The anticipation of rewards turns out to have its own hedonic value, on top of that of the reward itself; a wide range of behavioral and neurophysiological data suggest that this anticipation is boosted by prediction errors.

Administration of dopamine and opioid receptor antagonists resulted in reduced reward anticipation (effort and increased negative facial reactions), but only administration of opioid antagonists resulted in reduced liking (facial reactions).

The pleasure of rewards in humans is mediated by an opioidergic mechanism.

In adolescent rats, whose actions are more impulsive, neuronal striatal activity that precedes self-initiated action sequences has a steeper modulation by waiting time compared to the modulation found in adults.

Cerebellar climbing fibers can generate learned reward-predictive instructional signals, suggesting a role for cerebellar learning in the reinforcement of reward-driven behaviors.

Loss of REM sleep increases sucrose and fat consumption in mice; and inhibiting the prefrontal cortex reverses the increased consumption of sucrose, but not fat, following REM sleep loss.

Neural confidence signals can take the role of reward signals and explain perceptual learning without external feedback as a form of internal reinforcement learning.

In the orbitofrontal cortex, mTORC1, a multiprotein complex centered around the kinase mTOR, contributes to the development and/or maintenance of habitual alcohol seeking.

Dopamine modulates behavioral measures of learning and pleasantness in a learning task guided by intrinsic reward, inducing long-term memory benefits specially in those participants with a high sensitivity to reward.