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The “Siamese Twinship” of the Cerebral Hemispheres and of the Brain-Mind Continuum
Hemispheric Specialization
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The "Siamese Twinship" of the Cerebral Hemispheres and of the Brain-Mind Continuum Toward a "Psychology" for the Corpus Callosum
] ames S. Grotstein, M .D. *
Recent research in neuroscience, especially cerebral hemispheric laterality studies, have impacted psychoanalysis in a variety of ways, not the least of which is a realization of a need to reconcile these new data with its already established psychological theory and/or to effect modifications in its own metapsychology which would bring it into alignment with the thrust of this new research . Most basically there still exists an impasse in studying these two domains, one that has long been known as the mind-brain dilemma- dilemma because there seems to be no available way for us to reconcile the two domains, especially since neuropsychology and psychoanalysis follow different laws of functioning . In a recent contribution, I offered the conception of the dual-track theorem as a way of embracing both disparate domains . 22-26 In profferring the dual-track theorem, I wish first of all to distinguish it from the traditional concept of dualism, with which it is in danger of being confused. Dualism is the conception attributed to Western scientific thinking, beginning with Descartes, that there is a fundamental, irreconcilable differentiation between the observer and the observed, which, by implication, devolves into a basic distinction between the mind and the body, the former being the perceiver and the latter the perceived. The dual-track hypothesis reconciles cartesian dualism with Eastern, holistic monism through its implications that separateness and wholeness (or at-one-ness) comprise the Yin and Yang of a fundamental and irreducible bimodal unity. The dual track is the instrument of dialectical understanding, and it is my thesis that the two cerebral hemispheres represent an outstanding concrete example of dialectic operations . In order to express this bimodal, dialectic conception of separation/ nonseparation, I should like to proffer the visual image of "Siamese twins," *Clinical Professor of Psychiatry, University of California, Los Angeles, Los Angeles, California
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which could be imagined either as two heads and one body or two bodies and one head, depending upon the use to which the image is put. Thus, the functioning of the brain-mind can be consequently envisioned as (a) the operation of both cerebral hemispheres as a holistic entity and (b) the simultaneous operation of each and/or both cerebral hemispheres independently. Before pursuing the uses to which I wish to put this image as an instrument in studying brain laterality and the mind-brain dilemma, I wish to recognize that this image has already been anticipated by Nunberg's 50 and Modell's 48 concept of the "Janus-face" organization (bimodality) of the transference and by Rothenberg's 5 1 concept of "janusian" thinking and homospatiality. The principle of bimodality, as discussed by Nunberg and Modell, applies to the dialectic phenomenon in the transference in which frustrations from the past are experienced in the transference neurosis sideby-side with transference expectations of wish-fulfillment. Janusian thinking, as conceived by Rothenberg, designates a special type of secondary process in which opposites or reversals appear side-by-side for analogic comparison. It is the essence of "mirror-imaging." Homospatial thinking is more elaborate, involves spatial montaging of contrasting images, facilitates the creative integration of janusian thinking, but, unlike the latter, involves primary as well as secondary processes . Sperry65 has contributed the concept of the Y configuration to designate the duplication-complementarity of cerebral hemispheric functioning . My own conception of the Siamese twinship is an elaboration of both janusian and homospatial thinking. Fundamentally, the image of the "Siamese twinship" allows not only for separateness and connectedness simultaneously and/or alternately but allows also for a variety of complex interactions between two (or more) living entities that are experienced as separate and nonseparate, whose nonseparation can be understood as a sense of discontinuous continuity via the Moebius phenomenon, that is, where there is a mysterious twist in a "ribbon of awareness" which connects and yet disconnects two domains . The Moebius twist allows its two (or more) components to link up with each other in a variety of ways, one of which would be a montage . This conception would seem to apply appropriately, for instance, to the functionings of the two cerebral hemispheres, to sleep and wakefulness, to the conscious and the unconscious, between the id, ego, and superego, etc. It would appear to be particularly apt in describing the reversal or inversion of images as they cross the corpus callosum from each hemisphere to the other. This mysterious discontinuous continuity, albeit paradoxic, gives new perspective to the psychoanalytic conception of the repressive barrier, for instance. We can now conceptualize the repressive barrier as defending, not only the ego from instinctual eruptions from the id but also the reverse, that is, the need for the id to be protected from the intrusions of the ego and its connections with reality. The "Siamese twinship" allows for the id and the ego to be full partners, much like the cerebral hemispheres. The notion of a dual track is fundamental to the architecture and functioning , not only of the brain and of the mind, but even more basically to the structure of the double helix of the gene itself.
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The "Siamese twinship" image allows us to conceive of the two cerebral hemispheres as both separate and connected, functioning separately and together. It allows for the conceptualization for a "non-anatomic third brain" (a holistic brain comprising a homospatial montage of its components), which in terms of this image, can be pictured as the whole "Siamese twin" figure as the brain comprising of a single entity interfacing with either or both the hemispheres for independently concordant, complementary, oppositional, or commensal functions. Bogen3 states that the cerebral hemispheres duplicate and complement each other. Further, it is now known that the left hemisphere functions via propositional thinking and the right hemisphere through appositional thinking, which has to do with comparing. To these variables I should like to add two other possibilities. One would be that the two hemispheres can at times appear to be individually anthropomorphic and may even oppose* each other as if each became a veritable "enemy" of the other. The latter condition is demonstrated in an example offered by Goldstein, 21 in which he described a patient who attempted to strangle herself with one hand and to release the strangling hand with the other. On postmortem examination it was found that she had suffered from a dissecting tumor of the corpus callosum. The "oppositional" type of relationship between the two hemispheres has achieved veritable anthropomorphic realization in split-brain research, whether by commissurotmy for the treatment of epileptic seizures or by sophisticated neuropsychologic testing in which the two hemispheres are purposely isolated from each other in order to demonstrate the functions of each individual hemisphere. 2• 9 · 18 · 19 · 29 · 30 · 32 · 33 • 53 - 55 Hoppe 31 adds yet another perspective to oppositionalism in his discussion of Lorenzer' s concepts of deconstruction-reconstruction oflanguage and forms. This could be applied to brain laterality as, for instance, the propensity of the right-hemispheric cognitive style to challenge and "deconstruct" fixed belief systems formed by the left-hemispheric cognitive style. t The final possibility would be that of commensal functioning, in which the two hemispheres function optimally but independently of each other, a condition that occurs frequently on normal occasions but is typical of cases of agenesis or surgical dissection of the corpus callosum. The commensal perspective is of great importance insofar as it can also represent the unsuspected element, the "stranger," so to speak. Creative thinking would thus be enhanced by one's ability (the ability of one or both hemispheric consciousnesses) to transgress its putative boundaries and thereby encounter the unsuspected.
*Here I employ the term "oppose" in the affective and intentional sense, not in the strictly neuroanatomic sense. t Witelson, doing psychological testing research, isolated a group of dyslexics whom she states function as if they had "two right hemispheres and none left." The two "right hemi spheres" duplicated and th erefore competed with each other. She also left room for the possibility of "two left hemispheres and none right."
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SOME HYPOTHETICAL ASSUMPTIONS ABOUT THE RELATIONSHIP BETWEEN HEMISPHERIC STRUCTURE AND MENTAL FUNCTION Interest in brain and mind laterality was considerable in the last century . An English physician, A.L. Wigan, 60 published a book in 1844 in which he conceptualized a dysynchrony between the two hemispheres as the key issue in insanity. The main emphasis was in literature, however, in which novelists on both sides of the Atlantic were writing about the mysterious phenomenon of the "second self" or "alter ego. "24 Side by side with the literary preoccupation with the second self, medical science was also interested in the subject, as attested to by the great interest in hypnosis, autoscopy (heautoscopy), and the predominance of hysteria as a focus of attention for nineteenth century psychiatrists. Hysteria had long been associated with demoniac possession, according to Veith. 58 Charcot8 was one of the principal exponents of the dissociated factors in hysteria, and Freud was introduced to this when he studied under Charcot at the Salpetriere in Paris. Later, Breuer and Freud, 7 and ultimately Freud alone, were to study these hysterical patients and to make hypotheses about them which were to launch the field of psychoanalysis. It is very interesting to watch the development of their interest in the dissociated phenomenon in hysteria. Charcot believed that the dissociation was due to a weakness in the organizational capacity of the brain, a hypothesis that was extended later by Janet.34 Breuer and Freud, however, came to believe that the dissociation was (a) entirely mental and (b) that the mentally dissociated element (the second self) was due to a censorship of a traumatic reality, the latter of which finally came to be first sexual abuse as a child and then later sexual fantasies, whereas the concept of the censorship underwent a development into the later concept of repression. It is very important to note, however, that all the patients Breuer and Freud report on in Studies on Hysteria were characterized by double consciousness, a finding that was in conformity with a general understanding in the nineteenth century of possessing a second self or alter ego. When Freud 16 later developed his topographical system and still later the structural system, the axis of doubleness rotated from a vertical plane to a horizontal plane and the content of the repressed changed from a second self to (a) traumatic memory and (b) libido, thereby depersonifying the second self and transforming its residue into preternatural instinctual drives whose destiny it is to erupt with peremptory intentionality. The second self became extinct and had to await the arrival of brain laterality research to be exhumed. Harrington28 recently reviewed the widespread enthusiasm for brain duality in nineteenth century neurology. Today, thanks to a reawakening of attention to this area by laterality research, we once again are interested in multiple states of brain-mind consciousness, including those caused by gross dissociation. We would also be interested in the possible correlation between neuropsychology and such entities as internal objects, object representations, archetypal objects, alter egos ("second selves"), affect and cognitive disorders, out-of-body experi-
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ences, somatization disorders of the brain, depersonalization, psychosis, etc. For instance, is psychosis a psychosomatic and/or somatopsychic disorder of the brain/mind? Is panic disorder a somatization of the brain by the mind, or is it a somatopsychic involvement of the mind by the brain? What is the relationship between mental illnesses and possible dysfunctions of the corpus callosum? On the other hand, speaking from the imaginative context of the possible "psychologization" of neuropsychologic functioning, is there such a thing as "hemispheric consciousness" or "modular consciousness?" On a deeper level, how is neuropsychologic decision-making achieved? Who orchestrates or choreographs the neuroschematics of selective and integrated brain function? How and why did the right hemisphere "decide" to accept its status as the silent moiety? Is there any validity to conjecturing personifications for brain functioning? The ultimate question to be posed is "Does the brain 'talk' to itself (selves?), and, if so, how?" In a current contribution, I proffered the notion that psychoanalytic instinctual drives could be understood in part as semiotic signifiers embedded in the ancient matrix of group communication via signals, signs, and gestures, phenomena that are easily demonstrable in ethologic studies and in psychosis. 25 Could it be that the right hemisphere communicates with the left (on occasion) via urgent, peremptory posturings-in sign language? The remainder of this article will speculate about these and similar questions. The cerebral hemispheres seem to have evolved asymmetrically, presumably in order to minimize mutual competitive inhibition. Beaton 1 states that " ... left hemisphere control of motor sequencing is the evolutionary precursor that attracted speech and language to the left side of the brain. Such an approach may well be appropriate, given that Man is the only known animal to show a species-specific preference for the limb on one side ... " (p 288). Gazzaniga and LeDoux 19 believe that the asymmetry of the brain is complex, giving each hemisphere an advantage depending upon the specific function. They believe that there arose within the left hemisphere, but not within the right, competition for the neurospace for verbal functions. They believe, in other words, that language pre-empts neurospace in the left hemisphere and manipulospatial functions in the right hemisphere. Levy4 1 believes that lateralization achieved a separation of two different patterns of neuro-organization. The kind of neurocircuitry best fitted to serve the needs of language and its cognitive correlates is not well adapted to the most efficient execution of visual-spatial tasks, she believes. Kinsbourne36 --38 believes that the brain is a paired organ, but in order to resolve neural "problems of indecision" to achieve some form of neurointegration, one hemisphere had to gain ascendancy over the bilateral locomotor apparatus. Dimond 11- 14 believes that, in the normal intact brain, the two hemispheres act as separate channels in analyzing incoming information and that this finding correlates with the capacity for parallel processing of information in each hemisphere. This concept of parallel processing of information fits in with Gazzaniga's 18 conception of the modularity of the two hemispheres. He states:
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I argue that the normal person does not possess a unitary conscious mechanism in which the conscious system is privy to the sources of all his/her actions. I want to build the argument that the normal brain is organized into modules and that most of these modules are capable of actions, moods, and responses. All except one work in nonverbal ways such that their modes of expression are solely through overt behaviors or more covert actions (p 74) .
The concept of parallel processing, especially as it pertains to the putative parallel processing by the two hemispheres (as well as component modular structures), suggests, especially as Gazzaniga interprets it, a beginning neurobasis that can easily allow for personifications of functions and, as a consequence, of the experience of multiple subselves within the neuromental substrate. How are the two cerebral hemispheres related to each othe r? They obviously are duplicates of one another and also are complementary as well as oppositional. Perhaps we can state that the relationship between the two cerebral hemispheres is based therefore upon the following possibilities: (a) concordant, (b) complementary, (c) disconcordant (or oppositional), and (d) commensal, the latter referring to the normal, independent, noninteractive functionings between the two hemispheres when each is processing data separately. These four modes might be encompassed by the term identification or mutual correspondence. Research studies in bisected brains in which experiments are conducted separately on each hemisphere would be an artificial example of this phenomenon. It undoubtedly occurs more normally much of the time in which commissurotomy is not an issue. Further, it is now known that images transferred from the left hemisphere to the right undergo a transformation as they traverse the corpus callosum and end up as negative and reversed images in the right hemisphere, a finding that correlates with the mirror-image functions that Rothenberg52 assigns to janusian and homospatial thinking. We know that, in the immune system, for instance, amino acid sequences on the structure of the protein molecules of the antibodies constitute a "language." When confronting an antigen, these amino acid chains realign themselves to conform to the amino acid sequence of the invading antigen, upon the successful conclusion of which the antibody, having "decoded" the antigen, devours it. Obversely, the antigen achieves its own invasive success originally in a similar decoding procedure. 35 Presumably "mirror-imaging" is involved in this deciphering. Might the right hemisphere attempt to communicate to or even purloin the functions of the left in such a manner? Later in this article I shall describe the dreams of two patients which strongly hint at such a scenario. An example of complementary functioning between the two hemispheres is commonly seen in songs. The lyrics, being verbal and therefore sequential, follow a diachronic sequence, whereas the music itself, although sequential in part, is also melodic and harmonic, indicative of the synchronic mode of presentation. Imagery in general, whether auditory, visual, or pictorial, demonstrates the quality of multiple, simultaneous facets of expressiveness. When this sensory shower falls on the threshold of the left hemisphere for expression, a complex transformation must take place, one from the synchronic modality to that of the diachronic. An analogue to this transformation occurs in the mental sphere. Freud 16 termed it the
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change from primary process to secondary process . Matte Blanco43 discussed it from the standpoint of mathematical concepts; that is, the unconscious is characterized by "infinite sets" and is symmetrical, whereas consciousness is characterized by limited sets and by asymmetry. Thus, as adumbrated earlier, the hemispheres, like the mind, each operate vis-a-vis the other under different, incompatible, complementary cosmic laws-best imagined as "Siamese twins" linked via a discontinuous-continuous Moebius strip. The details of hemispheric interaction and the findings relevant to the separate functioning are too detailed to list here. There is some agreement that the left hemisphere seems to be the more dominant one because of its access to verbal functioning. Moreover, it functions linearly and sequentially, is time-oriented, and is propositional. The right hemisphere duplicates most of the functions of the left hemisphere (as does the left for the right) but seems to be oriented in terms of space, attention, arousal, and scanning for fine distinctions, is more perceptually oriented, and is appositional-that is, has the facility for comparing two different shapes or images by apposing one to the other. Not only does each hemisphere function as a concordant "Siamese twin" -that is, each is capable of data processing and encoding data separately and concordantly-but also functions complementarily in a variety of ways, one of which may be parallel processing (separate but independent) but on complementary issues (for example, fine details versus gross details, time versus space, etc.). Moreover, each hemisphere may function, if I can be forgiven a personification, as a "background object" for the other; that is, the right hemisphere may offer a spatial background screen on which the detail-conscious left hemisphere may contemplate the figure on which it is focused. Thus, although each hemisphere is capable of independent sensory functioning, each can back up the other. It is already assumed that the right hemisphere offers contextualization to the more specific findings of the left. 9 The reverse may also be possible-the left hemisphere may offer a background for the functions of the right. Perhaps a song, poem, painting, or sculpture could be a demonstration of this possibility. Thus, left hemisphere and right hemisphere could correspond to a "figure-ground" configuration. It has been postulated that the left hemisphere relates to abstract details concerning objective reality relationships, whereas the right hemisphere deals more with affective and/or personal experiences in relationship to perceived objects. It has even been claimed that the right hemisphere corresponds to Freud's primary process, 16 whereas the left hemisphere corresponds to the secondary process. I think it more probable that each hemisphere is capable of affective and objective as well as primary process and secondary process functions, but a specialization does seem to occur by "common consent." Kohut (as quoted by Hoppe 29 ) believed that empathy, however, was distinctly a right-hemispheric function. The question emerges as to how this cooperation between the hemispheres (or, for that matter, among the "multifarious modules" which Gazzaniga and Ledoux 19 and Gazzaniga 18 posit) is achieved. Who or what makes the decision, the assignment of differentiated roles, who or what monitors it and orchestrates it, etc? Further, how can we understand the origination
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of intentionality and will, given the nature of brain anatomy and function which we understand so far? Involved in the difficulty of our even contemplating the mysterious connection between mental and neuronal function, we must realize that mind and brain function according to different regulatory schemata, laws, etc. They occupy different domains- thus the need in the first place for a dual-track theorem. Second, as a consequence of the preceding, we must remember that the central nervous system is composed of networks of neurons that function in parallel as well as by neurons that can be thought of as individually functioning in series. Utilizing the "Siamese twin" image, we can envision the whole twinship operating as an indivisible entity (as a single, whole unity) directing its hemispheric (or modular) components, now envisioned as parts of the "Siamese twinship," and being influenced by each of the hemispheric (neuronal feedback) sources. One system is whole, the other is part; another system is parallel, the other is serial; one is a network, the other is an individual. Somewhere in the dynamic interplay of these dialectic interactions, a "third force" emerges in which human intentionality, feeling, autonomy, and personalness seem to occur.
TOWARD A "PSYCHOLOGY" OF THE CORPUS CALLOSUM To push the motif of anthropomorphism even further, can one apply the concept of bonding and attachment4- 6 to hemispheric functioning? We now know that the two hemispheres only gradually begin to "know" each other over developmental time. The corpus callosum and the deep cerebral commissures do not begin their myelination until about three months of age and do not complete it until adolescence or early adulthood. 40 If each hemisphere is capable of the phenomenon of consciousness, as is stated by Sperry, 53-S5 by Gazzaniga and LeDoux, 19 and by Gazzaniga, 18 is each capable of self-consciousness and of consciousness of the other? What is the experience of each as it becomes aware of the other? Is it a mixture or montage of bonding and attachment on the one hand and of stranger anxiety on the other? Might the "individual psychologies" of each hemisphere (to say nothing of their "group psychology" after their union) account for incomplete and/or mixed lateralization-or even of functional commissurotomy?29· 30· 32· 33 For that matter, how can we explain the elaborate and ingenious attempts of either hemisphere by which, when cut off communicatively from the other in split-brain studies, each is able, via "cross-cuing," to rationalize or justify the otherwise inexplicable perception from the other hemisphere (particularly the left hemisphere attempting to explain perceptions from the right hemisphere)? The hypothesis-generating capacity of the left hemisphere demonstrates its confabulatory justification of the mysterious, unencoded messages from the right hemisphere and functions to regulate meaninglessness, as if by tacit agreement with the latter, by assigning imaginative meaning in order to achieve meaningful closure. This "interpretation function" is but a part of the left hemisphere's capacity to generate hypotheses and to develop quasi-permanent and permanent, stable belief systems. 18 In dream-
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ing, for instance, the left hemisphere offers representational reconciliation and coherence to the less organized imagery presented by the right hemisphere. Dreams from commissurotomized patients, lacking this cooperative integration, seem bland, superficial, and unimaginative, according to Hoppe. 30 At the same time, the right hemisphere can "set up" the left in the following way, according to Gazzaniga, who describes the following experiment: J.W. is told to fixate a point and either a 1 or a 2 is flashed to the left or right hemisphere. It comes as no surprise that when the number is flashed to the left brain it is named normally. What is intruiging is if J.W .'s left brain knows that the right is also only seeing a 1 or a 2, the left brain can accurately name which of the two numbers is flashed to the right brain on the right-brain trials. For a variety of reasons, we know J. W. 's right brain is not doing the talking. It is his disconnected left brain; somehow the right brain is able to set up the correct speech behavior in
the left. * It is interesting to consider whether or not the left brain is consciously aware that its left-based speech apparatus possesses the information for the correct response. Could it be the right brain has somehow accessed the left speech/motor system and deposited the correct information for the spoken response, but that the information is not accessible to the left brain's conscious processes? The study suggests this is exactly the case (p 119).
One of the fascinating, unpredicted results of brain laterality research, as mentioned above, is the realization of the existence of the duality (at least) of consciousness. With the discovery of the existence of modularity in the central nervous system, Gazzaniga and LeDoux 19 state: We are faced, it seems, with the new problem in analyzing the person. The person is a conglomeration of selves-a sociological entity. Because of our cultural bias toward language and its use, as well as the richness and flexibility that it adds to our existence, the governor of these multiple cells comes to be the verbal system. Indeed, a case can be made that the entire process of maturing in our culture is the process of the verbal systems trying to note and eventually control the behavior impulses of the many cells that dwell inside of us (p 161).
One of the interesting offshoots of modularity studies is the finding that extensive information processing occurs independent of verbal processing. The implications of this for psychoanalysis are vast, and I shall address this issue later. It is premature at this time to speculate about the possible correlations between certain forms of schizophrenia and the now documented phenomenon of the enlargement of the corpus callosum which takes place in that condition. 49 It is tempting to speculate, however, that this enlargement may represent a condition of hypertrophy secondary to a distress in communication between the hemispheres due to faulty data processing in one or another or both of the two hemispheres in addition to the possibility of an aversion of each to cooperate with the other. Thus, the corpus callosum seems to qualify either as the hypothetical localization of a "nonanatomic third brain" or as its putative facilitator inso*Italics mine .
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far as it is the single most important structure governing communication between the two hemispheres. In terms of the Siamese-twin image, it can be understood as the connection between the two heads. At the same time, it can be correlated with the alternate Siamese-twin image, that of one head and two bodies, to designate the function of the "nonanatomic third brain" and its executive capacity. I have already commented that the corpus callosum corresponds to a two-way repressive barrier- to which should be added, a two-way expressive channel. The mutual inhibition that the callosal projection fibers seem to enforce contributes specific and generalized regulatory or modulatory effects on varieties of brain functions. Apparently, this mutual inhibition-regulation comprises what Cook 9 calls the "brain's code" and constitutes a subset to the new principle of selfregulation. 25 Further, newer work seems to suggest that each hemisphere is specialized for different emotions, for example, positive emotions in the left frontal lobes and negative emotions in the right (Ahern and Schwartz, quoted by Miller47 ). Under normal situations, mood regulation in each hemisphere is achieved by contralateral inhibition. Anatomic studies demonstrate that the corpus callosum does not begin to myelinate until approximately three months of age and does not complete its myelination until well on into the second or even third decade. I have elsewhere postulated that this delayed myelination, and therefore delay of function, may correspond to Klein' s39 conception of the origin of normal splitting mechanisms in the infant, which seem to terminate at approximately three to four months of age, when, she hypothesizes, the depressive position ensues with all its integrative, reparative functions. This is also approximately the time that Mahler42 hypothesizes as the onset of "hatching." It is clearly correlated with the sequence of development of cognitive functions, beginning with the sensory-motor functions, as postulated by Piaget. 51 In other words, the slow progression in the myelination of the corpus callosum seems to correlate with the development of emotional and cognitive development along many different axes . I hypothesize that this delay in maturation allows for a postponement of maturity-that is, a postponement of the "stereoscopic" realization of the importance of one's experiences (the end of "innocence") as one begins to see things in the stereoscopic depth of two hemispheres focusing affectively and cognitively. The myelination of the corpus callosum, in other words, bequeaths maturity, depth, and realness to our experiences of ourselves and our world. The fact of the gradual myelination of the corpus callosum seems to allow, as mentioned earlier, for the experience of two separate consciousnesses that are, at the same time, experienced as one consciousness. It can be thought of as an offshoot of symbiotic consciousness but directed toward another aspect of self. Its most fruitful and dramatic manifestation is the transitional phenomenon of the imaginary companion of childhood, and its most sublimated form is the manifestation of janusian and homospatial thinking, as postulated by Rothenberg, 52 in which two separate mental phenomena can be arbitrarily linked in terms of similarities and then superimposed as in a montage to get a creatively new form. To me, the corpus
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callosum bespeaks the capacity of the brain-mind to use parallel processing, which I have elsewhere termed the dual track. 26 The advent of neurophysiology and neuropsychology has occasioned a shift in emphasis in neuroanatomy from fixed brain locales to the nature of the relationships between them, thereby substituting a dynamic model for a fixed one. Further, the unit of study has shifted from the neuron to the neuronal column on one hand and to neural networks on the other, with modules as intermediate structures. Could it be that that a certain resonance between certain columns or modules ("macro"-columns and/or modules?) and corresponding nerve networks can create sufficient augmentation of response that the phenomenon of subjectivity and selfness might actually develop?
SOME IMPLICATIONS FOR PSYCHOANALYSIS By its invocation of the free -associative technique and the employment of the couch, the very background setting of psychoanalysis seems to be rooted in hemispheric laterality considerations. The purpose of associating freely is purportedly to disengage the intellectual, controlling belief systems in the left hemisphere so as to allow background thoughts and feelings to emerge. This amounts to reversing the figure -ground perspective. The phenomenon of lying down also seems apparently to disengage the inhibitory dominance of the left hemisphere and consequently allows the right hemisphere to be "released." Whether or not the right hemisphere is the center for primary process seems inconclusive, but it has been speculated by McLaughlin. 44 Patients and therapists often report that they experience feelings via "right brain technique"; that is, they may experience emotions, for instance, as color images-for example, one patient experienced a black aura when she looked at her depressed father. Metzner45 speculates that the anorexic patients she has treated seem to behave as if they were identified with "left-brain" mothers in the act of repressing their own infantile "right-brain" urges. It is tempting to apply this speculation even more broadly to extend the lateralization hypothesis to include contralateral identifications (concordant, complementary, and oppositional) to mother/father, animus/anima, "true self"/"false self", pathological grandiose self/normal self, etc. Interestingly, Haag, 27 while conducting infant observations on normal and on autistic infants, found that infants in general tend to lateralize their experience of being the dependent infant to the right hemisphere (and therefore to the left side of the body, particularly the left hand) and their identification with the caretaking mother to the left hemisphere (and therefore to the right side). Whereas hand-to-hand transfer appears easy for normal infants, autistic infants seem unable to do so, suggesting early lateralization difficulties from the outset. At this juncture, we can only ask whether hysteria is a right-brained affliction, obsessive-compulsive neurosis a left-brained disorder, etc. FlorHenry15 and others are trying to determine the validity of these speculations.
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Earlier in this contribution I suggested that the slow and gradual myelination of the corpus callosum offers the infant and child the opportunity of world "innocence," that is, normal immaturity. Hoppe's 32 studies of Holocaust and trauma victims suggest that this "innocence" or immaturity may return under traumatic conditions. He posits a traumatic disconnection syndrome, a "functional commissurotomy" that devolves into a numbed alexithymia as the final protective withdrawal from the arena of painful sensory awarenesses and traumatic memory. Hoppe and Bogen33 and Miller46 have also studied this area. What seems to be suggested by this concept is that the very phenomenon of conversion or of dissociation may occur strictly on the neuropsychologic level and then affect mental functioning. Earlier, I alluded to the fact that verbal processing is only one of many processing modes taking place in the brain. The significance of this finding is that the generation, transmission, transformation, and reception of knowledge take place to a significant extent beyond the reaches of verbal encoding processes. Psychoanalysts shall have to cope with this truth. It certainly must have an impact on our verbalization-dominated theory of technique. It opens up the possibility that we "know" more than we think we know because we learn more than we think we learn. Mention must be made of the neurosociologic concepts of TenHouten, 57 who studies social hemisphericity in terms of cognitive styles characterizing different cultures. His development of the emergence of dialectic thought is of such relevance to this paper that I quote it at length: One interpretation of the difference between the functions of the two hemispheres is that they constitute two modes of thought. By seeing these modes of thought as real opposites, in a state of contradiction and complementarity it can be further inferred that the interaction between the appositional or synthetic mode of the right hemisphere and the propositional or analytic mode of the left hemisphere is able to produce a third mode of thought, the dialectical or creative. Because such concepts have also been utilized in social theory, a link is thereby established between dual-brain theory and social theory, especially the sociology of knowledge (p 355).
I conclude this contribution with two dreams, whose manifest content seems uncannily apposite to my theme: Dream A. "I was in my room (although the room was not familiar to me) and I kept getting phone calls from a stranger who would ring and just stay on the line till I hung up. I remember being very frightened in the dream because it seemed that the phone calls gave him some kind of access to me. I fell asleep on the bed and dreamed (in the dream) that he had broken in and was walking around my room looking through all my things while I was asleep. My breathing became constricted like there was a pressure on my abdomen. I then became aware that the man was sitting on my stomach. I was terrified and woke up from the inner dream and was relieved. Then suddenly I found a phone number written on a piece of paper that I knew he had dropped while he had been there in the room . This was the most horrifying part of the dream because it seemed to prove that what I thought was a dream had actually happened. My breathing became constricted again and I finally awoke trying to scream. When I really woke up, I thought I was still in the dream-that the dream was real!" Dream B. "I dreamed that I was asleep on my bed outside but on my property . It clearly was my territory. I woke up in the dream and saw a homeless young
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man in his thirties sleeping on the ground in his sleeping bag. I say, 'What are you doing here?' He said, 'I needed a place to sleep.' I said, 'No, not here. Don't you realize that this is my property?' I'm not upset about it because we're both sleeping outside. I then wake up in my bed but I'm still dreaming that he's there in my bedroom and I say, 'What are you doing in my house?' He said, 'I was dreaming that I was sleeping outside next to you, and that you were dreaming that you were outside sleeping next to me, and that we were in each other's dreams-the same dream, in fact, so now we're together in the same reality.' Then I had to get him out of my house, and I said, 'Listen, you have to go. How did you get into my house anyway? You didn't set off any alarms . There's no way you could have gotten in.' He said, 'Yes, I came in through the bedroom screen door.' I said, 'You couldn't have. It would have set off the alarm.' He responded, 'Well, the way I got in was that I got in through your dream because we both dreamed the same dream at the same time, which defused the alarm and opened the door.' I then said, 'Well, you have to get out.' "
I thought that these dreams suggested the possibility of a secret, uncanny relationship between two parts of the mind, alter egos or second selves on the mental level, but perhaps they were metaphors for personifications of the interactions between the two hemispheres. Earlier, I made reference to the decoding function of amino acid sequences and offered the hypothesis that a similar activity may take place especially when the right hemisphere wishes to force entry into the left.
SUMMARY The lateralization of the cerebral hemispheres constitutes a neuropsychologic parallel to the functioning of the mind. It is proposed that that the dual-track theorem generally and the Siamese-twin configuration (with the Moebius-strip twist) specifically offer a unique and useful paradigmatic perspective that allows us to organize and integrate the characteristics and functions of the brain-mind continuum. A hypothetical "psychology" for the corpus callosum and the two hemispheres was conjectured which would tentatively help to account for some of the brain's behavior, which conceivably approximates that of the mind. Ultimately, the concept of dialectics is suggested as being the best way of understanding all aspects of the brainmind.
REFERENCES l. Beaton A: Left Side, Right Side: A Review of Laterality Research. New Haven, Yale University Press, 1985 2. Benson DF, Zaidel E (eds): The Dual Brain: Hemispheric Specialization in Humans. New York, Guilford Press, 1985 3. Bogen JE: The dual brain: Some historical and methodological aspects . In Benson DF, Zaidel E (eds): The Dual Brain: Hemispheric Specialization in Humans. New York, Guilford Press, 1985, pp 27-46 4. Bowlby J: Attachment and Loss. Vol I: Attachment. New York, Basic Books, 1969 5. Bowlby J: Attachment and Loss. Vol II: Separation: Anxiety and Anger. New York, Basic Books, 1973
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6. Bowlby J: Attachment and Loss. Vol Ill: Sadness and Depression. New York, Basic Books, 1980 7. Breuer J, Freud S: Studies on Hysteria. Standard Edition 2. Hogarth and the Institute of Psychoanalysis, 1955, 1893-1895 8. Charcot JM: Oevres Completes. 9 vols. Paris, Bureaux du Progres Medical: Dlahaye & Elscrosnier, 1888-1894 9. Cook ND: The Brain Code. London, Methuen, 1986 10. Cox S: "The Stranger Within Thee": Concepts of the Self in Late Eighteenth Century Literature. Pittsburgh, University of Pittsburgh Press, 1980 11. Dimond SJ: The Double Brain. London, Churchill Livingstone, 1972 12. Dimond SJ: Evolution and lateralization of the brain: Concluding remarks. Ann NY Acad Sci 299:474-501, 1977 13. Dimond SJ: Symmetry and asymmetry in the vertebrate brain. In Oakley DA, Plutkin HC (eds): Brain, Behaviour and Evolution . London, Methuen, 1979, pp 189-218 14. Dimond SJ : Disconnection and psychopathology. In Gruzelier J, Flor-Henry P (eds): H emisphere Assymetries of Function in Psychopathology. Amsterdam , Elsevier Publishers, 1979, pp 35-46 15. Flor-Henry P: On certain aspects of the localization of the cerebral systems regulating and determining emotion. Biol Psychiatry 14:677-698, 1979 16. Freud S: Formulations on the two principles of mental functioning (1911). Standard Edition, 12:213-226. London, The Hogarth Press and the Institute of Psychoanalysis, 1958 17. Freud S: The Ego and the Id. Standard Edition. Hogarth and the Institute of Psychoanalysis, 1955, 19:3-68, 1923 18. Gazzaniga MS: The Social Brain. New York, Basic Books, 1985 19. Gazzaniga MS, LeDoux J: The Integrated Mind. New York, Plenum, 1978 20. Gilbert SM, Gubar S: The Mad Woman in the Attic. The Woman Writer and the Nineteenth Century Literary Imagination. New Haven, Yale University Press, 1979 21. Goldstein K: As quoted by Geschwind N: The organisation of the living brain: Dialogue with Norman Geschwind. In Miller J: States of Mind. New York, Pantheon, pp 116135 22. Grotstein JS: A proposed revision of the psychoanalytic concept of primitive mental states. I. Introduction to a newer psychoanalytic metapsychology. Contemp Psychoanal 16:479-546, 1980 23. Grotstein JS: Splitting and Projective Identification. New York, Jason Aronson, 1981 24. Grotstein JS: The dual track: Contribution for a neurobehavior model of cerebral processing. Psychiatr Clin North Am 9(2):353-366, 1986 25. Grotstein JS: The psychology of powerlessness: Disorders of self-regulation and interactional regulation as a newer paradigm for psychopathology. Psychoanal lnq 6(1):93118, 1986 26. Grotstein JS: The dual track theorem. Manuscript in preparation, 1988 27. Haag G: Personal communication, 1984 28. Harrington A: Medicine, Mind, and the Double Brain. Princeton, NJ, Princeton University Press, 1987 29. Hoppe KD: Split brains and psychoanalysis. Psychoanal Q 46:220-244, 1977 30. Hoppe KD: Split-brain: Psychoanalytic findings and hypotheses. J Am Acad Psychoanal 6:193-213, 1978 31. Hoppe KD: Destruction-reconstruction of language and forms of interaction: Clinical aspects of Lorenzer's concepts . Contemp Psychoanal 13:52-63, 1977 32. Hoppe KD: Severed ties. In Lue! SA, Marcus P (eds) : Psychoanalytic Reflections on the Holocaust: Selected Essays. New York, KTAC Publishing House, 1984, pp 94-111 33. Hoppe KD, Bogen JE: Alexithymia in twelve commissurotomized patients. Psychother Psychosom 28:148-156, 1977 34. Janet T: Quelques definitions recents de l'hysterie. Arch Neurol 25:417-438; 26:1-29, 1893 35. Jerne NK: The generative grammar of the immune system. Science 229:1057-1059, 1985 (adapted from the lecture delivered in Stockholm, December 8, 1984, when he received the Nobel Prize in Medicine) 36. Kinsbourne M: Lateral interaction in the brain. In Kinsbourne M, Smith WL (eds): Hemispheric Disconnection and Cerebral Function. Springfield, IL, Charles C Thomas, 1974, pp 239-259 37. Kinsbourne M: Asymmetrical Function of the Brain. New York, Academic Press, 1978
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38. Kinsbourne M: Hemispheric specialization and the growth of human understanding. Am Psycho! 37:411-420, 1982 39. Klein M: Mourning and its relation to manic-depressive states. Contribution to PsychoAnalysis, 1921-1945. London, The Hogarth Press, 1950, pp 311-338 40. Lemire RJ, Laesser JD, Leech RW, et al: Normal and Abnormal Development of the Human Nervous System. Hagerstown, MD, Harper & Row, 1975 41. Levy J: Possible bases for the evolution of lateral specialization of the human brain. Nature 224:614-615, 1969 42. Mahler MS: On Human Symbiosis and the Vicissitudes of Individuation . New York, International Universities Press, 1968 43. Matte Blanco I: The Unconscious and Infinite Sets. London, Duckworth, 1975 44. McLaughlin JT: Primary and secondary process in the context of cerebral hemispheric specialization. Psychoanal 47:237-266, 1978 45. Metzner L: Personal communication, 1988 46. Mill er L: Is alexithymia a disconnection syndrome? A neuropsychological analysis. Int J Psychiatry Med 16(3):199-209, 1986 47. Miller L: The emotional brain. Psycho! Today 22(2):34-42, 1988 48. Model! AH: Object Love and Reality. New York, International Universities Press, 1968 49. Newlin DB, Carpenter B, Goldman C: Hemispheric asymmetry in schizophrenia. Biol Psychiatry 16:561-582, 1981 50. Nun berg H: Transference and reality. In Practice and Theory of Psychoanalysis, Vol 2. New York, International Universities Press, 1965, pp 118-133 51. Piaget J: The Construction of Reality in the Child. New York, Ballantine, 1971 (translated by M Cook, 1937) 52. Rothenberg A: The Emerging Goddess: The Creative Process in Art, Science, and Other Fields. Chicago, University of Chicago Press, 1979 53. Sperry RW: Hemispheric deconnection and unity in conscious awareness. Am Psycho! 23:723- 733, 1968 54. Sperry RW: Perception in the absence of neocortical commissures. Res Pub! Assoc Nerv Ment Dis 47:123-138, 1969 55. Sperry RW: Consciousness, personal identity and the divided brain . In Benson OF, Zaidel E (eds): The Dual Brain: Hemispheric Lateralization in Humans. New York, Guilford Press, 1985, pp 11-26 56. Sperry HW, Gazzaniga MS, Bogen J: Interhemispheric relationships: The neocortical commissures-syndromes of hemispheric disconnection. In Vinker J, Bruyen CW (eds): Handbook of Clinical Neurology, Vol 4. Disorder of Speech, Perception, and Symbolic Behaviour Amsterdam, North Holland, 1969, pp 273-290 57. TenHouten WO: Cerebral-lateralization theory and the sociology of knowledge. In Benson OF, Zaidel E (eds): The Dual Brain: Hemispheric Lateralization in Humans. New York, Guilford Press, 1985, pp 341-358 58. Veith I: Hysteria: The History of a Disease. Chicago, The University of Chicago Press, 1965 59. Wallace HW: Mind-body: Monistic dual aspect interactionism. J Nerv Ment Dis 176(1):421, 1988 60. Wigan AL: Duality of the Mind. London, Longman, Brown, Green, & Longmans, 1844. Hepublished by Joseph Simon, 1985 61. Winnicott OW: Ego distortion in terms of true and false self. In The Maturational Processes and the Facilitating Environment. New York, International Universities Press, 1965, pp 140-152 62. Witelson S: Development dyslexia: Two right hemispheres and none left. Science 19.5:309- 311, 1977 9777 Wilshire Blvd., No. 905 Beverly Hills, California 90212
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The "Siamese Twinship" of the Cerebral Hemispheres and of the Brain-Mind Continuum Toward a "Psychology" for the Corpus Callosum
] ames S. Grotstein, M .D. *
Recent research in neuroscience, especially cerebral hemispheric laterality studies, have impacted psychoanalysis in a variety of ways, not the least of which is a realization of a need to reconcile these new data with its already established psychological theory and/or to effect modifications in its own metapsychology which would bring it into alignment with the thrust of this new research . Most basically there still exists an impasse in studying these two domains, one that has long been known as the mind-brain dilemma- dilemma because there seems to be no available way for us to reconcile the two domains, especially since neuropsychology and psychoanalysis follow different laws of functioning . In a recent contribution, I offered the conception of the dual-track theorem as a way of embracing both disparate domains . 22-26 In profferring the dual-track theorem, I wish first of all to distinguish it from the traditional concept of dualism, with which it is in danger of being confused. Dualism is the conception attributed to Western scientific thinking, beginning with Descartes, that there is a fundamental, irreconcilable differentiation between the observer and the observed, which, by implication, devolves into a basic distinction between the mind and the body, the former being the perceiver and the latter the perceived. The dual-track hypothesis reconciles cartesian dualism with Eastern, holistic monism through its implications that separateness and wholeness (or at-one-ness) comprise the Yin and Yang of a fundamental and irreducible bimodal unity. The dual track is the instrument of dialectical understanding, and it is my thesis that the two cerebral hemispheres represent an outstanding concrete example of dialectic operations . In order to express this bimodal, dialectic conception of separation/ nonseparation, I should like to proffer the visual image of "Siamese twins," *Clinical Professor of Psychiatry, University of California, Los Angeles, Los Angeles, California
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which could be imagined either as two heads and one body or two bodies and one head, depending upon the use to which the image is put. Thus, the functioning of the brain-mind can be consequently envisioned as (a) the operation of both cerebral hemispheres as a holistic entity and (b) the simultaneous operation of each and/or both cerebral hemispheres independently. Before pursuing the uses to which I wish to put this image as an instrument in studying brain laterality and the mind-brain dilemma, I wish to recognize that this image has already been anticipated by Nunberg's 50 and Modell's 48 concept of the "Janus-face" organization (bimodality) of the transference and by Rothenberg's 5 1 concept of "janusian" thinking and homospatiality. The principle of bimodality, as discussed by Nunberg and Modell, applies to the dialectic phenomenon in the transference in which frustrations from the past are experienced in the transference neurosis sideby-side with transference expectations of wish-fulfillment. Janusian thinking, as conceived by Rothenberg, designates a special type of secondary process in which opposites or reversals appear side-by-side for analogic comparison. It is the essence of "mirror-imaging." Homospatial thinking is more elaborate, involves spatial montaging of contrasting images, facilitates the creative integration of janusian thinking, but, unlike the latter, involves primary as well as secondary processes . Sperry65 has contributed the concept of the Y configuration to designate the duplication-complementarity of cerebral hemispheric functioning . My own conception of the Siamese twinship is an elaboration of both janusian and homospatial thinking. Fundamentally, the image of the "Siamese twinship" allows not only for separateness and connectedness simultaneously and/or alternately but allows also for a variety of complex interactions between two (or more) living entities that are experienced as separate and nonseparate, whose nonseparation can be understood as a sense of discontinuous continuity via the Moebius phenomenon, that is, where there is a mysterious twist in a "ribbon of awareness" which connects and yet disconnects two domains . The Moebius twist allows its two (or more) components to link up with each other in a variety of ways, one of which would be a montage . This conception would seem to apply appropriately, for instance, to the functionings of the two cerebral hemispheres, to sleep and wakefulness, to the conscious and the unconscious, between the id, ego, and superego, etc. It would appear to be particularly apt in describing the reversal or inversion of images as they cross the corpus callosum from each hemisphere to the other. This mysterious discontinuous continuity, albeit paradoxic, gives new perspective to the psychoanalytic conception of the repressive barrier, for instance. We can now conceptualize the repressive barrier as defending, not only the ego from instinctual eruptions from the id but also the reverse, that is, the need for the id to be protected from the intrusions of the ego and its connections with reality. The "Siamese twinship" allows for the id and the ego to be full partners, much like the cerebral hemispheres. The notion of a dual track is fundamental to the architecture and functioning , not only of the brain and of the mind, but even more basically to the structure of the double helix of the gene itself.
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The "Siamese twinship" image allows us to conceive of the two cerebral hemispheres as both separate and connected, functioning separately and together. It allows for the conceptualization for a "non-anatomic third brain" (a holistic brain comprising a homospatial montage of its components), which in terms of this image, can be pictured as the whole "Siamese twin" figure as the brain comprising of a single entity interfacing with either or both the hemispheres for independently concordant, complementary, oppositional, or commensal functions. Bogen3 states that the cerebral hemispheres duplicate and complement each other. Further, it is now known that the left hemisphere functions via propositional thinking and the right hemisphere through appositional thinking, which has to do with comparing. To these variables I should like to add two other possibilities. One would be that the two hemispheres can at times appear to be individually anthropomorphic and may even oppose* each other as if each became a veritable "enemy" of the other. The latter condition is demonstrated in an example offered by Goldstein, 21 in which he described a patient who attempted to strangle herself with one hand and to release the strangling hand with the other. On postmortem examination it was found that she had suffered from a dissecting tumor of the corpus callosum. The "oppositional" type of relationship between the two hemispheres has achieved veritable anthropomorphic realization in split-brain research, whether by commissurotmy for the treatment of epileptic seizures or by sophisticated neuropsychologic testing in which the two hemispheres are purposely isolated from each other in order to demonstrate the functions of each individual hemisphere. 2• 9 · 18 · 19 · 29 · 30 · 32 · 33 • 53 - 55 Hoppe 31 adds yet another perspective to oppositionalism in his discussion of Lorenzer' s concepts of deconstruction-reconstruction oflanguage and forms. This could be applied to brain laterality as, for instance, the propensity of the right-hemispheric cognitive style to challenge and "deconstruct" fixed belief systems formed by the left-hemispheric cognitive style. t The final possibility would be that of commensal functioning, in which the two hemispheres function optimally but independently of each other, a condition that occurs frequently on normal occasions but is typical of cases of agenesis or surgical dissection of the corpus callosum. The commensal perspective is of great importance insofar as it can also represent the unsuspected element, the "stranger," so to speak. Creative thinking would thus be enhanced by one's ability (the ability of one or both hemispheric consciousnesses) to transgress its putative boundaries and thereby encounter the unsuspected.
*Here I employ the term "oppose" in the affective and intentional sense, not in the strictly neuroanatomic sense. t Witelson, doing psychological testing research, isolated a group of dyslexics whom she states function as if they had "two right hemispheres and none left." The two "right hemi spheres" duplicated and th erefore competed with each other. She also left room for the possibility of "two left hemispheres and none right."
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SOME HYPOTHETICAL ASSUMPTIONS ABOUT THE RELATIONSHIP BETWEEN HEMISPHERIC STRUCTURE AND MENTAL FUNCTION Interest in brain and mind laterality was considerable in the last century . An English physician, A.L. Wigan, 60 published a book in 1844 in which he conceptualized a dysynchrony between the two hemispheres as the key issue in insanity. The main emphasis was in literature, however, in which novelists on both sides of the Atlantic were writing about the mysterious phenomenon of the "second self" or "alter ego. "24 Side by side with the literary preoccupation with the second self, medical science was also interested in the subject, as attested to by the great interest in hypnosis, autoscopy (heautoscopy), and the predominance of hysteria as a focus of attention for nineteenth century psychiatrists. Hysteria had long been associated with demoniac possession, according to Veith. 58 Charcot8 was one of the principal exponents of the dissociated factors in hysteria, and Freud was introduced to this when he studied under Charcot at the Salpetriere in Paris. Later, Breuer and Freud, 7 and ultimately Freud alone, were to study these hysterical patients and to make hypotheses about them which were to launch the field of psychoanalysis. It is very interesting to watch the development of their interest in the dissociated phenomenon in hysteria. Charcot believed that the dissociation was due to a weakness in the organizational capacity of the brain, a hypothesis that was extended later by Janet.34 Breuer and Freud, however, came to believe that the dissociation was (a) entirely mental and (b) that the mentally dissociated element (the second self) was due to a censorship of a traumatic reality, the latter of which finally came to be first sexual abuse as a child and then later sexual fantasies, whereas the concept of the censorship underwent a development into the later concept of repression. It is very important to note, however, that all the patients Breuer and Freud report on in Studies on Hysteria were characterized by double consciousness, a finding that was in conformity with a general understanding in the nineteenth century of possessing a second self or alter ego. When Freud 16 later developed his topographical system and still later the structural system, the axis of doubleness rotated from a vertical plane to a horizontal plane and the content of the repressed changed from a second self to (a) traumatic memory and (b) libido, thereby depersonifying the second self and transforming its residue into preternatural instinctual drives whose destiny it is to erupt with peremptory intentionality. The second self became extinct and had to await the arrival of brain laterality research to be exhumed. Harrington28 recently reviewed the widespread enthusiasm for brain duality in nineteenth century neurology. Today, thanks to a reawakening of attention to this area by laterality research, we once again are interested in multiple states of brain-mind consciousness, including those caused by gross dissociation. We would also be interested in the possible correlation between neuropsychology and such entities as internal objects, object representations, archetypal objects, alter egos ("second selves"), affect and cognitive disorders, out-of-body experi-
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ences, somatization disorders of the brain, depersonalization, psychosis, etc. For instance, is psychosis a psychosomatic and/or somatopsychic disorder of the brain/mind? Is panic disorder a somatization of the brain by the mind, or is it a somatopsychic involvement of the mind by the brain? What is the relationship between mental illnesses and possible dysfunctions of the corpus callosum? On the other hand, speaking from the imaginative context of the possible "psychologization" of neuropsychologic functioning, is there such a thing as "hemispheric consciousness" or "modular consciousness?" On a deeper level, how is neuropsychologic decision-making achieved? Who orchestrates or choreographs the neuroschematics of selective and integrated brain function? How and why did the right hemisphere "decide" to accept its status as the silent moiety? Is there any validity to conjecturing personifications for brain functioning? The ultimate question to be posed is "Does the brain 'talk' to itself (selves?), and, if so, how?" In a current contribution, I proffered the notion that psychoanalytic instinctual drives could be understood in part as semiotic signifiers embedded in the ancient matrix of group communication via signals, signs, and gestures, phenomena that are easily demonstrable in ethologic studies and in psychosis. 25 Could it be that the right hemisphere communicates with the left (on occasion) via urgent, peremptory posturings-in sign language? The remainder of this article will speculate about these and similar questions. The cerebral hemispheres seem to have evolved asymmetrically, presumably in order to minimize mutual competitive inhibition. Beaton 1 states that " ... left hemisphere control of motor sequencing is the evolutionary precursor that attracted speech and language to the left side of the brain. Such an approach may well be appropriate, given that Man is the only known animal to show a species-specific preference for the limb on one side ... " (p 288). Gazzaniga and LeDoux 19 believe that the asymmetry of the brain is complex, giving each hemisphere an advantage depending upon the specific function. They believe that there arose within the left hemisphere, but not within the right, competition for the neurospace for verbal functions. They believe, in other words, that language pre-empts neurospace in the left hemisphere and manipulospatial functions in the right hemisphere. Levy4 1 believes that lateralization achieved a separation of two different patterns of neuro-organization. The kind of neurocircuitry best fitted to serve the needs of language and its cognitive correlates is not well adapted to the most efficient execution of visual-spatial tasks, she believes. Kinsbourne36 --38 believes that the brain is a paired organ, but in order to resolve neural "problems of indecision" to achieve some form of neurointegration, one hemisphere had to gain ascendancy over the bilateral locomotor apparatus. Dimond 11- 14 believes that, in the normal intact brain, the two hemispheres act as separate channels in analyzing incoming information and that this finding correlates with the capacity for parallel processing of information in each hemisphere. This concept of parallel processing of information fits in with Gazzaniga's 18 conception of the modularity of the two hemispheres. He states:
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I argue that the normal person does not possess a unitary conscious mechanism in which the conscious system is privy to the sources of all his/her actions. I want to build the argument that the normal brain is organized into modules and that most of these modules are capable of actions, moods, and responses. All except one work in nonverbal ways such that their modes of expression are solely through overt behaviors or more covert actions (p 74) .
The concept of parallel processing, especially as it pertains to the putative parallel processing by the two hemispheres (as well as component modular structures), suggests, especially as Gazzaniga interprets it, a beginning neurobasis that can easily allow for personifications of functions and, as a consequence, of the experience of multiple subselves within the neuromental substrate. How are the two cerebral hemispheres related to each othe r? They obviously are duplicates of one another and also are complementary as well as oppositional. Perhaps we can state that the relationship between the two cerebral hemispheres is based therefore upon the following possibilities: (a) concordant, (b) complementary, (c) disconcordant (or oppositional), and (d) commensal, the latter referring to the normal, independent, noninteractive functionings between the two hemispheres when each is processing data separately. These four modes might be encompassed by the term identification or mutual correspondence. Research studies in bisected brains in which experiments are conducted separately on each hemisphere would be an artificial example of this phenomenon. It undoubtedly occurs more normally much of the time in which commissurotomy is not an issue. Further, it is now known that images transferred from the left hemisphere to the right undergo a transformation as they traverse the corpus callosum and end up as negative and reversed images in the right hemisphere, a finding that correlates with the mirror-image functions that Rothenberg52 assigns to janusian and homospatial thinking. We know that, in the immune system, for instance, amino acid sequences on the structure of the protein molecules of the antibodies constitute a "language." When confronting an antigen, these amino acid chains realign themselves to conform to the amino acid sequence of the invading antigen, upon the successful conclusion of which the antibody, having "decoded" the antigen, devours it. Obversely, the antigen achieves its own invasive success originally in a similar decoding procedure. 35 Presumably "mirror-imaging" is involved in this deciphering. Might the right hemisphere attempt to communicate to or even purloin the functions of the left in such a manner? Later in this article I shall describe the dreams of two patients which strongly hint at such a scenario. An example of complementary functioning between the two hemispheres is commonly seen in songs. The lyrics, being verbal and therefore sequential, follow a diachronic sequence, whereas the music itself, although sequential in part, is also melodic and harmonic, indicative of the synchronic mode of presentation. Imagery in general, whether auditory, visual, or pictorial, demonstrates the quality of multiple, simultaneous facets of expressiveness. When this sensory shower falls on the threshold of the left hemisphere for expression, a complex transformation must take place, one from the synchronic modality to that of the diachronic. An analogue to this transformation occurs in the mental sphere. Freud 16 termed it the
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change from primary process to secondary process . Matte Blanco43 discussed it from the standpoint of mathematical concepts; that is, the unconscious is characterized by "infinite sets" and is symmetrical, whereas consciousness is characterized by limited sets and by asymmetry. Thus, as adumbrated earlier, the hemispheres, like the mind, each operate vis-a-vis the other under different, incompatible, complementary cosmic laws-best imagined as "Siamese twins" linked via a discontinuous-continuous Moebius strip. The details of hemispheric interaction and the findings relevant to the separate functioning are too detailed to list here. There is some agreement that the left hemisphere seems to be the more dominant one because of its access to verbal functioning. Moreover, it functions linearly and sequentially, is time-oriented, and is propositional. The right hemisphere duplicates most of the functions of the left hemisphere (as does the left for the right) but seems to be oriented in terms of space, attention, arousal, and scanning for fine distinctions, is more perceptually oriented, and is appositional-that is, has the facility for comparing two different shapes or images by apposing one to the other. Not only does each hemisphere function as a concordant "Siamese twin" -that is, each is capable of data processing and encoding data separately and concordantly-but also functions complementarily in a variety of ways, one of which may be parallel processing (separate but independent) but on complementary issues (for example, fine details versus gross details, time versus space, etc.). Moreover, each hemisphere may function, if I can be forgiven a personification, as a "background object" for the other; that is, the right hemisphere may offer a spatial background screen on which the detail-conscious left hemisphere may contemplate the figure on which it is focused. Thus, although each hemisphere is capable of independent sensory functioning, each can back up the other. It is already assumed that the right hemisphere offers contextualization to the more specific findings of the left. 9 The reverse may also be possible-the left hemisphere may offer a background for the functions of the right. Perhaps a song, poem, painting, or sculpture could be a demonstration of this possibility. Thus, left hemisphere and right hemisphere could correspond to a "figure-ground" configuration. It has been postulated that the left hemisphere relates to abstract details concerning objective reality relationships, whereas the right hemisphere deals more with affective and/or personal experiences in relationship to perceived objects. It has even been claimed that the right hemisphere corresponds to Freud's primary process, 16 whereas the left hemisphere corresponds to the secondary process. I think it more probable that each hemisphere is capable of affective and objective as well as primary process and secondary process functions, but a specialization does seem to occur by "common consent." Kohut (as quoted by Hoppe 29 ) believed that empathy, however, was distinctly a right-hemispheric function. The question emerges as to how this cooperation between the hemispheres (or, for that matter, among the "multifarious modules" which Gazzaniga and Ledoux 19 and Gazzaniga 18 posit) is achieved. Who or what makes the decision, the assignment of differentiated roles, who or what monitors it and orchestrates it, etc? Further, how can we understand the origination
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of intentionality and will, given the nature of brain anatomy and function which we understand so far? Involved in the difficulty of our even contemplating the mysterious connection between mental and neuronal function, we must realize that mind and brain function according to different regulatory schemata, laws, etc. They occupy different domains- thus the need in the first place for a dual-track theorem. Second, as a consequence of the preceding, we must remember that the central nervous system is composed of networks of neurons that function in parallel as well as by neurons that can be thought of as individually functioning in series. Utilizing the "Siamese twin" image, we can envision the whole twinship operating as an indivisible entity (as a single, whole unity) directing its hemispheric (or modular) components, now envisioned as parts of the "Siamese twinship," and being influenced by each of the hemispheric (neuronal feedback) sources. One system is whole, the other is part; another system is parallel, the other is serial; one is a network, the other is an individual. Somewhere in the dynamic interplay of these dialectic interactions, a "third force" emerges in which human intentionality, feeling, autonomy, and personalness seem to occur.
TOWARD A "PSYCHOLOGY" OF THE CORPUS CALLOSUM To push the motif of anthropomorphism even further, can one apply the concept of bonding and attachment4- 6 to hemispheric functioning? We now know that the two hemispheres only gradually begin to "know" each other over developmental time. The corpus callosum and the deep cerebral commissures do not begin their myelination until about three months of age and do not complete it until adolescence or early adulthood. 40 If each hemisphere is capable of the phenomenon of consciousness, as is stated by Sperry, 53-S5 by Gazzaniga and LeDoux, 19 and by Gazzaniga, 18 is each capable of self-consciousness and of consciousness of the other? What is the experience of each as it becomes aware of the other? Is it a mixture or montage of bonding and attachment on the one hand and of stranger anxiety on the other? Might the "individual psychologies" of each hemisphere (to say nothing of their "group psychology" after their union) account for incomplete and/or mixed lateralization-or even of functional commissurotomy?29· 30· 32· 33 For that matter, how can we explain the elaborate and ingenious attempts of either hemisphere by which, when cut off communicatively from the other in split-brain studies, each is able, via "cross-cuing," to rationalize or justify the otherwise inexplicable perception from the other hemisphere (particularly the left hemisphere attempting to explain perceptions from the right hemisphere)? The hypothesis-generating capacity of the left hemisphere demonstrates its confabulatory justification of the mysterious, unencoded messages from the right hemisphere and functions to regulate meaninglessness, as if by tacit agreement with the latter, by assigning imaginative meaning in order to achieve meaningful closure. This "interpretation function" is but a part of the left hemisphere's capacity to generate hypotheses and to develop quasi-permanent and permanent, stable belief systems. 18 In dream-
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ing, for instance, the left hemisphere offers representational reconciliation and coherence to the less organized imagery presented by the right hemisphere. Dreams from commissurotomized patients, lacking this cooperative integration, seem bland, superficial, and unimaginative, according to Hoppe. 30 At the same time, the right hemisphere can "set up" the left in the following way, according to Gazzaniga, who describes the following experiment: J.W. is told to fixate a point and either a 1 or a 2 is flashed to the left or right hemisphere. It comes as no surprise that when the number is flashed to the left brain it is named normally. What is intruiging is if J.W .'s left brain knows that the right is also only seeing a 1 or a 2, the left brain can accurately name which of the two numbers is flashed to the right brain on the right-brain trials. For a variety of reasons, we know J. W. 's right brain is not doing the talking. It is his disconnected left brain; somehow the right brain is able to set up the correct speech behavior in
the left. * It is interesting to consider whether or not the left brain is consciously aware that its left-based speech apparatus possesses the information for the correct response. Could it be the right brain has somehow accessed the left speech/motor system and deposited the correct information for the spoken response, but that the information is not accessible to the left brain's conscious processes? The study suggests this is exactly the case (p 119).
One of the fascinating, unpredicted results of brain laterality research, as mentioned above, is the realization of the existence of the duality (at least) of consciousness. With the discovery of the existence of modularity in the central nervous system, Gazzaniga and LeDoux 19 state: We are faced, it seems, with the new problem in analyzing the person. The person is a conglomeration of selves-a sociological entity. Because of our cultural bias toward language and its use, as well as the richness and flexibility that it adds to our existence, the governor of these multiple cells comes to be the verbal system. Indeed, a case can be made that the entire process of maturing in our culture is the process of the verbal systems trying to note and eventually control the behavior impulses of the many cells that dwell inside of us (p 161).
One of the interesting offshoots of modularity studies is the finding that extensive information processing occurs independent of verbal processing. The implications of this for psychoanalysis are vast, and I shall address this issue later. It is premature at this time to speculate about the possible correlations between certain forms of schizophrenia and the now documented phenomenon of the enlargement of the corpus callosum which takes place in that condition. 49 It is tempting to speculate, however, that this enlargement may represent a condition of hypertrophy secondary to a distress in communication between the hemispheres due to faulty data processing in one or another or both of the two hemispheres in addition to the possibility of an aversion of each to cooperate with the other. Thus, the corpus callosum seems to qualify either as the hypothetical localization of a "nonanatomic third brain" or as its putative facilitator inso*Italics mine .
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far as it is the single most important structure governing communication between the two hemispheres. In terms of the Siamese-twin image, it can be understood as the connection between the two heads. At the same time, it can be correlated with the alternate Siamese-twin image, that of one head and two bodies, to designate the function of the "nonanatomic third brain" and its executive capacity. I have already commented that the corpus callosum corresponds to a two-way repressive barrier- to which should be added, a two-way expressive channel. The mutual inhibition that the callosal projection fibers seem to enforce contributes specific and generalized regulatory or modulatory effects on varieties of brain functions. Apparently, this mutual inhibition-regulation comprises what Cook 9 calls the "brain's code" and constitutes a subset to the new principle of selfregulation. 25 Further, newer work seems to suggest that each hemisphere is specialized for different emotions, for example, positive emotions in the left frontal lobes and negative emotions in the right (Ahern and Schwartz, quoted by Miller47 ). Under normal situations, mood regulation in each hemisphere is achieved by contralateral inhibition. Anatomic studies demonstrate that the corpus callosum does not begin to myelinate until approximately three months of age and does not complete its myelination until well on into the second or even third decade. I have elsewhere postulated that this delayed myelination, and therefore delay of function, may correspond to Klein' s39 conception of the origin of normal splitting mechanisms in the infant, which seem to terminate at approximately three to four months of age, when, she hypothesizes, the depressive position ensues with all its integrative, reparative functions. This is also approximately the time that Mahler42 hypothesizes as the onset of "hatching." It is clearly correlated with the sequence of development of cognitive functions, beginning with the sensory-motor functions, as postulated by Piaget. 51 In other words, the slow progression in the myelination of the corpus callosum seems to correlate with the development of emotional and cognitive development along many different axes . I hypothesize that this delay in maturation allows for a postponement of maturity-that is, a postponement of the "stereoscopic" realization of the importance of one's experiences (the end of "innocence") as one begins to see things in the stereoscopic depth of two hemispheres focusing affectively and cognitively. The myelination of the corpus callosum, in other words, bequeaths maturity, depth, and realness to our experiences of ourselves and our world. The fact of the gradual myelination of the corpus callosum seems to allow, as mentioned earlier, for the experience of two separate consciousnesses that are, at the same time, experienced as one consciousness. It can be thought of as an offshoot of symbiotic consciousness but directed toward another aspect of self. Its most fruitful and dramatic manifestation is the transitional phenomenon of the imaginary companion of childhood, and its most sublimated form is the manifestation of janusian and homospatial thinking, as postulated by Rothenberg, 52 in which two separate mental phenomena can be arbitrarily linked in terms of similarities and then superimposed as in a montage to get a creatively new form. To me, the corpus
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callosum bespeaks the capacity of the brain-mind to use parallel processing, which I have elsewhere termed the dual track. 26 The advent of neurophysiology and neuropsychology has occasioned a shift in emphasis in neuroanatomy from fixed brain locales to the nature of the relationships between them, thereby substituting a dynamic model for a fixed one. Further, the unit of study has shifted from the neuron to the neuronal column on one hand and to neural networks on the other, with modules as intermediate structures. Could it be that that a certain resonance between certain columns or modules ("macro"-columns and/or modules?) and corresponding nerve networks can create sufficient augmentation of response that the phenomenon of subjectivity and selfness might actually develop?
SOME IMPLICATIONS FOR PSYCHOANALYSIS By its invocation of the free -associative technique and the employment of the couch, the very background setting of psychoanalysis seems to be rooted in hemispheric laterality considerations. The purpose of associating freely is purportedly to disengage the intellectual, controlling belief systems in the left hemisphere so as to allow background thoughts and feelings to emerge. This amounts to reversing the figure -ground perspective. The phenomenon of lying down also seems apparently to disengage the inhibitory dominance of the left hemisphere and consequently allows the right hemisphere to be "released." Whether or not the right hemisphere is the center for primary process seems inconclusive, but it has been speculated by McLaughlin. 44 Patients and therapists often report that they experience feelings via "right brain technique"; that is, they may experience emotions, for instance, as color images-for example, one patient experienced a black aura when she looked at her depressed father. Metzner45 speculates that the anorexic patients she has treated seem to behave as if they were identified with "left-brain" mothers in the act of repressing their own infantile "right-brain" urges. It is tempting to apply this speculation even more broadly to extend the lateralization hypothesis to include contralateral identifications (concordant, complementary, and oppositional) to mother/father, animus/anima, "true self"/"false self", pathological grandiose self/normal self, etc. Interestingly, Haag, 27 while conducting infant observations on normal and on autistic infants, found that infants in general tend to lateralize their experience of being the dependent infant to the right hemisphere (and therefore to the left side of the body, particularly the left hand) and their identification with the caretaking mother to the left hemisphere (and therefore to the right side). Whereas hand-to-hand transfer appears easy for normal infants, autistic infants seem unable to do so, suggesting early lateralization difficulties from the outset. At this juncture, we can only ask whether hysteria is a right-brained affliction, obsessive-compulsive neurosis a left-brained disorder, etc. FlorHenry15 and others are trying to determine the validity of these speculations.
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Earlier in this contribution I suggested that the slow and gradual myelination of the corpus callosum offers the infant and child the opportunity of world "innocence," that is, normal immaturity. Hoppe's 32 studies of Holocaust and trauma victims suggest that this "innocence" or immaturity may return under traumatic conditions. He posits a traumatic disconnection syndrome, a "functional commissurotomy" that devolves into a numbed alexithymia as the final protective withdrawal from the arena of painful sensory awarenesses and traumatic memory. Hoppe and Bogen33 and Miller46 have also studied this area. What seems to be suggested by this concept is that the very phenomenon of conversion or of dissociation may occur strictly on the neuropsychologic level and then affect mental functioning. Earlier, I alluded to the fact that verbal processing is only one of many processing modes taking place in the brain. The significance of this finding is that the generation, transmission, transformation, and reception of knowledge take place to a significant extent beyond the reaches of verbal encoding processes. Psychoanalysts shall have to cope with this truth. It certainly must have an impact on our verbalization-dominated theory of technique. It opens up the possibility that we "know" more than we think we know because we learn more than we think we learn. Mention must be made of the neurosociologic concepts of TenHouten, 57 who studies social hemisphericity in terms of cognitive styles characterizing different cultures. His development of the emergence of dialectic thought is of such relevance to this paper that I quote it at length: One interpretation of the difference between the functions of the two hemispheres is that they constitute two modes of thought. By seeing these modes of thought as real opposites, in a state of contradiction and complementarity it can be further inferred that the interaction between the appositional or synthetic mode of the right hemisphere and the propositional or analytic mode of the left hemisphere is able to produce a third mode of thought, the dialectical or creative. Because such concepts have also been utilized in social theory, a link is thereby established between dual-brain theory and social theory, especially the sociology of knowledge (p 355).
I conclude this contribution with two dreams, whose manifest content seems uncannily apposite to my theme: Dream A. "I was in my room (although the room was not familiar to me) and I kept getting phone calls from a stranger who would ring and just stay on the line till I hung up. I remember being very frightened in the dream because it seemed that the phone calls gave him some kind of access to me. I fell asleep on the bed and dreamed (in the dream) that he had broken in and was walking around my room looking through all my things while I was asleep. My breathing became constricted like there was a pressure on my abdomen. I then became aware that the man was sitting on my stomach. I was terrified and woke up from the inner dream and was relieved. Then suddenly I found a phone number written on a piece of paper that I knew he had dropped while he had been there in the room . This was the most horrifying part of the dream because it seemed to prove that what I thought was a dream had actually happened. My breathing became constricted again and I finally awoke trying to scream. When I really woke up, I thought I was still in the dream-that the dream was real!" Dream B. "I dreamed that I was asleep on my bed outside but on my property . It clearly was my territory. I woke up in the dream and saw a homeless young
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man in his thirties sleeping on the ground in his sleeping bag. I say, 'What are you doing here?' He said, 'I needed a place to sleep.' I said, 'No, not here. Don't you realize that this is my property?' I'm not upset about it because we're both sleeping outside. I then wake up in my bed but I'm still dreaming that he's there in my bedroom and I say, 'What are you doing in my house?' He said, 'I was dreaming that I was sleeping outside next to you, and that you were dreaming that you were outside sleeping next to me, and that we were in each other's dreams-the same dream, in fact, so now we're together in the same reality.' Then I had to get him out of my house, and I said, 'Listen, you have to go. How did you get into my house anyway? You didn't set off any alarms . There's no way you could have gotten in.' He said, 'Yes, I came in through the bedroom screen door.' I said, 'You couldn't have. It would have set off the alarm.' He responded, 'Well, the way I got in was that I got in through your dream because we both dreamed the same dream at the same time, which defused the alarm and opened the door.' I then said, 'Well, you have to get out.' "
I thought that these dreams suggested the possibility of a secret, uncanny relationship between two parts of the mind, alter egos or second selves on the mental level, but perhaps they were metaphors for personifications of the interactions between the two hemispheres. Earlier, I made reference to the decoding function of amino acid sequences and offered the hypothesis that a similar activity may take place especially when the right hemisphere wishes to force entry into the left.
SUMMARY The lateralization of the cerebral hemispheres constitutes a neuropsychologic parallel to the functioning of the mind. It is proposed that that the dual-track theorem generally and the Siamese-twin configuration (with the Moebius-strip twist) specifically offer a unique and useful paradigmatic perspective that allows us to organize and integrate the characteristics and functions of the brain-mind continuum. A hypothetical "psychology" for the corpus callosum and the two hemispheres was conjectured which would tentatively help to account for some of the brain's behavior, which conceivably approximates that of the mind. Ultimately, the concept of dialectics is suggested as being the best way of understanding all aspects of the brainmind.
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