title: Imaginal response events in systematic desensitization: a pilot study.
abstract: The primary focus of systematic desensitization (SD) is physiological responsivity in the presence of a conditioned aversive stimulus. However, SD also effects changes in motorapproach behavior and self-report. This study explores the possibility that SD directly affects the motor response system by way of conditioning covert approach responses in the presence of the imaginal aversive stimulus. Two independent variables were investigated: the content of instructions and actual covert motor responses during SD. Twenty-four subjects were classified as high- or low-responders on the basis of electromyographic responsiveness to instructions to imagine movement. Half the high- and half the low-responders were given a series of instructions to imagine-motor-approach behavior toward snakes. The remaining subjects received instructions to imagine only the snakes themselves with no reference to motor response. Imaginal scenes of 30-sec duration were alternated with relaxation periods of the same length. A significant difference was found between the posttreatment scores of high- and low-responders on performance measures, the high-responders performing better. The difference between the two instruction groups was not statistically significant. Self-report data suggested some subjects given instructions to imagine only snakes actually imagined themselves approaching snakes. Therefore, data were re-analyzed after instruction groups were reconstructed accordingly. A statistically significant difference was found on both factors. Continued investigation may further support imagery as covert behavior, open to empirical study.
mesh_terms: D001521:Behavior Therapy; D003887:Desensitization, Psychologic; D004576:Electromyography; D005239:Fear / Q000502:physiology; D006801:Humans; D007092:Imagination / Q000502:physiology*; D009043:Motor Activity / Q000502:physiology*; D009132:Muscles / Q000502:physiology*