Deficits of position sense, unilateral neglect and optokinetic stimulation.
The effects of optokinetic stimulation on position sense disorders were investigated in a series of 30 patients with unilateral vascular lesions (10 right brain-damaged patients with visuospatial hemineglect, 10 right brain-damaged patients without visuo-spatial hemineglect, 10 left brain-damaged patients), and 10 control subjects. The position sense deficit was more severe in right brain-damaged patients with neglect, where both the contralateral and the ipsilateral arm were involved. Optokinetic stimulation was effective only in right brain-damaged patients with neglect: stimulation with a leftward movement (contralateral to the side of the hemispheric lesion) improved the position sense deficit, while stimulation with a rightward (ipsilateral) movement produced a worsening of the performance level. These findings suggest that in right brain-damaged patients with neglect the position sense deficit has a nonsensory component, related to neglect, which may be affected by optokinetic stimulation. The role of the derangement of sensory and perceptual-egocentric representations of the body and of extrapersonal space in producing position sense disorders is discussed.
Vallar
G
G
Dipartimento di Psicologia, Universitá di Roma, La Sapienza, Italia.
Antonucci
G
G
Guariglia
C
C
Pizzamiglio
L
L
D000368:Aged; D000704:Analysis of Variance; D002561:Cerebrovascular Disorders / Q000523:psychology; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008875:Middle Aged; D009039:Motion Perception / Q000502:physiology; D009068:Movement / Q000502:physiology; D010775:Photic Stimulation; D011187:Posture / Q000502:physiology*; D012678:Sensation Disorders / Q000503:physiopathology* / Q000523:psychology