Manifestation of scotomas created by transcranial magnetic stimulation of human visual cortex

Nat Neurosci. 1999 Aug;2(8):767-71. doi: 10.1038/11245.

Abstract

Reduced visual performance under transcranial magnetic stimulation (TMS) of human visual cortex demonstrates suppression whose spatial extent is not directly visible. We created an artificial scotoma (region missing from a visual pattern) to directly visualize the location, size and shape of the TMS-induced suppression by following a large-field, patterned, visual stimulus with a magnetic pulse. The scotoma shifted with coil position according to known topography of visual cortex. Visual suppression resulted in pattern-dependent distortion, and the scotoma was filled in with temporally adjacent stimuli, suggesting spatial and temporal completion mechanisms. Thus, perceptual measurements of TMS-induced suppression may provide information about cortical processing via neuronal connections and temporal interactions of neural signals.

Publication types

  • Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Humans
  • Magnetoencephalography*
  • Photic Stimulation
  • Retina / radiation effects
  • Scotoma / etiology*
  • Visual Cortex / physiology*