Topic: conditioned stimulus

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

Safety learning allows the identification of non-threatening situations, a learning process instrumental for survival and psychic health. In contrast to fear learning, in which a sensory cue (conditioned stimulus, CS) is temporally linked with a mildly aversive stimulus (US), safety learning can be studied by presenting the CS and US in an explicitly unpaired fashion during training. This should result in reduced contextual freezing when the learned CS is presented alone in a recall session within the same context. Here, we studied the effects of auditory stimuli on freezing responses in mice.

Aversive events in our environment shape our behaviours. Instrumental behaviours are punished when an action results in an aversive event. Yet there are instances where behaviours appear inappropriately sensitive to potential threats. The neural underpinnings of these inappropriate behaviours are poorly understood. In a conditioned punishment task, we trained rats to press two levers for pellets. Their responding suppressed on one lever when it also earned a conditioned stimulus (CS+) that was paired with a footshock, whilst responding continued on the other lever that earned a neutral conditi