The effects of competition and motor reprogramming on visuomotor selection in unilateral neglect

Mattingley, JB, Corben, LA, Bradshaw, JL, Bradshaw, JA, Phillips, JG and Horne, MK (1998) The effects of competition and motor reprogramming on visuomotor selection in unilateral neglect. Experimental Brain Research, 120 2: 243-256. doi:10.1007/s002210050398

Author Mattingley, JB
Corben, LA
Bradshaw, JL
Bradshaw, JA
Phillips, JG
Horne, MK
Title The effects of competition and motor reprogramming on visuomotor selection in unilateral neglect
Journal name Experimental Brain Research   Check publisher's open access policy
ISSN 0014-4819
Publication date 1998-01-01
Year available 1998
Sub-type Article (original research)
DOI 10.1007/s002210050398
Open Access Status Not yet assessed
Volume 120
Issue 2
Start page 243
End page 256
Total pages 14
Place of publication NEW YORK
Language eng
Subject 2800 Neuroscience
Abstract Patients with unilateral neglect following right hemisphere damage may have difficulty in moving towards contralesional targets. To test the hypothesis that this impairment arises from competing motor programs triggered by irrelevant ipsilesional stimuli, we examined 16 right hemisphere patients, eight with left visual neglect and eight without, in addition to eight healthy control subjects. In experiment 1 subjects performed sequences of movements using their right hand to targets on the contralesional or ipsilesional side of the responding limb. The locations of successive targets in each sequence were either predictable or unpredictable. In separate blocks of trials, targets appeared either alone or with a simultaneous distracter located at the immediately preceding target location. Neglect patients were significantly slower to execute movements to contralesional targets, but only for unpredictable movements and in the presence of a concurrent ipsilesional distracter. In contrast, healthy controls and right hemisphere patients without neglect showed no directional asymmetries of movement execution. In experiment 2 subjects were required to interrupt a predictable, reciprocating sequence of leftward and rightward movements in order to move to an occasional, unpredictable target that occurred either in the direction opposite to that expected, or in the same direction but twice the extent. Neglect patients were significantly slower in reprogramming the direction and extent of movements towards contralesional versus ipsilesional targets, and they also made significantly more errors when executing such movements. Right hemisphere patients without neglect showed a similar bias in reprogramming direction (but not extent) for contralesional targets, whereas healthy controls showed no directional asymmetry in either condition. On the basis of these findings we propose that neglect involves a competitive bias in favour of motor programs for actions directed towards ipsilesional versus contralesional events. We suggest that programming errors and increased latencies for contralesional movements arise because the damaged right hemisphere can no longer effectively inhibit the release of inappropriate motor programs towards ipsilesional events.
Keyword Extinction
Motor programming
Right hemisphere
Selective attention
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status Unknown

Document type: Journal Article
Sub-type: Article (original research)
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Citation counts: TR Web of Science Citation Count  Cited 29 times in Thomson Reuters Web of Science Article | Citations
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