Dynamics of perceptual switching in tri-stable visual stimuli
Gemma Huguet (Center for Neural Science, New York University)
(May 1, 2013 3:00 PM - 3:50 PM)
When observers view for extended time an ambiguous visual scene with two or more different interpretations they report switching between different perceptions. We focus on a classical paradigmatic stimulus, the visual plaids, consisting of two superimposed drifting gratings with transparent intersections (Wallach '35, Hupe & Rubin '03). For visual plaids, tristable perception is experienced: one coherent percept (the gratings move together as a single pattern) and two transparent percepts (the gratings slide across one another) with alternating depth order. In order to decipher the complex mechanisms of tristable perception, we gathered a large amount of psychophysical data on tristable plaids and developed a neural network, firing rate model of interaction between neural populations. The model developed can account for the dynamical properties (transition probabilities, distributions of percept time durations, etc) observed in the experiments and predicts that adaptation is strongly involved in perceptual switching.