Immediate extinction causes a less durable loss of performance than delayed extinction following either fear or appetitive conditioning

  1. Amanda M. Woods and
  2. Mark E. Bouton1
  1. Department of Psychology, University of Vermont, Burlington, Vermont 05405, USA

Abstract

Five experiments with rat subjects compared the effects of immediate and delayed extinction on the durability of extinction learning. Three experiments examined extinction of fear conditioning (using the conditioned emotional response method), and two experiments examined extinction of appetitive conditioning (using the food-cup entry method). In all experiments, conditioning and extinction were accomplished in single sessions, and retention testing took place 24 h after extinction. In both fear and appetitive conditioning, immediate extinction (beginning 10 min after conditioning) caused a faster loss of responding than delayed extinction (beginning 24 h after conditioning). However, immediate extinction was less durable than delayed extinction: There was stronger spontaneous recovery during the final retention test. There was also substantial renewal of responding when the physical context was changed between immediate extinction and testing (Experiment 1). The results suggest that, in these two widely used conditioning preparations, immediate extinction does not erase or depotentiate the original learning, and instead creates a less permanent reduction in conditioned responding. Results did not support the possibility that the strong recovery after immediate extinction was due to a mismatch in the recent “context” provided by the presence or absence of a recent conditioning experience. Several other accounts are considered.

Footnotes

  • 1 Corresponding author.

    1 E-mail Mark.bouton{at}uvm.edu; fax (802) 656-8783.

  • Article is online at http://www.learnmem.org/cgi/doi/10.1101/lm.1078508.

  • 2 A control experiment also found more spontaneous recovery following immediate than delayed extinction when the conditioning-to-test interval was controlled (A.M. Woods, unpubl.). Experiment 1, which instead controlled the extinction-to-test interval, provides a more compelling demonstration of the low durability of immediate extinction, because extinction performance is usually more readily lost over time than conditioning performance (e.g., Bouton 1993). When the conditioning-to-test interval is controlled, the extinction-to-test interval testing is necessarily longer for immediate than delayed extinction.

  • 3 A control experiment also found more spontaneous recovery following immediate than delayed extinction when the conditioning-to-test interval was controlled (A.M. Woods, unpubl.). See Footnote 2.

    • Received May 22, 2008.
    • Accepted October 7, 2008.
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