G. Pfurtscheller et al., EVENT-RELATED SYNCHRONIZATION (ERS) IN THE ALPHA-BAND - AN ELECTROPHYSIOLOGICAL CORRELATE OF CORTICAL IDLING - A REVIEW, International journal of psychophysiology, 24(1-2), 1996, pp. 39-46
EEG desynchronization is a reliable correlate of excited neural struct
ures or activated cortical areas. EEG synchronization within the alpha
band may be an electrophysiological correlate of deactivated cortical
areas. Such areas are not processing sensory information or motor out
put and can be considered to be in an idling state. One example of suc
h an idling cortical area is the enhancement of mu rhythms in the prim
ary hand area during visual processing or during foot movement. In bot
h circumstances, the neurons in the hand area are not needed for visua
l processing or preparation for foot movement. As a result of this, an
enhanced hand area mu rhythm can be observed.