An Accumulating Neural Signal Underlying Binocular Rivalry Dynamics.
The Journal of neuroscience : the official journal of the Society for Neuroscience December 13, 2023 Shaozhi Nie, Sucharit Katyal, Stephen A Engel
During binocular rivalry, when each eye sees a different image, perception alternates unpredictably between them. Models propose that neural signals for each image change gradually until reaching a threshold that triggers a switch, but direct evidence was lacking. Measuring steady-state visual evoked potentials (SSVEPs) via EEG in 84 human participants (62 females, 22 males) viewing orthogonal gratings flickering at different frequencies, the amplitude of the suppressed stimulus's signal increased and the dominant stimulus's signal decreased throughout each percept. Longer percepts corresponded to more gradual changes in these signals. The findings match a model where perceptual transitions arise from accumulating noisy signals, providing the first physiological evidence for such threshold-crossing dynamics in human visual cortex.