title: Visual hemispatial inattention: stimulus parameters and exploratory strategies.
abstract: Patients with unilateral hemispheric lesions were given visual target cancellation tasks. As expected, marked contralateral and less severe ipsilateral visual inattention were observed in patients with right-sided cerebral lesions whereas those with left-sided lesions showed only mild contralateral neglect. Stimulus material (shapes vs letters) and array (random vs structured) interacted in a complex manner to influence target detection only in patients with right-sided lesions. Furthermore, the search strategy of these patients tended to be erratic, particularly when the stimuli were in an unstructured array. A structured array prompted a more systematic and efficient search. It appears, therefore, that stimulus content and spatial array affect neglect behaviour in patients with right-sided lesions and that a lack of systematic visual exploration within the extrapersonal space is one factor that contributes to visual hemispatial inattention.
authors.affiliation: Division of Neuroscience and Behavioural Neurology, Beth Israel Hospital, Boston, MA 02215.
authors.forename: S
authors.initials: S
authors.lastname: Weintraub
authors.forename: M M
authors.initials: MM
authors.lastname: Mesulam
mesh_terms: D000368:Aged; D001288:Attention / Q000502:physiology*; D001921:Brain / Q000503:physiopathology; D001925:Brain Damage, Chronic / Q000503:physiopathology; D002561:Cerebrovascular Disorders / Q000503:physiopathology*; D004292:Dominance, Cerebral / Q000502:physiology*; D005260:Female; D005556:Form Perception / Q000502:physiology*; D006429:Hemiplegia / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010364:Pattern Recognition, Visual / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time / Q000502:physiology; D014794:Visual Fields