ABSTRACT
Scientists universally agree that sensation and perception are intimately linked with neural activity in the brain. Mental states correspond to physical states in the brain's neurons. A change in mental state, such as a change in one's perceptual experience, is always accompanied by a change in the pattern of neural activity in the brain. Psychophysical studies reveal that functional specialization has many significant consequences for perception across all the sensory systems, from selective adaptation to dramatic variations in sensitivity to different stimuli within a modality. Empirical data and theoretical analysis show that sensory processing is plagued by ambiguity, which takes two general forms, neural ambiguity and stimulus ambiguity. The pervasive nature of ambiguity means that perception is above all an inferential process in which decisions are based on incomplete sensory information, constrained guessing. Population codes are pivotal. Bayesian inference has become the dominant theoretical framework for resolving stimulus ambiguity across all the sensory systems.
