Multiple roles of experience in decoding the neural representation of sensory stimuli.

Experience and perception are deeply intertwined. Experience, particularly early in life, shapes how sensory information is represented in the brain. Experience also establishes associations and can affect how sensory information guides behaviour. Central to these kinds of perceptual abilities are neural mechanisms that interpret, or decode, the brain's sensory representation, but little is known about how these decoding mechanisms depend on experience. Here I discuss several critical roles that experience might play in shaping these mechanisms. First, experience is likely to drive changes in neural connectivity to select the spatially and temporally distributed sensory signals that provide relevant information about a stimulus. Second, even the most relevant sensory signals provide incomplete information about the presence of a stimulus; also necessary is knowledge of the a priori probability of the stimulus, which must be learned from experience. Third, decoding noisy information is necessarily imperfect and therefore involves trade-offs like speed versus accuracy and false alarms versus misses. Experience is likely to provide ongoing feedback about the value of these trade-offs so that they might be adjusted appropriately. Each of these mechanisms appear to be capable of causing dramatic changes in sensitivity, response bias, response times and other manifestations of perceptual ability.