Noise improves three-dimensional perception: Stochastic resonance and other impacts of noise to the perception of autostereograms

Autostereograms can be perceived in different well-defined spatial levels. Therefore they are an excellent tool with which to examine spatiotemporal p rocesses of multistable three-dimensional perception. We study properties o f spatial ambiguity such as phase transitions between different spatial lev els and hysteresis in perception with and without noise. We show that the p erception of physical noise-which is added to the autostereograms in the fo rm of a random dot pattern-is dependent on the perceived spatial level. We demonstrate that noise can be helpful for the perception of depth in some c ases. We show that the signal-to-noise ratio of depth perception is enhance d at an intermediate level of noise strength that is the signature of stoch astic resonance in depth perception.