Rehabilitative Imagery and Placebo Responding: An Objective Measure of Expectancy Effects

Abstract

Mental imagery (MI), or the process of re-creating an event within the mind, has been used in a variety of contexts. Imagery training has been used mostly within the context of sport (see Martin, Moritz, & Hall, 1999, for review), but also for other health conditions including Parkinson’s disease, chronic pain, and post-stroke patients, whom have all seen improvements following imagery training (Dickstein & Deutsch, 2007). Although various theories exist to account for its success in these instances including Lang’s (1979) Bioinformational Theory, and psychoneuromuscular theory (as reported in Vealey & Greenleaf, 2006), a neurophysiological approach has been taken to understanding the involved brain activity occurring (Decety, 1996). Sport injury rehabilitation is another area that attention has been given to the usefulness of MI. Williams and Scherzer (2006) discussed problems for athletes returning to competition after injury. Some athletes are not psychologically ready to return to competition, even when they have completed a rehabilitation program. Imagery can benefit the injured athlete by directing his/her response toward the injury. When imagery programs have been implemented into injury rehabilitation methods, it has been found beneficial for the athlete. The role of placebo responding should also be considered in the presence of imagery interventions, particularly when the athlete exhibits an expectation of recovery through controllability of the healing process. The proposed study will examine imagery interventions as a placebo, and whether MI (mental injury) serves as a rehabilitative mechanism in itself, or if it could be a variant of a placebo responding due to the suggestion of recovery made by the therapist. Across all conditions, it is anticipated that the participants in all imagery groups would perform better than the control group, which only received physical rehabilitation. Furthermore, it was expected that individuals in the three positive suggestion groups would exhibit a significant increase in rehabilitation factors as measured by quantitative physical rehabilitation measurements.