Psychogenic amnesia
- Key People:
- Théodule-Armand Ribot
Some forms of amnesia appear to be quite different from those associated with detectable injury or disease of the brain. These comprise, first, amnesias that can be induced in apparently normal individuals by means of suggestion under hypnosis; and, second, amnesias that arise spontaneously in reaction to acute conflict or stress. Such amnesias are reversible and have been explained wholly in psychological terms. Nevertheless, organic factors are not infrequently involved to some extent, and the distinction between organic and psychogenic amnesia may turn out to be far less absolute than has been supposed.
Hypnotic amnesia
Memory of a hypnotic trance is often vague and fragmentary, as in awakening from an ordinary dream. This may be due in part to a reduction of registration during the period of altered consciousness. At the same time, very much more complete posthypnotic amnesia can be induced if hypnotized individuals are told that, upon waking, they will remember nothing of what went on during the period of hypnosis. This is clearly a psychogenic phenomenon; memory is fully regained if a patient is rehypnotized and an appropriate countersuggestion given. It may also be regained if a person is persistently interrogated in the waking state, again suggesting that the amnesia is apparent rather than real. This observation led Freud to seek access to ostensibly forgotten (repressed) memories in his patients without the use of hypnosis.
Amnesia affecting specific memories
Amnesia that affects specific memories can involve the failure to recall particular past events or events falling within a particular period of the patient’s life. This is essentially retrograde amnesia, but it does not appear to depend upon an actual brain disorder, past or present. There also may be a failure to register—and, accordingly, later to recollect—current events in the patient’s ongoing life. This is essentially anterograde amnesia and, as an ostensibly psychogenic phenomenon, would appear to be rather rare and almost always encountered in cases in which there has been a preexisting amnesia of organic origin. Rarely, amnesia appears to cover the patient’s entire life, extending even to the person’s own identity and all particulars of the patient’s whereabouts and circumstances. Although most dramatic, such cases are extremely rare and seldom wholly convincing. They usually clear up with relative rapidity, with or without psychotherapy.
Amnesia of specific events or periods of time differs from organic amnesia in important respects. As a rule it is sharply bounded, relating only to particular memories, or groups of memories, often of direct or indirect emotional significance. It is also usually motivated in that it can be understood in terms of the patient’s needs or conflicts—e.g., the need to seek financial compensation after a road accident causing a mild head injury or to escape the memory of an exceptionally distressing or frightening event. It also may extend to basic school knowledge, such as spelling or arithmetic, which is never seen in organic amnesia unless there is concomitant aphasia or a very advanced state of dementia. A most distinctive feature of amnesia relating to specific memories is that it can almost always be relieved by such procedures as hypnosis. Although distinguishing organic from psychogenic amnesia is not always easy, it can usually be achieved on the basis of such criteria, especially when there is no reason to suspect actual brain damage.
Fugue states
The fugue is a condition in which an individual wanders from home or a place of work for periods of hours, days, or even weeks. One celebrated case was that of the Rev. Ansell Bourne, described by American psychologist William James. This clergyman wandered from home for two months and acquired a new identity. On his return, he was found to have no memory of the period of absence, though it was eventually restored under hypnosis. In not all cases, however, is the basis of the fugue so manifestly psychogenic. Indeed, close observation in some instances may reveal minor alterations in consciousness and behavior that suggest an organic basis, probably epileptic. According to one view, pathological wandering with subsequent amnesia is due to a constellation of factors, among which are a tendency toward periodic depression, history of trauma in childhood, and predisposition to states of altered consciousness, even in the absence of organic brain lesion. Psychoanalysts, on the other hand, see in the fugue a symbolic escape from severe emotional conflict.
Paramnesia and confabulation
The term paramnesia was introduced by German psychiatrist Emil Kraepelin in 1886 to denote errors of memory. He distinguished three main varieties, including simple memory deceptions, as when one remembers as genuine those events imagined or hallucinated in fantasy or dream. This is not uncommon among confused and amnesic people and also occurs in paranoid states. Kraepelin also wrote of associative memory deceptions, as when a person meeting someone for the first time claims to have seen the new individual on previous occasions. This has been renamed reduplicative paramnesia or simply reduplication. Last, there was identifying paramnesia, in which a novel situation is experienced as duplicating an earlier situation in every detail; this is more generally known as déjà vu or paramnesia tout court. The term confabulation denotes the production of false recollections generally.
Déjà vu
The déjà vu experience has aroused considerable interest and is occasionally felt by most people, especially in youth or when they are fatigued. It has also found its way into literature, having been well described by, among other creative writers, Shelley, Dickens, Hawthorne, Tolstoy, and Proust. The curious sense of extreme familiarity may be limited to a single sensory system, such as the sense of hearing, but as a rule it is generalized, affecting all aspects of experience including the subject’s own actions. As a rule, it passes off within a few seconds or minutes, though its repercussions may persist for some time. For some epileptics, however, déjà vu may continue for hours or even days and can provide a fertile subsoil for delusional elaboration.
In view of its occurrence among organically healthy individuals, déjà vu commonly has been regarded as psychogenic and as having its origin in some partly forgotten memory, fantasy, or dream. This explanation has appealed strongly to psychoanalysts; it also gains support from the finding that an experience very similar to déjà vu can be induced in people by hypnosis. If a picture is presented to hypnotized people with the instruction to forget it and then is shown with other pictures when the subjects are awake, they may report an intense familiarity that they are at a loss to justify. The déjà vu phenomenon also is attributable to minor neurophysiological variation; it is frequent in epilepsy. Indeed, déjà vu is accepted as a definite sign of epileptic activity originating in the temporal lobe of the brain and may occur as part of the seizure activity or frequently between convulsions. It seems to be more frequent in cases in which the disorder is in the right temporal lobe and has on occasion been evoked by electrical stimulation of the exposed brain during surgery. Some have been tempted to ascribe it to a dysrhythmic electrical discharge in some region of the temporal lobe that is closely associated with memory function.
Reduplicative paramnesia
Reduplication is observed mainly among acutely confused or severely amnesic people; for example, patients may say that they have been in one or more hospitals that are very similar to their present location and that all bear the same name. The effect also can be induced by showing subjects an object such as a picture and by testing them for recognition of the same picture a few minutes later. The affected people are apt to say that they have seen a similar picture but definitely not the one now being shown. This effect appears to depend on loss of a sense of familiarity and on failure to treat a single object seen on a number of occasions as one and the same. It has been reported that reduplication of this kind is typically associated with confabulation, speech disorder (paraphasia), disorientation, and denial of illness.
Confabulation
Spurious memories or fabrications are very common in psychiatric disorders and may take on an expansive and grandiose character. They may also embody obvious elements from fantasy and dream. At a more realistic level, the production of false memories (confabulation) is best studied among patients with Korsakoff syndrome, for whom consciousness and reasoning remain clear. When asked what they did on the previous day, such people may give a detailed account of a typical day in their life several months or years earlier. Evidently their retrograde amnesia and disorientation in time provide fertile soil for false reminiscence. When the confabulation embodies dramatic, fanciful elements, it is the exception rather than the rule.
Confabulation once was regarded as one’s reaction to the social embarrassment produced by a loss of memory—i.e., as an attempt to fill memory gaps plausibly. Despite this possibility, many severely amnesic patients confabulate little, if at all; and there appears to be no relation between the severity of amnesia and frequency of confabulation. In consequence, individual differences in preamnesic personality have been stressed, particularly in regard to suggestibility. Although many patients who confabulate are obviously highly suggestible, precise tests of suggestibility have not been used in most clinical evaluations. It also has been claimed that the superficially sociable, but basically secretive, individual is particularly prone to confabulate. The most critical factor appears to be the degree of insight patients have into their disorder; it has been observed that amnesia patients who most strongly deny any lapse in memory are most prone to confabulate. By contrast, it also has been claimed that in chronic Korsakoff states patients’ insight into their condition is no guarantee of freedom from confabulation.
While confabulation is pathological by definition, all people include an inventive (and thus spurious) element in their remembering. Indeed, it seems valid to say that all remembering depends heavily on reconstruction rather than on mere reproduction alone. Among those affected by amnesia, reconstruction is especially drastic, inventive, and error-prone, particularly in regard to chronological sequence. The difference, therefore, between ordinary and grossly amnesic confabulation may well be one of degree rather than kind.
