Visual search in spatial neglect studied with a preview paradigm.

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Serval ID
serval:BIB_26FB8D38BF96
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Visual search in spatial neglect studied with a preview paradigm.
Journal
Frontiers In Human Neuroscience
Author(s)
Fellrath J., Blanche-Durbec V., Schnider A., Jacquemoud A.S., Ptak R.
ISSN
1662-5161 (Electronic)
ISSN-L
1662-5161
Publication state
Published
Issued date
2012
Peer-reviewed
Oui
Volume
6
Pages
93
Language
english
Notes
Publication types: Journal ArticlePublication Status: ppublish
Abstract
Impaired visual search is a hallmark of spatial neglect. When searching for an unique feature (e.g., color) neglect patients often show only slight visual field asymmetries. In contrast, when the target is defined by a combination of features (e.g., color and form) they exhibit a severe deficit of contralesional search. This finding suggests a selective impairment of the serial deployment of spatial attention. Here, we examined this deficit with a preview paradigm. Neglect patients searched for a target defined by the conjunction of shape and color, presented together with varying numbers of distracters. The presentation time was varied such that on some trials participants previewed the target together with same-shape/different-color distracters, for 300 or 600 ms prior to the appearance of additional different-shape/same-color distracters. On the remaining trials the target and all distracters were shown simultaneously. Healthy participants exhibited a serial search strategy only when all items were presented simultaneously, whereas in both preview conditions a pop-out effect was observed. Neglect patients showed a similar pattern when the target was presented in the right hemifield. In contrast, when searching for a target in the left hemifield they showed serial search in the no-preview condition, as well as with a preview of 300 ms, and partly even at 600 ms. A control experiment suggested that the failure to fully benefit from item preview was probably independent of accurate perception of time. Our results, when viewed in the context of existing literature, lead us to conclude that the visual search deficit in neglect reflects two additive factors: a biased representation of attentional priority in favor of ipsilesional information and exaggerated capture of attention by ipsilesional abrupt onsets.
Pubmed
Web of science
Open Access
Yes
Create date
28/05/2012 17:17
Last modification date
20/08/2019 13:05
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