1
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Skadorwa T, Strzelecka J. QEEG findings in nonsyndromic sagittal craniosynostosis. Sci Rep 2024; 14:1301. [PMID: 38221524 PMCID: PMC10788330 DOI: 10.1038/s41598-024-51858-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2023] [Accepted: 01/10/2024] [Indexed: 01/16/2024] Open
Abstract
Despite the undertaken treatment, children with nonsyndromic sagittal craniosynostosis (NSC) are burdened with problems with speech development, visuospatial and other cognitive deficits. The electroencephalographic assessment has not influenced the diagnostics and treatment strategy of craniosynostosis so far but the introduction of quantitative EEG (QEEG) protocols renewed an interest in the functional aspect of this disease. In this study we retrospectively assessed the QEEG records of 25 children with NSC aged 1-18 months (mean age 9.62 months) before and after surgery. In each case, the amplitude, interhemispheric (ICoh) and intrahemispheric (HCoh) coherence indices were calculated. Obtained data were compared to age-matched control group of 25 normocephalic children. Children with NSC presented significantly lower values of amplitudes and intrahemispheric coherence in occipital, posterior parietal and posterior temporal regions than normocephalic children. The values of amplitudes, ICoh and HCoh in pre- and postoperative QEEG records mostly remained unchanged, with a slight improvement in HCoh in centro-parietal area. These findings suggest that NSC children present their own QEEG profile. The operative treatment improves an intrahemispheric connectivity, but there still exists a significant difference in the occipitotemporal, frontotemporal and centro-frontal areas, which may be considered as a functional substrate of reported speech and neurocognitive problems. QEEG findings in nonsyndromic sagittal craniosynostosis.
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Affiliation(s)
- Tymon Skadorwa
- Department of Pediatric Neurosurgery, Bogdanowicz Memorial Hospital for Children, 4/24 Nieklanska St., 03924, Warsaw, Poland.
- Department of Descriptive and Clinical Anatomy, Medical University of Warsaw, 5 Chalubinskiego St., 02004, Warsaw, Poland.
| | - Jolanta Strzelecka
- Department of Pediatric Neurology, Medical University of Warsaw, 63A Żwirki i Wigury St., 02091, Warsaw, Poland
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2
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Zhuravlev M, Agaltsov M, Kiselev A, Simonyan M, Novikov M, Selskii A, Ukolov R, Drapkina O, Orlova A, Penzel T, Runnova A. Compensatory mechanisms of reduced interhemispheric EEG connectivity during sleep in patients with apnea. Sci Rep 2023; 13:8444. [PMID: 37231107 PMCID: PMC10213009 DOI: 10.1038/s41598-023-35376-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2022] [Accepted: 05/17/2023] [Indexed: 05/27/2023] Open
Abstract
We performed a mathematical analysis of functional connectivity in electroencephalography (EEG) of patients with obstructive sleep apnea (OSA) (N = 10; age: 52.8 ± 13 years; median age: 49 years; male/female ratio: 7/3), compared with a group of apparently healthy participants (N = 15; age: 51.5 ± 29.5 years; median age: 42 years; male/female ratio: 8/7), based on the calculation of wavelet bicoherence from nighttime polysomnograms. Having observed the previously known phenomenon of interhemispheric synchronization deterioration, we demonstrated a compensatory increase in intrahemispheric connectivity, as well as a slight increase in the connectivity of the central and occipital areas for high-frequency EEG activity. Significant changes in functional connectivity were extremely stable in groups of apparently healthy participants and OSA patients, maintaining the overall pattern when comparing different recording nights and various sleep stages. The maximum variability of the connectivity was observed at fast oscillatory processes during REM sleep. The possibility of observing some changes in functional connectivity of brain activity in OSA patients in a state of passive wakefulness opens up prospects for further research. Developing the methods of hypnogram evaluation that are independent of functional connectivity may be useful for implementing a medical decision support system.
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Affiliation(s)
- Maksim Zhuravlev
- National Medical Research Center for Therapy and Preventive Medicine, Moscow, Russia
- Institute of Physics, Saratov State University, Saratov, Russia
| | - Mikhail Agaltsov
- National Medical Research Center for Therapy and Preventive Medicine, Moscow, Russia
| | - Anton Kiselev
- National Medical Research Center for Therapy and Preventive Medicine, Moscow, Russia
| | - Margarita Simonyan
- Institute of Physics, Saratov State University, Saratov, Russia
- Institute of Cardiology Research, Saratov State Medical University, Saratov, Russia
| | - Mikhail Novikov
- Institute of Cardiology Research, Saratov State Medical University, Saratov, Russia
| | - Anton Selskii
- Institute of Physics, Saratov State University, Saratov, Russia
| | - Rodion Ukolov
- Institute of Physics, Saratov State University, Saratov, Russia
| | - Oksana Drapkina
- National Medical Research Center for Therapy and Preventive Medicine, Moscow, Russia
| | - Anna Orlova
- National Medical Research Center for Therapy and Preventive Medicine, Moscow, Russia
| | - Thomas Penzel
- Interdisciplinary Sleep Medicine Center, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Anastasiya Runnova
- National Medical Research Center for Therapy and Preventive Medicine, Moscow, Russia.
- Institute of Physics, Saratov State University, Saratov, Russia.
- Institute of Cardiology Research, Saratov State Medical University, Saratov, Russia.
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3
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Coccaro A, Di Bono MG, Maffei A, Orefice C, Lievore R, Mammarella I, Liotti M. Resting State Dynamic Reconfiguration of Spatial Attention Cortical Networks and Visuospatial Functioning in Non-Verbal Learning Disability (NVLD): A HD-EEG Investigation. Brain Sci 2023; 13:brainsci13050731. [PMID: 37239203 DOI: 10.3390/brainsci13050731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2023] [Revised: 04/13/2023] [Accepted: 04/24/2023] [Indexed: 05/28/2023] Open
Abstract
Nonverbal learning disability (NVLD) is a neurodevelopmental disorder characterized by deficits in visuospatial processing but spared verbal competencies. Neurocognitive markers may provide confirmatory evidence for characterizing NVLD as a separate neurodevelopmental disorder. Visuospatial performance and high-density electroencephalography (EEG) were measured in 16 NLVD and in 16 typically developing (TD) children. Cortical source modeling was applied to assess resting-state functional connectivity (rs-FC) in spatial attention networks (dorsal (DAN) and ventral attention networks (VAN)) implicated in visuospatial abilities. A machine-learning approach was applied to investigate whether group membership could be predicted from rs-FC maps and if these connectivity patterns were predictive of visuospatial performance. Graph theoretical measures were applied to nodes inside each network. EEG rs-FC maps in the gamma and beta band differentiated children with and without NVLD, with increased but more diffuse and less efficient functional connections bilaterally in the NVLD group. While rs-FC of the left DAN in the gamma range predicted visuospatial scores for TD children, in the NVLD group rs-FC of the right DAN in the delta range predicted impaired visuospatial performance, confirming that NVLD is a disorder with a predominant dysfunction in right hemisphere connectivity patterns.
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Affiliation(s)
- Ambra Coccaro
- Department of Developmental and Social Psychology, University of Padova, Via Venezia 8, 35131 Padova, Italy
- Padova Neuroscience Center, University of Padova, Via Orus 2/B, 35129 Padova, Italy
| | - Maria Grazia Di Bono
- Department of Developmental and Social Psychology, University of Padova, Via Venezia 8, 35131 Padova, Italy
| | - Antonio Maffei
- Department of Developmental and Social Psychology, University of Padova, Via Venezia 8, 35131 Padova, Italy
- Padova Neuroscience Center, University of Padova, Via Orus 2/B, 35129 Padova, Italy
| | - Camilla Orefice
- Department of Developmental and Social Psychology, University of Padova, Via Venezia 8, 35131 Padova, Italy
| | - Rachele Lievore
- Department of Developmental and Social Psychology, University of Padova, Via Venezia 8, 35131 Padova, Italy
| | - Irene Mammarella
- Department of Developmental and Social Psychology, University of Padova, Via Venezia 8, 35131 Padova, Italy
| | - Mario Liotti
- Department of Developmental and Social Psychology, University of Padova, Via Venezia 8, 35131 Padova, Italy
- Padova Neuroscience Center, University of Padova, Via Orus 2/B, 35129 Padova, Italy
- Department of Psychology, Simon Fraser University, Burnaby, BC V5A1S6, Canada
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Mirifar A, Cross-Villasana F, Beckmann J, Ehrlenspiel F. Effects of the unilateral dynamic handgrip on resting cortical activity levels: A replication and extension. Int J Psychophysiol 2020; 156:40-48. [PMID: 32702385 DOI: 10.1016/j.ijpsycho.2020.07.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 05/28/2020] [Accepted: 07/07/2020] [Indexed: 10/23/2022]
Abstract
Previous studies have linked unilateral hand contractions to subsequent changes in hemispheric asymmetric activity, as reflected in the electroencephalographic alpha (8-12 Hz) range in each hemisphere. However, debate continues regarding the state of asymmetry induced by unilateral contractions. We have previously found a bilateral enhancement of alpha amplitude that occurs after contractions, reflecting cortical downregulation instead of changes in asymmetric activity. To corroborate our observations, we examined the effects of 45 s of unilateral dynamic handgrip contractions on subsequent resting alpha activity. Twenty-two right-handed participants were recruited (M = 25 years, 17 female). The study used a within-subjects design consisting of a pre- and post-test (2 min resting; eyes open) for the intervention (dynamic handgrip; at a self-determined pace of approximately twice a second for 45 s for each hand). Following the handgrip task, an increase in alpha amplitude above the baseline was observed over the entire cortex, which was greater after left-hand squeezing. This observation confirms our previous findings and we have extended them by adding more electrodes to gain further insights into the handgrip exercise as an external brain stimulator. Moreover, we grouped electrodes according to scalp regions to facilitate the visualization of the effects on the frequency spectrum. Our findings can be used to develop targeted interventions aimed at modifying behavioral outcomes affected by alpha activity.
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Affiliation(s)
- Arash Mirifar
- Department of Sport and Health Sciences, Chair of Sport Psychology, Technische Universität München, Germany.
| | - Fernando Cross-Villasana
- Department of Sport and Health Sciences, Chair of Sport Psychology, Technische Universität München, Germany
| | - Jürgen Beckmann
- School of Human Movement and Nutrition Sciences, University of Queensland, Australia
| | - Felix Ehrlenspiel
- Department of Sport and Health Sciences, Chair of Sport Psychology, Technische Universität München, Germany
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Livint Popa L, Dragos H, Pantelemon C, Verisezan Rosu O, Strilciuc S. The Role of Quantitative EEG in the Diagnosis of Neuropsychiatric Disorders. J Med Life 2020; 13:8-15. [PMID: 32341694 PMCID: PMC7175442 DOI: 10.25122/jml-2019-0085] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Quantitative electroencephalography (QEEG) is a modern type of electroencephalography (EEG) analysis that involves recording digital EEG signals which are processed, transformed, and analyzed using complex mathematical algorithms. QEEG has brought new techniques of EEG signals feature extraction: analysis of specific frequency band and signal complexity, analysis of connectivity, and network analysis. The clinical application of QEEG is extensive, including neuropsychiatric disorders, epilepsy, stroke, dementia, traumatic brain injury, mental health disorders, and many others. In this review, we talk through existing evidence on the practical applications of this clinical tool. We conclude that to date, the role of QEEG is not necessarily to pinpoint an immediate diagnosis but to provide additional insight in conjunction with other diagnostic evaluations in order to objective information necessary for obtaining a precise diagnosis, correct disease severity assessment, and specific treatment response evaluation.
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Affiliation(s)
- Livia Livint Popa
- "RoNeuro" Institute for Neurological Research and Diagnostic, Cluj-Napoca, Romania.,Department of Clinical Neurosciences, "Iuliu Hatieganu "University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Hanna Dragos
- "RoNeuro" Institute for Neurological Research and Diagnostic, Cluj-Napoca, Romania.,Department of Clinical Neurosciences, "Iuliu Hatieganu "University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Cristina Pantelemon
- "RoNeuro" Institute for Neurological Research and Diagnostic, Cluj-Napoca, Romania.,Department of Clinical Neurosciences, "Iuliu Hatieganu "University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Olivia Verisezan Rosu
- "RoNeuro" Institute for Neurological Research and Diagnostic, Cluj-Napoca, Romania.,Department of Clinical Neurosciences, "Iuliu Hatieganu "University of Medicine and Pharmacy, Cluj-Napoca, Romania
| | - Stefan Strilciuc
- "RoNeuro" Institute for Neurological Research and Diagnostic, Cluj-Napoca, Romania.,Department of Clinical Neurosciences, "Iuliu Hatieganu "University of Medicine and Pharmacy, Cluj-Napoca, Romania
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6
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Wang DJJ, Jann K, Fan C, Qiao Y, Zang YF, Lu H, Yang Y. Neurophysiological Basis of Multi-Scale Entropy of Brain Complexity and Its Relationship With Functional Connectivity. Front Neurosci 2018; 12:352. [PMID: 29896081 PMCID: PMC5986880 DOI: 10.3389/fnins.2018.00352] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 05/07/2018] [Indexed: 01/06/2023] Open
Abstract
Recently, non-linear statistical measures such as multi-scale entropy (MSE) have been introduced as indices of the complexity of electrophysiology and fMRI time-series across multiple time scales. In this work, we investigated the neurophysiological underpinnings of complexity (MSE) of electrophysiology and fMRI signals and their relations to functional connectivity (FC). MSE and FC analyses were performed on simulated data using neural mass model based brain network model with the Brain Dynamics Toolbox, on animal models with concurrent recording of fMRI and electrophysiology in conjunction with pharmacological manipulations, and on resting-state fMRI data from the Human Connectome Project. Our results show that the complexity of regional electrophysiology and fMRI signals is positively correlated with network FC. The associations between MSE and FC are dependent on the temporal scales or frequencies, with higher associations between MSE and FC at lower temporal frequencies. Our results from theoretical modeling, animal experiment and human fMRI indicate that (1) Regional neural complexity and network FC may be two related aspects of brain's information processing: the more complex regional neural activity, the higher FC this region has with other brain regions; (2) MSE at high and low frequencies may represent local and distributed information processing across brain regions. Based on literature and our data, we propose that the complexity of regional neural signals may serve as an index of the brain's capacity of information processing—increased complexity may indicate greater transition or exploration between different states of brain networks, thereby a greater propensity for information processing.
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Affiliation(s)
- Danny J J Wang
- Laboratory of FMRI Technology, Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Kay Jann
- Laboratory of FMRI Technology, Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Chang Fan
- Laboratory of FMRI Technology, Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, United States
| | - Yang Qiao
- Department of Psychology, Center for Cognition and Brain Disorders, Hangzhou Normal University, Hangzhou, China.,Neuroimaging Research Branch, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, United States
| | - Yu-Feng Zang
- Department of Psychology, Center for Cognition and Brain Disorders, Hangzhou Normal University, Hangzhou, China
| | - Hanbing Lu
- Neuroimaging Research Branch, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, United States
| | - Yihong Yang
- Neuroimaging Research Branch, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD, United States
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7
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Dasdemir Y, Yildirim E, Yildirim S. Analysis of functional brain connections for positive-negative emotions using phase locking value. Cogn Neurodyn 2017; 11:487-500. [PMID: 29147142 DOI: 10.1007/s11571-017-9447-z] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Revised: 05/24/2017] [Accepted: 07/06/2017] [Indexed: 01/01/2023] Open
Abstract
In this study, we investigate the brain networks during positive and negative emotions for different types of stimulus (audio only, video only and audio + video) in [Formula: see text], and [Formula: see text] bands in terms of phase locking value, a nonlinear method to study functional connectivity. Results show notable hemispheric lateralization as phase synchronization values between channels are significant and high in right hemisphere for all emotions. Left frontal electrodes are also found to have control over emotion in terms of functional connectivity. Besides significant inter-hemisphere phase locking values are observed between left and right frontal regions, specifically between left anterior frontal and right mid-frontal, inferior-frontal and anterior frontal regions; and also between left and right mid frontal regions. ANOVA analysis for stimulus types show that stimulus types are not separable for emotions having high valence. PLV values are significantly different only for negative emotions or neutral emotions between audio only/video only and audio only/audio + video stimuli. Finding no significant difference between video only and audio + video stimuli is interesting and might be interpreted as that video content is the most effective part of a stimulus.
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Affiliation(s)
- Yasar Dasdemir
- Computer Engineering Department, Iskenderun Technical University, Hatay, Turkey
| | - Esen Yildirim
- Electrical and Electronic Engineering Department, Adana Science and Technology University, Adana, Turkey
| | - Serdar Yildirim
- Computer Engineering Department, Adana Science and Technology University, Adana, Turkey
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8
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Miskovic V, Owens M, Kuntzelman K, Gibb BE. Charting moment-to-moment brain signal variability from early to late childhood. Cortex 2016; 83:51-61. [PMID: 27479615 DOI: 10.1016/j.cortex.2016.07.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Revised: 05/20/2016] [Accepted: 07/06/2016] [Indexed: 01/08/2023]
Abstract
Large-scale brain signals exhibit rich intermittent patterning, reflecting the fact that the cortex actively eschews fixed points in favor of itinerant wandering with frequent state transitions. Fluctuations in endogenous cortical activity occur at multiple time scales and index a dynamic repertoire of network states that are continuously explored, even in the absence of external sensory inputs. Here, we quantified such moment-to-moment brain signal variability at rest in a large, cross-sectional sample of children ranging in age from seven to eleven years. Our findings revealed a monotonic rise in the complexity of electroencephalogram (EEG) signals as measured by sample entropy, from the youngest to the oldest age cohort, across a range of time scales and spatial regions. From year to year, the greatest changes in intraindividual brain signal variability were recorded at electrodes covering the anterior cortical zones. These results provide converging evidence concerning the age-dependent expansion of functional cortical network states during a critical developmental period ranging from early to late childhood.
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Affiliation(s)
- Vladimir Miskovic
- Center for Affective Science, State University of New York at Binghamton, USA.
| | - Max Owens
- Center for Affective Science, State University of New York at Binghamton, USA
| | - Karl Kuntzelman
- Center for Affective Science, State University of New York at Binghamton, USA
| | - Brandon E Gibb
- Center for Affective Science, State University of New York at Binghamton, USA
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9
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Ghumman S, Fortin D, Noel-Lamy M, Cunnane SC, Whittingstall K. Exploratory study of the effect of brain tumors on the default mode network. J Neurooncol 2016; 128:437-44. [DOI: 10.1007/s11060-016-2129-6] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 04/07/2016] [Indexed: 11/24/2022]
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10
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Lazarev VV, de Carvalho Monteiro M, Vianna-Barbosa R, deAzevedo LC, Lent R, Tovar-Moll F. Electrophysiological Correlates of Morphological Neuroplasticity in Human Callosal Dysgenesis. PLoS One 2016; 11:e0152668. [PMID: 27055255 PMCID: PMC4824527 DOI: 10.1371/journal.pone.0152668] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Accepted: 03/17/2016] [Indexed: 12/19/2022] Open
Abstract
In search for the functional counterpart of the alternative Probst and sigmoid bundles, considered as morphological evidence of neuroplasticity in callosal dysgenesis, electroencephalographic (EEG) coherence analysis was combined with high resolution and diffusion tensor magnetic resonance imaging. Data of two patients with callosal agenesis, plus two with typical partial dysgenesis with a remnant genu, and one atypical patient with a substantially reduced genu were compared to those of fifteen neurotypic controls. The interhemispheric EEG coherence between homologous nontemporal brain regions corresponded to absence or partial presence of callosal connections. A generalized coherence reduction was observed in complete acallosal patients, as well as coherence preservation in the anterior areas of the two patients with a remnant genu. jThe sigmoid bundles found in three patients with partial dysgenesis correlated with augmented EEG coherence between anterior regions of one hemisphere and posterior regions of the other. These heterologous (crossed) interhemispheric connections were asymmetric in both imaging and EEG patterns, with predominance of the right-anterior-to-left-posterior connections over the mirror ones. The Probst bundles correlated with higher intrahemispheric long-distance coherence in all patients. The significant correlations observed for the delta, theta and alpha bands indicate that these alternative pathways are functional, although the neuropsychological nature of this function is still unknown.
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Affiliation(s)
- Vladimir V Lazarev
- National Institute of Women, Children and Adolescents Health Fernandes Figueira, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Myriam de Carvalho Monteiro
- National Institute of Women, Children and Adolescents Health Fernandes Figueira, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil.,Institute for Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.,D'Or Institute for Research and Education (IDOR), Rio de Janeiro, Brazil
| | - Rodrigo Vianna-Barbosa
- Institute for Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.,D'Or Institute for Research and Education (IDOR), Rio de Janeiro, Brazil
| | - Leonardo C deAzevedo
- National Institute of Women, Children and Adolescents Health Fernandes Figueira, Oswaldo Cruz Foundation, Rio de Janeiro, Brazil
| | - Roberto Lent
- Institute for Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Fernanda Tovar-Moll
- Institute for Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil.,D'Or Institute for Research and Education (IDOR), Rio de Janeiro, Brazil
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11
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Cross-Villasana F, Gröpel P, Doppelmayr M, Beckmann J. Unilateral Left-Hand Contractions Produce Widespread Depression of Cortical Activity after Their Execution. PLoS One 2015; 10:e0145867. [PMID: 26709832 PMCID: PMC4692494 DOI: 10.1371/journal.pone.0145867] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 12/09/2015] [Indexed: 01/17/2023] Open
Abstract
The execution of unilateral hand contractions before performance has been reported to produce behavioral aftereffects in various tasks. These effects have been regularly attributed to an induced shift in activation asymmetry to the contralateral hemisphere produced by the contractions. An alternative explanation proposes a generalized state of reduced bilateral cortical activity following unilateral hand contractions. The current experiment contrasted the above explanation models and tested the state of cortical activity after the termination of unilateral hand contractions. Twenty right-handed participants performed hand contractions in two blocks, one for each hand. Using electroencephalogram (EEG), the broad alpha band and its asymmetry between hemispheres before, during, and after hand contractions were analyzed. During contractions, significant bilateral decrease in alpha amplitudes (indicating cortical activation) emerged for both hands around sensory-motor regions. After contractions, alpha amplitudes increased significantly over the whole scalp when compared to baseline, but only for the left hand. No modulation of hemispheric asymmetry was observed at any phase. The results suggest that unilateral hand contractions produce a state of reduced cortical activity after their termination, which is more pronounced if the left hand was used. Consequently, we propose that the reduced cortical activity (and not the persistent activation asymmetry) may facilitate engagement in subsequent behavior, probably due to preventing interference from other, nonessential cortical regions.
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Affiliation(s)
| | - Peter Gröpel
- Chair of Sport Psychology, Technische Universität München, München, Germany
| | - Michael Doppelmayr
- Institute of Sport Science, Johannes Gutenberg Universität, Mainz, Germany
| | - Jürgen Beckmann
- Chair of Sport Psychology, Technische Universität München, München, Germany
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12
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Poortvliet PC, Tucker KJ, Finnigan S, Scott D, Sowman P, Hodges PW. Cortical activity differs between position- and force-control knee extension tasks. Exp Brain Res 2015; 233:3447-57. [DOI: 10.1007/s00221-015-4404-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2015] [Accepted: 08/03/2015] [Indexed: 11/24/2022]
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13
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Yang Y, Solis-Escalante T, Yao J, Daffertshofer A, Schouten AC, van der Helm FCT. A General Approach for Quantifying Nonlinear Connectivity in the Nervous System Based on Phase Coupling. Int J Neural Syst 2015; 26:1550031. [PMID: 26404514 DOI: 10.1142/s0129065715500318] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Interaction between distant neuronal populations is essential for communication within the nervous system and can occur as a highly nonlinear process. To better understand the functional role of neural interactions, it is important to quantify the nonlinear connectivity in the nervous system. We introduce a general approach to measure nonlinear connectivity through phase coupling: the multi-spectral phase coherence (MSPC). Using simulated data, we compare MSPC with existing phase coupling measures, namely n : m synchronization index and bi-phase locking value. MSPC provides a system description, including (i) the order of the nonlinearity, (ii) the direction of interaction, (iii) the time delay in the system, and both (iv) harmonic and (v) intermodulation coupling beyond the second order; which are only partly revealed by other methods. We apply MSPC to analyze data from a motor control experiment, where subjects performed isotonic wrist flexions while receiving movement perturbations. MSPC between the perturbation, EEG and EMG was calculated. Our results reveal directional nonlinear connectivity in the afferent and efferent pathways, as well as the time delay (43 ± 8 ms) between the perturbation and the brain response. In conclusion, MSPC is a novel approach capable to assess high-order nonlinear interaction and timing in the nervous system.
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Affiliation(s)
- Yuan Yang
- 1 Department of Biomechanical Engineering, Delft University of Technology, Delft 2628 CD, The Netherlands
| | - Teodoro Solis-Escalante
- 1 Department of Biomechanical Engineering, Delft University of Technology, Delft 2628 CD, The Netherlands
| | - Jun Yao
- 2 Department of Physical Therapy and Human Movement Sciences, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Andreas Daffertshofer
- 3 Faculty of Human Movement Sciences, VU University Amsterdam, Amsterdam, 1081 BT, The Netherlands
| | - Alfred C Schouten
- 1 Department of Biomechanical Engineering, Delft University of Technology, Delft 2628 CD, The Netherlands.,4 MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, 7500 AE, The Netherlands
| | - Frans C T van der Helm
- 1 Department of Biomechanical Engineering, Delft University of Technology, Delft 2628 CD, The Netherlands
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14
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Ribolsi M, Daskalakis ZJ, Siracusano A, Koch G. Abnormal asymmetry of brain connectivity in schizophrenia. Front Hum Neurosci 2014; 8:1010. [PMID: 25566030 PMCID: PMC4273663 DOI: 10.3389/fnhum.2014.01010] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Accepted: 11/26/2014] [Indexed: 01/09/2023] Open
Abstract
Recently, a growing body of data has revealed that beyond a dysfunction of connectivity among different brain areas in schizophrenia patients (SCZ), there is also an abnormal asymmetry of functional connectivity compared with healthy subjects. The loss of the cerebral torque and the abnormalities of gyrification, with an increased or more complex cortical folding in the right hemisphere may provide an anatomical basis for such aberrant connectivity in SCZ. Furthermore, diffusion tensor imaging studies have shown a significant reduction of leftward asymmetry in some key white-matter tracts in SCZ. In this paper, we review the studies that investigated both structural brain asymmetry and asymmetry of functional connectivity in healthy subjects and SCZ. From an analysis of the existing literature on this topic, we can hypothesize an overall generally attenuated asymmetry of functional connectivity in SCZ compared to healthy controls. Such attenuated asymmetry increases with the duration of the disease and correlates with psychotic symptoms. Finally, we hypothesize that structural deficits across the corpus callosum may contribute to the abnormal asymmetry of intra-hemispheric connectivity in schizophrenia.
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Affiliation(s)
- Michele Ribolsi
- Dipartimento di Medicina dei Sistemi, Clinica Psichiatrica, Università di Roma Tor Vergata , Rome , Italy ; Laboratorio di Neurologia Clinica e Comportamentale, Fondazione Santa Lucia IRCCS , Rome , Italy
| | - Zafiris J Daskalakis
- Temerty Centre for Therapeutic Brain Intervention, Centre for Addiction and Mental Health, University of Toronto , Toronto, ON , Canada
| | - Alberto Siracusano
- Dipartimento di Medicina dei Sistemi, Clinica Psichiatrica, Università di Roma Tor Vergata , Rome , Italy
| | - Giacomo Koch
- Laboratorio di Neurologia Clinica e Comportamentale, Fondazione Santa Lucia IRCCS , Rome , Italy
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Berkovich-Ohana A, Glicksohn J, Goldstein A. Studying the default mode and its mindfulness-induced changes using EEG functional connectivity. Soc Cogn Affect Neurosci 2014; 9:1616-24. [PMID: 24194576 PMCID: PMC4187278 DOI: 10.1093/scan/nst153] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2012] [Revised: 08/29/2013] [Accepted: 09/23/2013] [Indexed: 01/08/2023] Open
Abstract
The default mode network (DMN) has been largely studied by imaging, but not yet by neurodynamics, using electroencephalography (EEG) functional connectivity (FC). mindfulness meditation (MM), a receptive, non-elaborative training is theorized to lower DMN activity. We explored: (i) the usefulness of EEG-FC for investigating the DMN and (ii) the MM-induced EEG-FC effects. To this end, three MM groups were compared with controls, employing EEG-FC (-MPC, mean phase coherence). Our results show that: (i) DMN activity was identified as reduced overall inter-hemispheric gamma MPC during the transition from resting state to a time production task and (ii) MM-induced a state increase in alpha MPC as well as a trait decrease in EEG-FC. The MM-induced EEG-FC decrease was irrespective of expertise or band. Specifically, there was a relative reduction in right theta MPC, and left alpha and gamma MPC. The left gamma MPC was negatively correlated with MM expertise, possibly related to lower internal verbalization. The trait lower gamma MPC supports the notion of MM-induced reduction in DMN activity, related with self-reference and mind-wandering. This report emphasizes the possibility of studying the DMN using EEG-FC as well as the importance of studying meditation in relation to it.
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Affiliation(s)
- Aviva Berkovich-Ohana
- The Leslie and Susan Gonda (Goldschmied) Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat Gan 52900, Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Department of Criminology, and Department of Psychology, Bar-Ilan University, Ramat Gan 52900 Israel. The Leslie and Susan Gonda (Goldschmied) Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat Gan 52900, Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Department of Criminology, and Department of Psychology, Bar-Ilan University, Ramat Gan 52900 Israel.
| | - Joseph Glicksohn
- The Leslie and Susan Gonda (Goldschmied) Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat Gan 52900, Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Department of Criminology, and Department of Psychology, Bar-Ilan University, Ramat Gan 52900 Israel. The Leslie and Susan Gonda (Goldschmied) Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat Gan 52900, Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Department of Criminology, and Department of Psychology, Bar-Ilan University, Ramat Gan 52900 Israel
| | - Abraham Goldstein
- The Leslie and Susan Gonda (Goldschmied) Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat Gan 52900, Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Department of Criminology, and Department of Psychology, Bar-Ilan University, Ramat Gan 52900 Israel. The Leslie and Susan Gonda (Goldschmied) Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat Gan 52900, Department of Neurobiology, Weizmann Institute of Science, Rehovot 76100, Department of Criminology, and Department of Psychology, Bar-Ilan University, Ramat Gan 52900 Israel
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Nenadovic V, Perez Velazquez JL, Hutchison JS. Phase synchronization in electroencephalographic recordings prognosticates outcome in paediatric coma. PLoS One 2014; 9:e94942. [PMID: 24752289 PMCID: PMC3994059 DOI: 10.1371/journal.pone.0094942] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Accepted: 03/21/2014] [Indexed: 02/06/2023] Open
Abstract
Brain injury from trauma, cardiac arrest or stroke is the most important cause of death and acquired disability in the paediatric population. Due to the lifetime impact of brain injury, there is a need for methods to stratify patient risk and ultimately predict outcome. Early prognosis is fundamental to the implementation of interventions to improve recovery, but no clinical model as yet exists. Healthy physiology is associated with a relative high variability of physiologic signals in organ systems. This was first evaluated in heart rate variability research. Brain variability can be quantified through electroencephalographic (EEG) phase synchrony. We hypothesised that variability in brain signals from EEG recordings would correlate with patient outcome after brain injury. Lower variability in EEG phase synchronization, would be associated with poor patient prognosis. A retrospective study, spanning 10 years (2000-2010) analysed the scalp EEGs of children aged 1 month to 17 years in coma (Glasgow Coma Scale, GCS, <8) admitted to the paediatric critical care unit (PCCU) following brain injury from TBI, cardiac arrest or stroke. Phase synchrony of the EEGs was evaluated using the Hilbert transform and the variability of the phase synchrony calculated. Outcome was evaluated using the 6 point Paediatric Performance Category Score (PCPC) based on chart review at the time of hospital discharge. Outcome was dichotomized to good outcome (PCPC score 1 to 3) and poor outcome (PCPC score 4 to 6). Children who had a poor outcome following brain injury secondary to cardiac arrest, TBI or stroke, had a higher magnitude of synchrony (R index), a lower spatial complexity of the synchrony patterns and a lower temporal variability of the synchrony index values at 15 Hz when compared to those patients with a good outcome.
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Affiliation(s)
- Vera Nenadovic
- Division of Neurology Sick Kids, Toronto, Ontario, Canada
- Brain and Mental Health, Toronto, Ontario, Canada
| | - Jose Luis Perez Velazquez
- Brain and Mental Health, Toronto, Ontario, Canada
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
| | - James Saunders Hutchison
- Division of Neurology Sick Kids, Toronto, Ontario, Canada
- Brain and Mental Health, Toronto, Ontario, Canada
- Department of Critical Care Medicine Sick Kids, Toronto, Ontario, Canada
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada
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Boldyreva GN, Zhavoronkova LA, Sharova EV, Dobronravova IS. Electroencephalographic Intercentral Interaction as a Reflection of Normal and Pathological Human Brain Activity. SPANISH JOURNAL OF PSYCHOLOGY 2014; 10:167-77. [PMID: 17549890 DOI: 10.1017/s1138741600006430] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The authors summarized EEG findings and defined the nature of the intercentral EEG relationships in different functional states in healthy subjects and patients with organic cerebral pathology, based on a coherence analysis. Similar EEG characteristics in healthy individuals were identified: an anterior-posterior gradient of average coherence levels, the type of cortical-subcortical relationships in anterior cerebral structures. Right- and left-handed individuals showed frequent and regional differences in EEG coherence, which mainly reflected specificity of intracortical relationships. Development and regression of pathology in right-and left-handed individuals with organic brain lesions were thought to be caused by these differences. Lesions of regulatory structures (diencephalic, brain stem and limbic structures) provoked a more diffused kind of changes of intercentral relationships, in contrast to cortical pathology. These changes tended to reciprocate. The dynamic nature of intercentral relationships and their interhemispheric differences was revealed when changing functional states of the brain (increase and decrease of functional level) in healthy individuals and patients with organic cerebral pathology in the process of conscious and psychic activity restoration. Changing activity predominance of certain regulatory structures was considered one of the most important factors determining the dynamic nature of EEG coherence.
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Affiliation(s)
- Galina N Boldyreva
- Institute of Higher Nervous Activity and Neurophysiology of the Russian Academy of Sciences, Moscow.
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18
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Coherent Relations in Ongoing Encephalograms of Preschool Boys with Neurosis-Like Stammering. NEUROPHYSIOLOGY+ 2013. [DOI: 10.1007/s11062-013-9396-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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19
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Developmental changes of functional and directed resting-state connectivities associated with neuronal oscillations in EEG. Neuroimage 2013; 81:231-242. [DOI: 10.1016/j.neuroimage.2013.04.030] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 04/02/2013] [Accepted: 04/10/2013] [Indexed: 11/23/2022] Open
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Soroko SI, Bekshaev SS, Rozhkov VP. EEG Correlates of Genophenotypic Characteristics of Brain Development in Children of the Aboriginal and Settler Populations in Northeast Russia. ACTA ACUST UNITED AC 2013. [DOI: 10.1007/s11055-013-9809-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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21
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Locus of Subjective Control: Peculiarities of the Coherence of EEG Activity in the Resting State. NEUROPHYSIOLOGY+ 2013. [DOI: 10.1007/s11062-013-9364-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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22
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Does the resting state connectivity have hemispheric asymmetry? A near-infrared spectroscopy study. Neuroimage 2013; 85 Pt 1:400-7. [PMID: 23721726 DOI: 10.1016/j.neuroimage.2013.05.092] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Revised: 04/14/2013] [Accepted: 05/17/2013] [Indexed: 11/22/2022] Open
Abstract
Near-infrared spectroscopy (NIRS) is a novel technology for low-cost noninvasive brain imaging suitable for use in virtually all subject and patient populations. Numerous studies of brain functional connectivity using fMRI, and recently NIRS, suggest new tools for the assessment of cognitive functions during task performance and the resting state (RS). We analyzed functional connectivity and its possible hemispheric asymmetry measuring coherence of optical signals at low frequencies (0.01-0.1 Hz) in the prefrontal cortex in 13 right-handed (RH) and 2 left-handed (LH) healthy subjects at rest (4-8 min) using a continuous-wave NIRS instrument CW5 (TechEn, Milford, MA). Two optical probes were placed bilaterally over the inferior frontal gyrus (IFG) and the middle frontal gyrus (MFG) using anatomical landmarks of the 10-20 system. As a result, 28 optical channels (14 for each hemisphere) were recorded for changes in oxygenated (HbO) and de-oxygenated (HbR) hemoglobin. Global physiological signals (respiratory and cardiac) were removed using Principal and Independent Component Analyses. Inter-channel coherences for HbO and HbR signals were calculated using Morlet wavelets along with correlation coefficients. Connectivity matrices showed specific patterns of connectivity which was higher within each anatomical region (IFG and MFG) and between hemispheres (e.g., left IFG<->right IFG) than between IFG and MFG in the same hemisphere. Laterality indexes were calculated as t-values for the 'left>right' comparisons of intrinsic connectivity within each regional group of channels in each subject. Regardless of handedness, the group average laterality indexes were negative thus revealing significantly higher connectivity in the right hemisphere in the majority of RH subjects and in both LH subjects. The analysis of Granger causality between hemispheres has also shown a greater flow of information from the right to the left hemisphere which may point to an important role of the right hemisphere in the resting state. These data encourage further exploration of the NIRS connectivity and its application for the analysis of hemispheric relationships within the functional architecture of the brain.
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Dotan Ben-Soussan T, Glicksohn J, Goldstein A, Berkovich-Ohana A, Donchin O. Into the square and out of the box: the effects of Quadrato Motor Training on creativity and alpha coherence. PLoS One 2013; 8:e55023. [PMID: 23383043 PMCID: PMC3559385 DOI: 10.1371/journal.pone.0055023] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Accepted: 12/18/2012] [Indexed: 11/18/2022] Open
Abstract
The objective of the present study was to investigate the body-cognitive relationship through behavioral and electrophysiological measures in an attempt to uncover the underlying mediating neuronal mechanism for movement-induced cognitive change. To this end we examined the effects of Quadrato Motor Training (QMT), a new whole-body training paradigm on cognitive performance, including creativity and reaction time tasks, and electrophysiological change, using a within-subject pre-post design. Creativity was studied by means of the Alternate Uses Task, measuring ideational fluency and ideational flexibility. Electrophysiological effects were measured in terms of alpha power and coherence. In order to determine whether training-induced changes were driven by the cognitive or the motor aspects of the training, we used two control groups: Verbal Training (VT, identical cognitive training with verbal response) and Simple Motor Training (SMT, similar motor training with reduced choice requirements). Twenty-seven participants were randomly assigned to one of the groups. Following QMT, we found enhanced inter-hemispheric and intra-hemispheric alpha coherence, and increased ideational flexibility, which was not the case for either the SMT or VT groups. These findings indicate that it is the combination of the motor and cognitive aspects embedded in the QMT which is important for increasing ideational flexibility and alpha coherence.
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Affiliation(s)
- Tal Dotan Ben-Soussan
- The Leslie and Susan Gonda (Goldschmied) Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat Gan, Israel.
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24
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Kuhnert MT, Geier C, Elger CE, Lehnertz K. Identifying important nodes in weighted functional brain networks: a comparison of different centrality approaches. CHAOS (WOODBURY, N.Y.) 2012; 22:023142. [PMID: 22757549 DOI: 10.1063/1.4729185] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We compare different centrality metrics which aim at an identification of important nodes in complex networks. We investigate weighted functional brain networks derived from multichannel electroencephalograms recorded from 23 healthy subject under resting-state eyes-open or eyes-closed conditions. Although we observe the metrics strength, closeness, and betweenness centrality to be related to each other, they capture different spatial and temporal aspects of important nodes in these networks associated with behavioral changes. Identifying and characterizing of these nodes thus benefits from the application of several centrality metrics.
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Affiliation(s)
- Marie-Therese Kuhnert
- Department of Epileptology, University of Bonn, Sigmund-Freud-Strasse 25, 53105 Bonn, Germany.
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25
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EEG-based functional brain networks: does the network size matter? PLoS One 2012; 7:e35673. [PMID: 22558196 PMCID: PMC3338445 DOI: 10.1371/journal.pone.0035673] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Accepted: 03/22/2012] [Indexed: 01/22/2023] Open
Abstract
Functional connectivity in human brain can be represented as a network using electroencephalography (EEG) signals. These networks--whose nodes can vary from tens to hundreds--are characterized by neurobiologically meaningful graph theory metrics. This study investigates the degree to which various graph metrics depend upon the network size. To this end, EEGs from 32 normal subjects were recorded and functional networks of three different sizes were extracted. A state-space based method was used to calculate cross-correlation matrices between different brain regions. These correlation matrices were used to construct binary adjacency connectomes, which were assessed with regards to a number of graph metrics such as clustering coefficient, modularity, efficiency, economic efficiency, and assortativity. We showed that the estimates of these metrics significantly differ depending on the network size. Larger networks had higher efficiency, higher assortativity and lower modularity compared to those with smaller size and the same density. These findings indicate that the network size should be considered in any comparison of networks across studies.
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26
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Campus C, Brayda L, De Carli F, Chellali R, Famà F, Bruzzo C, Lucagrossi L, Rodriguez G. Tactile exploration of virtual objects for blind and sighted people: the role of beta 1 EEG band in sensory substitution and supramodal mental mapping. J Neurophysiol 2012; 107:2713-29. [PMID: 22338024 DOI: 10.1152/jn.00624.2011] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The neural correlates of exploration and cognitive mapping in blindness remain elusive. The role of visuo-spatial pathways in blind vs. sighted subjects is still under debate. In this preliminary study, we investigate, as a possible estimation of the activity in the visuo-spatial pathways, the EEG patterns of blind and blindfolded-sighted subjects during the active tactile construction of cognitive maps from virtual objects compared with rest and passive tactile stimulation. Ten blind and ten matched, blindfolded-sighted subjects participated in the study. Events were defined as moments when the finger was only stimulated (passive stimulation) or the contour of a virtual object was touched (during active exploration). Event-related spectral power and coherence perturbations were evaluated within the beta 1 band (14-18 Hz). They were then related to a subjective cognitive-load estimation required by the explorations [namely, perceived levels of difficulty (PLD)]. We found complementary cues for sensory substitution and spatial processing in both groups: both blind and sighted subjects showed, while exploring, late power decreases and early power increases, potentially associated with motor programming and touch, respectively. The latter involved occipital areas only for blind subjects (long-term plasticity) and only during active exploration, thus supporting tactile-to-visual sensory substitution. In both groups, coherences emerged among the fronto-central, centro-parietal, and occipito-temporal derivations associated with visuo-spatial processing. This seems in accordance with mental map construction involving spatial processing, sensory-motor processing, and working memory. The observed involvement of the occipital regions suggests that a substitution process also occurs in sighted subjects. Only during explorations did coherence correlate positively with PLD for both groups and in derivations, which can be related to visuo-spatial processing, supporting the existence of supramodal spatial processing independently of vision capabilities.
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Affiliation(s)
- C Campus
- Istituto Italiano di Tecnologia, Via Morego, 30, I 16163, Genoa, Italy.
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27
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Gmehlin D, Thomas C, Weisbrod M, Walther S, Resch F, Oelkers-Ax R. Development of brain synchronisation within school-age – Individual analysis of resting (alpha) coherence in a longitudinal data set. Clin Neurophysiol 2011; 122:1973-83. [DOI: 10.1016/j.clinph.2011.03.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2010] [Revised: 03/06/2011] [Accepted: 03/19/2011] [Indexed: 10/18/2022]
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28
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Abstract
The cerebral hemispheres are anatomically and neurophysiologically asymmetrical. The evolutionary basis for these differences remains uncertain. There are, however, highly consistent differences between the hemispheres, evident in reptiles, birds, and mammals, as well as in humans, in the nature of the attention each applies to the environment. This permits the simultaneous application of precisely focused, but narrow, attention, needed for grasping food or prey, with broad, open, and uncommitted attention, needed to watch out for predators and to interpret the intentions of conspecifics. These different modes of attention can account for a very wide range of repeated observations relating to hemisphere specialization, and suggest that hemisphere differences lie not in discrete functional domains as such, but distinct modes of functioning within any one domain. These modes of attention are mutually incompatible, and their application depends on inhibitory transmission in the corpus callosum. There is also an asymmetry of interaction between the hemispheres at the phenomenological level.
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29
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Brázdil M, Brichta J, Krajča V, Kuba R, Daniel P. Interhemispheric EEG coherence after corpus callosotomy. Eur J Neurol 2011. [DOI: 10.1111/j.1468-1331.1997.tb00373.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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30
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Hanlon HW, Thatcher RW, Cline MJ. Gender Differences in the Development of EEG Coherence in Normal Children. Dev Neuropsychol 2010. [DOI: 10.1207/s15326942dn1603_27] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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31
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Adolescent females exposed to child maltreatment exhibit atypical EEG coherence and psychiatric impairment: Linking early adversity, the brain, and psychopathology. Dev Psychopathol 2010; 22:419-32. [DOI: 10.1017/s0954579410000155] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
AbstractAlthough the relation between child maltreatment and psychiatric impairment is well documented and preliminary evidence has linked child maltreatment with aberrant cortical connectivity of the left hemisphere, no investigations have attempted to examine these relations in the same study. Here, we examined the links among early adversity, brain connectivity, and functional outcomes. We collected resting regional EEG intra- and interhemispheric α-band (7.5–12.5 Hz) coherence and measures of general psychiatric impairment from a cohort of 38 adolescent females exposed to child maltreatment (Mage = 14.47) and 24 adolescent females not exposed to child maltreatment (Mage = 14.00). Maltreated youths exhibited more left hemisphere EEG coherence than the control youths, suggesting a suboptimal organization of cortical networks. Maltreated participants also showed reduced frontal (anterior) interhemispheric coherence. These differences in brain circuitry remained statistically significant even after controlling for group differences in pubertal status and socioeconomic status. Measures of functional brain connectivity were associated with several subtypes of abuse and neglect. It was important that atypical left hemisphere EEG coherencemediatedthe effects of child maltreatment on levels of psychiatric impairment. The findings are discussed in the context of models linking early adversity to brain function and psychopathology.
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32
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Meindl T, Teipel S, Elmouden R, Mueller S, Koch W, Dietrich O, Coates U, Reiser M, Glaser C. Test-retest reproducibility of the default-mode network in healthy individuals. Hum Brain Mapp 2010; 31:237-46. [PMID: 19621371 DOI: 10.1002/hbm.20860] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Independent component analysis (ICA) of functional magnetic resonance imaging (fMRI) time-series reveals distinct coactivation patterns in the resting brain representing spatially coherent spontaneous fluctuations of the fMRI signal. Among these patterns, the so-called default-mode network (DMN) has been attributed to the ongoing mental activity of the brain during wakeful resting state. Studies suggest that many neuropsychiatric diseases disconnect brain areas belonging to the DMN. The potential use of the DMN as functional imaging marker for individuals at risk for these diseases, however, requires that the components of the DMN are reproducible over time in healthy individuals. In this study, we assessed the reproducibility of the DMN components within and between imaging sessions in 18 healthy young subjects (mean age, 27.5 years) who were scanned three times with two resting state scans during each session at 3.0 T field strength. Statistical analysis of fMRI time-series was done using ICA implemented with BrainVoyager QX. At all three sessions the essential components of the DMN could be identified in each individual. Spatial extent of DMN activity and size of overlap within and between sessions were most reproducible for the anterior and posterior cingulate gyrus. The degree of reproducibility of the DMN agrees with the degree of reproducibility found with motor paradigms. We conclude that DMN coactivation patterns are reproducible in healthy young subjects. Therefore, these data can serve as basis to further explore the effects of aging and neuropsychiatric diseases on the DMN of the brain.
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Affiliation(s)
- Thomas Meindl
- Institute for Clinical Radiology, University of Munich, Ziemssenstrasse 1, Munich, Germany.
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33
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Lu CM, Zhang YJ, Biswal BB, Zang YF, Peng DL, Zhu CZ. Use of fNIRS to assess resting state functional connectivity. J Neurosci Methods 2010; 186:242-9. [PMID: 19931310 DOI: 10.1016/j.jneumeth.2009.11.010] [Citation(s) in RCA: 188] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2009] [Revised: 10/19/2009] [Accepted: 11/11/2009] [Indexed: 10/20/2022]
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34
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Jalili M, Meuli R, Do KQ, Hasler M, Crow TJ, Knyazeva MG. Attenuated asymmetry of functional connectivity in schizophrenia: a high-resolution EEG study. Psychophysiology 2010; 47:706-16. [PMID: 20102536 DOI: 10.1111/j.1469-8986.2009.00971.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The interhemispheric asymmetries that originate from connectivity-related structuring of the cortex are compromised in schizophrenia (SZ). Under the assumption that such abnormalities affect functional connectivity, we analyzed its correlate-EEG synchronization-in SZ patients and matched controls. We applied multivariate synchronization measures based on Laplacian EEG and tuned to various spatial scales. Compared to the controls who had rightward asymmetry at a local level (EEG power), rightward anterior and leftward posterior asymmetries at an intraregional level (1st and 2nd order S-estimator), and rightward global asymmetry (hemispheric S-estimator), SZ patients showed generally attenuated asymmetry, the effect being strongest for intraregional synchronization in the alpha and beta bands. The abnormalities of asymmetry increased with the duration of the disease and correlated with the negative symptoms. We discuss the tentative links between these findings and gross anatomical asymmetries, including the cerebral torque and gyrification pattern, in normal subjects and SZ patients.
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Affiliation(s)
- Mahdi Jalili
- Department of Computer Engineering, Sharif University of Technology, Tehran, Iran.
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Leon-Carrion J, Martin-Rodriguez JF, Damas-Lopez J, Y Martin JMB, Dominguez-Morales MDR. A QEEG index of level of functional dependence for people sustaining acquired brain injury: The Seville Independence Index (SINDI). Brain Inj 2009; 22:61-74. [DOI: 10.1080/02699050701824143] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Regional electroencephalogram (EEG) spectral power and hemispheric coherence in young adults born at extremely low birth weight. Clin Neurophysiol 2009; 120:231-8. [DOI: 10.1016/j.clinph.2008.11.004] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2008] [Revised: 10/07/2008] [Accepted: 11/04/2008] [Indexed: 11/20/2022]
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Reduced Electroencephalographic Coherence Asymmetry in the Chernobyl Accident Survivors. THE SPANISH JOURNAL OF PSYCHOLOGY 2008. [DOI: 10.1017/s113874160000439x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
An electroencephalograph (EEG) study was carried out from 1990 to 2006, using power spectra, averaged coherence, and integral EEG coherence asymmetry coefficients to compare 189 clean-up workers of the Chernobyl accident with 63 age-matched healthy controls. Most of the Chernobyl workers showed three abnormal EEG patterns, as indicated by EEG power mapping. The higher power, most prominent in slow alpha and theta bands, or in fast alpha frequencies, were observed in persons 3-5 years after the clean-up works (the early stage). The lower EEG power in alpha band was found in Chernobyl workers 10 or more years after the accident (the late stage). EEG coherence analysis revealed the existence of two stages in EEG alterations following the Chernobyl clean-up. In the early stage, an increase of EEG coherence in the central brain areas was observed, whereas at the later stage, a decrease of EEG coherence, most prominent in the frontal brain areas, and reduced brain asymmetry prevailed. These results allow us to propose that the described EEG signs may be a reflection of radiation-induced brain dysfunction at the late period after the Chernobyl clean-up and were similar to the EEG markers of brain ageing. The results, in comparison to data of the literature, provide additional support to the premature brain ageing hypothesis in Chernobyl survivors as a result of the radiation brain damage after-effect.
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Abstract
AbstractA new theory of frontal lobe development is presented in which the role of the human frontal lobes during normal development and the psychopathological consequences of early frontal lobe injury are explored. Analyses of the development of human electroencephalograph (EEG) coherence indicate that there are oscillations and cyclic growth processes along the mediolateral and anterior-posterior planes of the brain. The cycles of EEG coherence are interpreted as repetitive sequences of increasing and decreasing synaptic effectiveness that reflects a convergence process that narrows the disparity between structure and function by slowly sculpting and reshaping the brain's microanatomy. This process is modeled as a developmental spiral staircase in which brain structures are periodically revisited resulting in stepwise increases in differentiation and integration. The frontal lobes play a crucial role because they are largely responsible for the selection and pruning of synaptic contacts throughout the postnatal period. A mathematical model of cycles of synaptic effectiveness is presented in which the frontal lobes behave as gentle synaptic “predators” whereas posterior cortical regions behave as synaptic “prey” in a periodic reorganization process. The psychopathological consequences of early frontal lobe damage are discussed in the context of this model.
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Nenadovic V, Hutchison JS, Dominguez LG, Otsubo H, Gray MP, Sharma R, Belkas J, Perez Velazquez JL. Fluctuations in cortical synchronization in pediatric traumatic brain injury. J Neurotrauma 2008; 25:615-27. [PMID: 18578633 DOI: 10.1089/neu.2007.0474] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Traumatic brain injury (TBI) is the leading cause of death and acquired disability in the pediatric population worldwide. We hypothesized that electroencephalography (EEG) synchrony and its temporal variability, analyzed during the acute phase following TBI, would be altered from that of normal children and as such would offer insights into TBI pathophysiology. Seventeen pediatric patients with mild to severe head injury admitted to a pediatric critical care unit were recruited along with 10 age- and gender-matched controls. Patients had two electroencephalographs performed 3 days apart. Outcome was measured at 1 year post-TBI utilizing the Pediatric Cerebral Performance Category score (PCPC). Maximal synchrony between EEG channels correlated to areas of primary injury as seen on computed tomography (CT) scan. The temporal variability of phase synchronization among EEG electrodes increased as patients recovered and emerged from coma (p < 0.001). This temporal variability correlated with outcome (Pearson coefficient of 0.74) better than the worst Glasgow Coma Scale score, length of coma, or extent of injury on CT scan. This represents a novel approach in the evaluation of TBI in children.
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Affiliation(s)
- Vera Nenadovic
- Critical Care Medicine Program, Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada
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Lacruz ME, García Seoane JJ, Valentin A, Selway R, Alarcón G. Frontal and temporal functional connections of the living human brain. Eur J Neurosci 2007; 26:1357-70. [PMID: 17767512 DOI: 10.1111/j.1460-9568.2007.05730.x] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Connections between human temporal and frontal cortices were investigated by intracranial electroencephalographic responses to electrical stimulation with 1-ms single pulses in 51 patients assessed for surgery for treatment of epilepsy. The areas studied were medial temporal, entorhinal, lateral temporal, medial frontal, lateral frontal and orbital frontal cortices. Findings were assumed to be representative of human brain as no differences were found between epileptogenic and non-epileptogenic hemispheres. Connections between intralobar temporal and frontal regions were common (43-95%). Connections from temporal to ipsilateral frontal regions were relatively uncommon (seen in 0-25% of hemispheres). Connections from frontal to ipsilateral temporal cortices were more common, particularly from orbital to ipsilateral medial temporal regions (40%). Contralateral temporal connections were rare (< 9%) whereas contralateral frontal connections were frequent and faster, particularly from medial frontal to contralateral medial frontal (61%) and orbital frontal cortices (57%), and between both orbital cortices (67%). Orbital cortex receives profuse connections from the ipsilateral medial (78%) and lateral (88%) frontal cortices, and from the contralateral medial (57%) and orbital (67%) frontal cortices. The high incidence of intralobar temporal connections supports the presence of temporal reverberating circuits. Frontal cortex projects within the lobe and beyond, to ipsilateral and contralateral structures.
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Affiliation(s)
- M E Lacruz
- Department of Clinical Neuroscience, Institute of Psychiatry, 16 De Crespigny Park, London SES 8AF, UK
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41
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Murias M, Swanson JM, Srinivasan R. Functional connectivity of frontal cortex in healthy and ADHD children reflected in EEG coherence. Cereb Cortex 2007; 17:1788-99. [PMID: 17023555 PMCID: PMC2084383 DOI: 10.1093/cercor/bhl089] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abnormal functional brain connectivity is a candidate factor in developmental brain disorders associated with cognitive dysfunction. We analyzed a substantial (10 min per subject) record of dense array electroencephalography with spectral power and coherence methods in attention-deficit hyperactivity disorder (ADHD) (n = 42) and control (n = 21) 10- to 13-year-old children. We found topographically distinct narrow band coherence differences between subject groups: ADHD subjects showed elevated coherence in the lower alpha (8 Hz) band and reduced coherence in the upper alpha (10-11 Hz) band. The 8-Hz ADHD elevation and a 2- to 6-Hz control group coherence elevation were independent of stimulus presentation. In response to visual stimulation, the ADHD group exhibited reduced evoked potential power and elevated frontal coherence. Only the upper alpha band control group coherence elevation discriminated according to ADHD group medication status. The findings suggest a static state of deficient connectivity in ADHD and a stimulus-induced state of overconnectivity within and between frontal hemispheres.
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Affiliation(s)
- Michael Murias
- University of Washington, Autism Center, Center on Human Development and Disability, Seattle, USA
| | - James M. Swanson
- University of California Irvine, Child Development Center
- Sacker Institute of Cornell University, NY
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Junpeng Z, Dezhong Y, Yuan C, Liujun Y. Multivariate coherence decomposition: a simulation study. CONFERENCE PROCEEDINGS : ... ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL CONFERENCE 2007; 2005:1518-20. [PMID: 17282490 DOI: 10.1109/iembs.2005.1616721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
This paper presented a method, termed MVCCD<inf>FD</inf>(Multivariate coherence decomposition), for mapping coherent brain sources at given frequencies. By calculating averaged coherence over all pairs of channels, we can know at which frequencies there are strong coherence. And then, by utilizing MVCCD<inf>FD</inf>to corresponding frequencies we can get the 2D distributions of coherent sources at given frequencies. Computer Simulation shows that this method can identify the coherent brain sources at different frequencies.
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Affiliation(s)
- Zhang Junpeng
- student Member IEEE, Department of Computer Science, Chengdu Medical College, Chengdu China, 610083(e-mail: )
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43
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Abstract
The purpose of this study was to explore spatial-temporal correlations between 3-dimensional current density estimates using Low Resolution Electromagnetic Tomography (LORETA). The electroencephalogram (EEG) was recorded from 19 scalp locations from 97 subjects. LORETA current density was computed for 2,394 gray matter pixels. The gray matter pixels were grouped into 33 left hemisphere and 33 right hemisphere regions of interest (ROIs) based on groupings of Brodmann areas. The average source current density in a given region of interest (ROI) was computed for each 2 second epoch of EEG and then a Pearson product correlation coefficient was computed over the time series of successive 2 second epochs of current density between all pairwise combinations of ROIs during the resting eyes-closed EEG session. Rhythmic changes in source correlation as a function of distance were present in all regions of interest. Also, maximum correlations at certain frequencies were present independent of distance. The occipital regions exhibited the highest short distance correlations and the frontal regions exhibited the highest long distance correlations. In general, the right hemisphere exhibited higher intra-hemispheric source correlations than the left hemisphere especially in the temporal, parietal and occipital cortex. The strongest left vs. right hemisphere differences were in the alpha frequency band (8-12 Hz) and in the gamma frequency band (37-40 Hz). The pattern of spatial frequencies in different cortical lobules is consistent with differences in neural packing density and the operation of 'U' shaped fiber systems. The general conclusions were: 1--the higher the packing density then the greater the intra-cortical connection contribution to LORETA source correlations, 2--spatial frequencies are primarily due to intra-cortical 'U' shaped fiber connections and long distance fiber connections, 3--posterior and temporal cortical intra-hemispheric coupling is generally stronger in the right hemisphere than in the left hemisphere.
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Affiliation(s)
- R W Thatcher
- Department of EEG and NeuroImaging Laboratory, Bay Pines VA Medical Center, St. Petersburg, Florida, USA.
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De Martino F, Gentile F, Esposito F, Balsi M, Di Salle F, Goebel R, Formisano E. Classification of fMRI independent components using IC-fingerprints and support vector machine classifiers. Neuroimage 2007; 34:177-94. [PMID: 17070708 DOI: 10.1016/j.neuroimage.2006.08.041] [Citation(s) in RCA: 188] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2006] [Revised: 08/23/2006] [Accepted: 08/29/2006] [Indexed: 10/24/2022] Open
Abstract
We present a general method for the classification of independent components (ICs) extracted from functional MRI (fMRI) data sets. The method consists of two steps. In the first step, each fMRI-IC is associated with an IC-fingerprint, i.e., a representation of the component in a multidimensional space of parameters. These parameters are post hoc estimates of global properties of the ICs and are largely independent of a specific experimental design and stimulus timing. In the second step a machine learning algorithm automatically separates the IC-fingerprints into six general classes after preliminary training performed on a small subset of expert-labeled components. We illustrate this approach in a multisubject fMRI study employing visual structure-from-motion stimuli encoding faces and control random shapes. We show that: (1) IC-fingerprints are a valuable tool for the inspection, characterization and selection of fMRI-ICs and (2) automatic classifications of fMRI-ICs in new subjects present a high correspondence with those obtained by expert visual inspection of the components. Importantly, our classification procedure highlights several neurophysiologically interesting processes. The most intriguing of which is reflected, with high intra- and inter-subject reproducibility, in one IC exhibiting a transiently task-related activation in the 'face' region of the primary sensorimotor cortex. This suggests that in addition to or as part of the mirror system, somatotopic regions of the sensorimotor cortex are involved in disambiguating the perception of a moving body part. Finally, we show that the same classification algorithm can be successfully applied, without re-training, to fMRI collected using acquisition parameters, stimulation modality and timing considerably different from those used for training.
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Affiliation(s)
- Federico De Martino
- Department of Cognitive Neurosciences, Faculty of Psychology, University of Maastricht, Maastricht, The Netherlands
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EEG Spectral-Power and Coherence: LORETA Neurofeedback Training in the Anterior Cingulate Gyrus. ACTA ACUST UNITED AC 2006. [DOI: 10.1300/j184v10n01_02] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Corsi-Cabrera M, Galindo-Vilchis L, del-Río-Portilla Y, Arce C, Ramos-Loyo J. Within-subject reliability and inter-session stability of EEG power and coherent activity in women evaluated monthly over nine months. Clin Neurophysiol 2006; 118:9-21. [PMID: 17055781 DOI: 10.1016/j.clinph.2006.08.013] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2005] [Revised: 08/15/2006] [Accepted: 08/27/2006] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Quantitative EEG parameters during resting conditions are used as baseline in research on cognition and in serial-EEG recordings. Despite its increasing use in cognitive research and the numerous evidences of the existence of sex differences in EEG, EEG stability has been mainly investigated in men. Particularly, studies on stability of coherent activity are scarce. The aim of this study was to investigate within-subject reliability and inter-session stability of resting EEG over a nine-month period in women. METHODS Within-subject reliability and inter-session stability were analyzed for absolute power and inter- and intrahemispheric coherent activity at central and posterior regions, once a month, in resting conditions, with eyes open and closed. RESULTS Within-subject reliability was very high (r>0.89) for all subjects and EEG parameters. Inter-session stability was higher with eyes closed and for interhemispheric coherent activity, and poorer with eyes open especially in the alpha band. CONCLUSIONS Present results indicate high reliability of the pattern of power and coherent activity of each individual woman during rest, and group stability of EEG activity with eyes closed at least over a nine-month period. SIGNIFICANCE These results provide information on EEG stability in women over a long period.
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Affiliation(s)
- M Corsi-Cabrera
- Facultad de Psicología, Posgrado, Universidad Nacional Autónoma de México, Mexico.
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Bermond B, Vorst HCM, Moormann PP. Cognitive neuropsychology of alexithymia: implications for personality typology. Cogn Neuropsychiatry 2006; 11:332-60. [PMID: 17354075 DOI: 10.1080/13546800500368607] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
INTRODUCTION We examine the cognitive neuroscience of the five components of the alexithymia syndrome, and propose a classification of alexithymia types based on psychobiological traits. METHOD Literature review. RESULTS The following neural structures have been shown to be prominent in emotional function: right and left hemisphere, corpus callosum, anterior commissure, anterior cingulate, prefrontal cortex, amygdala, and insular cortex. The specific relevance of these structures to alexithymia is discussed. CONCLUSIONS The following conclusions and/or propositions are presented: The right hemisphere produces a global, nonverbal overview of emotional information; the left hemisphere seems dedicated to analysing emotions and higher explicit emotional cognitions. Both orbitoprefrontal cortices are important in affective aspects of alexithymia, while right temporal cortex is involved in cognitive aspects. Two subparts of anterior cingulate fulfil functions in the affective and cognitive dimensions of alexithymia. The amygdalae are involved in both cognitive and affective aspects. All structures mentioned can modulate one another. The role of interhemispheric information transfer via the corpus callosum and the anterior commissure is also discussed. The evidence that that cognitive processing of emotional information inhibits affective processing of such information is discussed in terms of its implications for a theory of alexithymia subtypes.
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Kułak W, Sobaniec W, Kuzia JS, Boćkowski L. Neurophysiologic and neuroimaging studies of brain plasticity in children with spastic cerebral palsy. Exp Neurol 2006; 198:4-11. [PMID: 16414042 DOI: 10.1016/j.expneurol.2005.11.014] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2005] [Revised: 10/27/2005] [Accepted: 11/11/2005] [Indexed: 01/19/2023]
Abstract
Patients with cerebral palsy (CP) may have some problems other than this motor impairment: mental retardation, epilepsy and sensory disturbance. Healthy children and children with CP have an enhanced capacity for learning and memory compared to adults. There are few tools for brain plasticity investigations. The utility of the neurophysiologic and MRI techniques in the determination of brain reorganization and repair in patients with cerebral palsy is described. The authors discuss their results of quantitative EEG and spectroscopy MRI studies in children with CP. Quantitative EEG and spectroscopy MRI can be useful tools in the determination of these processes in children with CP.
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Affiliation(s)
- Wojciech Kułak
- Department of Pediatric Neurology and Rehabilitation, Medical University of Bialystok, Waszyngtona 17, 15-274 Bialystok, Poland.
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Gootjes L, Bouma A, Van Strien JW, Scheltens P, Stam CJ. Attention modulates hemispheric differences in functional connectivity: evidence from MEG recordings. Neuroimage 2005; 30:245-53. [PMID: 16253520 DOI: 10.1016/j.neuroimage.2005.09.015] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2005] [Revised: 09/08/2005] [Accepted: 09/12/2005] [Indexed: 11/20/2022] Open
Abstract
The present study examined intrahemispheric functional connectivity during rest and dichotic listening in 8 male and 9 female healthy young adults measured with magnetoencephalography (MEG). Generalized synchronization within the separate hemispheres was estimated by means of the synchronization likelihood that is sensitive to linear as well as non-linear coupling of MEG signals. We found higher functional intrahemispheric connectivity of frontal and temporal areas within the right as compared to the left hemisphere in the lower and higher theta band during rest and in the lower theta band during dichotic listening. In addition, higher synchronization in the lower theta band correlated with better task performance. In the upper alpha band, hemispheric differences in intrahemispheric connectivity of the frontal regions were found to be modulated by focused attention instructions. That is, attention to the right ear exaggerates the pattern of higher synchronization likelihood for the right frontal region, while attention to the left ear has an opposite effect. We found higher intrahemispheric connectivity in males compared to females as shown by higher synchronization in the lower alpha band. Taken together, our results reflect a physiological basis for functional hemispheric laterality and support the general assumption of sex differences in brain organization. Furthermore, in addition to studies that show that controlled attention processes modulate activation of the frontal areas, our study indicates that attention modulates ipsilateral functional connectivity in the frontal areas. This supports the idea of a supervisory role for the frontal cortex in attention processes.
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Affiliation(s)
- Liselotte Gootjes
- Department of Clinical Neuropsychology, Vrije Universiteit, Amsterdam, The Netherlands.
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50
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Clarke AR, Barry RJ, McCarthy R, Selikowitz M, Johnstone SJ, Abbott I, Croft RJ, Magee CA, Hsu CI, Lawrence CA. Effects of methylphenidate on EEG coherence in Attention-Deficit/Hyperactivity Disorder. Int J Psychophysiol 2005; 58:4-11. [PMID: 15921774 DOI: 10.1016/j.ijpsycho.2005.03.004] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2004] [Revised: 01/05/2005] [Accepted: 02/03/2005] [Indexed: 11/18/2022]
Abstract
This study investigated the effects of methylphenidate on intrahemispheric and interhemispheric EEG coherence in children with Attention-Deficit/Hyperactivity Disorder (AD/HD). Twenty boys with AD/HD Combined type and 20 age- and sex-matched control subjects, aged 8 to 13 years, participated in this study. EEG was recorded from 21 sites during an eyes-closed resting condition. Wave-shape coherence was calculated for eight intrahemispheric electrode pairs (four in each hemisphere), and eight interhemispheric electrode pairs, within each of the delta, theta, alpha and beta bands. AD/HD children were tested both off and, 6 months later, on a therapeutic dose of methylphenidate. In intrahemispheric comparisons, AD/HD children had lower theta coherences at long inter-electrode distances, and reduced lateralisation at both long and short-medium inter-electrode distances than controls. For interhemispheric comparisons, AD/HD children showed increased coherences in the frontal regions for the low frequency bands (delta and theta), and reduced coherences in the alpha bands in all other regions. These EEG coherences suggest reduced cortical differentiation and specialisation in AD/HD, particularly in the frontal regions. Methylphenidate did not produce any changes in coherence values. The lack of sensitivity of coherence measures to methylphenidate in the present study suggests that eyes-closed resting EEG coherence measures are associated with structural connectivity of the underlying regions of the brain rather than the degree of functionality of these regions. These results suggest the existence of structural as well as functional brain dysfunction in AD/HD.
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Affiliation(s)
- Adam R Clarke
- Brain & Behaviour Research Institute and Department of Psychology, University of Wollongong, Wollongong 2522, Australia.
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