Topic: belief-states

Associative learning relies on the contingency between stimuli and outcomes, yet the neural mechanisms instantiating contingency remain unclear. We investigated dopamine activity in the ventral striatum of mice performing a Pavlovian contingency degradation task. Both anticipatory licking behavior and dopamine responses to a conditioned stimulus diminished when additional rewards were delivered without cues (uncued) but remained consistent when the same additional rewards were paired with a new cue. These findings challenge traditional contingency-based accounts and the recent causal learning

Reinforcement Learning algorithms allow agents to learn the probabilistic structure of the environment. These structures, termed belief-states, predict future outcomes and guide choice policies to maximize rewards. The ability to utilize new evidence to update belief-states is vital for adaptive behaviors, a process often impaired in schizophrenia contributing to psychosis, cognitive deficits, and avolition.A critical challenge persists in determining the underlying neuronal mechanisms governing belief-state updating and its impact on learning and reasoning. To address this, we train wildtype-