Abstract
Bistable perception (binocular rivalry) occurs when one eye views dots moving upward while the other eye's dots move rightward. Perception switches between up and right. With ambiguous motion, dots moving on elliptical trajectories as a transparent sphere switch perceptually between opposite directions of motion (e.g., left and right). Multistable perception (switching among left, right, up or down) occurs when one eye views horizontal ambiguous motion while the other eye views vertical ambiguous motion. Most of the time, transition probabilities for switching among those states were similar; there was little mutual information in these particular switching time series. However, many observers had intermittent periods of highly predictable switching (high mutual information). Examples include: (1) long sequences switching between opposite directions on one axis (avoiding the other axis), (2) long sequences avoiding the opposite direction on the same axis (always switching axes), and (3) three-state sequences (vertical-horizontal-vertical and horizontal-vertical-horizontal) in which first and third directions were the same much more often than being opposite directions. Fluctuating mutual information characterizes certain nonlinear systems, and some nonlinear systems have a characteristic that adding the right amount of noise at the input will paradoxically reduce noise in the output (stochastic resonance). Adding zero-mean Gaussian velocity noise with standard deviations of 0.5%, 1%, … of mean stimulus velocity to the multistable display typically increased the variances of perceptual dominance times, but not if the noise standard deviation was 1.5%. Perceptual dominance time variance was significantly smaller in the latter condition than when viewing stimuli with no added noise. The present findings extend previous work by Kim, Grabowecky & Suzuki (2003), Leopold, et al. (2002) and Suzuki & Grabowecky (2002).