| Previous research indicates that exposure therapy is a well-established treatment for specific phobias. Outcomes of exposure therapy include reduction in avoidance behavior, physiological changes, and decrease in self-reported levels of anxiety. Studies examining the role of therapist characteristics in psychotherapy, in addition to communication research, suggest that treatment outcome in imaginal exposure may be affected by vocal qualities, as well as by soliciting feedback from clients throughout the intervention. The current study investigated the effects of therapist vocal quality by varying the presentation style used during a one-session imaginal exposure intervention for the treatment of snake phobia. Participants were 46 snake-fearful undergraduate students who were randomly assigned to one of four treatment conditions: dramatic/feedback, dramatic/no feedback, neutral/feedback, and neutral/no feedback. The dramatic conditions received emotionally expressive imagery, whereas the neutral groups heard a monotonous voice present the same imagery. These groups were crossed, in a 2 x 2 x (2) mixed design, with the variable of eliciting subject feedback at multiple points during the session. Outcome measures included a behavioral avoidance test (BAT) and change in electrodermal activity (ΔEDA) as objective measures, and subjective units of distress (SUDS) as a self-report measure. Results indicate that the main effect of feedback was statistically significant at the .05 alpha level, with subjects from whom feedback was elicited having a higher BAT score at post- intervention than preceding intervention, while subjects from whom feedback was not elicited having a lower BAT score following treatment. This finding suggests that the presence of therapist-elicited feedback was effective in raising anxiety and avoidance. SUDS ratings throughout treatment were found to increase significantly over time, indicating that the exposure evoked subjective distress during the intervention. Results for ΔEDA were not significant. Presentation style did not have a statistically significant effect on any of the outcome measures, indicating that further research on specific vocal qualities may be necessary to determine whether this variable is critical for the effectiveness of exposure therapy. Lack of significant results for overall treatment suggests that while current intervention may have evoked subjective distress, length of exposure sessions was insufficient to produce treatment effects. |
