Physiological activation and co-activation in an imagery-based treatment for test anxiety.

Objective: The effectiveness of Imagery Rescripting (IR) has been demonstrated in the treatment of various psychological disorders, but the mechanisms underlying it remain unclear. While current investigations predominantly refer to memory processes, physiological processes have received less attention. The main aim of this study is to test whether client physiological activation (i.e., arousal) and client-therapist physiological activation (i.e., synchrony) during IR segments predicted improvement on next-session outcomes and overall treatment response, and to compare these to the role of physiological (co)-activation during traditional cognitive-behavioral (CB) segments. Methods: The results are based on 177 therapy sessions from an imagery-based treatment for test anxiety with 60 clients. Client and therapist electrodermal activity was continuously monitored, next-session outcome was assessed with the Outcome Rating Scale and treatment outcome was assessed using the Test Anxiety Inventory. Results: Hierarchical linear models demonstrated that average physiological synchrony during IR segments (but not during CB ones) was significantly associated with higher well-being at both the session and the overall treatment levels. Clients' physiological arousal in either IR or CB segments was not predictive of either outcome. Conclusion: These results provide initial evidence for the idea that physiological synchrony might be an important underlying mechanism in IR.