Preattentive and attentive visual search in individuals with hemispatial neglect

Preattentive and attentive visual processing was examined in patients with hemispatial neglect, hemispatial neglect with hemianopia, nd control participants. In the preattentive search task, targets possessed a unique feature that was not shared by distractors. In the attentive search task, targets lacked a feature that was present in the distractors. Preattentive search was normal in 3 neglect patients with cortical esions but not in 2 neglect patients with hemianopia. A 4th neglect patient without hemianopia with a subcortical infarct abnormally used serial search mechanisms in the preattentive task. Neglect patients were characteristi-cally impaired in the contralesional field in the attentive search task. This study demonstrates preserved explicit detection of visual features in cases of hemispatial neglect. Hemispatial neglect is an acquired disorder in which patients fail to acknowledge, report, or otherwise make explicit use of information falling in the hemispace con-tralateral to their lesion. Although hemispatial neglect may present after a lesion to the left cerebral hemisphere, it is most often observed after damage to a number of differen