RECOGNITION OF DIRECTION OF THE EVEN AND NON-EVEN MOVEMENT AND EEG ALPHA-WAVE

In experiments with 7 human observers the recognition of side and dire ction of the even and non-even (compensating the magnification factor) light motion in the left or right visual hemifield and to- or from th e fixation point was studied. The onset of the movement coincided with different phases of the EEG alpha-wave in the occipital region. In a control study stimuli were presented irrespectively to alpha-wave phas es. Synchronization of non-even motion with some of the alpha-wave pha ses leads to an increase of its recognition probability and relative s hortening of the response latency for directions from the center of ga ze, while opposite directions became worse recognized and evoked relat ively long-latency responses. Recognition of the even motion was not c hanged in experiment in compare with control. The obtained date are di scussed in relation to Pitts and McCulloch (1947) hypothesis on a peri odical (with alpha-wave frequency) scanning wave spreading over the vi sual cortex.