Stimulus hierarchy generalization in systematic desensitization

A group of snake phobic Ss were desensitized to the first 5 items of a standard 7 item snake fear hierarchy in which the items were ordered on the basis of distance from a snake. This group and a no-treatment control group (which did not receive the desensitization) were treated for fear of all the hierarchy stimuli in terms of ratings both before and after the desensitization. The Ss rated their fear responses to all the stimuli as presented to them in (1) real form (2) by slide, and (3) in imaginal form. The results verified all four experimental hypotheses: (1) The experimental Ss showed greater fear reduction than the control Ss to both the training stimuli (the stimuli on which desensitization done) and the generalization stimuli (the other two stimuli), (2) The systematic desensitization (SD) group showed (a) more fear reduction to the last training stimuli than to the lower generalization stimulus and (b) more to the latter than to the higher generalization stimulus, (3) The SD group showed less fear reduction to the generalization stimuli in their real form than in both the slide and imaginai modalities (in the desensitization each stimulus presentation was done first in slide form and then in imaginal form), and (4) There were significant overall individual differences in generalization of fear reduction to the generalization stimuli.     

The effect of duration of exposure on systematic desensitization and extinction.

An important variable which has only recently received attention (Proctor, 1968; Watts, 1971) is the influence of intra-item exposure time to aversive stimuli on systematic desensitization. Long single exposure to hierarchy items was more effective in reducing avoidance behavior than short exposure (Ross and Proctor, 1973). It is possible, therefore, for duration of exposure to be a confounding variable in previous desensitization research.In studies where exposure only conditions were ineffective (Davison, 1968; Lomont and Edwards, 1967), the visualization time was less than 15 sec. Successful utilization of extinction-like procedures employed longer exposure times (Vodde and Gilner, 1971 for 20–30 sec; Crowder and Thornton, 1970 for 30 sec; Sue, 1972 for 20 sec; Nawas, Welsch and Fishman, 1970 for 60 sec: Wolpin and Raines, 1966 for up to 10 min).Intra-item exposure time may also account for the discrepant findings on the influence of cognitive variables on the efficacy of systematic desensitization. In the studies where expectations or therapeutic instructions were important (Leitenberg et al., 1969; Valins and Ray, 1967), subjects were exposed to aversive stimuli for 10–15 sec. Where positive expectations were unimportant, the exposure time was longer (McGlynn and Mapp, 1970 for 20–30 sec; McGlynn, Gaynor and Puhr, 1972 for 20–30 sec; McGlynn, Reynolds and Linder, 1971 for 20–40 sec; Lomont and Brock, 1971 for 60 sec). Therapeutic expectations, relaxation, and other variables may assume importance during periods of short exposure.So far, there has been no adequate investigation of intra-item exposure time on both extinction and desensitization. The procedures employed by Watts (1971) and Proctor (1968) do not allow such a comparison to be made. The purpose of the present study is to examine the influence of short (5 sec) and lengthy (30 sec) exposure to aversive stimuli on extinction and desensitization conditions.In line with the results of Davison (1968) and Lomont and Edwards (1967), it was predicted that exposure of short duration would be less effective than exposure of longer duration under the extinction condition (Vodde and Gilner, 1971 ; Crowder and Thronton, 1970; Nawas et al., 1970; Wolpin and Raines, 1966). No specific predictions were made on the desensitization groups. There were four experimental groups: (1) two exposure only groups (visualization for either 5 sec or 30 sec), and (2) two systematic desensitization groups (visualization for 5 sec or 30 sec). A no-treatment control group was also employed.     

An animal analogue to systematic desensitization and elimination of avoidance

Rats first acquired a two-way avoidance response to a discrete warning signal (80 db white noise.) The effects of 3 experimental and 3 control treatments on elimination of the response were evaluated on a nonshock posttreatment extinction test. Group Systematic Desensitization (SD) received graded exposure to the warning signal while they were eating. Rats in Graded Hierarchy (GH) and Extinction (Ext) groups were yoked to Ss in the SD group such that GH and Ext treatment was identical with that of SD except that neither group ate and the Ext group was exposed to the full intensity warning signal (nongraded exposure) on all trials. None of the control groups was exposed to the warning signal between acquisition and the posttreatment test. Results indicated that SD, while interfering with avoidance during treatment, did not differ in effectiveness from control treatment and was significantly less effective than GH and Ext, when avoidance was tested in extinction. It was suggested that the present analogue SD technique impaired S's reception of (exposure to) the warning signal during treatment.     

Psychophysiological responses during analogue systematic desensitization and non-relaxation control procedures

This investigation tested the hypotheses than an analogue systematic desensitization procedure (SD) would be both more effective and more efficient than a comparable non-relaxation control procedure (NRC) with respect to subjective report, behavioral and psychophysiological variables. Phobic subjects responded to slides depicting a feared aversive stimulus. The SD procedure resulted in significantly less reported fear, fewer trials to a criterion level of decrease in subjective fear, and significantly greater decreases in ANS baseline measures. However, measures of behavioral avoidance and measures of decrease in psychophysiological responsivity to the aversive stimuli revealed significant changes within both SD and NRC groups, and no significant differences between the groups, whether or not the groups were equated for number of stimulus presentations. The results, indicating equivalent efficacy and efficiency for the SD and NRC procedures, suggested a limited role for relaxation in systematic desensitization. An extinction or habituation hypothesis was supported at the expense of a counterconditioning hypothesis.     

Role-reversed systematic desensitization in the treatment of a writing phobia

A role-reversal technique was employed to teach cognitive coping skills to a patient with a writing phobia. The patient presented desensitization scenes to the therapist and devised coping strategies for lessening anxiety. Treatment resulted in a reduction of anxiety and an increased ability to write in the presence of other people. A 10-mo. follow-up showed no relapse.