Estimation of the exact moment of human cognition of RDS

Random-dot stereograms (RDS) has been used for the research for neurophysiological mechanism of binocular vision. In such studies, visually evoked potentials (VEP) were often recorded as the characteristic brain wave concerning with binocular vision. However, in common experimental procedure of those studies, there is a possibility that those VEPs are not specifically reflected the cognition of solid figure of RDS. Because, in those experiment, VEP was recorded during a short period when subject´s perception of RDS presentation itself and his/her cognition of an embedded figure could not be distinguished. Therefore, we designed an experiment which subject´s perception of RDS presentation and cognition of an embedded figure were able to distinguish. We attempted to estimate the moment by analyzing characteristics through electrooculography (EOG). As a result, a remarkable brain potential is observed with respect to the onset of estimated cognition moment of the embedded figure.