Article

Functional imaging studies of spatial attention regularly report activation of
the intraparietal sulcus (IPS) and dorsal premotor cortex including the frontal
eye fields (FEF) in tasks requiring overt or covert shifting of attention. In
contrast, lesion-overlap studies of patients with spatial neglect - a syndrome
characterized by severe impairments of spatial attention - show that the critical
damage concerns more ventral regions, comprising the inferior parietal lobule,
the temporal-parietal junction (TPJ), and the superior temporal gyrus. We
performed voxel-based lesion-symptom mapping of 29 right-hemisphere stroke
patients, using several performance indices derived from a cueing task as
measures of spatial attention. In contrast to previous studies, we focused our
analyses on eight regions of interest defined according to results of previous
functional imaging studies. A direct comparison of neglect with control patients
revealed that neglect was associated with damage to the TPJ, the middle frontal
gyrus, and the posterior IPS. The latter region was also a significant predictor
of the degree of contralesional slowing of target detection and the extent to
which ipsilesional distracters captured attention of neglect patients. Finally,
damage to the FEF and posterior IPS was negatively correlated with the tendency
of neglect patients to orient attention toward behaviourally relevant
distracters. These findings support the results of functional imaging studies of
spatial attention and provide evidence for a network account of neglect,
according to which attentional selection of relevant environmental stimuli and
the reorienting of attention result from dynamic interactions between the IPS,
the dorsal premotor cortex, and the TPJ.
CI - Copyright (c) 2011 Elsevier Ltd. All rights reserved.

Langue : ANGLAIS