Article

Transcranial magnetic stimulation disrupts eye-hand interactions in the posterior parietal cortex.

Department of Exercise and Movement Science and Institute of Neuroscience, University of Oregon, Eugene, Oregon 97403-1240, USA.
Journal of Neurophysiology (impact factor: 3.32). 10/2000; 84(3):1677-80. pp.1677-80
Source: PubMed

ABSTRACT Recent neurophysiological studies have started to shed some light on the cortical areas that contribute to eye-hand coordination. In the present study we investigated the role of the posterior parietal cortex (PPC) in this process in normal, healthy subjects. This was accomplished by delivering single pulses of transcranial magnetic stimulation (TMS) over the PPC to transiently disrupt the putative contribution of this area to the processing of information related to eye-hand coordination. Subjects made open-loop pointing movements accompanied by saccades of the same required amplitude or by saccades that were substantially larger. Without TMS the hand movement amplitude was influenced by the amplitude of the corresponding saccade; hand movements accompanied by larger saccades were larger than those accompanied by smaller saccades. When TMS was applied over the left PPC just prior to the onset of the saccade, a marked reduction in the saccadic influence on manual motor output was observed. TMS delivered at earlier or later periods during the response had no effect. Taken together, these data suggest that the PPC integrates signals related to saccade amplitude with limb movement information just prior to the onset of the saccade.

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Keywords

corresponding saccade
 
eye-hand coordination
 
hand movement amplitude
 
hand movements
 
healthy subjects
 
larger saccades
 
left PPC
 
limb movement information
 
manual motor output
 
marked reduction
 
movements
 
normal
 
posterior parietal cortex
 
PPC integrates signals
 
Recent neurophysiological studies
 
saccade amplitude
 
saccades
 
saccadic influence
 
smaller saccades
 
transcranial magnetic stimulation
 

P van Donkelaar