In:
Journal of the International Neuropsychological Society, Cambridge University Press (CUP), Vol. 6, No. 1 ( 2000-01), p. 71-75
Abstract:
In a previous study, we demonstrated that unilateral
cerebral lesions produce hypometric limb movements of the contralateral arm and hemispatial (i.e., directional) hypometria
for movements towards contralateral hemispace. In the present study, we investigated 10 patients with right cerebral
lesions and 25 healthy controls using a task to uncouple deficits in sensory perceptual systems and motor-action
output systems on directional hypometria. This task required participants, with their eyes closed, to reproduce lateral
and medial horizontal displacements (15–27 cm) with each arm. Each participant was seated at a waist high table
and had their hand placed at an origin point aligned with the axillary fold on the same side. Their hand was moved
by the investigator from the origin point to a target point and brought back to the point of origin (input displacement).
The participant was then asked to return their hand to either the same target point or to an equidistant target
point in the opposite direction. Healthy dextral participants were significantly more hypometric with their right arm,
but patients with right cerebral lesions exhibited an opposite pattern with overall left arm hypometria. In addition,
patients were significantly more hypometric for movements when output displacements were toward left hemispace. No
effect was found for direction of sensory input. The results suggest that the directional hypometria is predominantly
produced by hemispatial output deficits. ( JINS ,
2000, 6 , 71–75.)
Type of Medium:
Online Resource
ISSN:
1355-6177
,
1469-7661
DOI:
10.1017/S1355617700611086
Language:
English
Publisher:
Cambridge University Press (CUP)
Publication Date:
2000
detail.hit.zdb_id:
2000018-2
SSG:
5,2
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