Scalp distribution of the attenuated EEG rhythmic activities for dissimilar and/or moving images in binocular vision.

Spontaneous EEGs, at 16 electrode positions over the entire head in five healthy subjects, were measured and analyzed while the subjects gazed at a variety of images in binocular vision. A significant difference in the EEG alpha rhythm (8-13 Hz) was observed between the two states of gazing at stationary and moving gratings in binocular fusion (BF). The variation was large at the parietal and right posterior temporal regions. We also confirmed a significant difference of the alpha rhythm between binocular rivalry (BR) and BF, which was reported in our previous paper, using different images. A large variation between BR and BF was observed at the occipital, parietal and posterior temporal regions when a pair of stationary diagonal gratings was used. On the other hand, the variation was large at the parietal region when a pair of moving diagonal gratings was used. We may conclude from these results that neurophysiological activities in the vicinity of the parietal region are mainly involved in BR. On the other hand, neurophysiological activities in the occipital and posterior temporal regions may be involved not only in BR, but also in the processing of the movement. In the beta band (16-24 Hz), a large variation was observed at the parietal and central regions in all cases described above.