Why visual perception is a decision process
Staadt R, Philipp ST, Cremers JL, Kornmeier J, Jancke D (2020).
Perception of the difference between past and present stimulus: a rare orientation illusion may indicate incidental access to prediction error-like signals
PLoS ONE 15(5): e0232349 (Open Access) doi: 10.1371/journal.pone.0232349
The study shows that humans occasionally perceive prediction errors as illusory percepts. Thus, in contrast to popular predictive coding theories, where the brain 'explains away' prediction errors along a hierarchical processing scheme, our data demonstrate continued access to residual prediction errors. We propose that such a strategy maintains flexibility at perceptual decision stages when coping with highly dynamic and ambiguous sensory input.