Temporal coding organized by coupled alpha and gamma oscillations prioritize visual processing

Trends Neurosci. 2014 Jul;37(7):357-69. doi: 10.1016/j.tins.2014.04.001. Epub 2014 May 14.


Sensory systems must rely on powerful mechanisms for organizing complex information. We propose a framework in which inhibitory alpha oscillations limit and prioritize neuronal processing. At oscillatory peaks, inhibition prevents neuronal firing. As the inhibition ramps down within a cycle, a set of neuronal representations will activate sequentially according to their respective excitability. Both top-down and bottom-up drives determine excitability; in particular, spatial attention is a major top-down influence. On a shorter time scale, fast recurrent inhibition segments representations in slots 10-30 ms apart, generating gamma-band activity at the population level. The proposed mechanism serves to convert spatially distributed representations in early visual regions to a temporal phase code: that is, 'to-do lists' that can be processed sequentially by downstream regions.

Publication types

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

MeSH terms

  • Alpha Rhythm / physiology*
  • Brain / physiology*
  • Brain Mapping*
  • Electroencephalography
  • Gamma Rhythm / physiology*
  • Humans
  • Photic Stimulation
  • Visual Pathways / physiology*
  • Visual Perception / physiology*