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Marenna S, Rossi E, Huang SC, Castoldi V, Comi G, Leocani L. Visual evoked potentials waveform analysis to measure intracortical damage in a preclinical model of multiple sclerosis. Front Cell Neurosci 2023; 17:1186110. [PMID: 37323584 PMCID: PMC10264580 DOI: 10.3389/fncel.2023.1186110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 05/08/2023] [Indexed: 06/17/2023] Open
Abstract
Introduction Visual evoked potentials (VEPs) are a non-invasive technique routinely used in clinical and preclinical practice. Discussion about inclusion of VEPs in McDonald criteria, used for Multiple Sclerosis (MS) diagnosis, increased the importance of VEP in MS preclinical models. While the interpretation of the N1 peak is recognized, less is known about the first and second positive VEP peaks, P1 and P2, and the implicit time of the different segments. Our hypothesis is that P2 latency delay describes intracortical neurophysiological dysfunction from the visual cortex to the other cortical areas. Methods In this work, we analyzed VEP traces that were included in our two recently published papers on Experimental Autoimmune Encephalomyelitis (EAE) mouse model. Compared with these previous publications other VEP peaks, P1 and P2, and the implicit time of components P1-N1, N1-P2 and P1-P2, were analyzed in blind. Results Latencies of P2, P1-P2, P1-N1 and N1-P2 were increased in all EAE mice, including group without N1 latency change delay at early time points. In particular, at 7 dpi the P2 latency delay change was significantly higher compared with N1 latency change delay. Moreover, new analysis of these VEP components under the influence of neurostimulation revealed a decrease in P2 delay in stimulated animals. Discussion P2 latency delay, P1-P2, P1-N1, and N1-P2 latency changes which reflect intracortical dysfunction, were consistently detected across all EAE groups before N1 change. Results underline the importance of analyzing all VEP components for a complete overview of the neurophysiological visual pathway dysfunction and treatment efficacy.
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Affiliation(s)
- Silvia Marenna
- Experimental Neurophysiology Unit, Institute of Experimental Neurology (INSPE)–IRCCS-Scientific Institute San Raffaele, Milan, Italy
| | - Elena Rossi
- Experimental Neurophysiology Unit, Institute of Experimental Neurology (INSPE)–IRCCS-Scientific Institute San Raffaele, Milan, Italy
- Faculty of Medicine, Università Vita-Salute San Raffaele, Milan, Italy
| | - Su-Chun Huang
- Experimental Neurophysiology Unit, Institute of Experimental Neurology (INSPE)–IRCCS-Scientific Institute San Raffaele, Milan, Italy
| | - Valerio Castoldi
- Experimental Neurophysiology Unit, Institute of Experimental Neurology (INSPE)–IRCCS-Scientific Institute San Raffaele, Milan, Italy
| | - Giancarlo Comi
- Faculty of Medicine, Università Vita-Salute San Raffaele, Milan, Italy
- Department of Neurorehabilitation Sciences, Casa di Cura Igea, Milan, Italy
| | - Letizia Leocani
- Experimental Neurophysiology Unit, Institute of Experimental Neurology (INSPE)–IRCCS-Scientific Institute San Raffaele, Milan, Italy
- Faculty of Medicine, Università Vita-Salute San Raffaele, Milan, Italy
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Xue C, Tang Y, Wang C, Yang H, Li L. The Effects of Normal Aging, Subjective Cognitive Decline, Mild Cognitive Impairment, or Alzheimer’s Disease on Visual Search. J Alzheimers Dis 2022; 88:1639-1650. [PMID: 35811526 DOI: 10.3233/jad-220209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Background: Alzheimer’s disease (AD) has been confirmed as an influencing factor of visual impairment, but potential concomitant effects on visual and cognitive performance are not well understood. Objective: To provide a new method for early screening of Alzheimer’s disease and further explore the theoretical mechanism of the decline of whole visual and cognitive performance in AD. Methods: We studied 60 individuals without dementia as normal control (NC), 74 individuals with subjective cognitive decline (SCD), 60 individuals with amnesia mild cognitive impairment (aMCI), and 75 patients with AD on a battery of tests designed to measure multiple aspects of basic and higher-order visual perception and cognition. All subjects performed on same visual and cognitive test batteries. Results: The results showed both of four groups, with the stimulus-presentation time being longer, the visual-search performance improved, and both the eye interest-area first fixation duration and the interest-area-fixation count increased. Particularly under the noise-masking condition, the AD group performed the worst at stimulus-presentation times between 300 and 900 ms. The aMCI group, but not the SCD group, performed worse than the NC group at the stimulus-presentation time of either 300 or 500 ms. The interest-area-fixation count was higher in all the patient groups than that in the NC group, and distinguishable between participants with AD and those with SCD or aMCI. Conclusion: The visual-search performance combined with eye-movement tracking under the noise-masking condition can be used for distinguishing AD from normal aging, SCD, and aMCI.
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Affiliation(s)
- Chuanwei Xue
- Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China
- Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, China
- Fuwai Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Yi Tang
- Xuan Wu Hospital, Capital Medical University, Beijing, China
| | - Changming Wang
- Xuan Wu Hospital, Capital Medical University, Beijing, China
| | - Haibo Yang
- Academy of Psychology and Behavior, Tianjin Normal University, Tianjin, China
| | - Liang Li
- Beijing Institute for Brain Disorders, Capital Medical University, Beijing, China
- Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, China
- School of Psychological and Cognitive Sciences, Beijing Key Laboratory of Behavior and Mental Health, Peking University, Beijing, China
- Speech and Hearing Research Center, Key Laboratory on Machine Perception (Ministry of Education), Peking University, Beijing, China
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Improved spatio-temporal measurements of visually evoked fields using optically-pumped magnetometers. Sci Rep 2021; 11:22412. [PMID: 34789806 PMCID: PMC8599680 DOI: 10.1038/s41598-021-01854-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 11/01/2021] [Indexed: 12/23/2022] Open
Abstract
Recent developments in performance and practicality of optically-pumped magnetometers (OPMs) have enabled new capabilities in non-invasive brain function mapping through magnetoencephalography. In particular, the lack of cryogenic operating conditions allows for more flexible placement of sensor heads closer to the brain, leading to improved spatial resolution and source localisation capabilities. Through recording visually evoked brain fields (VEFs), we demonstrate that the closer sensor proximity can be exploited to improve temporal resolution. We use OPMs, and superconducting quantum interference devices (SQUIDs) for reference, to measure brain responses to flash and pattern reversal stimuli. We find highly reproducible signals with consistency across multiple participants, stimulus paradigms and sensor modalities. The temporal resolution advantage of OPMs is manifest in a twofold improvement, compared to SQUIDs. The capability for improved spatio-temporal signal tracing is illustrated by simultaneous vector recordings of VEFs in the primary and associative visual cortex, where a time lag on the order of 10–20 ms is consistently found. This paves the way for further spatio-temporal studies of neurophysiological signal tracking in visual stimulus processing, and other brain responses, with potentially far-reaching consequences for time-critical mapping of functionality in healthy and pathological brains.
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Kelly JP, Phillips JO, Saneto RP, Khalatbari H, Poliakov A, Tarczy-Hornoch K, Weiss AH. Cerebral Visual Impairment Characterized by Abnormal Visual Orienting Behavior With Preserved Visual Cortical Activation. Invest Ophthalmol Vis Sci 2021; 62:15. [PMID: 33984120 PMCID: PMC8132015 DOI: 10.1167/iovs.62.6.15] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Children with cerebral visual impairment (CVI) often have abnormal visual orienting behaviors due to impaired or damaged visual cortex. Alternatively, visual-cortical function is intact but visual information is not transformed downstream into an appropriate oculomotor output (visuomotor dysfunction). We examined visual, anatomic, and oculomotor assessments to distinguish visuomotor dysfunction from CVI associated with severely reduced visual-cortical response. Methods We reviewed the medical records from children with CVI having abnormal visual orienting behaviors, normal ocular examinations, and born near term. Relevant data were visual evoked potentials (VEPs), Teller card acuity, eye movements recorded by video-oculography (VOG), and neuroimaging (magnetic resonance imaging [MRI]) including diffusion tensor imaging (DTI) tractography. Results Thirty subjects had visuomotor dysfunction based on a normal VEP; of these 33% had a normal MRI and 67% had white matter abnormalities associated with metabolic disease and/or decreased volume of brain parenchyma. VOG recordings showed smooth pursuit gains were uniformly reduced and saccades were dysmetric but followed the main sequence. Ten subjects had severe CVI based on VEPs at noise levels; visual acuities and MRI findings overlapped those of the visuomotor dysfunction group. Developmental delay, seizures, microcephaly, and hypotonia were common across all groups. All subjects with an abnormal conventional MRI had abnormal metrics on DTI tractography from the occipital lobe. Conclusions A subset of patients with CVI have abnormal visual orienting behaviors despite a normal VEP (visuomotor dysfunction). A majority have abnormal white matter metrics on tractography suggesting a downstream defect in sensorimotor transformation. Clinically, visuomotor dysfunction is indistinguishable from severe CVI.
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Affiliation(s)
- John P Kelly
- Roger H. Johnson Vision Clinic, Seattle Children's Hospital, Division of Ophthalmology, Seattle, Washington, United States.,University of Washington, Department of Ophthalmology, Seattle, Washington, United States
| | - James O Phillips
- Roger H. Johnson Vision Clinic, Seattle Children's Hospital, Division of Ophthalmology, Seattle, Washington, United States.,University of Washington School of Medicine, Department of Otolaryngology, Seattle, Washington, United States
| | - Russell P Saneto
- Seattle Children's Hospital, Department of Neurology/Division of Pediatric Neurology, Neuroscience Institute, Seattle, Washington, United States
| | - Hedieh Khalatbari
- Seattle Children's Hospital, Department of Radiology, Seattle, Washington, United States
| | - Andrew Poliakov
- Seattle Children's Hospital, Department of Radiology, Seattle, Washington, United States
| | - Kristina Tarczy-Hornoch
- Roger H. Johnson Vision Clinic, Seattle Children's Hospital, Division of Ophthalmology, Seattle, Washington, United States.,University of Washington, Department of Ophthalmology, Seattle, Washington, United States
| | - Avery H Weiss
- University of Washington, Department of Ophthalmology, Seattle, Washington, United States
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Bowyer SM, Pang EW, Huang M, Papanicolaou AC, Lee RR. Presurgical Functional Mapping with Magnetoencephalography. Neuroimaging Clin N Am 2020; 30:159-174. [DOI: 10.1016/j.nic.2020.02.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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van Es MWJ, Schoffelen JM. Stimulus-induced gamma power predicts the amplitude of the subsequent visual evoked response. Neuroimage 2018; 186:703-712. [PMID: 30468771 DOI: 10.1016/j.neuroimage.2018.11.029] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 11/01/2018] [Accepted: 11/19/2018] [Indexed: 11/18/2022] Open
Abstract
The efficiency of neuronal information transfer in activated brain networks may affect behavioral performance. Gamma-band synchronization has been proposed to be a mechanism that facilitates neuronal processing of behaviorally relevant stimuli. In line with this, it has been shown that strong gamma-band activity in visual cortical areas leads to faster responses to a visual go cue. We investigated whether there are directly observable consequences of trial-by-trial fluctuations in non-invasively observed gamma-band activity on the neuronal response. Specifically, we hypothesized that the amplitude of the visual evoked response to a go cue can be predicted by gamma power in the visual system, in the window preceding the evoked response. Thirty-three human subjects (22 female) performed a visual speeded response task while their magnetoencephalogram (MEG) was recorded. The participants had to respond to a pattern reversal of a concentric moving grating. We estimated single trial stimulus-induced visual cortical gamma power, and correlated this with the estimated single trial amplitude of the most prominent event-related field (ERF) peak within the first 100 ms after the pattern reversal. In parieto-occipital cortical areas, the amplitude of the ERF correlated positively with gamma power, and correlated negatively with reaction times. No effects were observed for the alpha and beta frequency bands, despite clear stimulus onset induced modulation at those frequencies. These results support a mechanistic model, in which gamma-band synchronization enhances the neuronal gain to relevant visual input, thus leading to more efficient downstream processing and to faster responses.
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Affiliation(s)
- Mats W J van Es
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Kapittelweg 29, 6525 EN, Nijmegen, Netherlands.
| | - Jan-Mathijs Schoffelen
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Nijmegen, Kapittelweg 29, 6525 EN, Nijmegen, Netherlands
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New insights into the role of motion and form vision in neurodevelopmental disorders. Neurosci Biobehav Rev 2017; 83:32-45. [PMID: 28965963 DOI: 10.1016/j.neubiorev.2017.09.031] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 09/21/2017] [Accepted: 09/27/2017] [Indexed: 12/21/2022]
Abstract
A selective deficit in processing the global (overall) motion, but not form, of spatially extensive objects in the visual scene is frequently associated with several neurodevelopmental disorders, including preterm birth. Existing theories that proposed to explain the origin of this visual impairment are, however, challenged by recent research. In this review, we explore alternative hypotheses for why deficits in the processing of global motion, relative to global form, might arise. We describe recent evidence that has utilised novel tasks of global motion and global form to elucidate the underlying nature of the visual deficit reported in different neurodevelopmental disorders. We also examine the role of IQ and how the sex of an individual can influence performance on these tasks, as these are factors that are associated with performance on global motion tasks, but have not been systematically controlled for in previous studies exploring visual processing in clinical populations. Finally, we suggest that a new theoretical framework is needed for visual processing in neurodevelopmental disorders and present recommendations for future research.
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Winther GN, Niedeggen M. Adaptability and specificity of inhibition processes in distractor-induced blindness. Psychophysiology 2017; 54:1882-1898. [DOI: 10.1111/psyp.12974] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 06/29/2017] [Accepted: 07/06/2017] [Indexed: 11/29/2022]
Affiliation(s)
- Gesche N. Winther
- Department of Education and Psychology; Freie Universität Berlin; Berlin Germany
| | - Michael Niedeggen
- Department of Education and Psychology; Freie Universität Berlin; Berlin Germany
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Szanyi J, Kremlacek J, Kubova Z, Kuba M, Gebousky P, Kapla J, Szanyi J, Vit F, Langrova J. Pattern- and motion-related visual evoked potentials in HIV-infected adults. Doc Ophthalmol 2017; 134:45-55. [PMID: 28074347 DOI: 10.1007/s10633-016-9570-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 12/28/2016] [Indexed: 02/03/2023]
Abstract
PURPOSE The goal of the current study was to explore visual function in virally suppressed HIV patients undergoing combined antiretroviral therapy (cART) by using pattern-reversal and motion-onset visual evoked potentials (VEPs). METHODS The pattern-reversal and motion-onset VEPs were recorded in 20 adult HIV+ patients with a mean age of 38 years and CD4 cell counts ≥230 × 106 cells/L of blood. RESULTS Nine out of 20 patients displayed VEP abnormalities. Pattern-reversal VEPs pathology was observed in 20% of subjects, and 45% HIV patients had impaired motion-onset VEPs. Five out of 16 neurologically asymptomatic HIV patients had prolonged motion-onset VEP latencies in both eyes. Four neurologically symptomatic patients displayed simultaneously abnormal motion-onset and pattern-reversal VEP latencies: monocular involvement was observed in two patients with Lyme and cytomegalovirus unilateral optic neuritis. Binocular involvement was noted in two patients with cognitive deficits. Correlation analysis between disease duration, CD4 cell count, HIV copies in plasma, MoCA and electrophysiological parameters did not show any significant relationships. CONCLUSIONS The functional changes of the visual system in neurologically asymptomatic virally suppressed HIV patients displayed higher motion-onset VEP sensitivity than in standard pattern-reversal VEP examinations. This promising marker, however, has no significant association with clinical conditions. Further exploration is warranted.
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Affiliation(s)
- Jana Szanyi
- Department of Pathological Physiology, Faculty of Medicine in Hradec Kralove, Charles University, Simkova 870, 500 03, Hradec Kralove, Czech Republic.
| | - Jan Kremlacek
- Department of Pathological Physiology, Faculty of Medicine in Hradec Kralove, Charles University, Simkova 870, 500 03, Hradec Kralove, Czech Republic
| | - Zuzana Kubova
- Department of Pathological Physiology, Faculty of Medicine in Hradec Kralove, Charles University, Simkova 870, 500 03, Hradec Kralove, Czech Republic
| | - Miroslav Kuba
- Department of Pathological Physiology, Faculty of Medicine in Hradec Kralove, Charles University, Simkova 870, 500 03, Hradec Kralove, Czech Republic
| | - Pavel Gebousky
- Department of Infectious Diseases, Faculty Hospital in Hradec Kralove, Hradec Kralove, Czech Republic
| | - Jaroslav Kapla
- Department of Infectious Diseases, Faculty Hospital in Hradec Kralove, Hradec Kralove, Czech Republic
| | - Juraj Szanyi
- Department of Infectious Diseases, Faculty Hospital in Hradec Kralove, Hradec Kralove, Czech Republic.,Department of Epidemiology, Faculty of Military Health Sciences, University of Defence in Hradec Kralove, Hradec Kralove, Czech Republic
| | - Frantisek Vit
- Department of Pathological Physiology, Faculty of Medicine in Hradec Kralove, Charles University, Simkova 870, 500 03, Hradec Kralove, Czech Republic
| | - Jana Langrova
- Department of Pathological Physiology, Faculty of Medicine in Hradec Kralove, Charles University, Simkova 870, 500 03, Hradec Kralove, Czech Republic
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Papadelis C, Arfeller C, Erla S, Nollo G, Cattaneo L, Braun C. Inferior frontal gyrus links visual and motor cortices during a visuomotor precision grip force task. Brain Res 2016; 1650:252-266. [DOI: 10.1016/j.brainres.2016.09.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Revised: 09/06/2016] [Accepted: 09/07/2016] [Indexed: 11/29/2022]
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HÜLSDÜNKER THORBEN, STRÜDER HEIKOK, MIERAU ANDREAS. Neural Correlates of Expert Visuomotor Performance in Badminton Players. Med Sci Sports Exerc 2016; 48:2125-2134. [DOI: 10.1249/mss.0000000000001010] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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12
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Shigihara Y, Hoshi H, Zeki S. Early visual cortical responses produced by checkerboard pattern stimulation. Neuroimage 2016; 134:532-539. [DOI: 10.1016/j.neuroimage.2016.03.078] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Revised: 01/20/2016] [Accepted: 03/31/2016] [Indexed: 11/25/2022] Open
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Abstract
Although the visual system has been extensively investigated, an integrated account of the spatiotemporal dynamics of long-range signal propagation along the human visual pathways is not completely known or validated. In this work, we used dynamic causal modeling approach to provide insights into the underlying neural circuit dynamics of pattern reversal visual-evoked potentials extracted from concurrent EEG-fMRI data. A recurrent forward-backward connectivity model, consisting of multiple interacting brain regions identified by EEG source localization aided by fMRI spatial priors, best accounted for the data dynamics. Sources were first identified in the thalamic area, primary visual cortex, as well as higher cortical areas along the ventral and dorsal visual processing streams. Consistent with hierarchical early visual processing, the model disclosed and quantified the neural temporal dynamics across the identified activity sources. This signal propagation is dominated by a feedforward process, but we also found weaker effective feedback connectivity. Using effective connectivity analysis, the optimal dynamic causal modeling revealed enhanced connectivity along the dorsal pathway but slightly suppressed connectivity along the ventral pathway. A bias was also found in favor of the right hemisphere consistent with functional attentional asymmetry. This study validates, for the first time, the long-range signal propagation timing in the human visual pathways. A similar modeling approach can potentially be used to understand other cognitive processes and dysfunctions in signal propagation in neurological and neuropsychiatric disorders. Significance statement: An integrated account of long-range visual signal propagation in the human brain is currently incomplete. Using computational neural modeling on our acquired concurrent EEG-fMRI data under a visual evoked task, we found not only a substantial forward propagation toward "higher-order" brain regions but also a weaker backward propagation. Asymmetry in our model's long-range connectivity accounted for the various observed activity biases. Importantly, the model disclosed the timing of signal propagation across these connectivity pathways and validates, for the first time, long-range signal propagation in the human visual system. A similar modeling approach could be used to identify neural pathways for other cognitive processes and their dysfunctions in brain disorders.
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Ambrosini A, Iezzi E, Perrotta A, Kisialiou A, Nardella A, Berardelli A, Pierelli F, Schoenen J. Correlation between habituation of visual-evoked potentials and magnetophosphene thresholds in migraine: A case-control study. Cephalalgia 2015; 36:258-64. [DOI: 10.1177/0333102415590241] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2014] [Accepted: 04/25/2015] [Indexed: 01/03/2023]
Abstract
Introduction In migraine most studies report an interictal deficit of habituation of visual-evoked potentials (VEP-hab) and reduced thresholds for phosphene induction (PT) by transcranial magnetic stimulation (TMS). We searched for a possible correlation between VEP-hab and PT in migraine patients and healthy controls to test whether they reflect the same pathophysiological abnormality. Methods We assessed PT and VEP-hab measured as the percentage change of N1/P1 amplitude over six blocks of 100 responses in 15 healthy volunteers (HV) and in 13 episodic migraineurs without aura (MO) between attacks. Results were compared using Mann-Whitney U test. Interrelationships were examined using Spearman's correlation. Results In MO patients VEP-hab was reduced compared to HV ( p = 0.001), while PT were not significantly different between HV and MO. There was no correlation between PT and VEP-hab in either group of participants. Conclusions We confirm that in interictal migraine VEP habituation is deficient, but magnetophosphene threshold normal. VEP-hab and PT were not correlated with each other in healthy controls or in migraineurs. This finding suggests that they index different facets of cortical excitability in migraine, i.e. a punctual normal measure of the cortical activation threshold for PT and a dynamic response pattern to repeated stimuli for VEP habituation.
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Affiliation(s)
| | - Ennio Iezzi
- IRCCS Neuromed, Clinical Neurophysiology Unit, Italy
| | | | - Aliaksei Kisialiou
- IRCCS San Raffaele Pisana, Unit of Clinical and Molecular Epidemiology, Italy
| | | | - Alfredo Berardelli
- IRCCS Neuromed, Clinical Neurophysiology Unit, Italy
- Sapienza University of Rome, Department of Neurology and Psychiatry, Italy
| | - Francesco Pierelli
- IRCCS Neuromed, Headache Unit, Italy
- Sapienza University of Rome, Department of Medical-Surgical Sciences and Biotechnologies, Italy
| | - Jean Schoenen
- University of Liège – CHR Citadelle, University Dept. of Neurology, Headache Research Unit, Belgium
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Styliadis C, Ioannides AA, Bamidis PD, Papadelis C. Distinct cerebellar lobules process arousal, valence and their interaction in parallel following a temporal hierarchy. Neuroimage 2015; 110:149-61. [DOI: 10.1016/j.neuroimage.2015.02.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 01/15/2015] [Accepted: 02/03/2015] [Indexed: 01/27/2023] Open
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Zilles K, Amunts K. Anatomical Basis for Functional Specialization. FMRI: FROM NUCLEAR SPINS TO BRAIN FUNCTIONS 2015. [DOI: 10.1007/978-1-4899-7591-1_4] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Núñez D, Oelkers-Ax R, de Haan S, Ludwig M, Sattel H, Resch F, Weisbrod M, Fuchs T. Do deficits in the magnocellular priming underlie visual derealization phenomena? Preliminary neurophysiological and self-report results in first-episode schizophrenia patients. Schizophr Res 2014; 159:441-9. [PMID: 25239127 DOI: 10.1016/j.schres.2014.08.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Revised: 08/04/2014] [Accepted: 08/19/2014] [Indexed: 10/24/2022]
Abstract
BACKGROUND Early visual impairments probably partially caused by impaired interactions between magnocellular (M) and parvocellular (P) pathways (M priming deficit), and disturbances of basic self-awareness or self-disorders (SDs) are core features of schizophrenia. The relationships between these features have not yet been studied. We hypothesized that the M priming was impaired in first-episode patients and that this deficit was associated with visual aspects of SDs. AIM To investigate early visual processing in a sample of first-episode schizophrenia patients and to explore the relationships between M and P functioning and visual aspects of SDs addressed by the Examination of Anomalous Self-Experience (EASE) interview. METHOD Nine stimulating conditions were used to investigate M and P pathways and their interaction in a pattern reversal visually evoked potential (VEP) paradigm. N80 at mixed M- and P-conditions was used to investigate magnocellular priming. Generators were analyzed using source localization (Brain Electrical Source Analysis software: BESA). VEPs of nineteen first-episode schizophrenia patients were compared to those of twenty matched healthy controls by a bootstrap resample procedure. Visual aspects of SDs were analyzed through a factor analysis to separate symptom clusters of derealization phenomena. Thereafter, the associations between the main factors and the N80 component were explored using linear mixed models. RESULTS Factor analyses separated two EASE factors ("distance to the world", and "intrusive world"). The N80 component was represented by a single dipole located in the occipital visual cortex. The bootstrap analysis yielded significant amplitude reductions and prolonged latencies in first-episode patients relative to controls in response to mixed M-P conditions, and normal amplitudes and latencies in response to isolated P- and M-biased stimulation. Exploratory analyses showed significant negative correlations between the N80 amplitude values at mixed M-P conditions and the EASE factor "distance to the world", i.e. relatively higher amplitudes in the patient group were associated with higher subjective perceived derealization ("distance to the world"). CONCLUSIONS The early VEP component N80 evoked by mixed M-P conditions is assumed to be a correlate of M priming, and showed reduced amplitudes and longer latencies in first-episode patients. It probably reflects a hypoactivation of the M-pathway. The negative association between visual SDs (derealization phenomena characterized by visual experiences of being more distant to the world), and the M priming deficit was counterintuitive. It might indicate a dysregulated activity of the M-pathway in patients with SDs. Further research is needed to better understand this preliminary finding.
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Affiliation(s)
- D Núñez
- Faculty of Psychology, University de Talca, Chile; Psychiatry Department, Centre for Psychosocial Medicine, University of Heidelberg, Voßstr. 4, 69115 Heidelberg, Germany.
| | - R Oelkers-Ax
- Psychiatry Department, Centre for Psychosocial Medicine, University of Heidelberg, Voßstr. 4, 69115 Heidelberg, Germany; Department of Child and Adolescent Psychiatry, University of Heidelberg, Blumenstraße 8, 69115 Heidelberg, Germany.
| | - S de Haan
- Psychiatry Department, Centre for Psychosocial Medicine, University of Heidelberg, Voßstr. 4, 69115 Heidelberg, Germany
| | - M Ludwig
- Psychiatry Department, Centre for Psychosocial Medicine, University of Heidelberg, Voßstr. 4, 69115 Heidelberg, Germany
| | - H Sattel
- Department of Psychosomatic Medicine and Psychotherapy, Klinikum rechts der Isar, Technische Universitaet Muenchen, Langerstraße 3, 81675 Munich, Germany.
| | - F Resch
- Department of Child and Adolescent Psychiatry, University of Heidelberg, Blumenstraße 8, 69115 Heidelberg, Germany.
| | - M Weisbrod
- Psychiatry Department, Centre for Psychosocial Medicine, University of Heidelberg, Voßstr. 4, 69115 Heidelberg, Germany; Klinikum Karlsbad-Langensteinbach, Guttmannstrasse 1, 76307 Karlsbad, Germany.
| | - T Fuchs
- Psychiatry Department, Centre for Psychosocial Medicine, University of Heidelberg, Voßstr. 4, 69115 Heidelberg, Germany.
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Pang EW, Chu BHW, Otsubo H. Occipital lobe lesions result in a displacement of magnetoencephalography visual evoked field dipoles. J Clin Neurophysiol 2014; 31:456-61. [PMID: 25271686 DOI: 10.1097/wnp.0000000000000077] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
PURPOSE The pattern-reversal visual evoked potential measured electrically from scalp electrodes is known to be decreased, or absent, in patients with occipital lobe lesions. We questioned whether the measurement and source analysis of the neuromagnetic visual evoked field (VEF) might offer additional information regarding visual cortex relative to the occipital lesion. METHODS We retrospectively examined 12 children (6-18 years) with occipital lesions on MRI, who underwent magnetoencephalography and ophthalmology as part of their presurgical assessment. Binocular half-field pattern-reversal VEFs were obtained in a 151-channel whole-head magnetoencephalography. Data were averaged and dipole source analyses were performed for each half-field stimulation. RESULTS A significant lateral shift (P < 0.02) in the dipole location was observed in the lesional hemisphere compared with those in the nonlesional hemisphere, regardless of the lesion location. No differences were observed in latency, strength (moment), and residual errors of VEF dipoles between the lesional and nonlesional hemispheres. CONCLUSIONS Magnetoencephalography demonstrated the mass effect on the dipole location of VEF in children with occipital lesions. Magnetoencephalography may be useful as a screening test of visual function in young patients. We discuss potential explanations for this lateral shift and emphasize the utility of adding the magnetoencephalography pattern-reversal visual evoked field protocol to the neurologic work-up.
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Affiliation(s)
- Elizabeth W Pang
- *Division of Neurology, The Hospital for Sick Children, Toronto, Ontario, Canada; and †Department of Paediatrics, The University of Toronto, Toronto, Ontario, Canada
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Amygdala responses to valence and its interaction by arousal revealed by MEG. Int J Psychophysiol 2014; 93:121-33. [DOI: 10.1016/j.ijpsycho.2013.05.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Revised: 04/17/2013] [Accepted: 05/10/2013] [Indexed: 11/24/2022]
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Mizuno K, Tsuji T, Rossetti Y, Pisella L, Ohde H, Liu M. Early Visual Processing is Affected by Clinical Subtype in Patients with Unilateral Spatial Neglect: A Magnetoencephalography Study. Front Hum Neurosci 2013; 7:432. [PMID: 23914171 PMCID: PMC3728490 DOI: 10.3389/fnhum.2013.00432] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Accepted: 07/15/2013] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVE To determine whether visual evoked magnetic fields (VEFs) elicited by right and left hemifield stimulation differ in patients with unilateral spatial neglect (USN) that results from cerebrovascular accident. METHODS Pattern-reversal stimulation of the right and left hemifield was performed in three patients with left USN. Magnetoencephalography (MEG) was recorded using a 160-channel system, and VEFs were quantified in the 400 ms after each stimulus. The presence or absence of VEF components at around 100 ms (P100m component) and 145 ms (N145m component) after stimulus onset was determined. The source of the VEF was determined using a single equivalent current dipole model for spherical volume conduction. All patients were evaluated using the behavioral inattention test (BIT). RESULTS In response to right hemifield stimulation, the P100m and N145m components of the VEF were evident in all three patients. In response to left hemifield stimulation, both components were evident in Patient 3, whereas only the P100m component was evident in Patient 1 and only the N145m component was evident in Patient 2. Patient 1 exhibited impairments on the line bisection and cancelation tasks of the BIT, Patient 2 exhibited impairments on the copying, drawing and cancelation tasks of the BIT, and Patient 3 exhibited impairments on the cancelation task of the BIT. CONCLUSION These results demonstrate that early VEFs are disrupted in patients with USN and support the concept that deficits in visual processing differ according to the clinical subtype of USN and the lesion location. This study also demonstrates the feasibility of using MEG to explore subtypes of neglect.
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Affiliation(s)
- Katsuhiro Mizuno
- Department of Rehabilitation Medicine, Keio University School of Medicine , Tokyo , Japan ; ImpAct Team, INSERM U1028, CNRS UMR5292, Lyon Neuroscience Research Center , Bron , France ; National Sanatorium Tama Zenshoen , Tokyo , Japan
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Spared cognitive processing of visual oddballs despite delayed visual evoked potentials in patient with partial recovery of vision after 53years of blindness. Vision Res 2013; 81:1-5. [DOI: 10.1016/j.visres.2012.12.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Revised: 11/29/2012] [Accepted: 12/08/2012] [Indexed: 11/17/2022]
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22
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Núñez D, Rauch J, Herwig K, Rupp A, Andermann M, Weisbrod M, Resch F, Oelkers-Ax R. Evidence for a magnocellular disadvantage in early-onset schizophrenic patients: a source analysis of the N80 visual-evoked component. Schizophr Res 2013; 144:16-23. [PMID: 23305611 DOI: 10.1016/j.schres.2012.12.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2012] [Revised: 11/09/2012] [Accepted: 12/04/2012] [Indexed: 12/01/2022]
Abstract
BACKGROUND Visual impairments in schizophrenia have been suggested to be partly caused by early processing deficits of the magnocellular (M) pathway. This might include disturbed interactions between the M and parvocellular (P) pathways and especially impaired M priming, which can disturb highlighting of relevant information. Such disorders may result from neurodevelopmental irregularities, which are assumed to be substantially involved in schizophrenia. This study sought to test the hypothesis that M priming is impaired in schizophrenia. In order to elucidate this neurodevelopmental aspect, we investigated patients with different ages of schizophrenia onset. This provided a useful design to integrate visual information processing in a neurodevelopmental model of schizophrenia. METHOD Nine stimulus conditions were used to investigate the M- and P-pathways and their interaction in a pattern reversal VEP paradigm. N80 generators were analyzed using source localization (Brain Electrical Source Analysis software: BESA). Forty schizophrenia patients (early-onset=19; adult-onset=21) were compared with age- and gender-matched healthy controls (early-onset controls=19; adult-onset controls=21). Hypotheses were tested using a bootstrap resampling procedure. RESULTS The N80 component was represented by a single dipole located in the occipital visual cortex. The bootstrap analysis yielded significant differences between early-onset schizophrenia patients and controls. We found lower amplitudes in response to mixed M-P conditions and normal amplitudes in response to isolated P- and M-biased stimulation. Concerning the latencies, significant differences were found between adult-onset subjects and their controls, with prolonged latencies for schizophrenia patients. CONCLUSIONS The early VEP component N80 evoked by mixed M-P conditions is assumed to be a correlate of M priming and showed reduced amplitude in early-onset schizophrenic patients but not in adult-onset patients. These findings point towards an M priming deficit in early-onset patients and are compatible with a neurodevelopmental hypothesis of schizophrenia, probably reflecting asynchronies in brain maturational abnormalities occurring at different ages of illness onset.
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Affiliation(s)
- D Núñez
- Faculty of Psychology, Universidad de Talca, Chile; Psychiatry Department, Centre for Psychosocial Medicine, University of Heidelberg, Voßstr. 4, 69115 Heidelberg, Germany.
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Niedeggen M, Michael L, Hesselmann G. Closing the Gates to Consciousness: Distractors Activate a Central Inhibition Process. J Cogn Neurosci 2012; 24:1294-304. [DOI: 10.1162/jocn_a_00177] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Abstract
The paradigm of distractor-induced blindness has previously been used to track the transition from unconscious to conscious visual processing. In a variation of this paradigm used in this study, participants (n = 13) had to detect an orientation change of tilted bars (target) embedded in a dynamic random pattern; the onset of the target was signaled by the presentation of a color cue. Occasional orientation changes preceding the cue served as distractors and severely impaired the target's detection. ERPs showed that a frontal negativity was cumulatively activated by the distractors, and early sensory components were not affected. In a control condition, the target was defined by a coherent motion of the bars. Orientation changes preceding the motion target did not affect its detection, and the frontal suppression process was not observed. However, we obtained a significant reduction of the sensory components. The data support the notion that distractors that share the target's features trigger a cumulative inhibition process preventing the conscious representation of the inhibited features. Explorative source modeling suggests that this process originates in the pFC. A top–down modulation of sensory processing could not be observed.
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Dockstader C, Gaetz W, Rockel C, Mabbott DJ. White matter maturation in visual and motor areas predicts the latency of visual activation in children. Hum Brain Mapp 2011; 33:179-91. [PMID: 21432944 DOI: 10.1002/hbm.21203] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2010] [Revised: 08/31/2010] [Accepted: 10/20/2010] [Indexed: 11/09/2022] Open
Abstract
In humans, white matter maturation is important for the improvement of cognitive function and performance with age. Across studies the variables of white matter maturity and age are highly correlated; however, the unique contributions of white matter to information processing speed remain relatively unknown. We investigated the relations between the speed of the visually-evoked P100m response and the biophysical properties of white matter in 11 healthy children performing a simple, visually-cued finger movement. We found that: (1) the latency of the early, visually-evoked response was related to the integrity of white matter in both visual and motor association areas and (2) white matter maturation in these areas accounted for the variations in visual processing speed, independent of age. Our study is a novel investigation of spatial-temporal dynamics in the developing brain and provides evidence that white matter maturation accounts for age-related decreases in the speed of visual response. Developmental models of cortical specialization should incorporate the unique role of white matter maturation in mediating changes in performance during tasks involving visual processing.
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Affiliation(s)
- Colleen Dockstader
- The Hospital for Sick Children Psychology, 555 University Ave, Toronto, Ontario, Canada
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25
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Neuromagnetic biomarkers of visuocortical development in healthy children. Clin Neurophysiol 2010; 121:1555-1562. [DOI: 10.1016/j.clinph.2010.03.029] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2009] [Revised: 02/19/2010] [Accepted: 03/23/2010] [Indexed: 11/22/2022]
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Papadelis C, Eickhoff SB, Zilles K, Ioannides AA. BA3b and BA1 activate in a serial fashion after median nerve stimulation: direct evidence from combining source analysis of evoked fields and cytoarchitectonic probabilistic maps. Neuroimage 2010; 54:60-73. [PMID: 20691793 DOI: 10.1016/j.neuroimage.2010.07.054] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2010] [Revised: 07/20/2010] [Accepted: 07/25/2010] [Indexed: 11/24/2022] Open
Abstract
This study combines source analysis imaging data for early somatosensory processing and the probabilistic cytoarchitectonic maps (PCMs). Human somatosensory evoked fields (SEFs) were recorded by stimulating left and right median nerves. Filtering the recorded responses in different frequency ranges identified the most responsive frequency band. The short-latency averaged SEFs were analyzed using a single equivalent current dipole (ECD) model and magnetic field tomography (MFT). The identified foci of activity were superimposed with PCMs. Two major components of opposite polarity were prominent around 21 and 31 ms. A weak component around 25 ms was also identified. For the most responsive frequency band (50-150 Hz) ECD and MFT revealed one focal source at the contralateral Brodmann area 3b (BA3b) at the peak of N20. The component ~25 ms was localised in Brodmann area 1 (BA1) in 50-150 Hz. By using ECD, focal generators around 28-30 ms located initially in BA3b and 2 ms later to BA1. MFT also revealed two focal sources - one in BA3b and one in BA1 for these latencies. Our results provide direct evidence that the earliest cortical response after median nerve stimulation is generated within the contralateral BA3b. BA1 activation few milliseconds later indicates a serial mode of somatosensory processing within cytoarchitectonic SI subdivisions. Analysis of non-invasive magnetoencephalography (MEG) data and the use of PCMs allow unambiguous and quantitative (probabilistic) interpretation of cytoarchitectonic identity of activated areas following median nerve stimulation, even with the simple ECD model, but only when the model fits the data extremely well.
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Affiliation(s)
- Christos Papadelis
- Laboratory for Human Brain Dynamics, Brain Science Institute (BSI), RIKEN, Saitama, Japan.
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Chaminade T, Zecca M, Blakemore SJ, Takanishi A, Frith CD, Micera S, Dario P, Rizzolatti G, Gallese V, Umiltà MA. Brain response to a humanoid robot in areas implicated in the perception of human emotional gestures. PLoS One 2010; 5:e11577. [PMID: 20657777 PMCID: PMC2908128 DOI: 10.1371/journal.pone.0011577] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2010] [Accepted: 06/07/2010] [Indexed: 12/03/2022] Open
Abstract
Background The humanoid robot WE4-RII was designed to express human emotions in order to improve human-robot interaction. We can read the emotions depicted in its gestures, yet might utilize different neural processes than those used for reading the emotions in human agents. Methodology Here, fMRI was used to assess how brain areas activated by the perception of human basic emotions (facial expression of Anger, Joy, Disgust) and silent speech respond to a humanoid robot impersonating the same emotions, while participants were instructed to attend either to the emotion or to the motion depicted. Principal Findings Increased responses to robot compared to human stimuli in the occipital and posterior temporal cortices suggest additional visual processing when perceiving a mechanical anthropomorphic agent. In contrast, activity in cortical areas endowed with mirror properties, like left Broca's area for the perception of speech, and in the processing of emotions like the left anterior insula for the perception of disgust and the orbitofrontal cortex for the perception of anger, is reduced for robot stimuli, suggesting lesser resonance with the mechanical agent. Finally, instructions to explicitly attend to the emotion significantly increased response to robot, but not human facial expressions in the anterior part of the left inferior frontal gyrus, a neural marker of motor resonance. Conclusions Motor resonance towards a humanoid robot, but not a human, display of facial emotion is increased when attention is directed towards judging emotions. Significance Artificial agents can be used to assess how factors like anthropomorphism affect neural response to the perception of human actions.
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Affiliation(s)
- Thierry Chaminade
- Wellcome Trust Centre for Neuroimaging, University College London, London, United Kingdom.
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Naruse Y, Matani A, Miyawaki Y, Okada M. Influence of coherence between multiple cortical columns on alpha rhythm: a computational modeling study. Hum Brain Mapp 2010; 31:703-15. [PMID: 19890847 DOI: 10.1002/hbm.20899] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
In electroencephalographic (EEG) and magnetoencephalographic (MEG) signals, stimulus-induced amplitude increase and decrease in the alpha rhythm, known as event-related synchronization and desynchronization (ERS/ERD), emerge after a task onset. ERS/ERD is assumed to reflect neural processes relevant to cognitive tasks. Previous studies suggest that several sources of alpha rhythm, each of which can serve as an alpha rhythm generator, exist in the cortex. Since EEG/MEG signals represent spatially summed neural activities, ERS/ERD of the alpha rhythm may reflect the consequence of the interactions between multiple alpha rhythm generators. Two candidates modulate the magnitude of ERS/ERD: (1) coherence between the activities of the alpha rhythm generators and (2) mean amplitude of the activities of the alpha rhythm generators. In this study, we use a computational model of multiple alpha rhythm generators to determine the factor that dominantly causes ERS/ERD. Each alpha rhythm generator is modeled based on local column circuits in the primary visual cortex and made to interact with the neighboring generators through excitatory connections. We observe that the model consistently reproduces spontaneous alpha rhythms, event-related potentials, phase-locked alpha rhythms, and ERS/ERD in a specific range of connectivity coefficients. Independent analyses of the coherence and amplitude of multiple alpha rhythm generators reveal that the ERS/ERD in the simulated data is dominantly caused by stimulus-induced changes in the coherence between multiple alpha rhythm generators. Nonlinear phenomena such as phase-resetting and entrainment of the alpha rhythm are related to the neural mechanism underlying ERS/ERD.
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Affiliation(s)
- Yasushi Naruse
- Biological ICT Group, Kobe Advanced ICT Research Center, National Institute of Information and Communications Technology, Kobe, Japan.
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Cannon KB, Sherlin L, Lyle RR. Neurofeedback Efficacy in the Treatment of a 43-Year-Old Female Stroke Victim: A Case Study. ACTA ACUST UNITED AC 2010. [DOI: 10.1080/10874201003772155] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Wilms M, Eickhoff SB, Hömke L, Rottschy C, Kujovic M, Amunts K, Fink GR. Comparison of functional and cytoarchitectonic maps of human visual areas V1, V2, V3d, V3v, and V4(v). Neuroimage 2010; 49:1171-9. [DOI: 10.1016/j.neuroimage.2009.09.063] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2009] [Revised: 09/16/2009] [Accepted: 09/25/2009] [Indexed: 10/20/2022] Open
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Kalaycıoğlu C, Nalçacı E, Schmiedt-Fehr C, Başar-Eroğlu C. Corpus callosum has different channels for transmission of spatial frequency information. Brain Res 2009; 1296:85-93. [DOI: 10.1016/j.brainres.2009.08.018] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2009] [Revised: 07/16/2009] [Accepted: 08/06/2009] [Indexed: 10/20/2022]
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Joliot M, Leroux G, Dubal S, Tzourio-Mazoyer N, Houdé O, Mazoyer B, Petit L. Cognitive inhibition of number/length interference in a Piaget-like task: evidence by combining ERP and MEG. Clin Neurophysiol 2009; 120:1501-13. [PMID: 19576847 DOI: 10.1016/j.clinph.2009.06.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2009] [Revised: 06/02/2009] [Accepted: 06/04/2009] [Indexed: 11/30/2022]
Abstract
OBJECTIVE We combined event-related potential (ERP) and magnetoencephalography (MEG) acquisition and analysis to investigate the electrophysiological markers of the inhibitory processes involved in the number/length interference in a Piaget-like numerical task. METHODS Eleven healthy subjects performed four gradually interfering conditions with the heuristic "length equals number" to be inhibited. Low resolution tomography reconstruction was performed on the combined grand averaged electromagnetic data at the early (N1, P1) and late (P2, N2, P3(early) and P3(late)) latencies. Every condition was analyzed at both scalp and regional brain levels. RESULTS The inhibitory processes were visible on the late components of the electromagnetic brain activity. A right P2-related frontal orbital activation reflected the change of strategy in the inhibitory processes. N2-related SMA/cingulate activation revealed the first occurrence of the stimuli processing to be inhibited. Both P3 components revealed the working memory processes operating in a medial temporal complex and the mental imagery processes subtended by the precuneus. CONCLUSIONS Simultaneous ERP and MEG signal acquisition and analysis allowed to describe the spatiotemporal patterns of neural networks involved in the inhibition of the "length equals number" interference. SIGNIFICANCE Combining ERP and MEG ensured a sensitivity which could be reached previously only through invasive intracortical recordings.
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Affiliation(s)
- Marc Joliot
- CI-NAPS, Centre d'Imagerie Neurosciences et Applications aux Pathologies, UMR6232, CNRS, CEA, Université de Caen Basse Normandie et Université Paris Descartes, GIP Cyceron, BP 5229, Caen, France.
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Liu Z, Zhang N, Chen W, He B. Mapping the bilateral visual integration by EEG and fMRI. Neuroimage 2009; 46:989-97. [PMID: 19306933 DOI: 10.1016/j.neuroimage.2009.03.028] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2008] [Revised: 02/18/2009] [Accepted: 03/10/2009] [Indexed: 11/19/2022] Open
Abstract
In the human visual system, the internal representation of the left and right visual hemifields is split at the midline of the two cerebral hemispheres. The present study aims to address the questions of when and where the lateralized cortical visual representations are merged to form an intact percept by using a multimodal neuroimaging approach. Visual evoked potential (VEP) and functional magnetic resonance imaging (fMRI) data were acquired from a group of healthy subjects presented with unilateral versus bilateral visual stimuli. Cortical activities involved in processing bilateral visual information are expected to be equally responsive to ipsilateral and contralateral stimuli, and demonstrate spatial nonlinearity in the response to bilateral stimuli. Utilizing these features, we performed integrative as well as separate analyses for both VEP and fMRI data. The present results suggest that i) the majority of cortical activity that integrates visual information across hemifields takes place at extrastriate areas during late visual processing, and that ii) the lateral occipito-temporal (LOT) regions (likely the MT+ complex) and the medial occipital cortex (i.e. V1) may contribute to bilateral visual integration during early visual processing. Our findings are generally in agreement with the bottom-up visual hierarchy, with the exception of the evidence suggesting an early activation of the higher-tier LOT areas and the influence from ipsilateral visual inputs upon the V1 response.
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Affiliation(s)
- Zhongming Liu
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455, USA
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Bai X, Liu Z, Zhang N, Chen W, He B. Three-dimensional source imaging from simultaneously recorded ERP and BOLD-fMRI. IEEE Trans Neural Syst Rehabil Eng 2009; 17:101-6. [PMID: 19228562 DOI: 10.1109/tnsre.2009.2015196] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We present the 3-D EEG source images reconstructed by using the minimum norm least square (MNLS) method in combination with the functional magnetic resonance imaging (fMRI) statistical parametric mapping. For a group of five normal subjects, electroencephalogram (EEG) and fMRI signals responding to the full-view checkerboard pattern-reversal visual stimulation were recorded simultaneously and separately. The electrical activities in V1/V2 and V5 were successfully imaged in the N75-P100-N145 and P100-N145 components, respectively. The present results demonstrate the merits of high-resolution spatiotemporal functional neuroimaging by integrating the simultaneously recorded fMRI and EEG data.
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Affiliation(s)
- Xiaoxiao Bai
- Department of Biomedical Engineering, University of Minnesota, Minneapolis, MN 55455, USA
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Minati L, Rosazza C, Zucca I, D'Incerti L, Scaioli V, Bruzzone MG. Spatial correspondence between functional MRI (fMRI) activations and cortical current density maps of event-related potentials (ERP): a study with four tasks. Brain Topogr 2008; 21:112-27. [PMID: 18758934 DOI: 10.1007/s10548-008-0064-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2008] [Accepted: 08/15/2008] [Indexed: 10/21/2022]
Abstract
We investigated the spatial correspondence between functional MRI (fMRI) activations and cortical current density maps of event-related potentials (ERPs) reconstructed without fMRI priors. The presence of a significant spatial correspondence is a prerequisite for direct integration of the two modalities, enabling to combine the high spatial resolution of fMRI with the high temporal resolution of ERPs. Four separate tasks were employed: visual stimulation with a pattern-reversal chequerboard, recognition of images of nameable objects, recognition of written words, and auditory stimulation with a piano note. ERPs were acquired with 19 recording channels, and source localisation was performed using a realistic head model, a standard cortical mesh and the multiple sparse priors method. Spatial correspondence was evaluated at group level over 10 subjects, by means of a voxel-by-voxel test and a test on the distribution of local maxima. Although not complete, it was significant for the visual stimulation task, image and word recognition tasks (P < 0.001 for both types of test), but not for the auditory stimulation task. These findings indicate that partial but significant spatial correspondence between the two modalities can be found even with a small number of channels, for three of the four tasks employed. Absence of correspondence for the auditory stimulation task was caused by the unfavourable situation of the activated cortex being perpendicular to the overlying scalp, whose consequences were exacerbated by the small number of channels. The present study corroborates existing literature in this field, and may be of particular relevance to those interested in combining fMRI with ERPs acquired with the standard 10-20 system.
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Affiliation(s)
- Ludovico Minati
- Science Direction Unit, Fondazione IRCCS Istituto Neurologico Carlo Besta, Via Celoria 11, 20133, Milano, MI, Italy.
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Visual information processing in recently abstaining methamphetamine-dependent individuals: evoked potentials study. Doc Ophthalmol 2008; 117:245-55. [DOI: 10.1007/s10633-008-9135-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2008] [Accepted: 06/03/2008] [Indexed: 10/21/2022]
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Bender S, Oelkers-Ax R, Hellwig S, Resch F, Weisbrod M. The topography of the scalp-recorded visual N700. Clin Neurophysiol 2007; 119:587-604. [PMID: 18164238 DOI: 10.1016/j.clinph.2007.11.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2007] [Revised: 10/31/2007] [Accepted: 11/06/2007] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To describe the topography of the N700 component of the scalp-recorded visual event-related potential (ERP) and to provide fundamental knowledge of the conditions under which it occurs. METHODS We examined the time-course of visual ERP in response to the short (100ms) and prolonged (7s) presentation of simple salient visual stimuli separated by long interstimulus intervals employing high-resolution 64-channel DC-EEG. Current source density (CSD) mapping and spatio-temporal dipole source analysis were performed. RESULTS CSD analysis revealed highly significant bilateral current sinks over occipito-temporal areas from about 450ms up to 1s after stimulus offset (visual N700). CSD topography and dipole source analysis suggested late prolonged activation of extrastriate visual areas which did not depend merely upon a stimulus offset response, afterimages or blinking, as confirmed by control conditions. CONCLUSIONS Our findings provide basic knowledge about the time-course of sensory activation. We found that passive watching of rare salient short stimuli automatically evoked sustained activity in the extrastriate visual cortex up to 1s after stimulus offset. SIGNIFICANCE Visual N700 provides a promising tool for important insights into the cortical mechanisms of stimulus post-processing. Its role in associative learning of temporally non-overlapping stimuli (automatic ultra-short-term sensory memory) should be explored.
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Affiliation(s)
- S Bender
- Department for Child and Adolescent Psychiatry, University of Heidelberg, Blumenstraße 8, D-69115 Heidelberg, Germany; Section for Experimental Psychopathology, Psychiatric Hospital, Voßstraße 4, University of Heidelberg, D-69115 Heidelberg, Germany; Psychosomatic Hospital, University of Heidelberg, Im Neuenheimer Feld 410, D-69120 Heidelberg, Germany.
| | - R Oelkers-Ax
- Department for Child and Adolescent Psychiatry, University of Heidelberg, Blumenstraße 8, D-69115 Heidelberg, Germany
| | - S Hellwig
- Section for Experimental Psychopathology, Psychiatric Hospital, Voßstraße 4, University of Heidelberg, D-69115 Heidelberg, Germany
| | - F Resch
- Department for Child and Adolescent Psychiatry, University of Heidelberg, Blumenstraße 8, D-69115 Heidelberg, Germany
| | - M Weisbrod
- Department for Child and Adolescent Psychiatry, University of Heidelberg, Blumenstraße 8, D-69115 Heidelberg, Germany; SRH-Klinikum Karlsbad-Langensteinbach, Psychiatric Hospital, Guttmannstraße 1, 76307 Karlsbad, Germany
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39
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Rottschy C, Eickhoff SB, Schleicher A, Mohlberg H, Kujovic M, Zilles K, Amunts K. Ventral visual cortex in humans: cytoarchitectonic mapping of two extrastriate areas. Hum Brain Mapp 2007; 28:1045-59. [PMID: 17266106 PMCID: PMC6871378 DOI: 10.1002/hbm.20348] [Citation(s) in RCA: 142] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
The extrastriate visual cortex forms a complex system enabling the analysis of visually presented objects. To gain deeper insight into the anatomical basis of this system, we cytoarchitectonically mapped the ventral occipital cortex lateral to BA 18/V2 in 10 human postmortem brains. The anatomical characterization of this part of the ventral stream was performed by examination of cell-body-stained histological sections using quantitative cytoarchitectonic analysis. First, the gray level index (GLI) was measured in the ventral occipital lobe. Cytoarchitectonic borders, i.e., significant changes in the cortical lamination pattern, were then identified using an observer-independent algorithm based on multivariate analysis of GLI profiles. Two distinct cytoarchitectonic areas (hOC3v, hOC4v) were characterized in the ventral extrastriate cortex lateral to BA 18/V2. Area hOC3v was found in the collateral sulcus. hOC4v was located in this sulcus and also covered the fusiform gyrus in more occipital sections. Topographically, these areas thus seem to represent the anatomical substrates of functionally defined areas, VP/V3v and V4/V4v. Following histological analysis, the delineated cytoarchitectonic areas were transferred to 3D reconstructions of the respective postmortem brains, which in turn were spatially normalized to the Montreal Neurological Institute reference space. A probabilistic map was generated for each area which describes how many brains had a representation of this area in a particular voxel. These maps can now be used to identify the anatomical correlates of functional activations observed in neuroimaging experiments to enable a more informed investigation into the many open questions regarding the organization of the human visual cortex.
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Affiliation(s)
- Claudia Rottschy
- Institute of Medicine, Research Centre Jülich, Germany
- C. & O. Vogt Institute for Brain Research, University of Düsseldorf, Germany
| | - Simon B. Eickhoff
- Institute of Medicine, Research Centre Jülich, Germany
- C. & O. Vogt Institute for Brain Research, University of Düsseldorf, Germany
| | - Axel Schleicher
- C. & O. Vogt Institute for Brain Research, University of Düsseldorf, Germany
| | | | - Milenko Kujovic
- C. & O. Vogt Institute for Brain Research, University of Düsseldorf, Germany
| | - Karl Zilles
- Institute of Medicine, Research Centre Jülich, Germany
- C. & O. Vogt Institute for Brain Research, University of Düsseldorf, Germany
- Brain Imaging Centre West, Research Centre Jülich, Germany
| | - Katrin Amunts
- Institute of Medicine, Research Centre Jülich, Germany
- Brain Imaging Centre West, Research Centre Jülich, Germany
- Department of Psychiatry and Psychotherapy, RWTH Aachen University, Germany
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40
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Di Russo F, Aprile T, Spitoni G, Spinelli D. Impaired visual processing of contralesional stimuli in neglect patients: a visual-evoked potential study. Brain 2007; 131:842-54. [DOI: 10.1093/brain/awm281] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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41
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Zvyagintsev M, Thönnessen H, Dammers J, Boers F, Mathiak K. An automatic procedure for the analysis of electric and magnetic mismatch negativity based on anatomical brain mapping. J Neurosci Methods 2007; 168:325-33. [PMID: 18093661 DOI: 10.1016/j.jneumeth.2007.10.025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2007] [Revised: 10/22/2007] [Accepted: 10/24/2007] [Indexed: 10/22/2022]
Abstract
Data processing techniques in electroencephalography (EEG) and magnetoencephalography (MEG) need user interactions. However, particularly in clinical applications, fast and objective data processing is important. Here we present an observer-independent method for EEG and MEG analysis of mismatch negativity (MMN) that allows reliable estimation of source activity based on objective anatomical references. The procedure integrates several steps including artifact rejection, source estimation and statistical analysis. It enables the evaluation of source activity in a fully automatic and unsupervised manner. To test its feasibility we obtained EEG and MEG responses in an auditory oddball paradigm in 12 healthy volunteers. The automatized method of EEG and MEG data analysis estimated source activity. The automatically detected MMN was closely comparable with the results obtained by a user-controlled method based on the dipole fitting. The presented workflow can be performed easily, rapidly, and reliably. This development may open new fields in research and clinical applications of source-based EEG and MEG.
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Affiliation(s)
- Mikhail Zvyagintsev
- Department of Psychiatry and Psychotherapy, University Hospital Aachen, RWTH Aachen, 52074 Aachen, Germany.
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42
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Prieto EA, Barnikol UB, Soler EP, Dolan K, Hesselmann G, Mohlberg H, Amunts K, Zilles K, Niedeggen M, Tass PA. Timing of V1/V2 and V5+ activations during coherent motion of dots: an MEG study. Neuroimage 2007; 37:1384-95. [PMID: 17689986 DOI: 10.1016/j.neuroimage.2007.03.080] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2006] [Revised: 03/20/2007] [Accepted: 03/23/2007] [Indexed: 11/25/2022] Open
Abstract
In order to study the temporal activation course of visual areas V1 and V5 in response to a motion stimulus, a random dots kinematogram paradigm was applied to eight subjects while magnetic fields were recorded using magnetoencephalography (MEG). Sources generating the registered magnetic fields were localized with Magnetic Field Tomography (MFT). Anatomical identification of cytoarchitectonically defined areas V1/V2 and V5 was achieved by means of probabilistic cytoarchitectonic maps. We found that the areas V1/V2 and V5+ (V5 and other adjacent motion sensitive areas) exhibited two main activations peaks at 100-130 ms and at 140-200 ms after motion onset. The first peak found for V1/V2, which corresponds to the visual evoked field (VEF) M1, always preceded the peak found in V5+. Additionally, the V5+ peak was correlated significantly and positively with the second V1/V2 peak. This result supports the idea that the M1 component is generated not only by the visual area V1/V2 (as it is usually proposed), but also by V5+. It reflects a forward connection between both structures, and a feedback projection to V1/V2, which provokes a second activation in V1/V2 around 200 ms. This second V1/V2 activation (corresponding to motion VEF M2) appeared earlier than the second V5+ activation but both peaked simultaneously. This result supports the hypothesis that both areas also generate the M2 component, which reflects a feedback input from V5+ to V1/V2 and a crosstalk between both structures. Our study indicates that during visual motion analysis, V1/V2 and V5+ are activated repeatedly through forward and feedback connections and both contribute to m-VEFs M1 and M2.
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43
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Ioannides AA. Dynamic functional connectivity. Curr Opin Neurobiol 2007; 17:161-70. [PMID: 17379500 DOI: 10.1016/j.conb.2007.03.008] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2007] [Accepted: 03/13/2007] [Indexed: 12/31/2022]
Abstract
Recent studies show that anatomical and functional brain networks exhibit similar small-world properties. However, the networks that are compared often differ in what the nodes represent (e.g. sensors or brain areas), what kind of connectivity is measured, and what temporal and spatial scales are probed. Here, I review studies of large-scale connectivity and recent results from a variety of real-time recording techniques, which together suggest that an adequate description of brain organization requires a hierarchy of networks rather than the single, binary networks that are currently in vogue. Pattern analysis methods now offer a principled way for constructing such network hierarchies. As shown at the end of this review, a correspondence principle can be formulated to guide the interpretation across network levels and to relate nodes to well defined anatomical entities.
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Affiliation(s)
- Andreas A Ioannides
- Laboratory for Human Brain Dynamics, RIKEN Brain Science Institute, 2-1 Hirosawa, Wakoshi, Saitama, Japan 351-0198.
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44
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Abstract
Magnetoencephalography (MEG) is a noninvasive neuroimaging method for detecting, analyzing, and interpreting the magnetic field generated by the electrical activity in the brain. Modern hardware can capture the MEG signal at hundreds of points around the head in a snapshot lasting only a fraction of a millisecond. The sensitivity of modern hardware is high enough to permit the extraction of a clean signal generated by the brain well above the noise level of the MEG hardware. It is possible to identify signatures of superficial and often deep generators in the raw MEG signal, even in snapshots of data. In a more quantitative way, tomographic images of the electrical current density in the brain can be extracted from each snapshot of MEG signal, providing a direct correlate of coherent collective neuronal activity. A number of recent studies have scrutinized brain function in the new spatiotemporal window that real-time tomographic analysis of MEG signals has opened. The results have allowed the variability in a single area to be seen in the context of activity in other areas and background rhythmic activity. In this view, normal brain function is seen as a cascade of extremely fast events and the unfolding of specialized processes, segregated in space and time and organized into well-defined stages of processing.
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Affiliation(s)
- Andreas A Ioannides
- Laboratory for Human Brain Dynamics, RIKEN Brain Science Institute, Saitama, Japan.
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45
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Heinrich SP. A primer on motion visual evoked potentials. Doc Ophthalmol 2007; 114:83-105. [PMID: 17431818 DOI: 10.1007/s10633-006-9043-8] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2006] [Revised: 11/28/2006] [Indexed: 12/18/2022]
Abstract
Motion visual evoked potentials (motion VEPs) have been used since the late 1960s to investigate the properties of human visual motion processing, and continue to be a popular tool with a possible future in clinical diagnosis. This review first provides a synopsis of the characteristics of motion VEPs and then summarizes important methodological aspects. A subsequent overview illustrates how motion VEPs have been applied to study basic functions of human motion processing and shows perspectives for their use as a diagnostic tool.
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Affiliation(s)
- Sven P Heinrich
- Sektion Funktionelle Sehforschung, Universitäts-Augenklinik, Freiburg, Germany.
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Amunts K, Armstrong E, Malikovic A, Hömke L, Mohlberg H, Schleicher A, Zilles K. Gender-specific left-right asymmetries in human visual cortex. J Neurosci 2007; 27:1356-64. [PMID: 17287510 PMCID: PMC6673571 DOI: 10.1523/jneurosci.4753-06.2007] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2006] [Revised: 12/22/2006] [Accepted: 12/22/2006] [Indexed: 11/21/2022] Open
Abstract
The structural correlates of gender differences in visuospatial processing are essentially unknown. Our quantitative analysis of the cytoarchitecture of the human primary visual cortex [V1/Brodmann area 17 (BA17)], neighboring area V2 (BA18), and the cytoarchitectonic correlate of the motion-sensitive complex (V5/MT+/hOc5) shows that the visual areas are sexually dimorphic and that the type of dimorphism differs among the areas. Gender differences exist in the interhemispheric asymmetry of hOc5 volumes and in the right-hemispheric volumetric ratio of hOc5 to BA17, an area that projects to V5/MT+/hOc5. Asymmetry was also observed in the surface area of hOc5 but not in its cortical thickness. The differences give males potentially more space in which to process additional information, a finding consistent with superior male processing in particular visuospatial tasks, such as mental rotation. Gender differences in hOc5 exist with similar volume fractions of cell bodies, implying that, overall, the visual neural circuitry is similar in males and females.
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Affiliation(s)
- Katrin Amunts
- Institute of Medicine, Research Center Jülich, D-52525 Jülich, Germany.
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47
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Dammers J, Mohlberg H, Boers F, Tass P, Amunts K, Mathiak K. A new toolbox for combining magnetoencephalographic source analysis and cytoarchitectonic probabilistic data for anatomical classification of dynamic brain activity. Neuroimage 2007; 34:1577-87. [PMID: 17187996 DOI: 10.1016/j.neuroimage.2006.09.040] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2006] [Revised: 09/05/2006] [Accepted: 09/26/2006] [Indexed: 10/23/2022] Open
Abstract
Size and location of activated cortical areas are often identified in relation to their surrounding macro-anatomical landmarks such as gyri and sulci. The sulcal pattern, however, is highly variable. In addition, many cortical areas are not linked to well defined landmarks, which in turn do not have a fixed relationship to functional and cytoarchitectonic boundaries. Therefore, it is difficult to unambiguously attribute localized neuronal activity to the corresponding cortical areas in the living human brain. Here we present new methods that are implemented in a toolbox for the objective anatomical identification of neuromagnetic activity with respect to cortical areas. The toolbox enables the platform independent integration of many types of source analysis obtained from magnetoencephalography (MEG) together with probabilistic cytoarchitectonic maps obtained in postmortem brains. The probability maps provide information about the relative frequency of a given cortical area being located at a given position in the brain. In the new software, the neuromagnetic data are analyzed with respect to cytoarchitectonic maps that have been transformed to the individual subject brain space. A number of measures define the degree of overlap between and distance from the activated areas and the corresponding cytoarchitectonic maps. The implemented algorithms enable the investigator to quantify how much of the reconstructed current density can be attributed to distinct cortical areas. Dynamic correspondence patterns between the millisecond-resolved MEG data and the static cytoarchitectonic maps are obtained. We show examples for auditory and visual activation patterns. However, size and location of the postmortem brain areas as well as the inverse method applied to the neuromagnetic data bias the anatomical classification. Therefore, the adaptation to the respective application and a combination of the objective quantities are discussed.
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Affiliation(s)
- Jürgen Dammers
- Institute of Medicin, Research Center Jülich GmBH, 52425 Jülich, Germany.
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