Perceptual load modulates visual cortex excitability to magnetic stimulation

J Neurophysiol. 2008 Jul;100(1):516-9. doi: 10.1152/jn.01287.2007. Epub 2008 May 21.

Abstract

Much recent research has shown that the level of perceptual load in a task determines the perception of task-irrelevant stimuli and associated neural activity, but the mediating neural mechanisms remain unclear. Here we show that increasing the level of perceptual load in a static letter search task results in an increase in the intensity of transcranial magnetic stimulation over V5/MT required to elicit the perception of a moving phosphene. These findings suggest that the neural mechanisms mediating the effects of perceptual load involve reduced visual cortex excitability in task-unrelated areas.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Dose-Response Relationship, Radiation
  • Electric Stimulation
  • Functional Laterality
  • Humans
  • Memory, Short-Term / physiology
  • Memory, Short-Term / radiation effects
  • Neuropsychological Tests
  • Phosphenes / physiology*
  • Photic Stimulation
  • Psychophysics
  • Sensory Thresholds / physiology
  • Sensory Thresholds / radiation effects
  • Transcranial Magnetic Stimulation*
  • Visual Cortex / radiation effects*
  • Visual Perception / physiology*