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, and control parti cipants. In the preattentive search task, targets possessed a unique featur e that was not shared by distracters. In the attentive search task, targets lacked a feature that was present in the distracters. Preattentive search was normal in 3 neglect patients with cortical lesions 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 preatte ntive task. Neglect patients were characteristically impaired in the contra lesional field in the attentive search task. This study demonstrates preser ved explicit detection of visual features in cases of hemispatial neglect.