I have summarized the key points from various research studies: [Research](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9062982/): Dopamine and the interdependency of time perception and reward (2021) * Dopaminergic signals are now more often conceptualized as a reinforcement signal that facilitates learning, rather than directly causing pleasure. * Reward prediction error: Temporal difference learning (which is a reinforcement learning algorithm) simplifies an environment into a collection of states, then learns values associated with each state to guide choices while navigating the environment. Reward prediction errors allow a temporal difference learning agent to update state values by reporting the difference between expected and actual value after each transition between states. When an unexpected reward is encountered, the reward prediction error generated increases the value of the previous state, such that the reward can be better anticipated and thus shape behavior. * Two key properties of reward prediction errors in the phasic activity of dopamine neurons: The first is that when a cue is predictably paired with a reward, the reward prediction error for the reward will slowly transfer to the cue. The second is that when an expected reward is omitted, a negative reward prediction error is produced to signal that the previous state overestimated the upcoming reward. * When the delay between a cue and the reward it predicts is longer, there is a greater dopamine response to the reward itself. This has been assumed to reflect the greater uncertainty in temporal precision, which is manifested as the scalar property of time perception, as well as reduced associative learning * Motivation is the behavioral or cognitive state of an agent due to a prospective reward Your thoughts?