-MRI using FreeSurfer software in 29 ALS patients and 20 healthy controls. We explored three clinical traits of the disease, subdividing the patients into two groups for each of them: the bulbar or spinal onset, the higher or lower upper motor neuron burden, the faster or slower disease progression. We used both a whole brain vertex-wise analysis and a ROI analysis on primary motor areas. ALS patients showed cortical thinning in bilateral precentral gyrus, bilateral middle frontal gyrus, right superior temporal gyrus and right occipital cortex. ALS patients with higher upper motor neuron burden showed a significant cortical thinning in the right precentral gyrus and in other frontal extra-motor areas, compared to healthy controls. ALS patients with spinal onset showed a significant cortical thinning in the right precentral gyrus and paracentral lobule, compared to healthy controls. ALS patients with faster progressive disease showed a significant cortical thinning in widespread bilateral frontal and temporal areas, including the bilateral precentral gyrus, compared to healthy controls. Focusing on the primary motor areas, the ROI analysis revealed that the mean cortical thickness values were significantly reduced in ALS patients with higher upper motor neuron burden, spinal onset and faster disease progression related to healthy controls. In conclusion, the thickness of primary motor cortex could be a useful surrogate marker of upper motor neuron involvement in ALS; also our results suggest that cortical thinning in motor and non motor areas seem to reflect the clinical heterogeneity of the disease.

  2. Cortical entrainment to music and its modulation by expertise.

    Science.gov (United States)

    Doelling, Keith B; Poeppel, David

    2015-11-10

    Recent studies establish that cortical oscillations track naturalistic speech in a remarkably faithful way. Here, we test whether such neural activity, particularly low-frequency (music and whether experience modifies such a cortical phenomenon. Music of varying tempi was used to test entrainment at different rates. In three magnetoencephalography experiments, we recorded from nonmusicians, as well as musicians with varying years of experience. Recordings from nonmusicians demonstrate cortical entrainment that tracks musical stimuli over a typical range of tempi, but not at tempi below 1 note per second. Importantly, the observed entrainment correlates with performance on a concurrent pitch-related behavioral task. In contrast, the data from musicians show that entrainment is enhanced by years of musical training, at all presented tempi. This suggests a bidirectional relationship between behavior and cortical entrainment, a phenomenon that has not previously been reported. Additional analyses focus on responses in the beta range (∼15-30 Hz)-often linked to delta activity in the context of temporal predictions. Our findings provide evidence that the role of beta in temporal predictions scales to the complex hierarchical rhythms in natural music and enhances processing of musical content. This study builds on important findings on brainstem plasticity and represents a compelling demonstration that cortical neural entrainment is tightly coupled to both musical training and task performance, further supporting a role for cortical oscillatory activity in music perception and cognition.

  3. Neurodevelopmental origins of abnormal cortical morphology in dissociative identity disorder.

    Science.gov (United States)

    Reinders, A A T S; Chalavi, S; Schlumpf, Y R; Vissia, E M; Nijenhuis, E R S; Jäncke, L; Veltman, D J; Ecker, C

    2018-02-01

    To examine the two constitutes of cortical volume (CV), that is, cortical thickness (CT) and surface area (SA), in individuals with dissociative identity disorder (DID) with the view of gaining important novel insights into the underlying neurobiological mechanisms mediating DID. This study included 32 female patients with DID and 43 matched healthy controls. Between-group differences in CV, thickness, and SA, the degree of spatial overlap between differences in CT and SA, and their relative contribution to differences in regional CV were assessed using a novel spatially unbiased vertex-wise approach. Whole-brain correlation analyses were performed between measures of cortical anatomy and dissociative symptoms and traumatization. Individuals with DID differed from controls in CV, CT, and SA, with significantly decreased CT in the insula, anterior cingulate, and parietal regions and reduced cortical SA in temporal and orbitofrontal cortices. Abnormalities in CT and SA shared only about 3% of all significantly different cerebral surface locations and involved distinct contributions to the abnormality of CV in DID. Significant negative associations between abnormal brain morphology (SA and CV) and dissociative symptoms and early childhood traumatization (0 and 3 years of age) were found. In DID, neuroanatomical areas with decreased CT and SA are in different locations in the brain. As CT and SA have distinct genetic and developmental origins, our findings may indicate that different neurobiological mechanisms and environmental factors impact on cortical morphology in DID, such as early childhood traumatization. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Heavy-ion optical potential for sub-barrier fusion deduced from a dispersion relation

    International Nuclear Information System (INIS)

    Kim, B.T.; Kim, H.C.; Park, K.E.

    1988-01-01

    The heavy-ion energy-dependent optical potentials for the 16 O+ 208 Pb system are deduced from a dispersion relation. These potentials are used to analyze the elastic scattering, fusion, and spin distributions of compound nuclei for the system in a unified way based on the direct reaction theory. It turns out that the energy dependence of the optical potential is essential in explaining the data at near- and sub-barrier energies. The real part of the energy-dependent optical potential deduced was also used in calculating the elastic and fusion cross sections by the conventional barrier penetration model using an incoming wave boundary condition. The predictions of the elastic scattering, fusion cross sections, and the spin distributions of compound nuclei are not satisfactory compared with those from the direct reaction approach. It seems to originate from the fact that this model neglects absorption around the Coulomb barrier region

  5. The Potential of Chitosan and Its Derivatives in Prevention and Treatment of Age-Related Diseases

    Science.gov (United States)

    Kerch, Garry

    2015-01-01

    Age-related, diet-related and protein conformational diseases, such as atherosclerosis, diabetes mellitus, cancer, hypercholesterolemia, cardiovascular and neurodegenerative diseases are common in the elderly population. The potential of chitosan, chitooligosaccharides and their derivatives in prevention and treatment of age-related dysfunctions is reviewed and discussed in this paper. The influence of oxidative stress, low density lipoprotein oxidation, increase of tissue stiffness, protein conformational changes, aging-associated chronic inflammation and their pathobiological significance have been considered. The chitosan-based functional food also has been reviewed. PMID:25871293

  6. Horizontal integration and cortical dynamics.

    Science.gov (United States)

    Gilbert, C D

    1992-07-01

    We have discussed several results that lead to a view that cells in the visual system are endowed with dynamic properties, influenced by context, expectation, and long-term modifications of the cortical network. These observations will be important for understanding how neuronal ensembles produce a system that perceives, remembers, and adapts to injury. The advantage to being able to observe changes at early stages in a sensory pathway is that one may be able to understand the way in which neuronal ensembles encode and represent images at the level of their receptive field properties, of cortical topographies, and of the patterns of connections between cells participating in a network.

  7. Trade-off of cerebello-cortical and cortico-cortical functional networks for planning in 6-year-old children.

    Science.gov (United States)

    Kipping, Judy A; Margulies, Daniel S; Eickhoff, Simon B; Lee, Annie; Qiu, Anqi

    2018-05-03

    Childhood is a critical period for the development of cognitive planning. There is a lack of knowledge on its neural mechanisms in children. This study aimed to examine cerebello-cortical and cortico-cortical functional connectivity in association with planning skills in 6-year-olds (n = 76). We identified the cerebello-cortical and cortico-cortical functional networks related to cognitive planning using activation likelihood estimation (ALE) meta-analysis on existing functional imaging studies on spatial planning, and data-driven independent component analysis (ICA) of children's resting-state functional MRI (rs-fMRI). We investigated associations of cerebello-cortical and cortico-cortical functional connectivity with planning ability in 6-year-olds, as assessed using the Stockings of Cambridge task. Long-range functional connectivity of two cerebellar networks (lobules VI and lateral VIIa) with the prefrontal and premotor cortex were greater in children with poorer planning ability. In contrast, cortico-cortical association networks were not associated with the performance of planning in children. These results highlighted the key contribution of the lateral cerebello-frontal functional connectivity, but not cortico-cortical association functional connectivity, for planning ability in 6-year-olds. Our results suggested that brain adaptation to the acquisition of planning ability during childhood is partially achieved through the engagement of the cerebello-cortical functional connectivity. Copyright © 2018 Elsevier Inc. All rights reserved.

  8. Posterior Thalamic Nucleus Modulation of Tactile Stimuli Processing in Rat Motor and Primary Somatosensory Cortices

    Directory of Open Access Journals (Sweden)

    Diana Casas-Torremocha

    2017-09-01

    Full Text Available Rodents move rhythmically their facial whiskers and compute differences between signals predicted and those resulting from the movement to infer information about objects near their head. These computations are carried out by a large network of forebrain structures that includes the thalamus and the primary somatosensory (S1BF and motor (M1wk cortices. Spatially and temporally precise mechanorreceptive whisker information reaches the S1BF cortex via the ventroposterior medial thalamic nucleus (VPM. Other whisker-related information may reach both M1wk and S1BF via the axons from the posterior thalamic nucleus (Po. However, Po axons may convey, in addition to direct sensory signals, the dynamic output of computations between whisker signals and descending motor commands. It has been proposed that this input may be relevant for adjusting cortical responses to predicted vs. unpredicted whisker signals, but the effects of Po input on M1wk and S1BF function have not been directly tested or compared in vivo. Here, using electrophysiology, optogenetics and pharmacological tools, we compared in adult rats M1wk and S1BF in vivo responses in the whisker areas of the motor and primary somatosensory cortices to passive multi-whisker deflection, their dependence on Po activity, and their changes after a brief intense activation of Po axons. We report that the latencies of the first component of tactile-evoked local field potentials in M1wk and S1BF are similar. The evoked potentials decrease markedly in M1wk, but not in S1BF, by injection in Po of the GABAA agonist muscimol. A brief high-frequency electrical stimulation of Po decreases the responsivity of M1wk and S1BF cells to subsequent whisker stimulation. This effect is prevented by the local application of omega-agatoxin, suggesting that it may in part depend on GABA release by fast-spiking parvalbumin (PV-expressing cortical interneurons. Local optogenetic activation of Po synapses in different

  9. Cortical Thinning and Altered Cortico-Cortical Structural Covariance of the Default Mode Network in Patients with Persistent Insomnia Symptoms.

    Science.gov (United States)

    Suh, Sooyeon; Kim, Hosung; Dang-Vu, Thien Thanh; Joo, Eunyeon; Shin, Chol

    2016-01-01

    Recent studies have suggested that structural abnormalities in insomnia may be linked with alterations in the default-mode network (DMN). This study compared cortical thickness and structural connectivity linked to the DMN in patients with persistent insomnia (PI) and good sleepers (GS). The current study used a clinical subsample from the longitudinal community-based Korean Genome and Epidemiology Study (KoGES). Cortical thickness and structural connectivity linked to the DMN in patients with persistent insomnia symptoms (PIS; n = 57) were compared to good sleepers (GS; n = 40). All participants underwent MRI acquisition. Based on literature review, we selected cortical regions corresponding to the DMN. A seed-based structural covariance analysis measured cortical thickness correlation between each seed region of the DMN and other cortical areas. Association of cortical thickness and covariance with sleep quality and neuropsychological assessments were further assessed. Compared to GS, cortical thinning was found in PIS in the anterior cingulate cortex, precentral cortex, and lateral prefrontal cortex. Decreased structural connectivity between anterior and posterior regions of the DMN was observed in the PIS group. Decreased structural covariance within the DMN was associated with higher PSQI scores. Cortical thinning in the lateral frontal lobe was related to poor performance in executive function in PIS. Disrupted structural covariance network in PIS might reflect malfunctioning of antero-posterior disconnection of the DMN during the wake to sleep transition that is commonly found during normal sleep. The observed structural network alteration may further implicate commonly observed sustained sleep difficulties and cognitive impairment in insomnia. © 2016 Associated Professional Sleep Societies, LLC.

  10. Plasma soluble prion protein, a potential biomarker for sport-related concussions: a pilot study.

    Science.gov (United States)

    Pham, Nam; Akonasu, Hungbo; Shishkin, Rhonda; Taghibiglou, Changiz

    2015-01-01

    Sport-related mild traumatic brain injury (mTBI) or concussion is a significant health concern to athletes with potential long-term consequences. The diagnosis of sport concussion and return to sport decision making is one of the greatest challenges facing health care clinicians working in sports. Blood biomarkers have recently demonstrated their potential in assisting the detection of brain injury particularly, in those cases with no obvious physical injury. We have recently discovered plasma soluble cellular prion protein (PrP(C)) as a potential reliable biomarker for blast induced TBI (bTBI) in a rodent animal model. In order to explore the application of this novel TBI biomarker to sport-related concussion, we conducted a pilot study at the University of Saskatchewan (U of S) by recruiting athlete and non-athlete 18 to 30 year-old students. Using a modified quantitative ELISA method, we first established normal values for the plasma soluble PrP(C) in male and female students. The measured plasma soluble PrP(C) in confirmed concussion cases demonstrated a significant elevation of this analyte in post-concussion samples. Data collected from our pilot study indicates that the plasma soluble PrP(C) is a potential biomarker for sport-related concussion, which may be further developed into a clinical diagnostic tool to assist clinicians in the assessment of sport concussion and return-to-play decision making.

  11. Plasma soluble prion protein, a potential biomarker for sport-related concussions: a pilot study.

    Directory of Open Access Journals (Sweden)

    Nam Pham

    Full Text Available Sport-related mild traumatic brain injury (mTBI or concussion is a significant health concern to athletes with potential long-term consequences. The diagnosis of sport concussion and return to sport decision making is one of the greatest challenges facing health care clinicians working in sports. Blood biomarkers have recently demonstrated their potential in assisting the detection of brain injury particularly, in those cases with no obvious physical injury. We have recently discovered plasma soluble cellular prion protein (PrP(C as a potential reliable biomarker for blast induced TBI (bTBI in a rodent animal model. In order to explore the application of this novel TBI biomarker to sport-related concussion, we conducted a pilot study at the University of Saskatchewan (U of S by recruiting athlete and non-athlete 18 to 30 year-old students. Using a modified quantitative ELISA method, we first established normal values for the plasma soluble PrP(C in male and female students. The measured plasma soluble PrP(C in confirmed concussion cases demonstrated a significant elevation of this analyte in post-concussion samples. Data collected from our pilot study indicates that the plasma soluble PrP(C is a potential biomarker for sport-related concussion, which may be further developed into a clinical diagnostic tool to assist clinicians in the assessment of sport concussion and return-to-play decision making.

  12. Cortical hubs form a module for multisensory integration on top of the hierarchy of cortical networks

    Directory of Open Access Journals (Sweden)

    Gorka Zamora-López

    2010-03-01

    Full Text Available Sensory stimuli entering the nervous system follow particular paths of processing, typically separated (segregated from the paths of other modal information. However, sensory perception, awareness and cognition emerge from the combination of information (integration. The corticocortical networks of cats and macaque monkeys display three prominent characteristics: (i modular organisation (facilitating the segregation, (ii abundant alternative processing paths and (iii the presence of highly connected hubs. Here, we study in detail the organisation and potential function of the cortical hubs by graph analysis and information theoretical methods. We find that the cortical hubs form a spatially delocalised, but topologically central module with the capacity to integrate multisensory information in a collaborative manner. With this, we resolve the underlying anatomical substrate that supports the simultaneous capacity of the cortex to segregate and to integrate multisensory information.

  13. NR2B subunit-dependent long-term potentiation enhancement in the rat cortical auditory system in vivo following masking of patterned auditory input by white noise exposure during early postnatal life.

    Science.gov (United States)

    Hogsden, Jennifer L; Dringenberg, Hans C

    2009-08-01

    The composition of N-methyl-D-aspartate (NMDA) receptor subunits influences the degree of synaptic plasticity expressed during development and into adulthood. Here, we show that theta-burst stimulation of the medial geniculate nucleus reliably induced NMDA receptor-dependent long-term potentiation (LTP) of field postsynaptic potentials recorded in the primary auditory cortex (A1) of urethane-anesthetized rats. Furthermore, substantially greater levels of LTP were elicited in juvenile animals (30-37 days old; approximately 55% maximal potentiation) than in adult animals (approximately 30% potentiation). Masking patterned sound via continuous white noise exposure during early postnatal life (from postnatal day 5 to postnatal day 50-60) resulted in enhanced, juvenile-like levels of LTP (approximately 70% maximal potentiation) relative to age-matched controls reared in unaltered acoustic environments (approximately 30%). Rats reared in white noise and then placed in unaltered acoustic environments for 40-50 days showed levels of LTP comparable to those of adult controls, indicating that white noise rearing results in a form of developmental arrest that can be overcome by subsequent patterned sound exposure. We explored the mechanisms mediating white noise-induced plasticity enhancements by local NR2B subunit antagonist application in A1. NR2B subunit antagonists (Ro 25-6981 or ifenprodil) completely reversed white noise-induced LTP enhancement at concentrations that did not affect LTP in adult or age-matched controls. We conclude that white noise exposure during early postnatal life results in the maintenance of juvenile-like, higher levels of plasticity in A1, an effect that appears to be critically dependent on NR2B subunit activation.

  14. Physical insight into the thermodynamic uncertainty relation using Brownian motion in tilted periodic potentials

    Science.gov (United States)

    Hyeon, Changbong; Hwang, Wonseok

    2017-07-01

    Using Brownian motion in periodic potentials V (x ) tilted by a force f , we provide physical insight into the thermodynamic uncertainty relation, a recently conjectured principle for statistical errors and irreversible heat dissipation in nonequilibrium steady states. According to the relation, nonequilibrium output generated from dissipative processes necessarily incurs an energetic cost or heat dissipation q , and in order to limit the output fluctuation within a relative uncertainty ɛ , at least 2 kBT /ɛ2 of heat must be dissipated. Our model shows that this bound is attained not only at near-equilibrium [f ≪V'(x ) ] but also at far-from-equilibrium [f ≫V'(x ) ] , more generally when the dissipated heat is normally distributed. Furthermore, the energetic cost is maximized near the critical force when the barrier separating the potential wells is about to vanish and the fluctuation of Brownian particles is maximized. These findings indicate that the deviation of heat distribution from Gaussianity gives rise to the inequality of the uncertainty relation, further clarifying the meaning of the uncertainty relation. Our derivation of the uncertainty relation also recognizes a bound of nonequilibrium fluctuations that the variance of dissipated heat (σq2) increases with its mean (μq), and it cannot be smaller than 2 kBT μq .

  15. A relation to predict the failure of materials and potential application to volcanic eruptions and landslides.

    Science.gov (United States)

    Hao, Shengwang; Liu, Chao; Lu, Chunsheng; Elsworth, Derek

    2016-06-16

    A theoretical explanation of a time-to-failure relation is presented, with this relationship then used to describe the failure of materials. This provides the potential to predict timing (tf - t) immediately before failure by extrapolating the trajectory as it asymptotes to zero with no need to fit unknown exponents as previously proposed in critical power law behaviors. This generalized relation is verified by comparison with approaches to criticality for volcanic eruptions and creep failure. A new relation based on changes with stress is proposed as an alternative expression of Voight's relation, which is widely used to describe the accelerating precursory signals before material failure and broadly applied to volcanic eruptions, landslides and other phenomena. The new generalized relation reduces to Voight's relation if stress is limited to increase at a constant rate with time. This implies that the time-derivatives in Voight's analysis may be a subset of a more general expression connecting stress derivatives, and thus provides a potential method for forecasting these events.

  16. Supersymmetric quantum mechanics: Engineered hierarchies of integrable potentials and related orthogonal polynomials

    International Nuclear Information System (INIS)

    Balondo Iyela, Daddy; Govaerts, Jan; Hounkonnou, M. Norbert

    2013-01-01

    Within the context of supersymmetric quantum mechanics and its related hierarchies of integrable quantum Hamiltonians and potentials, a general programme is outlined and applied to its first two simplest illustrations. Going beyond the usual restriction of shape invariance for intertwined potentials, it is suggested to require a similar relation for Hamiltonians in the hierarchy separated by an arbitrary number of levels, N. By requiring further that these two Hamiltonians be in fact identical up to an overall shift in energy, a periodic structure is installed in the hierarchy which should allow for its resolution. Specific classes of orthogonal polynomials characteristic of such periodic hierarchies are thereby generated, while the methods of supersymmetric quantum mechanics then lead to generalised Rodrigues formulae and recursion relations for such polynomials. The approach also offers the practical prospect of quantum modelling through the engineering of quantum potentials from experimental energy spectra. In this paper, these ideas are presented and solved explicitly for the cases N= 1 and N= 2. The latter case is related to the generalised Laguerre polynomials, for which indeed new results are thereby obtained. In the context of dressing chains and deformed polynomial Heisenberg algebras, some partial results for N⩾ 3 also exist in the literature, which should be relevant to a complete study of the N⩾ 3 general periodic hierarchies

  17. Supersymmetric quantum mechanics: Engineered hierarchies of integrable potentials and related orthogonal polynomials

    Energy Technology Data Exchange (ETDEWEB)

    Balondo Iyela, Daddy [International Chair in Mathematical Physics and Applications (ICMPA–UNESCO Chair), University of Abomey–Calavi, 072 B. P. 50 Cotonou, Republic of Benin (Benin); Centre for Cosmology, Particle Physics and Phenomenology (CP3), Institut de Recherche en Mathématique et Physique (IRMP), Université catholique de Louvain U.C.L., 2, Chemin du Cyclotron, B-1348 Louvain-la-Neuve (Belgium); Département de Physique, Université de Kinshasa (UNIKIN), B.P. 190 Kinshasa XI, Democratic Republic of Congo (Congo, The Democratic Republic of the); Govaerts, Jan [International Chair in Mathematical Physics and Applications (ICMPA–UNESCO Chair), University of Abomey–Calavi, 072 B. P. 50 Cotonou, Republic of Benin (Benin); Centre for Cosmology, Particle Physics and Phenomenology (CP3), Institut de Recherche en Mathématique et Physique (IRMP), Université catholique de Louvain U.C.L., 2, Chemin du Cyclotron, B-1348 Louvain-la-Neuve (Belgium); Hounkonnou, M. Norbert [International Chair in Mathematical Physics and Applications (ICMPA–UNESCO Chair), University of Abomey–Calavi, 072 B. P. 50 Cotonou, Republic of Benin (Benin)

    2013-09-15

    Within the context of supersymmetric quantum mechanics and its related hierarchies of integrable quantum Hamiltonians and potentials, a general programme is outlined and applied to its first two simplest illustrations. Going beyond the usual restriction of shape invariance for intertwined potentials, it is suggested to require a similar relation for Hamiltonians in the hierarchy separated by an arbitrary number of levels, N. By requiring further that these two Hamiltonians be in fact identical up to an overall shift in energy, a periodic structure is installed in the hierarchy which should allow for its resolution. Specific classes of orthogonal polynomials characteristic of such periodic hierarchies are thereby generated, while the methods of supersymmetric quantum mechanics then lead to generalised Rodrigues formulae and recursion relations for such polynomials. The approach also offers the practical prospect of quantum modelling through the engineering of quantum potentials from experimental energy spectra. In this paper, these ideas are presented and solved explicitly for the cases N= 1 and N= 2. The latter case is related to the generalised Laguerre polynomials, for which indeed new results are thereby obtained. In the context of dressing chains and deformed polynomial Heisenberg algebras, some partial results for N⩾ 3 also exist in the literature, which should be relevant to a complete study of the N⩾ 3 general periodic hierarchies.

  18. Cerebellar Shaping of Motor Cortical Firing Is Correlated with Timing of Motor Actions

    Directory of Open Access Journals (Sweden)

    Abdulraheem Nashef

    2018-05-01

    Full Text Available Summary: In higher mammals, motor timing is considered to be dictated by cerebellar control of motor cortical activity, relayed th