Schmidt-Samoa, Carsten

[["dc.bibliographiccitation.firstpage","46"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Neurobiology of Learning and Memory"],["dc.bibliographiccitation.lastpage","55"],["dc.bibliographiccitation.volume","93"],["dc.contributor.author","Weniger, Godehard"],["dc.contributor.author","Siemerkus, Jakob"],["dc.contributor.author","Schmidt-Samoa, Carsten"],["dc.contributor.author","Mehlitz, Markus"],["dc.contributor.author","Baudewig, Juergen"],["dc.contributor.author","Dechent, Peter"],["dc.contributor.author","Irle, Eva"],["dc.date.accessioned","2018-11-07T08:48:13Z"],["dc.date.available","2018-11-07T08:48:13Z"],["dc.date.issued","2010"],["dc.description.abstract","Background: Present evidence suggests that the hippocampus (HC) and the parahippocampal cortex (PHC) are involved in allocentric (world-centered) spatial memory. However, the putative role of the PHC in egocentric (body-centered) spatial learning has received only limited systematic investigation. Methods: To examine the role of the PHC in egocentric learning, 19 healthy volunteers learned to find their way in a virtual maze during functional magnetic resonance imaging (fMRI). The virtual maze presented a first-person view, lacked any topographical landmarks and could be learned only using egocentric navigation strategies. Results: During learning, increased medial temporal lobe activity was observed in the PHC bilaterally. Activity was also observed in cortical areas known to project to the PHC and proposed to contribute to egocentric spatial navigation and memory. Conclusions: Our results point to a role of the PHC for the representation and storage of egocentric information. It seems possible that the PHC contributes to egocentric memory by its feedback projections to the posterior parietal cortex. Moreover, access to allocentric and egocentric streams of spatial information may enable the PHC to construct a global and comprehensive representation of spatial environments and to promote the construction of stable cognitive maps by translating between egocentric and allocentric frames of memory. (C) 2009 Elsevier Inc. All rights reserved."],["dc.description.sponsorship","Deutsche Forschungsgemeinschaft [RI 1000/1-1]; Volkswagenstiftung"],["dc.identifier.doi","10.1016/j.nlm.2009.08.003"],["dc.identifier.isi","000274315600006"],["dc.identifier.pmid","19683063"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/21155"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Academic Press Inc Elsevier Science"],["dc.relation.issn","1074-7427"],["dc.title","The human parahippocampal cortex subserves egocentric spatial learning during navigation in a virtual maze"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","898"],["dc.bibliographiccitation.issue","6"],["dc.bibliographiccitation.journal","Neurobiology of Aging"],["dc.bibliographiccitation.lastpage","902"],["dc.bibliographiccitation.volume","30"],["dc.contributor.author","Koschack, Janka"],["dc.contributor.author","Luetjohann, Dieter"],["dc.contributor.author","Schmidt-Samoa, Carsten"],["dc.contributor.author","Irle, Eva"],["dc.date.accessioned","2018-11-07T08:29:32Z"],["dc.date.available","2018-11-07T08:29:32Z"],["dc.date.issued","2009"],["dc.description.abstract","The present study assessed the association between serum 24S-hydroxycholesterol (24S-OH-Chol) and 27-hydroxycholesterol (27-OH-Chol) and hippocampal volumes in 69 middle-aged cognitively normal individuals. Results showed that subjects with high levels of oxysterols, had significantly larger hippocampal volumes than subjects with low levels of oxysterols. Multiple regression analysis revealed that 24S-OH-Chol, but not 27-OH-Chol or cholesterol, was able to significantly predict hippocampal size. Future studies should elucidate whether high brain cholesterol metabolism in the middle age is protective against hippocampal atrophy and cognitive decline. (C) 2007 Elsevier Inc. All rights reserved."],["dc.description.sponsorship","Deutsche Forschungsgemeinschaft [IR 15/6-2]; University of Gottingen"],["dc.identifier.doi","10.1016/j.neurobiolaging.2007.10.010"],["dc.identifier.isi","000266062300005"],["dc.identifier.pmid","18061309"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/16676"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.issn","0197-4580"],["dc.relation.orgunit","Institut für Allgemeinmedizin"],["dc.title","Serum 24S-hydroxycholesterol and hippocampal size in middle-aged normal individuals"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","116"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","Psychiatry Research Neuroimaging"],["dc.bibliographiccitation.lastpage","124"],["dc.bibliographiccitation.volume","212"],["dc.contributor.author","Weniger, Godehard"],["dc.contributor.author","Siemerkus, Jakob"],["dc.contributor.author","Barke, Antonia"],["dc.contributor.author","Lange, Claudia"],["dc.contributor.author","Ruhleder, Mirjana"],["dc.contributor.author","Sachsse, Ulrich"],["dc.contributor.author","Schmidt-Samoa, Carsten"],["dc.contributor.author","Dechent, Peter"],["dc.contributor.author","Irle, Eva"],["dc.date.accessioned","2018-11-07T09:24:33Z"],["dc.date.available","2018-11-07T09:24:33Z"],["dc.date.issued","2013"],["dc.description.abstract","Present neuroimaging findings suggest two subtypes of trauma response, one characterized predominantly by hyperarousal and intrusions, and the other primarily by dissociative symptoms. The neural underpinnings of these two subtypes need to be better defined. Fourteen women with childhood abuse and the current diagnosis of dissociative amnesia or dissociative identity disorder but without posttraumatic stress disorder (PTSD) and 14 matched healthy comparison subjects underwent functional magnetic resonance imaging (fMRI) while finding their way in a virtual maze. The virtual maze presented a first-person view (egocentric), lacked any topographical landmarks and could be learned only by using egocentric navigation strategies. Participants with dissociative disorders (DD) were not impaired in learning the virtual maze when compared with controls, and showed a similar, although weaker, pattern of activity changes during egocentric learning when compared with controls. Stronger dissociative disorder severity of participants with DD was related to better virtual maze performance, and to stronger activity increase within the cingulate gyrus and the precuneus. Our results add to the present knowledge of preserved attentional and visuospatial mnemonic functioning in individuals with DD. (c) 2012 Elsevier Ireland Ltd. All rights reserved."],["dc.identifier.doi","10.1016/j.pscychresns.2012.11.004"],["dc.identifier.isi","000319366300004"],["dc.identifier.pmid","23522878"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/29852"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Ireland Ltd"],["dc.relation.issn","0925-4927"],["dc.title","Egocentric virtual maze learning in adult survivors of childhood abuse with dissociative disorders: Evidence from functional magnetic resonance imaging"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","386"],["dc.bibliographiccitation.issue","2-3"],["dc.bibliographiccitation.journal","Schizophrenia Research"],["dc.bibliographiccitation.lastpage","396"],["dc.bibliographiccitation.volume","84"],["dc.contributor.author","Exner, C."],["dc.contributor.author","Weniger, Godehard"],["dc.contributor.author","Schmidt-Samoa, Carsten"],["dc.contributor.author","Irle, Eva"],["dc.date.accessioned","2018-11-07T09:47:50Z"],["dc.date.available","2018-11-07T09:47:50Z"],["dc.date.issued","2006"],["dc.description.abstract","Increasing evidence suggests that schizophrenia is associated with various morphological and functional abnormalities of the frontal cortex. So far research has concentrated on the dorsolateral and orbitofrontal cortex. Behavioral evidence suggests however that regions responsible for higher motor control are compromised in schizophrenia as well. The current study assessed volumes of the anterior supplementary motor area (pre-SMA) and implicit motor sequence learning in 15 subjects with first-episode schizophrenia and 15 healthy matched controls. Pre-SMA volumes were assessed by three-dimensional structural magnetic resonance imaging (3D-MRI) and manual parcellation according to an established protocol. Implicit motor sequence learning was assessed using the Serial Reaction-Time Task (SRTT). Compared with control subjects, schizophrenia subjects had significantly smaller volumes of the left pre-SNIA (16%). Subjects with schizophrenia were severely impaired on sequence-specific implicit motor learning. Size of the left pre-SNIA of schizophrenia subjects was significantly related to impaired implicit learning. We conclude that subjects with first-episode schizophrenia have a morphological abnormality of the left pre-SMA that might predispose them to develop disturbances of higher motor control during acute episodes of psychosis. These structural and behavioral abnormalities might be conceptualized within a broader model that views schizophrenia as a disorder of disturbed coordination of thought and action. (c) 2006 Elsevier B.V. All rights reserved."],["dc.identifier.doi","10.1016/j.schres.2006.03.013"],["dc.identifier.isi","000238160500021"],["dc.identifier.pmid","16624528"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/35180"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Bv"],["dc.relation.issn","0920-9964"],["dc.title","Reduced size of the pre-supplementary motor cortex and impaired motor sequence learning in first-episode schizophrenia"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]