title: The rhythm of cortical excitability.
abstract: Evidence has been gained which suggests that the spectral properties of the excitability cycle are other than those first proposed or assumed to exist in a number of experiments and theories. Instead of appearing as a sinusoidal cycle at the alpha frequency, the excitability cycle seems to be irregular and slower on the average than the EEG alpha rhythm. The rhythm appears to be continuously operative. It is not very sensitive in its spectral composition to the conditions of illumination or the level of behavioral activity. The rhythm operates synchronously in the right and left visual cortex. Methods similar to those described here could be used to map the extent to which synchrony is maintained in structures throughout the brain. They also suggest new approaches for psycho-physical studies which are aimed at establishing relationships between behavioral or perceptual phenomena and measures of neural activity.
mesh_terms: D000513:Alpha Rhythm; D000818:Animals; D002415:Cats; D002540:Cerebral Cortex / Q000502:physiology*; D004594:Electrophysiology