Abstract
In order to investigate neuronal activities related to binocular rivalry (BR), we have studied spatio-temporal characteristics of EEG rhythmic activities and event-related-potentials (ERPs) elicited by the switching from binocular fusion (BF) to BR and vice versa. EEGs were measured and analyzed at 20 electrode positions over the entire head in nine healthy subjects. The variance of EEGs in the α band (8-13Hz) was attenuated largely in the occipital, posterior-temporal and parietal regions and the minimum variance was observed at 727ms (P3) after the switching from BF to BR (F to R). Subsequently the variance was recovered slightly. On the other hand, the variance in the α band recovered largely after the slight attenuation until 719ms (P3) in the alternation from BR to BF (R to F). In the steady state of BR before the switching of the stimuli, the variance in the α band was significantly smaller than the one in BF (paired t-test, n=9, p<0.01). A similar attenuation and recovery of variance in the β band (16-24Hz) was observed in the parietal and central regions. A prominent late negative component peaking at about 500ms was observed in the parietal region in the ERPs elicited by the switching from R to F and from F to R. The amplitude of the late negative component in R to F was significantly smaller than that of F to R (n=9, p<0.01). Therefore, it is possible to interpret that the difference of the late negative component and attenuation of variance in the α band reflects neural activities related to the perception of pattern alternation and the difference of variance in steady state in the α band reflects the difference in the neural activities involved in BR and BF.
