POTENTIAL FLOW OF ALPHA-ACTIVITY IN THE HUMAN ELECTROENCEPHALOGRAM

The movement of potential field of alpha activity was investigated wit h a potential flow technique. alpha activity was divided into slow, me dium and fast subbands. The peak-to-peak amplitude and source density distribution of each subband was also constructed. The potential flow of medium alpha was from medial to lateral in the anterior region, and from lateral to medial in the posterior region. The flow patterns of slow and fast alpha were more complicated. Similar flow directions for med a group. Different groups met or diverged at discontinuous grid po ints around the local maxima of potential distribution. The discontinu ous points of medium alpha were centered in the parieto-occipital regi on, and those of slow and fast alpha were more equally distributed ove r the scalp. Against potential gradients, several groups of similar fl ow directions participated in the formation of potential field. The ge neration of potential field was assumed to be controlled widely for me dium alpha and locally for slow and fast alpha.