Associative learning studies have shown that the anticipation of reward and punishment shape the representation of sensory stimuli which is further modulated by dopamine. Less is known about whether and how reward delivery activates sensory cortices and the role of dopamine at that time point of learning. We used an appetitive instrumental learning task where participants had to learn that a specific class of frequency modulated tones predicts a monetary reward, following fast and correct responses in a succeeding reaction time task. This fMRI data was previously analyzed regarding the effect of reward anticipation, but here we focus on neural activity to the reward outcome relative to the reward expectation and tested whether such activation in the reward reception phase is modulated by L-dopa. We analyzed neural responses at the time point of reward outcome under three different conditions i) when a reward was expected and received ii) when a reward was expected but not received and iii) when a reward was not expected and not received. Neural activity in auditory cortex was enhanced during feedback delivery when either an expected reward was received or when the expectation of obtaining no reward was correct. This differential neural activity in auditory cortex was only seen in subjects who learned the reward association and not under dopaminergic modulation. Our data provide evidence that auditory cortices are active at the time point of reward outcome. However, responses are not dependent on the reward itself, but on whether the outcome confirmed the subject's expectations.
- reward delivery
- auditory cortex
- instrumental learning
- Copyright © 2013, Journal of Neurophysiology