Retinotopic activity in V1 reflects the perceived and not the retinal size of an afterimage

Nat Neurosci. 2012 Mar 11;15(4):540-2. doi: 10.1038/nn.3069.


An afterimage looks larger when one fixates on a distant than on a closer surface. We show that the retinotopic activity in the primary visual cortex (V1) associated with viewing an afterimage is modulated by perceived size, even when the size of the retinal image remains constant. This suggests that V1 has an important role in size constancy when the viewing distance of the stimulus changes.

Publication types

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

MeSH terms

  • Adult
  • Afterimage / physiology*
  • Female
  • Humans
  • Magnetic Resonance Imaging / methods
  • Photic Stimulation / methods*
  • Retina / physiology*
  • Size Perception / physiology*
  • Time Factors
  • Visual Cortex / physiology*
  • Visual Perception / physiology*
  • Young Adult