Immediate Extinction Attenuates Spontaneous Recovery and Reinstatement in a Passive Avoidance Paradigm.

Recent research suggests that extinction occurring shortly after fear conditioning attenuates spontaneous recovery and reinstatement of fear. Two experiments investigated whether immediate extinction would prevent spontaneous recovery and reinstatement of fear using a passive avoidance paradigm. In Experiment 1, naive female adult rats (N = 40) received extinction training either immediately or 24 hours (delayed) after fear conditioning.

Mild hypothermia can disrupt extinction learning but not original conditioning.

Using a retrograde amnesia procedure, the susceptibility of the extinction of fear conditioning was assessed in two experiments. Extinction of a passive-avoidance task was impaired by a body-cooling treatment (e.g.