Evidence for recovery of fear following immediate extinction in rats and humans.
Fear responses can be eliminated through extinction, a procedure involving the presentation of fear-eliciting stimuli without aversive outcomes. Extinction is believed to be mediated by new inhibitory learning that acts to suppress fear expression without erasing the original memory trace. This hypothesis is supported mainly by behavioral data demonstrating that fear can recover following extinction. However, a recent report by Myers and coworkers suggests that extinction conducted immediately after fear learning may erase or prevent the consolidation of the fear memory trace. Since extinction is a major component of nearly all behavioral therapies for human fear disorders, this finding supports the notion that therapeutic intervention beginning very soon after a traumatic event will be more efficacious. Given the importance of this issue, and the controversy regarding immediate versus delayed therapeutic interventions, we examined two fear recovery phenomena in both rats and humans: spontaneous recovery (SR) and reinstatement. We found evidence for SR and reinstatement in both rats and humans even when extinction was conducted immediately after fear learning. Thus, our data do not support the hypothesis that immediate extinction erases the original memory trace, nor do they suggest that a close temporal proximity of therapeutic intervention to the traumatic event might be advantageous.
Psychology Department, New York University, New York, New York 10003, USA.
Daniela
D
Schiller
Christopher K
CK
Cain
Nina G
NG
Curley
Jennifer S
JS
Schwartz
Sarah A
SA
Stern
Joseph E
JE
Ledoux
Elizabeth A
EA
Phelps
D000293:Adolescent; D000328:Adult; D000818:Animals; D003214:Conditioning, Classical / Q000502:physiology*; D004597:Electroshock; D005108:Extinction, Psychological / Q000502:physiology*; D005239:Fear / Q000502:physiology*; D005260:Female; D046352:Freezing Reaction, Cataleptic / Q000502:physiology; D005712:Galvanic Skin Response; D006185:Habituation, Psychophysiologic; D006801:Humans; D008297:Male; D010775:Photic Stimulation; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D012055:Reinforcement Schedule; D013997:Time Factors