Many disruptions of consciousness, such as those seen in the amnesic syndrome, blindsight, anesthesia, and sleep, are associated with clear alterations in the structure and/or function of the nervous system. However, there are other, "functional" alterations in consciousness where nervous-system changes are absent -- or, at least, much more subtle.
Historically, the most prominent of these "functional" disorders of consciousness have been subsumed under the label of "hysteria" -- a term that was very popular in psychiatric diagnosis well into the 20th century. The term itself has been abandoned in the "official" nomenclature, represented by the American Psychiatric Association's Diagnostic and Statistical Manual (DSM; since the 2nd edition), along with other terms that carry the flavor of psychoanalysis, such as neurosis and psychosis. However, once shorn of its sexist implications (i.e., that hysteria is a "women's mental illness"), the concept itself is perfectly legitimate. No opprobrium should surround the continued use of the term, so long as it's used responsible.
Finally, in 1907, Pierre Janet
(Charcot's protege and Sigmund Freud's early rival) argued
that the symptoms of hysteria involved a constriction of
awareness, such that complex behavioral responses (what Janet
called psychological automatisms) were executed
outside of conscious awareness and control. In Janet's
view, these automatisms were "split off", from the normal
stream of consciousness.
Janet (1904, 1907) illustrated his theory with the case of Irene, who is amnesic for her mother's illness and death, but who re-enacts in "somnambulistic" episodes the circumstances of her mother's death.
"Allow me to represent to you this system of psychological facts, which constitutes an idea, by a system of points connected together by some lines, forming a sort of polygon. The point S represents the sight of the face of the dead mother, the point V is the sound of her voice; another point M, is the feeling of the movements made to carry up the body, and so on. This polygon is like the system of thoughts which was developed in the mind and in the brain of our patient Irene. Each point is connected with the others, so one cannot excite the first without giving birth to the second, and the entire system has a tendency to develop itself to the utmost.
"But at the same time in healthy minds these systems pertaining to each idea are connected with an infinitely wider system of which they are only a part, -- the system of our entire consciousness, of our entire individuality. the remembrance of the mother's death, even the affection Irene feels for her mother, with all the memories that are connected with it, forms only a part of the whole consciousness of the young girl with all its memories and other tendencies. Let this large circle, P, near the little polygon represent the whole personality of the girl, the memory of all that happened in her previous life.
"Normally, in good health, the little system must be connected with the large one, and must in great part depend on it. Generally the partial system remains subject to the laws of the total system: it is called up only when the whole consciousness is willing, and within the limits in which this consciousness allows it.
"Now, to picture to ourselves what has taken place during somnambulism, we may adopt a simple provisional resume. Things happen as if an idea, a partial system of thoughts, emancipated itself, became independent and developed itself on its own account. The result is, on one hand, that it develops far too much, and, on the other hand, that consciousness appears no longer to control it" (1907, pp. 41-42).
Sigmund Freud offered an alternative
view. In his Studies on Hysteria (1893-1895),
co-authored with Josef Breuer, Freud had asserted that
"hysterics suffer from reminiscences" -- that the symptoms of
hysteria are symbolic representations of traumatic experiences
which are not consciously remembered; and that hysteria could
be cured by restoring conscious access to the traumatic
his 1896 paper "On the Etiology of Hysteria", Freud (no longer
writing with Breuer) elaborated on this view, based on his
doctrine of repression, and involving a particular
chain of memories (the graphic illustrating the theory is from
Ellenberger, 1970, p. 489).
Freud's claim that all hysterical patients had been seduced as children made him famous -- and it formed the basis for modern theories of the role of childhood sexual abuse in the dissociative disorders. But in less than a year, Freud was forced to admit, in a letter to his friend and colleague Wilhelm Fliess, that he had been misled, and that his patients' accounts of their childhood seductions had been fantasies on their part (it never occurred to Freud that they had actually been fantasies on his part!). This realization set the stage for Freud's revised (1905) theory of infantile sexuality -- the idea that children harbor erotic attachments to their parents of the opposite sex, and that it is these fantasies, rather than actual sexual trauma, that are repressed.
Modern psychiatric practice no
longer employs the term "hysteria", but does include a
category of dissociative disorders including
psychogenic (functional) amnesia (named "dissociative amnesia
in DSM-5, the most recent version of the Diagnostic
and Statistical Manual of Mental
Disorders), psychogenic (dissociative) fugue,
multiple personality disorder (also known as dissociative
identity disorder), and depersonalization/derealization
disorder. In these syndromes, the terms "psychogenic",
"functional", and "dissociative" are used pretty much
interchangeably. In what follows, I adopt the usage in DSM-5.
All the dissociative disorders share in
common a disruption in memory and/or identity.
More (Much More!) on the Dissociative Disorders
For more thorough coverage of these syndromes, including a history of the diagnosis, see the papers on Dissociation and Dissociative Disorders collected on my scholarly website.
Some psychiatrists claim that the dissociative disorders occur in response to physical or psychological trauma, marking them as a variety of post-traumatic stress disorder (PTSD). However, the traumatic etiology of the dissociative disorders is controversial, and far from proven. For detailed coverage of this issue, see the papers on Trauma and Memory collected on my scholarly website.
And some commentators suggest that people diagnosed with
dissociative disorder are just faking it -- enacting a
cultural role in order to gain some reward.
Certainly the most famous case of
multiple personality disorder was The Three Faces of Eve,
described by Thigpen and Cleckley -- first in a professional
journal article (1954), and later in a popular-press book
(1957) that was turned into a move which won an Oscar for
Joanne Woodward. Eve White, the "host" personality, was
a somewhat reserved rural Georgia housewife who suffered from
"blackouts". During clinical evaluation, a much more
vivacious personality emerged, "Eve Black", who apparently had
awareness and control of Eve White's actions during those
blackout periods. For example, once Eve Black orderd a
slinky negligee; it's arrival in the mail surprised Eve White
(and disconcerted her husband). A third personality,
"Jane", emerged during therapy. "Eve White" had no
awareness of "Eve Black" or "Jane". "Eve Black" knew all
about "Eve White", but nothing about "Jane". "Jane" knew
famous case, Jonah (Ludwig et al., 1972), there were four
personalities: Jonah, also known as "The Square", was the host
personality, an African-American soldier based in the United
States, very shy, retiring, and sensitive; he, too, complained
of "blackout" periods, where he evidently did things that he
couldn't remember later. "Sammy", "The Lawyer", was
rather intellectual, and rational. "King Young", "The
Lover", was a pleasure-oriented glib talker. "Usoffa
Abdulla, the Son of Omega", "The Warrior", was cold,
belligerent, and angry. Jonah would go out for a night
on the town with his barracks-mates; King Young would try to
pick up women; Sammy would try to talk his way out of the
inevitable confrontation with their dates; if that failed
Usoffa Abdullah would fight his way out of trouble.
Jonah didn't know about any of these other personalities, and
they had limited knowledge of each other, but they all knew
I.C., a case that my
colleagues and I had an opportunity to study, also showed a
complex pattern of amnesia. She was a 24-yer-old woman,
a world-class performer in her field, who was referred for
"disorganized" and self-injurious behavior. As with Eve
White, it turned out that there were several other
personalities involved: There was "I.C." herself (named for
Irene Coriot, another famous case of multiple personality,
from the 19th century), married and a mother; "Heather" was
still an adolescent; "Joan" was a lesbian; and "Gloria" was a
drug abuser. "I.C."'s memories were accessible to
everyone else, but "I.C." knew nothing about the others --
though the others knew about each other.
Formal testing of I.C. focused on the "Crovitz-Galton technique", pioneered by Sir Francis Galton (Darwin's half-cousin) and developed further by Herbert Crovitz, an American psychologist, in which a familiar word (e.g., car or dance) is used as a cue for the retrieval of a specific autobiographical memory (e.g., "I remember when my father brought home a new car, a 1955 Plymouth sedan with salmon-pink trim"; "I remember taking Sharon E. to my first school dance in 8th grade"). Because of difficulties gaining access to I.C.'s alter egos, testing focused on I.C., the host personality, herself. We also tested a group of age-matched normal women.
|When tested at age 24, I.C. had virtually no memories from the first 14 years of her life, compared to controls|
|In another session, we constrained her recall to events occurring before age 12. She was able to produce some memories from ages 10-12, but not from earlier ages.|
|Her earliest recollection of herself was dated to age 12, compared to the more usual dating of about age 4. Her earliest memory of her father was dated age 16.|
Based on these findings, we speculated that, perhaps, what we thought was the "host" personality was actually an alter ego that began to emerge around age 12. Unfortunately, we were unable to do further follow up testing with this patient.
The interpersonality amnesia in MPD/DID is usually assessed in terms of explicit memory. However, there is some evidence that implicit memory can "transfer" between personalities. For example, of Jonah, the case described earlier, had been given some laboratory tests of memory, which confirmed his interpersonality amnesia with tests of recall, but showed some interpersonality transfer of memory on tests of savings in relearning (Ludwig et al. 1972).
A dramatic example of preserved implicit memory occurred in the case of "Jane Doe", a British woman who was discovered by the police disheveled and wandering the streets (Lyon, 1985). She could not identify herself, and she had no identification and no autobiographical memory. During her clinical evaluation the psychologist tested her fund of semantic and procedural knowledge. He pointed to the telephone on his desk, and asked her what it was. When she responded correctly, he asked her to show her how it was used. She dialed a number and -- before she could replace the receiver on the cradle -- the psychologist took the phone to talk to whoever answered on the other end. That turned out to be the victim's mother. Jane Doe lacked conscious awareness of her memory and identity, but her procedural knowledge -- including how to dial her mother's phone number -- remained intact.
Because MPD/DID is so rare, most experimental
studies have been confined to single cases, like Eve, or
Jonah, or I.C. But a study by Eich et al. (1997),
compared explicit and implicit memory in a substantial number
of such patients. The general design of the study was to
present some information to one alter ego (call it P1), and
then test memory for that information in the same and a
different alter ego (call the latter P2). The results
were ambiguous. Eich et al. found no interpersonality
priming on a test of stem-completion. But they did find
some evidence of transfer on a test of picture-fragment
identification. On this test, subjects are presented
with a very fragmentary picture of an object, and over trials
further details are added until they can correctly identify
The conversion disorders
involve "pseudoneurological" symptoms affecting sensation and
voluntary motor behavior.
In all cases, neurological examination reveals
no rain insult, injury, or disease that can account for the
As with the dissociative disorders affecting memory and identity, the conversion disorders are sometimes referred to as "psychogenic" deafness (or whatever), because they presumably have psychological, rather than organic, causes (if they were caused by some form of peripheral or central nerve damage, they would be seen by neurologists, not psychologists). These symptoms are also functional in nature,Under the label of "hysteria", the covnersion disorders are among the oldest known mental illnesses, but psychiatry has never known quite what to do with them (Kihlstrom, 1994). The earliest editions of the DSM simply put them under the category of hysteria (where they belonged). But more recently, they have been ensconced in categories like "medical symptoms without known cause". In DSM-5, they are listed under a catch-all category of "Somatic Symptom and Related Disorders".
However, the conversion disorders
should be distinguished from other that also involve
complaints of bodily dysfunction.
What sorts of changes? In the classical instance, the conversion disorders seem to involve a dissociation between explicit and implicit perception. For example, "hysterically" blind patients are commonly found to be responsive to visual stimuli, even though they are not aware of them. This was noted by Charcot and Janet, as long ago as the19th century -- for example, in Janet's treatise on the Major Symptoms of Hysteria.Early evidence of visual processing came from a classic study of "hysterical" blindness by Brady & Lind (1961). The patient claimed total blindness, even though medical examination could find no organic pathology that would explain the complaint. As part of their assessment and treatment of the problem, Brady and Lind employed an instrumental conditioning procedure known as the differential reinforcement of low rates (Brady was a psychiatrist who was an early advocate of behavior therapy). The patient was instructed to push a button once within a certain interval, every 18-21 seconds; if he succeeded, a buzzer went off, and he received immediate social approval and accumulated points toward hospital privileges. This is not easy -- not least, because the patient wasn't told precisely what the target interval was; but also because that's a fairly long period of time.
Just as there is some degree of implicit memory in MPD/DID, so there appears to be some degree of implicit perception in visual conversion disorder.
In the final analysis, the dissociative disorders all seem to
share the following features:
This page last revised 02/26/2017.