Holz, Petra

[["dc.bibliographiccitation.firstpage","45"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Magnetic Resonance Imaging"],["dc.bibliographiccitation.lastpage","53"],["dc.bibliographiccitation.volume","26"],["dc.contributor.author","Morawetz, Cannen"],["dc.contributor.author","Holz, Petra"],["dc.contributor.author","Lange, Claudia"],["dc.contributor.author","Baudewig, Juergen"],["dc.contributor.author","Weniger, Godehard"],["dc.contributor.author","Irle, Eva"],["dc.contributor.author","Dechent, Peter"],["dc.date.accessioned","2018-11-07T11:20:21Z"],["dc.date.available","2018-11-07T11:20:21Z"],["dc.date.issued","2008"],["dc.description.abstract","As the amygdala is involved in various aspects of emotional processing, its characterization using neuroimaging modalities, such as functional magnetic resonance imaging (fMRI), is of great interest. However, in fMRI, the amygdala region suffers from susceptibility artifacts that are composed of signal dropouts and image distortions. Various technically demanding approaches to reduce these artifacts have been proposed, and most require alterations beyond a mere change of the acquisition parameters and cannot be easily implemented by the user without changing the MR sequence code. In the present study, we therefore evaluated the impact of simple alterations of the acquisition parameters of a standard gradient-echo echo-planar imaging technique at 3 T composed of echo times (TEs) of 27 and 36 ms as well as section thicknesses of 2 and 4 mm while retaining a section orientation parallel to the intercommissural plane and an in-plane resolution of 2 X 2 mm(2). In contrast to previous studies, we based our evaluation on the resulting activation maps using an emotional stimulation paradigm rather than on MR raw image quality only. Furthermore, we tested the effects of spatial smoothing of the functional raw data in the course of postprocessing using spatial filters of 4 and 8 mm. Regarding MR raw image quality, a TE of 27 ms and 2-mm sections resulted in the least susceptibility artifacts in the anteromedial aspect of the temporal lobe. The emotional stimulation paradigm resulted in robust bilateral amygdala activation for the approaches with 2-mm sections only - but with larger activation volumes for a TE of 36 ms as compared with that of 27 ms. Moderate smoothing with a 4-mm spatial filter represented a good compromise between increased sensitivity and preserved specificity. In summary, we showed that rather than applying advanced modifications of the MR sequence, a simple increase in spatial resolution (i.e., the reduction of section thickness) is sufficient to improve the delectability of amygdala activation. (c) 2008 Elsevier Inc. All rights reserved."],["dc.identifier.doi","10.1016/j.mri.2007.04.014"],["dc.identifier.isi","000252288500006"],["dc.identifier.pmid","17574366"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/55513"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Inc"],["dc.relation.issn","0730-725X"],["dc.title","Improved functional mapping of the human amygdala using a standard functional magnetic resonance imaging sequence with simple modifications"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","817"],["dc.bibliographiccitation.issue","6"],["dc.bibliographiccitation.journal","Visual Neuroscience"],["dc.bibliographiccitation.lastpage","826"],["dc.bibliographiccitation.volume","24"],["dc.contributor.author","Morawetz, Carmen"],["dc.contributor.author","Holz, Petra"],["dc.contributor.author","Baudewig, Jürgen"],["dc.contributor.author","Treue, Stefan"],["dc.contributor.author","Dechent, Peter"],["dc.date.accessioned","2021-06-01T10:50:25Z"],["dc.date.available","2021-06-01T10:50:25Z"],["dc.date.issued","2007"],["dc.description.abstract","Visual spatial attention has been described as a process that favors the processing of sensory information that falls into the “spotlight of attention.” Recent studies have provided support for an ability to split this attentional focus to selectively process spatially separate locations. Using functional magnetic resonance imaging, the signature for the presence of multiple spotlights is the presence of multiple retinotopically specific foci of activation in striate and extrastriate visual areas. We used this approach to investigate the presence of such separable activations as a function of the eccentricity of the spatial foci of attention. Visual stimuli consisted of letters and digits displayed in rapid serial visual presentation (RSVP). Five RSVP streams were presented simultaneously, one in the center of the visual field and one in each visual field quadrant. Subjects had to deploy their attention either to a single peripheral location or two non-contiguous regions performing a match-mismatch judgment. The results show that dividing attention leads to multiple spotlights of attention for central as well as more peripheral locations of the visual field. However, depending on the exact location and width of the attentional spotlights, resulting activation maps might reveal merged activation patterns even in the presence of distinct attentional spotlights."],["dc.identifier.doi","10.1017/S0952523807070745"],["dc.identifier.gro","3151564"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/86652"],["dc.language.iso","en"],["dc.notes.intern","DOI-Import GROB-425"],["dc.notes.status","final"],["dc.notes.submitter","chake"],["dc.relation.eissn","1469-8714"],["dc.relation.issn","0952-5238"],["dc.title","Split of attentional resources in human visual cortex"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]