@article{ref1,
title="The neural correlates of impaired collision avoidance in hemianopic patients",
journal="Acta ophthalmologica (Copenhagen)",
year="2011",
author="Papageorgiou, Eleni and Hardiess, Gregor and Wiethölter, Horst and Ackermann, Hermann and Dietz, Klaus and Mallot, Hanspeter A. and Schiefer, Ulrich",
volume="90",
number="3",
pages="e198-205",
abstract="Purpose:  The aim of this study was to assess the brain regions associated with impaired performance in a virtual, dynamic collision avoidance task, in a group of patients with homonymous visual field defects (HVFDs) because of unilateral vascular brain lesions. Methods:  Overall task performance was quantitatively assessed as the number of collisions while crossing an intersection at two levels of traffic density. Twenty-six patients were divided into two subgroups using the median split method: patients with 'performance above average' (HVFD(A) , i.e. lower number of collisions) and patients with 'performance below average' (HVFD(B) , i.e. higher number of collisions). In order to identify the anatomical structures that might be specifically affected in HVFD(B) patients but spared in HVFD(A) patients, overlap, subtraction and voxel-based lesion-symptom mapping analyses were performed using the MRIcron software. Results:  No significant difference in collision avoidance between patients with left- and right-hemispheric lesions was revealed. Separate lesion analysis in 12 patients with right- and 14 patients with left-hemispheric lesions showed that the cortical structures associated with impaired collision avoidance were the parieto-occipital region and posterior cingulate gyrus in the right hemisphere and the inferior occipital cortex and parts of the fusiform (occipito-temporal) gyrus in the left hemisphere. Conclusion:  In the present collision avoidance paradigm, impaired performance of patients with right-hemispheric lesions is associated with damage in the dorsal processing stream and potential impact on the visual spatial working memory (WM), while impaired performance of patients with left-hemispheric lesions is associated with damage in the ventral stream and potential impact on the visual object WM.<p /><p>Language: en</p>",
language="en",
issn="0001-639X",
doi="10.1111/j.1755-3768.2011.02315.x",
url="http://dx.doi.org/10.1111/j.1755-3768.2011.02315.x"
}