task 4

dopamine learning: prediction error

primary/secondary reinforcer

Willuhn/ addiction

  1. verntral striatum: during phase of feedback-based learning --> motivational addiction 2. after acquiring addition, feedback is not necessary --> dorsal striatum takes over --> bheavioral addiction

DLS: efficiency of response --> can be reversed if dopmaine is blocked

DLS not sufficient to account for loss of control over drug intake --> training did not produce compulsive responding --> DLS depends on VMS

unconditioned primary reinforcer: biological basis, no learning needed

conditioned/secondary reinforcer: strengthen behavior by being associated with reward

generalized conditioned reinforcer: money, attention, affection

partially condiitoned stimuli: fall in between conditioned/unconditioned categories

Blocking paradigm: A 2nd stimulus coupled with a CS will not become CS (conditioning is blocked)

Reward omission: a reward predicted by a CS that is not presented elicits a depression in neural activity

The learning based on dopamine is assumed to be through short- and long-term modification of corticostriatal synaptic transmission.

Conditioned inhibition paradigm: A 2nd stimulus together with the CS and no reward, leads to a conditioned inhibitor.

dopamine responses co-vary with both magnitude AND probability of reward.

DA signal is also sensitive to the time of the predicted reward

reward prediction error hypothesis

Dopaminergic midbrain neurons and their targets respond at 2 timepoints during a learning trial

After appearance of a reward predicting stimulus 🡪 subjective value

After the receipt/omission of the expected reward 🡪 difference between expected and received rewards

primary rewards: activate nucleus accumbens

ventral striatum: response to social situations, response to surprising rewards, settings that require learning optimal response, shows subjective vlaue

indirect learning

VS activity is modulated by implications for yourself, perceived similarity btw oersin and you

VS: when task-relevant info can be acquired or when observing task relevatn stimulus-stimulus associations

dopamine in motivation: energized organism, directs bheavio to oal, enables learning about outcomes

uncertainty: slow, sustained activity betwen predicting stimulus and reward --> the less likely reward occurs the less activity