Abstract
In a review of the salient aspects of research in hypnotic age regression an evaluation of the data tended to indicate that under certain conditions valid regression could be obtained. The problem of valid and invalid measures of age regression is discussed in the light of a neuropsychological theory of age regression. This theory based upon a concept of hypnotic retrogression views regression and progression phenomena in hypnosis as a form of psychological activity involving disorientation for the subject and a reorganization of his perceptual equilibrium and control mechanisms with particular reference to time-space perception. The term hypnotic retrogression is used to describe the centrally induced state which alters time-space perception and renders hypnotic regression and progression possible.