In search of the unconscious; evidence for some cornerstones of Freudian theory is coming from an unlikely source – basic neuroscience
Laurence Miller
In Search of the Unconscious
Is Freud outdated? In an era when neuroscientistsare mapping the chemical pathways of the brain, probing the microsecrets of the neural synapse, computer analyzing human brain-wave patterns and quantifying the cognitive effects of cerebral injury, Freud’s grand system of theory and therapy may appear imminently doomed to the status of historical curiosity. With the advance in scientific understanding of behavior, some have argued, notions such as the unconscious, dream interpretation and the importance of sexuality may be so much psychological baggage. “Psychoanalysis, born amid doubt in 1900,’ says J. Allan Hobson, Harvard Medical School professor of psychiatry, “could well be dead by the year 2000.’
But Hobson’s prediction may be a bit premature.The brain and behavioral sciences, far from sounding the death knell of psychoanalytic theory and practice, may instead be rallying to Freud’s support. Witness the recent profusion of books, professional conferences, scientific papers and popular accounts, all speaking to the potential rapprochement between psychoanalysis and research in the basic neurosciences. Freud himself predicted that his provisional ideas about human psychology would some day find a basis in human biology. Today, a century after the first psychoanalyst opened up his practice in Vienna, the tools, techniques and concepts of the human neurosciences are being used to examine scientifically such fundamental Freudian concepts as the unconscious mind, repression, dream symbolism, sexuality and the development of neurotic symptoms.
A good example of such research isthe study of neurosurgery patients carried out by Benjamin Libet and his associates at the University of California School of Medicine. They have shown that a weak electrical pulse delivered either to the hand or to the exposed sensory cortex requires about a half-second of processing time in the brain to reach consciousness. But interestingly, when the pulse is delivered to the hand the patient becomes conscious of the stimulus at the same instant it was delivered, not a half-second later. In other words, some brain mechanism must be “correcting’ for the half-second processing delay in the case of natural sensory stimulation, so that subjectively, we regard our perception of an experience as occurring at the same time as the experience itself, not a half-second later.
According to Rockefeller Universityneuroscientist Jonathan Winson, the one-half second it takes for a sensation to make its way into consciousness provides a possible neurophysiological basis for Freud’s notion of repression, the mental burying of disturbing thoughts out of normal awareness; the brain, by allowing a brief interval for certain preconscious mechanisms to analyze thoughts, feelings and memories, is able to repress them if their content is too unpleasant.
Others agree. “Libet’s work hasenormous implications for understanding unconscious processes,’ says Howard Shevrin of the University of Michigan Medical Center. Shevrin’s own work has involved the study of subliminal perception–the information processing that goes on just below the threshold of conscious awareness. Shevrin uses a technique called “evoked potential’ (EP) recording, in which the patterns of brain-wave activity accompanying particular kinds of input are recorded by the electroencephalograph (EEG) and analyzed. In a typical experiment, someone is presented with two kinds of visual stimuli for intervals too brief to register in conscious awareness. The first consists of a “meaningful’ picture, such as a fountain pen pointed at a person’s knee; the second is a similar, but more abstract and less meaningful, arrangement of shapes. After each presentation, the person is asked to relate all the words that come to mind.
The results have typically shownthat the meaningful stimulus–the pen-knee combination, for example– produces a greater degree of brain activity as recorded by the EP, even though the person denies having seen anything. This suggests that a more intrinsically interesting or meaningful stimulus elicits more attention and mental processing, even if this attention and mental processing are “unconscious.’
How do such findings bolster psychoanalytictheory? Freud hypothesized that during early child development, mental life is dominated by a style of nonrational, impulse-oriented thought, which he called “primary process.’ Only later, he theorized, does this style of thinking give way to the logical, planning-oriented and judgmental “secondary process’ thinking necessary for dealing with the demands of reality. Residue of this early primary-process thinking can show up in adult life in the form of dreams and in some of the delusions and hallucinations of madness.
The verbal associations elicited bythe subliminal pen-knee stimulus in Shevrin’s experiments have been of several types, some relating conceptually to the stimulus, such as “ink’ and “paper,’ or “leg’ and “bone,’ others relating more to simple sound-associations, such as “pennant,’ “happen,’ or “neither,’ “any.’ Any Shevrin has found that different types of brain activity are connected with sound associations and conceptual associations– expressions, he believes, of primaryand secondary-process thinking, respectively.
Further, Shevrin has found that peoplewho characteristically show a tendency to keep unpleasant thoughts, feelings and experiences out of conscious awareness–called “repressers’ –typically show less brain activity in response to meaningful stimuli and make fewer associations. Since the stimuli are presented too quickly to register in consciousness, this must mean that the repressers are perceiving the stimuli at least well enough for some unconscious evaluative process to keep them out of awareness. What brain mechanisms might account for this?
Neuropsychological studies haveshown that for most people the left hemisphere is specialized for language and for sequential, logical analysis and problem-solving. It is good at perceiving details and particulars and making literal, descriptive interpretations of things. By contrast, the right hemisphere is specialized for spatial processing and the synthesis of images and forms; it is more intuitive, emotional and inferential and generally takes a more symbolic and associational approach to information processing.
David Galin of the Langley PorterNeuropsychiatric Institute regards certain aspects of right-hemisphere functioning as congruent with Freudian primary-process thinking. The right hemisphere, according to Galin, reasons in a nonlinear style rather than by syllogistic logic. Conversely, other neuropsychologists have associated the faculty we call rationality with the logical, verbal and analytical cognition of the left hemisphere–a form of thought similar to Freudian secondary-process thinking.
Normally, the two hemisphereswork together so that a person’s perception and consciousness form a unitary whole. But in some people, intractable neurological conditions require that the main cerebral “commissures,’ the fiber pathways connecting the two hemispheres, be surgically severed. These so-called “split-brain’ patients sometimes show a curious dissociation of perception and thinking, especially under certain experimental conditions. For example, an erotic visual image flashed to the right hemisphere elicits emotional signs of embarrassment, but the person is unable to describe what was seen. The right hemisphere is processing the image and emotional content of the message, but this information cannot be communicated to the left hemisphere for verbal analysis and labeling. The person can’t articulate –either to himself or the experimenter –what is causing the embarrassment. For all intents and purposes, this information is “unconscious.’
Psychoanalyst Klaus Hoppe of theUniversity of California, Los Angeles, School of Medicine postulates that one effect of surgical commissurotomy is to interrupt the normal preconscious stream of thought between the two hemispheres. This allows right-hemisphere primary-process thinking to go on, unaccounted for and uninterpreted by the analytic left hemisphere. To explain the similar lack of self-awareness seen in many neurotic, but neurologically intact, individuals, Hoppe hypothesizes the existence of a “functional commissurotomy,’ which may serve as the cerebral foundation for the concept of repression. Such a psychological impairment would account for the inability of some neurotic patients to develop fresh insights into their feelings, motives and behavior.
Working with neurosurgeon JosephBogen of the University of Southern California, Hoppe studied a group of 12 split-brain patients using what is called a psychosomatic questionnaire, which has been used to measure the symptoms seen in a type of psychoanalytic patient called alexithymic. Alexithymia refers to the bland, emotionless, fantasy-poor and virtually dreamless mental style of these overly repressed patients who typically show a marked tendency to develop psychosomatic symptoms. It’s as if the physical sympton serves to express the feelings and conflicts that the alexithymic can’t consciously get in touch with or verbalize in therapy.
The results of the psychosomaticquestionnaire for the split-brain patients were similar to those obtained from diagnosed alexithymics, suggesting that there may be a relationship between the effects of surgical commissurotomy and the thinking style of overly repressed psychoanalytic patients. Are alexithymics and their split-brain counterparts similar to repressers?
Of course, most of us are neitheralexithymic nor commissurotomized. Yet we all carry around little pockets of memories, feelings and fantasies of which we may not be fully aware, but which nevertheless may insidiously influence our perceptions and actions. Galin has some thoughts about how such a condition may develop. Suppose, he says, that a mother gives her child a positive verbal message (“what a good boy’) but at the same time speaks in an angry tone and scowls. Since the pathways connecting the brain’s two hemispheres are developmentally immature in young children, and the hemispheres are still highly specialized for either emotional or verbal processing, each hemisphere perceives and interprets independently the different aspects of the mother’s message. The left hemisphere processes and responds to the positive verbal message, while the negative emotional connotation percolates simultaneously in the right hemisphere.
Then, in future situations in whichan authority figure gives an inconsistent message, the individual may find himself experiencing all the raging emotions of an intense conflict–but without knowing why. Because of the early lack of interhemispheric communication, the conflictual material has remained, in effect, “repressed.’
Is there any evidence that this kindof primary-process thinking can be traced to right-hemisphere activity? This brings us back to dreaming. Michael Stone of Cornell University suggests that the right hemisphere may contribute to the special, visual, surrealistic and symbolic aspects of dreams. Others, like Bogen, see the right hemisphere as the source of certain kinds of dream material. Commissurotomy patients frequently report fewer dreams than before the operation, suggesting to Bogen that dream material elaborated in the right hemisphere is no longer available for conscious recognition by the left.
Several studies and case reportshave found that loss or reduction of subjective dreaming is more likely to occur following right-hemisphere injury than left-hemisphere damage. Yet one EEG sleep study of a supposedly “dreamless’ patient born without the main cerebral commissure showed that he exhibited a normal amount of REM sleep. This suggests that right-hemisphere dream elaboration was in fact occurring but was not being communicated to the left, where it could be comprehended and reported.
Paul Bakan of Simon Fraser Universitynotes that during REM sleep the right hemisphere is more active than the left. He hypothesizes that during REM sleep the connections between the two hemispheres are somehow reduced, allowing the right hemisphere more autonomy of functioning. Certain types of mental illness, such as schizophrenia, represent in part a “spillover’ of dream-like primary-process thinking into waking consciousness, according to Bakan.
Sexuality is a prominent dreamtheme and, of course, a central theme in the Freudian psychic drama. If dreaming, including sexual dreaming, can be conceptualized as a predominantly right-hemisphere function, what about sexual responses in general? In an experiment done in the lab of Leonide Goldstein of the Robert Wood Johnson Medical School in New Jersey, male and female volunteers masturbated to orgasm while their brain activity was monitored by EEG. In addition, a few were asked to fake an orgasm. Real, but not feigned, orgasms were associated with increased right-hemisphere activity. This further suggests a major role for the right hemisphere in handling the expression of basic drives, a finding consistent with Freud’s emphasis on the importance of sexuality in human development and behavior.
Much of Freud’s early data on theunconscious came from the study of hypnosis. Could this, too, be a lateralized function? Studies by Bakan and others have indicated that lateral eye movements, or LEM’s, may be a way of assessing hemisphere dominance for certain types of psychological processes. For example, while reflecting on the answer to a question, most people’s eyes characteristically flit either to the right or the left, and any given individual makes about 75 percent of LEM’s in one or the other direction. Since direction of eye movement indicates activation of the opposite hemisphere, left-movers can be characterized as right-hemisphere-dominant and right-movers as left-hemisphere-dominant.
Bakan administered the StanfordHypnotic Susceptibility Scale to a group of college students who were also assessed for LEM direction. The results showed that left-movers were more hypnotizable and more likely to report clear visual imagery. To Bakan this suggests that hypnotizability, like dreaming, is a process that relies heavily on the right hemisphere.
LEM research has been used tostudy another aspect of Freudian theory, the idea that repression may lead to the development of psychosomatic symptoms. Raquel and Ruben Gur of the University of Pennsylvania studied the relationship between LEM direction, the tendency to use psychological defense mechanisms as measured by the Defense Mechanism Inventory and the presence of psychosomatic symptoms in a group of college undergraduates. They found that left-movers characteristically used defense mechanisms such as denial, repression and reaction formation–disguising an unwanted thought or feeling with the opposite thought or feeling–while right-movers used more projection and turning against others. And left-movers reported more psychosomatic symptoms.
Sandor Ferenczi, one of the earlyFreudian followers, postulated that the left side of the body is more accessible to unconscious influences than the right. More recently, studies have documented that “hysterical’ conversion symptoms–physical symptoms of psychological origin–tend to occur more frequently on the left side of the body (served by the right hemisphere), even in left-handers. Also, the so-called la belle indifference–paradoxical unconcern for a seemingly “serious’ conversion symptom such as paralysis–observed in some hysterics by clinicians from Freud’s day to the present, bears a striking clinical resemblance to the syndrome of anosognosia, or denial of illness, that frequently occurs after organic right-hemisphere injury. What this research on consciousness and hemisphericity suggests is that the cerebral mechanisms underlying our hidden motives may be similar to the more well-known neurological underpinnings of language, spatial reasoning and memory. And if the foundations in the brain are similar, then the tools and techniques may indeed be applicable to the study of our most fundamental selves.
So, the verdict for psychoanalysis?On balance, the general consensus seems positive. “That psychoanalysis will be blown over by increased research is wishful thinking’ on the part of the skeptics, says Shevrin, who perceives a “quiet revolution’ in the direction of scientific psychoanalysis, particularly with regard to such concepts as the unconscious mind and the influence of early experience on later personality and behavior.
“The laboratory and the consultingroom do seem to be sharing at least a common wall,’ he concludes, “which may in fact turn out to have a door in it.’
COPYRIGHT 1986 Sussex Publishers, Inc.
COPYRIGHT 2004 Gale Group
