Neuronal synchrony does not correlate with motion coherence in cortical area MT

Nature. 2003 Jan 23;421(6921):366-70. doi: 10.1038/nature01285.

Abstract

Natural visual scenes are cluttered with multiple objects whose individual features must somehow be selectively linked (or 'bound') if perception is to coincide with reality. Recent neurophysiological evidence supports a 'binding-by-synchrony' hypothesis: neurons excited by features of the same object fire synchronously, while neurons excited by features of different objects do not. Moving plaid patterns offer a straightforward means to test this idea. By appropriate manipulations of apparent transparency, the component gratings of a plaid pattern can be seen as parts of a single coherently moving surface or as two non-coherently moving surfaces. We examined directional tuning and synchrony of area-MT neurons in awake, fixating primates in response to perceptually coherent and non-coherent plaid patterns. Here we show that directional tuning correlated highly with perceptual coherence, which is consistent with an earlier study. Although we found stimulus-dependent synchrony, coherent plaids elicited significantly less synchrony than did non-coherent plaids. Our data therefore do not support the binding-by-synchrony hypothesis as applied to this class of motion stimuli in area MT.

MeSH terms

  • Action Potentials
  • Animals
  • Cerebral Cortex / cytology
  • Cerebral Cortex / physiology*
  • Depth Perception / physiology
  • Eye Movements
  • Fixation, Ocular
  • Macaca mulatta / physiology*
  • Motion
  • Motion Perception / physiology*
  • Neurons / physiology*
  • Photic Stimulation
  • Wakefulness