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Neuromagnetic correlates of categorization in normal controls and schizophrenic patients

Neuromagnetic correlates of categorization in normal controls and schizophrenic patients

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Prüfsumme: MD5:df8d61617c4a5b9cf57099cb035f2de7

LÖW, Andreas, 2007. Neuromagnetic correlates of categorization in normal controls and schizophrenic patients

@phdthesis{Low2007Neuro-11176, title={Neuromagnetic correlates of categorization in normal controls and schizophrenic patients}, year={2007}, author={Löw, Andreas}, address={Konstanz}, school={Universität Konstanz} }

2011-03-25T09:26:08Z 2007 Neuromagnetische Korrelate der Kategorisierung bei gesunden Kontrollprobanden und schizophrenen Patienten Neuromagnetic correlates of categorization in normal controls and schizophrenic patients 2011-03-25T09:26:08Z eng The present study examines object categorization in healthy controls (part A) and schizophrenic patients (part B). Objects from four superordinate categories (e.g. furniture) were presented and the megentoencephalogram (MEG) was recorded. Each superordinate category was represented by four different base level objects (e.g. table, chair). By means of spatio-temporal correlation of neighboring 'sensors' in the source space and by application of a unsupervised hierarchical clustering algorithm is shown, that objects from the same category have a more similar 'neuromagnetic signature' than objects belonging to different categories. This effect was most pronounced over temporal areas and is in line with findings from animal, neuropsychological and imaging studies of the localization of object categorization. A possible explanation are distributed neural networks in which different properties and attributes like form or color of an object are represented and which overlap stronger between exemplars of the same category.. In that sense, similarities in the MEG signal between two objects can be interpreted as a correlate of their associative network strength.<br />Part B applies these methods to a group of schizophrenic patients. A reduced differentiation of the categories by spatio-temporal correlations and a less well-defined organization by the hierarchical clustering indicate deficits in the neuroarchetectonic organization of the semantic system in schizophrenic patients. Loosened associations within neural networks of the temporal lobes are a possible cause for these deficits. Associations with clinic symptom scales indicate more severe positive symptomatic when a stronger disturbance of the semantic system is present. application/pdf Löw, Andreas Löw, Andreas deposit-license

Dateiabrufe seit 01.10.2014 (Informationen über die Zugriffsstatistik)

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