Rhythms in the alpha band in cats and their behavioural correlates.

We describe two sets of rhythmical field potentials that may be recorded from the neocortex of the behaving cat: those at about 14 Hz ('mu' rhythms), in part of the somatic area SI; others at about 10 Hz ('alpha' rhythms), in part of the visual cortex (lateral gyrus). We report their precise localization, their thalamic correlates, their dependence upon a noradrenergic brainstem modulatory mechanism, and finally their possible functional significance.