title: Hemispheric asymmetries in motor function: II. Ordering does not contribute to left-hemisphere specialization.
abstract: Patients with unilateral brain lesions of vascular origin were administered tests designed to determine if the left hemisphere is specialized for the ordering of motor acts. Patients with left- and right-sided lesions responded similarly to manipulations of ordering demands in two motor tasks, one a test of manual sequence learning and the other a test of speeded performance. A detailed analysis of performance on an Ideational Apraxia task indicated that the deficit of patients with left-sided lesions was best characterized as a deficit in generating appropriate acts rather than ordering them. It was concluded that there is no evidence for left-hemisphere specialization for the ordering of motor acts. It was hypothesized that there are two broad stages of motor function: generation of motor "target" acts (which is lateralized to the left hemisphere) and the ordering and execution of these acts (which are not lateralized).
mesh_terms: D001921:Brain / Q000503:physiopathology; D002561:Cerebrovascular Disorders / Q000503:physiopathology* / Q000523:psychology; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006225:Hand / Q000503:physiopathology; D006801:Humans; D007858:Learning / Q000502:physiology; D008297:Male; D011597:Psychomotor Performance / Q000502:physiology*