Reduced cortical motor potentials underlie reductions in memory-guided reaching performance

Motor Control. 2012 Jul;16(3):353-70. doi: 10.1123/mcj.16.3.353. Epub 2012 May 24.

Abstract

We used the event-related potential (ERP) methodology to examine differences in neural processing between visually and memory-guided reaches. Consistent with previous findings (e.g., Westwood, Heath, & Roy, 2003), memory-guided reaches undershot veridical target location to a greater extent than their visually guided counterparts. Analysis of the ERP data revealed that memory-guided reaches were associated with reduced potentials over medial-frontal cortex at target presentation and following movement onset. Further, we found that the amplitudes of the potentials over medial-frontal cortex for visually and memory-guided reaches were significantly correlated with the peak accelerations and decelerations of the reaching movements. Our results suggest that memory-guided reaches are mediated by a motor plan that is generated while a target is visible, and then stored in memory until needed--a result counter to recent behavioral theories asserting that memory-guided reaches are planned just before movement onset via a stored, sensory-based target representation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Evoked Potentials / physiology*
  • Female
  • Frontal Lobe / physiology*
  • Humans
  • Male
  • Memory*
  • Motor Skills / physiology*
  • Movement / physiology*
  • Psychomotor Performance / physiology*