title: Psychophysiological aspects of systematic desensitization: some outstanding issues.
mesh_terms: D001007:Anxiety; D001521:Behavior Therapy; D002540:Cerebral Cortex / Q000502:physiology; D003213:Conditioning, Psychological; D004569:Electroencephalography; D004644:Emotions; D005108:Extinction, Psychological; D006185:Habituation, Psychophysiologic; D006801:Humans; D007092:Imagination; D012063:Relaxation