The Stimulus Barrier and the Pathogenicity of Trauma

One of Freud's momentous early discoveries was the fact that certain discrete childhood experiences crucially influenced the subsequent lives of his patients. These events, which he termed 'psychical traumas' first impressed him because of the specific role they played in the causation of illness and in the formation of symptoms.

Freud's interest in these phenomena—which continued unabated for the rest of his life—was not restricted to their direct implications for psychopathology. The finding that many of the traumatic experiences were imagined, and had not actually occurred, at first astonished and discouraged him, but then led to an understanding of the importance of fantasy as the psychic representation of both the instinctual drives and the defences. Continuing clinical experience resulted in another group of observations which carried far-reaching implications. First he noted that practically all children experience psychic traumas, but that only some of these experiences result in pathologic formations. Second, that events which are traumatic for some individuals are experienced without ill effects by others. Third, that the age and stage of development of the child will determine in large measure, whether or not a given stimulus will have a traumatic effect. It became clear that the response of the psychic apparatus to stimuli and challenges was a complex process, and that the outcome in each instance was determined by the operation and interaction of a number of variables.

Strictly considered, psychic trauma is a phenomenon, not a concept. It refers to the specific type of breakdown which occurs when, within a short period of time, the mind is presented with a quantity of stimulus too great to be dealt with or assimilated in the usual way. It represents the failure of the psychic apparatus to perform what may be considered its basic function—that of mediating between the organism and its needs on the one hand, and the stimuli which constantly impinge