Neural correlates of perceptual learning in a sensory-motor but not a sensory cortical area

摘要

This study aimed to identify neural mechanisms that underlie perceptual learning on a visual discrimination task. We trained two monkeys to decide the direction of visual motion while recording from the middle temporal area (MT), which in trained monkeys represents motion information used to solve the task, and the lateral intraparietal area (LIP), which in trained monkeys represents the transformation of motion information into a saccadic choice. During training, improved behavioural sensitivity to weak motion signals was accompanied by changes in motion-driven responses of neurons in LIP but not MT. The time course and magnitude of the changes in LIP were correlated with the changes in behavioural sensitivity throughout training. Thus, for this task, perceptual learning appears to involve improvements not in how sensory information is represented in the brain but rather how the sensory representation is interpreted to form the decision that guides behaviour.