Perceptual learning and decision making in human medial frontal cortex

Abstract

The dominant view that visual perceptual learning is accompanied by changes in early sensory representations has recently been challenged. Here we tested the idea that visual perceptual learning can be accounted for by a reinforcement learning process involving changes in higher decision making areas. We trained subjects on an orientation-discrimination task involving external feedback over four days, acquiring fMRI data on the first and last day (1320 fMRI of 4620 trials). Behavioral improvements were well explained by a reinforcement-learning model in which learning leads to enhanced read-out of sensory information thereby establishing noise-robust representations of decision variables. Using a model based neuro-imaging approach and support vector regression, we find stimulus orientation encoded in early visual and higher cortical regions such as lateral parietal cortex and anterior cingulate cortex (ACC). However, only activity patterns in the ACC tracked changes in decision variables during learning. These results provide strong evidence for perceptual learning related changes in higher-order areas and suggest that perceptual and reward learning are based on a common neurobiological mechanism.

DFG-SFB779-A3.