Covariation bias, classical conditioning, and phobic fear.
The present study investigated whether phobics show an illusory correlation (IC) between phobia-relevant stimuli and aversive events. Nineteen treated and 19 untreated spider phobics were exposed to a series of 72 slides. Three different categories were used: Phobia-relevant slides (spiders), alternative fear-relevant slides (weapons), and neutral slides (flowers). Slides were randomly paired with either a shock, a siren, or nothing at all. All slide/outcome combinations occurred equally frequently. A posteriori recorded contingency estimates indicated that untreated phobics dramatically overestimate the covariation of spiders and shock. On-line recorded outcome expectancies revealed that the bias to overestimate the spider-shock contingency is highly resistant to extinction. The covariation bias was accompanied by differentially heightened electrodermal first interval responses (FIR) and unconditioned electrodermal responses (third interval responses: TIR) on phobia-relevant trials. Treated phobics did not show a covariation bias, indicating that such bias can be modulated by behavioral treatment. The present findings sustain the hypothesis that phobic subjects process information in a fear-confirming way.
de Jong
P J
PJ
Department of Mental Health Sciences, Limburg University, Maastricht, The Netherlands.
Merckelbach
H
H
D000328:Adult; D000818:Animals; D001245:Association Learning; D001521:Behavior Therapy; D003214:Conditioning, Classical; D004597:Electroshock; D005239:Fear; D005260:Female; D006801:Humans; D007088:Illusions; D008297:Male; D011939:Mental Recall; D010698:Phobic Disorders / Q000523:psychology* / Q000628:therapy; D013112:Spiders