The role of the human posterior parietal cortex in memory-guided saccade execution: a double-pulse transcranial magnetic stimulation study

Eur J Neurosci. 2005 Jul;22(2):535-8. doi: 10.1111/j.1460-9568.2005.04248.x.

Abstract

The present study investigated the role of the right posterior parietal cortex (PPC) in the triggering of memory-guided saccades by means of double-pulse transcranial magnetic stimulation (dTMS). Shortly before saccade onset, dTMS with different interstimulus intervals (ISI; 35, 50, 65 or 80 ms) was applied. For contralateral saccades, dTMS significantly decreased saccadic latency with an ISI of 80 ms and increased saccadic gain with an ISI of 65 and 80 ms. Together with the findings of a previous study during frontal eye field (FEF) stimulation the present results demonstrate similarities and differences between both regions in the execution of memory-guided saccades. Firstly, dTMS facilitates saccade triggering in both regions, but the timing is different. Secondly, dTMS over the PPC provokes a hypermetria of contralateral memory-guided saccades that was not observed during FEF stimulation. The results are discussed within the context of recent neurophysiological findings in monkeys.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Electric Stimulation*
  • Female
  • Functional Laterality
  • Humans
  • Male
  • Memory / physiology*
  • Memory / radiation effects
  • Parietal Lobe / physiology
  • Parietal Lobe / radiation effects*
  • Reaction Time / physiology
  • Reaction Time / radiation effects
  • Saccades / physiology*
  • Saccades / radiation effects
  • Time Factors
  • Transcranial Magnetic Stimulation*