Imaging vividness and the outcome of in vivo and imagined scene desensitization.

Abstract

This study reexamined the role of imaging vividness in desensitizati on success. Scores on the Betts Questionnaire on Mental Imagery were used to divide 48 snake-phobic subjects into high, medium, and low vivid groups, who were assigned to imagined scene or in vivo desensitization treatments. Imaging vividness was assessed at scheduled points during therapy. Significant decreases in behavioral and self-reported fear were observed after both treatments, though in vivo desensitization produced significantly greater fear reduction. Intherapy imaging vividness scores were significantly correlated with therapeutic success and were superior to pretherapy ratings as predictors of outcome. Imagination of fear-relevant scenes is central to most systematic desensitization procedures. However, previous investigators have failed to find a positive relation between imaging vividness and desensitization success. To examine this apparent paradox, we refined the method of previous studies and conducted the following experiment. Forty-eight snake phobics were pretested to establish initial fear level. A behavioral avoidance test, self-ratings of fear during this test, a questionnaire on attitudes toward snakes were used to assess fear of snakes, and the Fear Survey Schedule (Wolpe & Lang, 1964) was used to measure general fearfulness. Subjects were then separated into high, medium, and low imaging ability groups on the basis of scores on the Betts Questionnaire on imagery vividness, and were assigned to one of two standardized, individually administered desensitization procedures: imagined scene (conventional) or in vivo desensitization. Subjects in in vivo treatment were asked to enact, rather than imagine, each hierarchy scene. Imaging vividness during therapy was assessed by subject self-ratings at 19 scheduled points. Posttesting was scheduled between 1 and 3 days after completion of the treatment, and the behavioral and self-report measures were repeated. Analyses of variance of Treatment X Pretherapy Imaging Vividness Condition indicated no Requests for reprints and for an extended report of this study should be sent to John M. Dyckman, who is now at the Psychiatry Clinic, Kaiser Medical Center, 975 Sereno Drive, Vallejo, California 94590.