Neuroscience & Psychology Postgraduate Society Seminars

Fluctuations in visual awareness: motion-induced blindness and binocular rivalry

Motion-induced blindness (MIB) and binocular rivalry (BR) are examples of multistable phenomena in which our perception varies despite constant retinal input. It has been suggested that neural representations of objects in BR and MIB are subject to competition at some level of cortical visual processing, and that BR and MIB might share a common underlying mechanism. However, such a common mechanism was suggested by comparing temporal characteristics of MIB and BR across studies. In this study we sought to investigate the relationship between perceptual events in BR and MIB in a novel experimental paradigm that relates both phenomena in single display. Our results suggest that MIB and BR were both affected by motion, but not by rivalry in the mask. Target size had a significant effect on normalized target disappearance as well as perceptual reversals in BR. On the other hand contrast of dichoptic target dots in the left and right eye had a significant effect on perceptual reversals in BR but not on target disappearance. In summary, the different temporal patterns of perceptual events in MIB and BR suggest that both phenomena are relatively independent and that MIB is likely to occur at a later stage of visual processing than BR.