Neural Mechanisms of Incentive Salience in Naturalistic Human Vision

What role does reward play in real-world human vision? Reward coding in the midbrain is thought to cause the rapid prioritization of reward-associated visual stimuli. However, existing evidence for this incentive salience hypothesis in vision is equivocal, particularly in naturalistic circumstances, and little is known about underlying neural systems. Here we use human fMRI to test whether reward primes perceptual encoding of naturalistic visual stimuli and to identify the neural mechanisms underlying this function. Participants detected a cued object category in briefly presented images of city- and landscapes. Using multivoxel pattern analysis in visual cortex, we found that the encoding of reward-associated targets was enhanced, whereas encoding of reward-associated distractors was suppressed, with the strength of this effect predicted by activity in the dopaminergic midbrain and a connected cortical network. These results identify a novel interaction between neural systems responsible for reward processing and visual perception in the human brain.