Contrasting the overexpectation and extinction effects.

Full Abstract

After many target stimulus (X)-unconditioned stimulus (US) pairings, further conditioning of X in the presence of another well-established signal for the US (A) disrupts X's behavioral control. Some researchers have argued that the mechanism underlying this so-called overexpectation effect is similar to that underlying extinction (a reduction in X's behavioral control due to X-alone presentations). Three conditioned suppression experiments with rats as subjects compared overexpectation and extinction. Experiment 1 replicated the basic overexpectation effect by showing that A disrupts responding to X more than does a previously neutral stimulus. Experiment 2 found that posttraining context exposure disrupts extinction but not overexpectation. Experiment 3 suggested that overexpectation and extinction are differentially sensitive to the effects of overtraining (compound reinforced or nonreinforced, respectively), such that extinction is enhanced by increases in the amount of nonreinforced trials and overexpectation is unaffected. These results are inconsistent with the view that overexpectation and extinction are driven by a common mechanism.

Author information

Author/s: Witnauer, James E (JE); Miller, Ralph R (RR);

Affiliation: State University of New York at Binghamton, Binghamton, NY 13902-6000, USA.

Grants: 33881 (Agency:PHS HHS)

Journal and publication information

Publication Type: Journal Article; Research Support, N.I.H., Extramural

Journal: Behavioural processes (Behav Processes), published in Netherlands. (Language: eng)

Reference: 2009-Jun; vol 81 (issue 2) : pp 322-7

Dates: Created 2009/05/11; Completed 2009/07/15;

PMID: 19429226, status: MEDLINE (last retrieved date: 7/24/2009)

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