Remapping the remembered target location for anti-saccades in human posterior parietal cortex

J Neurophysiol. 2005 Jul;94(1):734-40. doi: 10.1152/jn.01331.2004. Epub 2005 Mar 23.

Abstract

We used functional magnetic resonance imaging (fMRI) to investigate the role of the human posterior parietal cortex (PPC) in anti-saccades. To do so, we exploited the laterality of a subregion of the PPC for remembered target location. Using an event-related design, we tracked fMRI signal changes in this region while subjects remembered the location of a flashed target, then were instructed to plan either an anti- or pro-saccade to that location, and finally were instructed to execute the movement. At first, the region responded preferentially to the memory of a target location presented in the contralateral visual field. However, when an anti-cue specified a saccadic response into the opposite visual field, we observed a dynamic shift in cortical activity from one hemisphere to the other. This shows that this region within the human posterior parietal cortex codes the target location for an upcoming saccade, rather than the location of the remembered visual stimulus in an anti-saccade task.

Publication types

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

MeSH terms

  • Adult
  • Analysis of Variance
  • Brain Mapping*
  • Evoked Potentials / physiology
  • Female
  • Functional Laterality / physiology
  • Humans
  • Magnetic Resonance Imaging / methods
  • Male
  • Memory / physiology*
  • Oxygen / blood
  • Parietal Lobe / blood supply
  • Parietal Lobe / physiology*
  • Photic Stimulation / methods
  • Psychomotor Performance / physiology
  • Reaction Time / physiology
  • Saccades / physiology*
  • Space Perception / physiology*
  • Time Factors
  • Visual Fields / physiology

Substances

  • Oxygen