Abstract
INTRODUCTION: It has been proposed that binocular rivalry and other forms of perceptual bi-stability are governed by distributed neural activity in multiple brain areas including those involved in motor action planning (Leopold & Logothesis, 1999, TiCS). This view is generally consistent with evidence pointing to strong links between perception and action (Knoblich & Flach, 2001, Psychol. Sci.). Inspired by this idea, we performed a series of experiments measuring sensorimotor influences in binocular rivalry dynamics. METHODS: Observers viewed dissimilar stimuli presented to the two eyes via a mirror stereoscope. One eye viewed a flickering, radial grating (RG) and the other eye viewed animations portraying dynamic 2D projections of a rotating sphere of dots (RS). While viewing these dichoptic stimuli, observers moved a hand-held mouse when they perceived one of two rival stimuli as dominant (RG or RS, depending on trial type). On some trials (manual: MAN), the concurrent mouse movement controlled the motion vectors of the dots defining the RS; on other trials, the RS dots were defined by motion vectors recorded from previous MAN trials, (i.e. the dot vectors were not controlled by the concurrent hand movements of the observers; AUTO). RESULTS: Rivalry dynamics varied dependent on motor control: average dominance durations of the RS rival target were longer during MAN tracking than during AUTO tracking, and suppression durations in MAN were briefer than suppression durations in AUTO. An additional experiment confirmed that observers varied in their ability to judge whether their concurrent mouse movements genuinely controlled the RS stimulus, but performance on this task was unrelated to the magnitude of control exerted on rivalry dynamics. CONCLUSION: These results indicate that sensorimortor signals can indeed bias perception of action-related stimulus under conditions of ambiguous stimulation.
Supported by NIH EY13358, KM is supported by JSPS