Little is known of the brain's dynamic properties and even less of the neuropsychological meaning of its anatomic structures. As a result, there are few studies to explain the precise nature of drives and other behavioral phenomena. Another reason for this lack is that the ideational processes, which distinguish humans from other living organisms, such as selfexperience, imagery, and creativity, as yet cannot be measured and analyzed because it is difficult to understand what makes up an emotion or an idea. Only the physiologic effects of a stimulus, as it affects behavior, can be explored in terms of cause-and-effect or input-and-output relationships. Thus, vegetative reflexes, conditioned responses, learned behavior, and problem-solving can be measured to some extent. Before one can predict, however, what specific areas of the brain will do in response to a specific emotional stimulus, more must be known about the biologic roots of creativity processes initiating it. Microbiologists believe that what takes place, as new organizing activity or creativity, is in essence a reduplication and amplification of those biologic processes that take place at the microcellular level. More succinctly, “micro-events in the genes produce macro-events in those new activities which man imposes upon his environment.”12 The entire process at both biologic levels is based on codified information and is self-regulated by feedback control—a concept which plays an important role in the organization of adaptive responses and behavior of all living and nonliving systems.
In this presentation, brain structures have been separated into arbitrary divisions but, unfortunately, simple spatial separations into discrete centers, each representing a specific function, do not explain how similar stimuli from respective regions contribute to differences in psychological functioning. More importantly, what interplay of forces in the central nervous system accounts for “spontaneous” activity, and what happens in the time between the initiation of an ideational stimulus and its resultant response? Is the reflex monitored by the “control of feedback”? Where and why are the ideas or mental images which are responsible for the diversity of drives in the organism produced? How are they influenced by motivation or expectation, mood swings, and changing life situations? What produces such fluctuating degrees of attention as sleep, wakefulness, and hypnosis?
These and other questions, especially that of localization, which only answers the “where” of higher nervous activity, have to be worked out before we can thoroughly understand “how” and “why” the brain works at hypnotic (selective attention) and nonhypnotic (less selective attention) levels. Until newer research sheds light on the organization of behavior, we are handicapped in our full understanding of brain functioning. However, in this chapter, we shall, for descriptive purposes only, discuss the more important brain structures separately and what is known about their neuropsychological functioning.
There is virtual agreement among neurophysiologists that the vertical or two-brain “concept” of a core system surmounted by a cerebral mantle, in contrast to classic “horizontal” types, represents a major change toward clarification of neuropsychological and neurophysiologic mechanisms. Thus the two arbitrary divisions of the brain, the cortical and subcortical portions, are complementary and interdependent. This dynamic and reciprocal interaction helps to maintain the purposeful goals necessary for survival. In achieving this optimal state of equilibrium, some of the brain's structures tend to influence the function of others by regulating and dominating these. An integration of cerebral mechanisms subject to the regulation of one another and ultimately dominated by one of them is called a hierarchy. Self-regulation of the hierarchic functioning enables the brain to become not only more adaptive but also more discriminative in its behavior. In this respect, the brain can be compared with an efficient, automatically regulated machine.3 However, brain functioning not only attempts to maintain self-regulation by feedback control but also to produce something new. Thus, its function is not only adaptive but also creative.
An attempt to reconcile the two speculative concepts—control of feedback and hierarchy—may provide a crude model for understanding the relation between behavior and higher neural organization. One significant drawback is that it is difficult to make definitive analogies to psychological processes. It is hoped that the development of modern computers and mathematical analog models will provide the tools required for simulating such brain processes as creativity and other poorly understood mechanisms.
At this point, the important brain structures involved in the mediation of emotional stimuli and their chief neurophysiologic functions at both hypnotic and nonhypnotic levels will be discussed.
ROLE OF THE CEREBRAL CORTEX
In man, the cerebral cortex has evolved to its highest neural level of integration. As a result, discriminatory thinking has been developed to a maximum with the ability to meet the present and anticipate the future in terms of past memory experiences stored as information. Though the biologic needs of an organism initiate behavior, behavioral patterns are integrated through higher neural levels and are also influenced by past learning.
The cerebral cortex represents a huge network of intricate and interlacing systems in which storage, comparison, and coding of impulses can occur to provide perception, memory, and learning. Wakefulness, sleep, hypnosis, and a wide variety of complex emotional affects depend upon varying degrees of arousal. These are a property of the midbrain or diencephalic level in which attention recently has been focused on the differences in organization and function of the ascending reticular activating system (A.R.A.S.) as it is involved in somatovisceral adjustments.28
These observations apparently confirm the existence in the upper brain stem of a network of interconnected neurons, the central reticular formation which acts as a sort of “mixing network” from widespread cortical areas. It is logical to conceive of such an integrating center here, because, within a few millimeters, one finds neurons with both ascending and descending connections to the frontal, temporal, parietal, and occipital lobes.
Also at this level, research has been concentrated on clarifying the functions of the thalamocortical and hypothalamic systems which connect with the A.R.A.S.8,16 Others have differentiated the functions of the medial and basal “limbic” formations of the forebrain from those of the more laterally located portions of the cerebral cortex.22,26,29
It seems likely that perceptual discrimination of stimuli, involving the cortex, operates in human and infrahuman animals to evoke arousal from sleep.
In narcolepsy, where the EEG shows typically slow waves, loud noise accelerates the EEG momentarily, but the patient does not awaken. However, softly speaking the patient's name produces prompt awakening with concomitant changes of the EEG to an alert pattern. Thus the central reticular formation may act like a tunable two-way amplifier to modulate important signals at hypnotic and nonhypnotic levels. Sperry and his associates severed the corpus callosum surgically and observed that the two halves of the brain are essentially two brains, almost identical but differing in function.46 In right-handed persons, the left hemisphere is primarily concerned with verbal behavior and analytic tasks. The right hemisphere is more involved with imagination, space perception, and music. The former acts like a stimulus-response digital computer. The latter acts like an analog computer—a “gestalt” brain. In left-handed persons, these relationships are reversed. The recognition that there are two cerebral hemispheres specialized to operate in different modes allows some understanding of the fundamental durability of what is referred to as consciousness or unconsciousness. Gur and Gur observed that a hemisphere preference correlates with measured hypnotizability.11
ROLE OF THE INTERPRETIVE CORTEX
Penfield has electrically stimulated certain areas of the temporal lobes of epileptics to activate memory sequences which may be classed as experiential and interpretive.37 An experiential response occurs as a flashback to a seemingly random event in the subject's past; it ceases when the stimulus is removed. Such scanning or interpretive “signaling” is manifested by strange emotional reactions such as fear, loneliness, panic, and a false sense of familiarity or the déjà vu phenomenon.
These scanning mechanisms functioning reciprocally with other specific brain areas are unquestionably involved in age regression, revivification, amnesia, hyperamnesia, negative and positive sensory hallucinations, and other hypnotic phenomena.
Although access to the past is available from either temporal lobe, both the experiential and interpretative responses indicate the existence of a permanent ganglionic recording of the stream of consciousness that is formed and preserved in a constant pattern of electrical impulses projected from a hypothetical integrating system for thought in the upper brain stem—the centrencephalic system.37This pattern is a sort of neuronal record in which present experience is preserved for life by means of successive facilitation through the cells and synapses which constitute this pathway. It seems likely that some of this same record is used when recurring judgments are made in regard to familiarity with and the meaning of each new experience. The actual recording of the stream of consciousness may be utilized for the purpose of comparison long after it has been lost to voluntary control.
ROLE OF THE LIMBIC SYSTEM
Research on the neurophysiologic mediation of emotions has pointed more clearly to the importance of a series of older cortical structures given the name “Papez action circuit” or, the limbic system.35 Structurally, this system constitutes the inner core of the brain concealed by the convolutions of the neocortex or the new brain. This ancient structure, the rhinencephalon, was the primitive “nose-brain.” Experimental evidence indicates that it may serve as a nonspecific activator for the cortex, facilitating or inhibiting learning, memory, overt behavior, and internal feelings, even though it is under neocortical control.13
Thus the limbic system is to feeling states what the reticular system is to somatovisceral adjustments. The presumed primacy of the role of the limbic system in emotional behavior supports the assumption that it is here that the important neural mechanisms for “feeling drive” and “conceptual will” are located.25 In this regard, the role of the limbic system, as it functions in the brain's hierarchic order, helps to elucidate the nature of hypnosis, hysteria, schizophrenia, and psychosomatic diseases.
Behavioristically, the limbic system gives expression to the visceral needs of the body rather than to its purely ideational functions. It interprets experience in terms of feeling rather than in terms of intellectualizing symbols. The latter type of interpretation is presumed to be predominantly under neocortical control. However, the modulating influence of the limbic system is not exclusively concerned with the mediation of subjective emotional expressions, but it also acts in correlating primitive motivational-emotional processes. Homeostatic and adaptive centers also are abundantly located around the third and fourth ventricles; these, too, react to neocortically directed activities in general, as for example, during voluntary physical work or intense intellectual concentration, or when we voluntarily induce ourselves to relax, or, as described below to enter into hypnosis.
Since both the striated and the smooth muscular systems are under the influence of the limbic system, this helps to explain the close relationship between voluntary and involuntary control of visceral functions during hypnotic behavior. The involuntary system is not as involuntary as it is believed to be, and portions of the voluntary system can come under neocortical control with appropriate conditioning, such as in biofeedback, Yoga, or hypnosis.
The controls which the limbic system exercises are massive and diffuse, and, as a result, entire organ systems as well as the body image appear to be symbolically represented as a whole rather than specific muscles or movements. This is different from the sharply exercised controls in the neocortex.19 Thus, because of the interconnections among the various structures of the limbic system, this subcortical region acts as a sort of “automatic pilot,” and, together with the reticular formation, seems to provide a mechanism in which
… sensory afferents and symbolic representations of the outside world, and sensory afferents from the symbolic representations of the bodily structures plus all the autonomic components of experience can become integrated. It is here that a triple linkage may occur involving the “I” or self, the “non-I” or non-self, and the intermediate or communicating worlds.10
The amygdaloid complex, an important structure of the limbic system, together with the reticular formation and the intralaminar systems, is capable of exerting a diffuse regulatory influence on the cortex.9 As evidence of the hierarchic relations, the electrical activity recorded from the amygdaloid complex changes when an animal is startled or when, as a result of conditioning, its “attention” is focused on some environmental event.
When the hippocampus—still another subdivision of the limbic system—is inhibited, the electrical activity from the amygdala changes whenever the animal touches, hears or sees any environmental event.32Hippocampal seizures result in catatoniclike states similar to catalepsy.26 Alterations in hippocampal activity also reflect the presence of a mechanism by which limbic system structures contribute a “staying” quality to emotion and pain. One important function of the hippocampus is to keep the brain attentive to carrying out goal-directed behavior and to prevent it from being shunted haphazardly by every fluctuation in the environment.6 Crasilneck and his co-workers have described how hypnosis terminated each time during brain surgery when the hippocampus was stimulated.7 They suggest that the hippocampus mediates whatever neural circuits are involved in hypnosis.
EEG findings indicate that the cortex can be desynchronized during arousal. Simultaneously, the hippocampus changes its electrical pattern in a way that has generally been associated with sleep. Livingston23 poses an interesting hypothesis to explain what appears to be a paradox. He thinks that the limbic system plays a trophic role to restore and conserve energy to maintain visceral well-being. In the presence of anxiety-evoking arousal in which energy is expended rapidly, the temporary “going to sleep” of the involved nervous structures may be protective to the organism. Might not this mechanism also explain the effectiveness of Pavlov's protective “sleep” inhibition therapy (hypnosis)? The limbic system apparently also can develop an odd type of memory loss. When large lesions of the limbic system are produced, execution of complex action sequences cannot be carried out. An interference with feeding, fighting, mating, and maternal behavior may occur as well.
Although many seemingly unrelated effects on behavior have been attributed to limbic system activity, it can be hypothesized on the basis of the above data that these systems comprise the substrate concerned with motivational and emotional behavior—primitive, instinctual and “visceral” reactions. The kind of effect obtained depends on which of the major divisions of the limbic systems are involved.32
In the course of performing lobotomies and related operations, Heath observed a consistent reduction in “emotional overflow from memories” following removal of a part of the prefrontal cortex connected with a rhinencephalic region below the corpus callosum (septal region).13 Stimulation of this area speeds movement and alerts the animal, whereas stimulation of the caudate nucleus has an opposite effect. Most important, his data indicated that the same emotional response always accompanied stimulation of a specific region. Such findings lend general support to ideas expressed by Herrick,14 Papez,34Klüver17 and others who opened up this line of investigation.
The foregoing data indicate that ideational processes which occur as a function of neocortical and limbic lobe activity reach peripheral nervous pathways via the R.A.S. Heath's work may have some connection with the increased alertness, the vividness of sensory-imagery and the facilitation of ideomotor activity noted during hypnosis. How else can we explain the alert behavior of the person who is ostensibly “asleep” or detached while in hypnosis or the person who is “awake” while supposedly asleep? And what about dreaming when cortical activity is completely inhibited? Does the rhinencephalon act as a “watch dog” to protect the dreamer? Even though their functional significance is different, the similarity between schizophrenic symptoms and states of reverie, hypnosis and sleep is well known.
In this section we have attempted to show how limbic system activity relates primarily to the execution of complex goal-directed emotional activities, as well as how and where these goals originated in the brain. The decision to execute a sequence of operations undoubtedly begins by transfer of control from the posterior “association areas” to the frontal “association areas” which have been referred to as the “organ of civilization.” These are intimately connected with the limbic system to “serve as a working memory” in which plans can be retained temporarily when they are being formed, transformed or executed.32 Thus selecting a goal from memory is largely a function of the primitive portions of the brain. The subjective experiencing of associated emotional affects in turn requires mediation by cortical portions of the brain.
ROLE OF THE HYPOTHALAMUS
The hypothalamus receives a complex pattern of afferent connections from higher brain areas such as the limbic and reticular activating systems. There are also two-way neural pathways, reverberating circuits or feedback mechanisms that reciprocally connect the hypothalamus and cortex via limbic system structures.8 It is generally accepted that the expression of emotions is mediated by the hypothalamus—not only the autonomic reactions, such as those which result in pallor, blushing, palpitation, elevation of blood pressure, sweating, and peristalsis, but also the responses involving striated muscle, such as the grimaces and trembling of rage. The hypothalamus mobilizes the body for emergencies—coordinating the necessary build-up of breathing and other autonomic functions. It also regulates hunger and sexual activities.
The emotional influence of both the A.R.A.S. and the limbic system is expressed in part by modulating the functions of the hypothalamus; all three systems overlap. Thus the thalamus and the hypothalamus occupy an important position in the maze of intricate connections between the neocortex and the subcortical structures.
ROLE OF THE RETICULAR ACTIVATING SYSTEM
The reticular formation is the central axial core of the brain stem, which acts as a neuron pool and seems to have an influence on almost all sensory inflow to the higher centers as well as their motor outflow. Besides participating in vital autonomic responses, it elicits generalized inhibition of movement. It also reduces, or may eliminate, incoming sensory impulses at the level of their entrance into the brain stem.
Magoun and co-workers found that sensory stimuli reach the cortex by two pathways: the classic lemniscal pathways to the primary receptive areas, and “a series of ascending relays coursing through the mesencephalic tegumentum, subthalamus, hypothalamus, and ventromedial thalamus to the internal capsule.”27 It is this collateral network that is referred to as the A.R.A.S.23,26,27,29
Activation of the brain stem reticular formation may cause generalized cortical arousal; that is, it induces electrical and behavioral manifestations of alertness. For this reason, it has been called the reticular activating system (R.A.S.). Corticofugal projections of the cortex, acting through the ventromedial nucleus of the hypothalamus, have some measure of reciprocal control of the reticular formation by exerting an inhibiting or deactivating effect so that painful stimuli are diminished or eliminated. Thus the R.A.S. is able “to burn the nervous system's candle at both ends.”23
Impulses also reach the R.A.S. from the cerebellum. The R.A.S. is activated by epinephrine and acetylcholine and by other adrenergic or cholinergic substances. It modifies muscle tone and movement and visceral regulatory mechanisms. Hence, stimulation, inhibition, arousal, and depression can be reciprocally exercised simultaneously in different areas by the A.R.A.S.27 When the cortex is prevented from being stimulated by impulses from the R.A.S., the brain is quiescent. Wakefulness is then maintained by lower brain centers which are activated by incoming afferent stimuli. As more of the R.A.S. is eliminated, the electrocortical activity changes from a waking to a sleeplike state.
Operationally, the relative quiescene of the brain may be observed in the variations of electroencephalographic patterns that occur in the transition from sleep to wakefulness. The arousal function of the R.A.S. and the thalamus have specific activating influences on the cortex. This may have relevance for the phenomena of hypnosis—it maintains wakefulness while some degree of cortical inhibition occurs. Although no significant alterations in the wave patterns have been noted in hypnosis, there may be sufficient basis, depending on the degree of cortical excitation and inhibition, to posit that the A.R.A.S. is an important screening mechanism for a continuum of sleep, hypnosis, and wakefulness.31
NEUROPHYSIOLOGIC MECHANISMS IN THE MEDIATION OF EMOTIONS DURING HYPNOSIS
The preceding section stressed that one difficulty in assaying cerebral functioning at any level of awareness is that the simplest neural event becomes enormously complex. Another problem is that the neuronal correlates responsible for hypnotic behavior are not likely to be found in the action and interaction of systems, nor in the activity of single brain structures. The reason for this is that hypnosis is a part of everyday behavior dynamics. Like other instinctual defense mechanisms, it is a phylogenetically determined adaptive response.18 The basis for this assumption is that the activity of an inherited network of neuronal synapses to produce altered states of awareness can be modified by experience through learning. There is evidence that inherited ingredients enter into every learning process, and that in turn an extensive modification of these inherited ingredients may occur through the process of learning and conditioning, so that these overlapping determinants constitute broad bands on a continuous spectrum.21 The capacity to enter hypnosis is already built into the organism and is merely elicited on the basis of altering the subject's “perceptions” and interpretations of himself and his surroundings.4
There are several other recent studies which have tried to elucidate the neural mechanisms by which hypnosis affects human thinking and behavior.2,42,46 Arnold believes that, when irrelevant action impulses are excluded, the subject develops a set or a state of expectancy to accept what the hypnotist is describing, with the result that the flow of sensory impressions is reduced.2 On a neurophysiologic level, cortical inhibition occurs in which the “set to imagine” is mediated by the limbic system; more specifically, the hippocampal action circuit connected with the diffuse thalamic system. The latter, in turn, mediates the reduction or the intensification of neural conduction to the limbic cortex and the hippocampus and is instrumental in excluding sensory impressions. The resultant distortion or exclusion of sensory information may help to explain negative or positive sensory hallucinations.
It is contended by Arnold that suggestions given for complete neuromuscular relaxation (cataplexy),* even though characterized by full awareness, are mediated via the limbic system connecting with the premotor and the motor cortex, and represent motor imagination (ideomotor) transformed into action.2 Suggested sensations (ideosensory) are mediated via the limbic system which connects with the frontal “association areas” and the primary sensory receiving areas. These represent projected memory images which are accepted as real because the impulse to appraise and evaluate has been excluded. Suggested goal-directed actions (posthypnotic suggestions) flow from the suggested situation (suggestions given during hypnosis) and are mediated via the limbic system just like any action carried out without hypnosis.1
However, Roberts questions the role of the diffuse projection of the thalamic reticular formation in the production of hypnotic phenomena, as it cannot be safely posited that this area could serve as a vehicle of perception.39 The pronounced loss of sensorymotor activity which occurs during hypnosis is consistent with the theory that perception may occur through a secondary system. This system may be in the upper part of the brain stem, where a switching over to the cortex occurs—that is, in the A.R.A.S. and the surrounding areas of the dorsal hypothalamus. Psychic excitement radiates from this center and probably has something to do with a central “pacemaker” of the cerebrum, possibly the centrencephalic system.37
Because of the resultant inhibition produced by electrodynamic factors (selective activity of brain rhythms of delta frequency), Roberts postulates:
During hypnosis the central nervous system is immobilized because the activating system has been deprived of the data—sensory, somesthetic, sensorimotor, affective, intentive, mnemonic—requisite to the normal direction of psychic activity and response. However, the continued activity of the A.R.A.S. and elaborative and effector cortical areas maintains the capacity for integration, higher elaboration and response.42
In accord with the principle of selective neural inhibition, he believes that the subject cannot check incoming information against the stored data because these have been blocked. As a result, the subject uncritically accepts the suggestions of the hypnotist.
Akstein implicates the A.R.A.S.,1 and Reyher theorizes on corticolumbar areas involving excitation and inhibition.41 West believes that recently observed bioelectric variations during the hypnotic state, as well as differing reactions of hypnotic subjects to drugs under various circumstances, are compatible with mediation by the A.R.A.S.46
Recently, neurophysiologists and behavioral scientists have attempted to understand hypnosis in terms of altered states of consciousness (A.S.C.). The author does not feel that the concept of A.S.C. will contribute materially to a better understanding of the mechanisms of hypnosis. Such notions merit consideration only if it can be shown that psychological processes are dominated by specialized cortical areas.33 Cortical left-right asymmetry, as discussed above, is illustrative. It is hoped that modern advances in electrophysiology will provide help in understanding the mediation of emotion at hypnotic and nonhypnotic levels.
Miller and his co-workers have postulated the TOTE unit (test-operate-test-exit) to show the relation between the Image (the experiential background) and a Plan (a hierarchic process which controls the order in which a sequence of operations is to be performed).32 The TOTE concept, which incorporates the important notion of feedback, is a fundamentally different explanation of behavior from that provided by the reflex arc. This author, however, cannot agree with their concept of hypnosis as a hypnotist-directed approach, because hypnosis is a subjective phenomenon. It is not true that a hypnotized person has stopped making his own Plans, and therefore, executes the hypnotist's version of the Plan, since this is the only one he has. However, the reader is strongly urged to read their excellent book, which helps to elucidate the neuropsychological mechanisms involved in thinking, memory, personality, motor skills, intention, instincts, problem-solving, and hypnosis.32
Ravitz attempts to explain the possible neural basis of hypnosis and its biologic significance as the result of electric force fields; he holds that hypnotic states can be “distinguished from sleep by the development of characteristic force-field shifts with preservation of a waking EEG configuration.”39,40 He also reported changes in direct current potentials at the point of induction of hypnosis and at the point of termination of hypnosis.
In the next section, attempts will be made to clarify what determines the brain's acceptance of suggestions in a noncritical manner during hypnosis, and also why some individuals at nonhypnotic levels have little or no difficulty in accepting suggestions uncritically. It is no wonder that Kubie remarked: “Hypnosis is at the crossroads for all levels of physiological and psychological organization, and … the phenomenon which we call hypnotism when more fully understood will be one of our most important tools for the study of normal sleep, of normal alertness, and of continuous interplay among normal, neurotic and psychotic processes.”21 The next chapter includes a practical discussion of the methods used by the hypnotherapist to induce an attitude of belief in his subject to alter his psychological processes in a particular way.
DISCUSSION
The induced state of selectively altered sensory awareness called hypnosis is mediated by exteroceptors (external signals), interoceptors (signals from internal processes), and proprioceptors (position of the body). During hypnosis, certain signals are selected for focused arousal and amplification to exclusion of irrelevant ones. In essence, hypnosis selectively rearranges certain stimulus-response cues so that they do not produce undesirable autonomic reaction patterns. The principal site of interaction between the C.N.S. and A.N.S. is the hypothalamus which also marks the junction between the brain stem and the cerebral hemispheres with the pituitary. Thus the hypothalamus becomes a three-way junction that integrates and coordinates the function of the C.N.S., the A.N.S., and the hormonal system.
The core of the brain stem (R.A.S.) up to the hypothalamus functions as a preamplifier for sensory (awareness) and motor (responsive) areas of the cortex. The R.A.S. performs two significant functions in conscious awareness. First, the “constant-pulse signal” it generates keeps the cortex alerted for incoming impulses, both from cranial nerves and spinal tracts mediating incoming sensory stimuli. Second, the R.A.S. operates as a “tunable amplifier” for the cortex, which selectively facilitates or amplifies some incoming sensory impulses (important ones) while suppressing others (unimportant ones). The R.A.S. is the site of significant neuroelectrical activity changes during hypnosis.
The A.N.S. incorporates two separate but interactive neural networks. Thus it functions as a “twophase governor,” regulating expenditure and conservation of emotional energy. The first is the sympathetic system, which energizes the activities of the visceral system. The second is the parasympathetic system, which relaxes or tranquilizes various visceral reactions. Many sympathetic or altered states can be pleasurable and not necessarily related to avoidance responses. Not all parasympathetic or relaxed states are related to pleasurable effects; some can be perceived as unpleasant experiences in the form of depressive reactions.
Hypnosis or altered states of consciousness can connect or associate sensory or cognitive stimuli with either sympathetic or parasympathetic reactions and effects. The key factor is that hypnosis involves saturation of one or more of the primary exteroceptive systems (auditory, visual, or tactile) combined with a directed inhibition of normal proprioceptor sensations and interoceptor awareness of visceral activity.
In sleep, nearly all channels of sensory input are inhibited from cortical awareness by the R.A.S. In chemical sedation, sensory blocking is generalized (as in normal sleep), while most of the inhibition occurs at the cortical level. Like hypnosis, the tranquilizing agents act on the hypothalamus and R.A.S., diminishing anxiety and tension without depressing cortical activity. However, under hypnosis, selective reconditioning is possible; posthypnotic suggestions are more readily followed. This cannot be attained with drugs.
The physiological basis for perceptual awareness is the result of the induced parasympathetic dominance of the visceral systems, resulting in generalized relaxation. As awareness becomes associated with heaviness and drowsiness, attention can be more readily focused on specific cognitive processes, all of which are essential to selective conditioning of the A.N.S.
REFERENCES
1. Akstein, D.: The induction of hypnosis in the light of reflexology. Am. J. Clin. Hypn., 7:281, 1965.
2. Arnold, M.B.: Brain function in hypnosis. Int. J. Clin. Exp. Hypn., 7:109, 1959.
3. Ashby, W.R.: Design for a Brain. New York, Wiley, 1954, p. 6.
4. Barber, T.X.: The concept of hypnosis. J. Psychol., 45:115, 1958.
5. Benson, H., et al.: The relaxation response. Psychiatry, 37:37, 1974.
6. Brazier, M.A.B. (ed.): Central nervous system and behavior. Transactions of the second conference of the J. Macy, Jr., Foundation, New York, February 22-25, 1959.
7. Crasilneck, H.B., et al: Special indications for hypnosis as a method of anesthesia. J.A.M.A., 162:1606, 1956.
8. Fields, W.S.: Hypothalamic-Hypophyseal Interrelationships. Springfield. Ill., Charles C. Thomas, 1956.
9. Feindel, W., and Gloor, P.: Comparison of electrographic effects of stimulation of the amygdala and brain stem reticular formation in cats. Electroencephal. Clin. Neurophysiol., 6:389, 1954.
10. Glaser, G.H.: Recent concepts of central neurophysiology. Psychosom. Med., 17:337, 1955.
11. Gur, R.E., and Gur, R.C.: Handedness, sex and eyedness as moderating variables in the relationship between hypnotic susceptibility and functional brain asymmetry. J. Abnorm. Psychol., 83:635, 1974.
12. Gutman, H.: The biological roots of creativity. Genetic Psych. Monog., 64:417, 1961.
13. Heath, R.G.: Correlations between levels of psychological awareness and physiological activity in the central nervous system. Psychosom. Med., 12:383, 1955.
14. Herrick, C.J.: The amphibian forebrain. VI. Necturus. J. Comp. Neurol., 58:1, 1933.
15. Hess, W.R.: Functional Organization of the Diencephalon. New York, Grune & Stratton, 1957.
16. Jasper, H.: Diffuse projection systems; the integrative action of the thalamic reticular system. Electroencephal. Clin. Neurophysiol., 1:405, 1949.
17. Klüver, H., and Bucy, P.C.: Preliminary analysis of functions of the temporal lobes in monkeys. Arch. Neurol. Psychiat., 42:979, 1939.
18. Kroger, W.S., and Freed, S.C.: Psychosomatic Gynecology. Chicago, Free Press, 1956 (reprinted, Los Angeles, Wilshire Book Company, 1962).
19. Kubie, L.S.: The central representation of the symbolic process in psychosomatic disorders. Psychosom. Med., 15:1, 1953.
20. _________: Appendix I: Body symbolization and development of language (reprinted from Psychoanal. Q., 3:430, 1934). Cybernetics. New York, Macy, 1951.
21. _________: Hypnotism: a focus for psychophysiological and psychoanalytical investigations, Arch. Gen. Psychiat., 4:53, 1961.
22. Lindsley, D.H.: Emotion. In Stevens, S.S. (ed.): Handbook of Experimental Psychology. New York, Wiley, 1951, pp. 473-516.
23. Livingston, R.B.: Some brain stem mechanisms relating to psychosomatic functions. Psychosom. Med., 17:347, 1955.
24. MacKay, D.M.: The epistemological problem for automata. In Shannon, C.E., and McCarthy, J. (eds.): Automata Studies. Princeton, Princeton University Press. 1956.
25. MacLean, P.D.: The limbic system and its hippocampal formation; studies in animals and their possible application to man. J. Neurosurg., 11:29, 1954.
26. _________: Limbic system (“visceral brain”) in relation to central gray and reticulum of brain stem: evidence of interdependence in emotional processes. Psychosom. Med., 17:355, 1955.
27. Magoun, H.W.: The ascending reticular activating system. Res. Publ., J. Nerv. Ment. Dis., 30:480, 1952.
28. _________: An ascending reticular activating system in the brain stem. Arch. Neurol. Psychiat., 67:145, 1952.
29. _________: The ascending reticular system and wakefulness. In Delafresnaye, J.F. (ed.): Brain Mechanisms and Consciousness. Springfield. Ill., Charles C. Thomas, 1954, pp. 1-15.
30. _________: Paper read at Third World Congress of Psychiatry, Montreal, June 10, 1961.
31. Marmer, M.J.: Hypnosis in Anesthesiology. Springfield, Ill., Charles C Thomas, 1959.
32. Miller, G.A., Galanter E., and Pribram, K.H.: Plans and the Structure of Behavior. New York, Holt, 1960.
33. Ornstein, R.E.: The Psychology of Consciousness. San Francisco, W. H. Freeman, 1972.
34. Papez, J.W.: A proposed mechanism of emotion. Arch. Neurol. Psychiat., 38:725, 1937.
35. Pavlov, I.P.: Selected Works. Moscow, Foreign Languages Publishing House, 1955.
36. Penfield, W.: Memory mechanisms. Arch. Neurol. Psychiat., 67:178, 1952.
37. _________: The interpretive cortex. Science, 129: 1719, 1959.
38. Pribram, K.H.: A review of theory in physiological psychology. In Annual Review of Psychology. Palo Alto, Cal., 1960, pp. 6-7.
39. Ravitz, L.J.: Application of the electrodynamic field theory in biology, psychiatry, medicine, and hypnosis. Am. J. Clin. Hypn., 1:135, 1959.
40. _________: Electrometric correlates of the hypnotic state. Science, 112:341, 1950.
41. Reyher, J.: Brain mechanisms, intrapsychic processes and behavior: a theory of hypnosis and psychopathology. Am. J. Clin. Hypn., 7:107, 1964.
42. Roberts, D.R.: An electrophysiological theory of hypnosis. Int. J. Clin. Exp. Hypn., 8:43, 1960.
43. Shaefer, H.: Physiology and psychosomatic medicine. Med. Arch. Gen. Psychiat., 3:99, 1960.
44. Snezhnevsky, A.V.: Paper read at World Psychiatry meeting, Montreal, June, 1961.
45. Sperry, R.: Quoted in Gazzaniga, M.S.: The Bisected Brain. New York, Appleton-Century-Crofts, 1970.
46. West, L.J.: Psychophysiology of hypnosis. J.A.M.A., 172:672, 1960.