“The entire multitiered system arborizes like a tree, with levels in each component linked to corresponding levels in other components. For example, an early (e.g., limbic) state in language (e.g., word meaning) is linked to an early stage in action (e.g., drive, proximal motility) and perception (e.g., hallucination, personal memory) …. In sum, a description of the spatial and temporal features of a _single_ unfolding series amounts to a description of the minimal unit of mind, the _absolute_ mental state” (p. 54).
The author’s discussion of an individual’s physical movement relates to the concept of nonvoluntary movement (or movement without awareness of volition) in hypnosis. “More precisely, levels in the brain state constitute the action structure. As it unfolds, this structure generates the conviction that a self-initiated act has occurred. This structure–the action representation–does not elaborate content in consciousness. … As with the sensory-perceptual interface, the transition to movement occurs across an abrupt boundary. In some manner, perhaps through a translation of cognitive rhythms in the action to kinetic patterns in the movement, levels in the emerging act discharge into motor (physical) events” (p. 57).
“The self has the nature of a global image or early representation within which objects-to-be are embedded. … The self is the accumulation of all the momentary cognitions developing in a brain configured by heredity and experience in a particular way (p. 70).
“The deposition of a holistic representation … creates the deception of a self that stands behind and propagates events. The feeling of the self as an agent is reinforced by the forward thrust of the process and the deeper locus of the self in relation to surface objects. The self appears to be an instigator of acts and images when in fact it is given up in their formation. The self does not cause or initiate, it only anticipates (p. 70).
The foregoing notes cover only the first five chapters, less than half the book. Other chapters relevant to hypnosis would be those titled ‘The Nature of Voluntary Action,’ ‘Psychology of Time Awareness,’ ‘From Will to Compassion,’ and ‘Mind and Brain.’
Brown, Peter (1991). The hypnotic brain: Hypnotherapy and social communication. New Haven, CT: Yale University Press.

Notes are taken from a review of this book: Diamond, Michael (1993). Book review. Bulletin of the Menninger Clinic, 57 (Winter), 120-121.
Brown “posits that because the fundamental matrix of the human brain is metaphoric, hypnosis results from skillful matching of metaphorical communication with the brain’s biological, rhythmic alterations. The most significant feature of trance experience is thereby located in the hypnotist-subject interaction” (p. 120).
“The middle section [of the book is comprised largely of] literature reviews in support of Rossi’s (1986) ultradian rhythm theory of hypnosis and Lakoff and Johnson’s (Johnson, 1987; Lakoff & Johnson, 1980) experientialist theory of conceptual thought” (p. 120). The final section includes “research evidence on medical uses of hypnosis, a theory of dissociation and multiple personality disorders, and an uncritical discussion of Milton Erickson’s naturalistic hypnotherapeutic approach … [and also] a brief discussion of the social-cultural functions of possession states among the Mayotte culture” (p. 120).
Brown, Peter (1991). Ultradian rhythms of cerebral function and hypnosis. Contemporary Hypnosis, 8, 17-24.

As a consequence of his observations of the clinical work of Milton Erickson, Ernest Rossi has proposed an ‘ultradian rhythm theory of hypnosis’. Rossi demonstrated that the spontaneous changes in cognition, affect and behaviour which occur as part of the ultradian cycle (which Erickson referred to as ‘the common everyday trance’) are similar to the changes which occur during hypnosis. A review of studies of the phasic changes in hemispheric function suggests that ultradian changes do parallel the changes found in hypnosis.

NOTES: Falling asleep and waking up are regulated by two separate mechanisms rather than being opposite poles of one mechanism (Winfree, 1980). Kleitman (1961) suggested a 90-min cycle, the basic rest-activity cycle (BRAC). In addition to physiological alterations, there are alterations in cognition, mood and behavior (Rossi & Cheek, 1988); vigilance (Okawa, Matousek & Petersen 1984); peripheral blood flow (Ramano & Gizdulich, 1980); respiratory amplitude (Horne & Whitehead, 1976); visual evoked potentials (Zimmerman, Gortelmeyer & Wiemann, 1983); pupillary diameter, stability and reactivity to light, and saccadic eye movements (Lavie & Kripke, 1981).
These diurnal variations may relate to hypnotic behavior. There is a recurring increase in daydream and fantasy, as well as visual imagery (Kripke & Sonnenschein, 1978). “There is evidence for a parallel recurring cognitive and emotional cycle with increased emotional responsiveness and a more subjective cognitive processing of information (Evans, 1972; Holloway, 1978; Overton, 1978; Thayer, 1987). Subjects appear to repeat the cycle approximately 16 times per day, with a range of 70-120 minutes. Kripke and Sonnenschein (1978) noted that the subjects were personally unaware of any repeating cycle in their mental lives” (p. 19).
The brainstem arousal mechanisms seem to be implicated in periodic changes in the EEG. Ultradian rhythms are “more easily detected under conditions of increased sleep need, reduced external performance demand and lowered motivation to focus externally (Broughton, 1985)” (p. 20). Sterman (1985) observed that the rhythm was most marked in resting state and disappears during complex visuomotor tasks. Relationship of EEG patterns to attentional patterns indicate there may be two different forms of attention, one for focused awareness (often thought to be associated with trance state) and the other a generalized vigilance (which would be reduced in hypnosis). Ultradian changes in consciousness reflected in the EEG may suggest increased internal absorption associated with visual imagery, a feature of the trance state.
“There has recently been a partial direct confirmation of Rossi’s hypothesis. Aldrich and Bernstein (1987 [International Journal of Clinical and Experimental Hypnosis]) reported a bimodal distribution of Harvard Group Scale Hypnotic Susceptibility (HGSHS) scores when they are done at different times throughout the day. They note the parallel of the changes in HGSHS scores and the circadian variations in body temperature which suggest changes in hypnotic responsiveness coinciding with the fluctuations of physiological rhythms.
“Other support comes from some highly original work involving breathing rhythms. There are cyclic alterations in relative air flow between the left and right nostrils with an average period of 2-3 hours (Hasegawa & Kern, 1977). This nasal ultradian rhythm is correlated with an increase in contralateral cerebral hemispheric activity (Werntz, Bickford, Bloom & Shannahoff-Khalsa, 1981, 1983; Klein, Pilon, Prosser & Shannahoff-Khalsa, 1986). The alterations in hemispheric function do appear to be related to changes both in the style of cognition, particularly in an increase in vivid visual imagery, and in performance on specific tasks (Klein et al., 1986). Thus these studies support the notion of an ultradian rhythm of cerebral function which is associated with characteristic physical manifestations mediated by the autonomic nervous system. Whether or not these changes are directly related to the findings reported by Aldrich and Bernstein has yet to be established” (p. 21).
The authors conclude that “the most consistent evidence for ultradian rhythms is demonstrated by the mechanisms of the hypothalamic-limbic system and by brain-stem mechanisms that regulate arousal and attention processes (Parmeggiani, 1987); neuroendocrine regulatory mechanisms (Follenius, Simon, Brandenberger & Lenzi, 1987) and autonomic nervous system function (Bossom, Natelson, Levin & Stokes, 1983; Gordon & Lavie, 1986). These studies also suggest an ongoing dynamic interaction between cortical and subcortical structures throughout the ultradian cycle (Parmeggiani, 1987), and suggest that these interactions may be of great significance in hypnosis” (p. 21).
Graffin, N. W. (1991, October). EEG concomitants of hypnotic susceptibility and hypnosis (Dissertation, Pennsylvania State University). Dissertation Abstracts International, 52 (4), 2296.

“Many previous studies of EEG and hypnosis were completed prior to development of spectral analysis and typically included data from a limited number of electrode sites. The categorization of subjects as high and low hypnotizables was often done inappropriately, and disparate findings were obtained. In this study, subjects scoring 10 or more and 3 or less on the Stanford Hypnotic Susceptibility Scale, Form C were defined as high and low respectively. EEG was monitored during resting baseline, mental arithmetic, and mental spatial rotation, and before, during, and after hypnotic induction. EEG was recorded monopolarly at frontal (F3,F4), parietal (P3,P4), temporal (T3,T4), and occipital (O1,O2) derivations, and data were fast Fourier analyzed. Mental arithmetic and mental spatial rotation did not produce differential hemispheric activation. High hypnotizables had greater frontal and temporal theta at baseline than lows. All subjects showed increases in parietal and occipital theta during hypnotic induction. During prehypnotic induction baseline, highs had greater parietal and occipital theta than lows, but this different was smaller after induction. Baseline temporal alpha was greater for highs than lows, but after hypnotic induction, all subjects had less alpha at all sites than before induction. Increases in alpha at all sites for all subjects occurred during hypnotic induction. Beta activity was unrelated to susceptibility but was greater in waking than in hypnotic states for all subjects at all sites. Increases in alpha at all sites for all subjects occurred during hypnotic induction. The theta activity observed suggests that high hypnotizables have a greater capacity for selective attention and imagery and that during hypnosis all subjects experience enhancement of these abilities. The alpha results may suggest an increase in the focusing of subjects on internal processes during hypnosis and greater scanning of the environment after induction” (p. 2296).

Kleinhauz, Moris (1991). Prolonged hypnosis with individualized therapy. International Journal of Clinical and Experimental Hypnosis, 39 (2), 82-92.

A therapeutic approach is presented which involves the use of prolonged hypnosis for the treatment of diverse medical and/or psychological conditions, including intractable pain. This approach may be indicated either as a complementary tool used in conjunction with other treatment approaches or as the only method of intervention. The technique is based on achieving a prolonged hypnotic response, during which hypno- relaxation serves as the foundation for the delivery of an individualized therapeutic plan which includes self-hypnosis, suggestive procedures, metaphors, and constructive imagery techniques. In debilitated patients, medical supervision and nursing care are essential, and hospitalization is recommended if necessary. Theoretical assumptions underlying this approach are presented, and clinical implications are discussed. The method is illustrated through case presentations.

The general procedure involves: 1. A flexible plan concerning the duration of treatment: days, weeks, or longer. 2. Information is given to the patient, the family and the medical staff if in hospital. Emphasize that while the patient may be in a ‘twilight-like’ state, most of the time he/she is able to fulfill his or her basic physiological needs, (drinking, eating, taking care of personal cleanliness, etc.). 3. The method of hypnotic induction is individualized. 4. The patient is trained in self- hypnosis, and for using signals for induction and dehypnotization either for self hypnosis or for the hypnotist to use. Thus if there is a physiological or emotional need for self-hypnosis the patient can do it. Suggestions and training are given and reinforced concerning the patient’s capability to fulfill his/her basic physiological needs. 5. The family and/or the medical staff are instructed and trained in induction and dehypnotization, until the patient responds to them satisfactorily. 6. At this stage, therapeutic suggestions aimed at ego-boosting and a change of attitudes and meanings towards the symptom and symptom removal/amelioration/substitution are added. 7. Metaphoric constructive imagery is introduced when indicated. 8. If required, other hypnotic phenomena are elicited and used (e.g. dissociation, time distortion, age regression, rehearsal, hypno/analgesia, change of muscular tonus, displacement of emotions, abreaction, etc.). 9. An audio cassette which contains the wording of the therapeutic intervention is used with some patients. 10. The family and/or the medical staff are instructed to supervise the patient properly and to avoid potential complications. 11. Termination of prolonged hypnosis with individualized therapy is gradual to permit appropriate re-orientation towards reality. 12. Treatment is evaluated and a posttreatment plan is outlined.
They provide case reports and discuss precautions. All the cases reported were treated while the patients were hospitalized for their physical condition (although in Case 3, prolonged hypnosis with individualized therapy was also continued at home after the patient’s discharge form the hospital), and the patients were monitored by the medical staff. In very debilitated patients, special care should be taken to avoid potential complications arising from their passivity, mainly the development of decubitus ulcer and of aspiration/choking while drinking or eating. Although precaution is taken routinely with these patients, these measures should be emphasized while the patient is in a state of prolonged hypno-relaxation.
Lubar, J. F.; Gordon, D. M.; Harrist, R. S.; Nash, M. R.; Mann, C. A.; Lacy, J. E. (1991). EEG correlates of hypnotic susceptibility based upon fast Fourier power spectral analysis. Biofeedback and Self-regulation, 16, 75-85.

Examined whether there were differences between high and low hypnotic susceptible subjects based upon fast Fourier power spectral analysis of the EEG recorded both before and during hypnotic tasks. Significant differences were obtained based upon EEG recording electrode location, EEG frequency within six different frequency domains, and hypnotic tasks. However, no main effect differences were obtained based upon hypnotic susceptibility. In contrast to some evoked potential studies in which a few differences have been obtained based on hypnotic susceptibility, the lack of any EEG differences in this study even when positive and negative hallucination tasks were employed may have implications for the role of the neocortex in mediating hypnotic phenomena.

When this study was presented at the annual meeting of the Society for Clinical and Experimental Hypnosis in 1988, in Ashville, the authors remarked that, “Since EEG comes from cortex, the results might be due to subcortical levels. Therefore one should look at cerebral blood flow and metabolism.”

Ader, Robert; Felton, David; Cohen, Nicholas (1990). Interactions between the brain and the immune system. In Cho, Arthur K.; George, Robert; Blaschke, Terrence (Ed.), null (30, pp. 561-602). Palo Alto, CA: Annual Reviews Inc..

“Without attempting to cover all the literature, we have used stress effects and conditioning phenomena as illustrations to point out that behavior can influence immune function. We have also described data indicating that the immune system can receive and respond to neural and endocrine signals. Conversely, behavioral, neural, and endocrine responses seem to be influenced by an activated immune system. Thus, a traditional view of immune function that is confined to cellular interactions occurring within lymphoid tissues is insufficient to account for changes in immunity observed in subhuman animals and man under real world conditions.
“These data question seriously the notion of an autonomous immune system. … The immune system is, indeed, capable of considerable self-regulation, and immune responses can be made to take place in vitro. The functions of that component of adaptive processes known as the immune system that are of ultimate concern, however, are those that take place in vivo. There are now compelling reasons to believe that in vivo immunoregulatory processes influence and are influenced by the neuroendocrine environment in which such processes actually take place … . The immune system appears to be modulated, not only by feedback mechanisms mediated through neural and endocrine processes, but by feedforward mechanisms as well. The immunologic effects of learning, an essential feedforward mechanism, suggest that, like direct neural and endocrine processes, behavior can, under appropriate circumstances, serve an immunoregulatory function in vivo. Conceptually, the capacity to suppress or enhance immune responses by conditioning has raised innumerable questions about the normal operation and modifiability of the immune system via neural and endocrine processes.
“We do not yet know the nature of all the channels of communication between the brain and the immune system or the functional significance of the neural and endocrine interrelationships that have been established….
“This integrated circuitry has extensive ascending and descending connections among the regions cited. These regions also share many similarities. They are sites intimately involved in visceral, autonomic, and neuroendocrine regulation. The cortical and limbic forebrain regions mediate both affective and cognitive processes and may be involved in the response to stressors, in affective states and disorders such as depression, in aversive conditioning, and in the emotional context of sensory inputs from the outside as well as the inside world. From an immunologic perspective, these regions are the sites in which lesions result in altered responses of cells of the immune system; they are the regions that respond to immunization or cytokines by altered neuronal activity or altered monoamine metabolism; and they are the regions that possess the highest concentration of glucocorticoid receptors and link some endocrine systems with neuronal outflow to the autonomic and neuroendocrine systems. Thus, this circuitry is the major system of the CNS suspected to play a key role in responding to immune signals and regulating CNS outflow to the immune system” (pp. 587-589).
Badia, Pietro (1990). Memories in sleep: Old and new. In Bootzin, Richard R.; Kihlstrom, John F.; Schacter, Daniel L. (Ed.), Sleep and cognition (pp. 67-76). Washington, DC: American Psychological Association.

Reviews literature. Conclusion: First, with reinforcement for responding, control of learned behavior can be maintained reliably by stimuli presented during sleep. Second, when stimuli are presented 4 min or more apart, behavioral control results in little or no change in sleep structure, in daytime sleepiness, or in perceptions of sleep quality. Neither perceived wakefulness nor wakefulness as it is scored on the sleep record are necessary for responding, although stimulus/response events typically result in brief EEG or EMG change. Third, within-subject, within-night variance in responsiveness is complexly related to time of night, sleep stage, and REM/NREM cycle.

Cikurel, Katia; Gruzelier, John (1990). The effect of an active-alert hypnotic induction on lateral asymmetry in haptic processing. British Journal of Experimental and Clinical Hypnosis, 7, 17-25.

In order to elucidate further left hemispherical inhibitory dynamics in response to instructions of hypnosis, bilateral haptic processing times were compared before and during a traditional hypnotic relaxation procedure and an active-alert procedure in which subjects pedaled a bicycle ergometer and instructions on mental alertness were incorporated with hypnosis. Previous evidence suggesting a slowing of left hemispherical processing and a facilitation of right hemispherical processing in susceptible subjects was replicated, and was shown to characterize high rather than medium susceptibles, the latter showing a bilateral slowing of processing. These effects occurred with both induction procedures whose influence on susceptibility was highly correlated. In fact the lateral shift in processing in the direction of left hemispherical inhibition and right hemispherical facilitation was favoured by the active-alert procedure, indicating that neuropsychological changes which occur with hypnosis cannot be discounted as a by-product of relaxation.

De Pascalis, Vilfredo; Penna, Pietronilla M. (1990). 40-Hz EEG activity during hypnotic induction and hypnotic testing. International Journal of Clinical and Experimental Hypnosis, 38 (2), 125-138.

Edmonston, William E., Jr.; Moscovitz, Harry C. (1990). Hypnosis and lateralized brain functions. International Journal of Clinical and Experimental Hypnosis, 38, 70-84.

Bilateral EEG measures were obtained on 16 high hypnotizable Ss (scores of >8 on the Harvard Group Scale of Hypnotic Susceptibility, Form A, Shor & E. Orne, 1962), while performing hemisphere-specific tasks during hypnosis and a no-hypnosis control condition. Conditions and tasks were presented in counterbalanced order, and Ss served as their own controls. The data call into question the right hemisphere activation interpretation of lateralized brain function during hypnosis; rather, the data suggest a lack of task appropriate activity during hypnosis. The failure to attend to baseline activity measurements and the use of ratios to evaluate interhemispheric lateralization may contribute to potential misinterpretations of data. It is critical that activity changes of the separate hemispheres be taken into account in the interpetative process.

Henninger, Polly (1990, August). Conditional handedness: Handedness changes in multiple personality disordered subject reflect shift in hemispheric dominance. [Unpublished manuscript] Presented at the annual meeting of the American Psychological Association, Boston.

This study investigates whether the host personality (Pe) and the primary alter personality (Pa) of a woman with multiple personality disorder are controlled by the left and right hemispheres respectively. Results support the hypothesis. Behavioral and preference measures indicate that Pe is strongly right-handed and Pa is left-handed. Verbal and musical dichotic tests show significantly greater accuracy for stimuli presented to the left ear for Pa and to the right ear for Pe. It is concluded that shifts in hemisphericity involve redistribution of attentional resources and callosal suppression. “Conditional handedness” is proposed as a handedness subtype characterizing persons who alternate personalities and consistently display alternate hand preferences linked to specific personality characteristics.

She uses the model of the split brain subject for dissociation in personality. The shift in personality reflects a shift in hemispheric dominance. “Dichotic testing of children suggests greater right hemisphere involvement in cognitive processing in children than in adults (Henninger, 1991). This finding suggests that in cases of dual personality, the younger alternate personality is more likely than the older to be lateralized to the right hemisphere.” [N.B. Jancke et al’s meta analysis doesn’t say this about children.] She also indicates that Henninger-Pechstedt, 1986, 1989, found that commissurotomy Ss tested with increasing strings of digits showed increased volume to the left ear shifted attention to the left side when task demands were low, but as task demands increased, right ear performance increased and left ear performance decreased.
Putnam et al (1986) indicates 37% of 100 MPDs changed handedness across alters, suggesting a relationship between MPD and lateralized functioning.
Patient was 19 yr old woman with six alters, a typical history of abuse, amnesia of primary personality for the 9 yr old alter tested here with the adult alter. Method included a cutting exercise, drawing exercise, verbal dichotic test, and music test.
Dichotic test used monosyllabic digits (1-12, excluding 7 and 11) of 307 msec duration, in which number of stimuli to be encoded increased from one to four as the test progressed (Henninger-Pechstedt, 1989). Presented in blocks of single, double, triple and quadruple pairs at rate of two pairs per second. Volume was set where S said stimuli presented to each ear sounded equal and appeared to be located at the center of her head.
On the initial tests Pa (child) asked for a decrease in volume in the left ear (6 dB); Pe requested a slight increase (2 dB). On the music test, the overall volume level on Pe’s initial test inadvertently was lower than that used for Pa, and she was recalled for a second testing at the same level as Pa. To make the volume equivalent, Pa (child) asked for a slight increase in the left channel (2 dB) and Pe (adult) asked for a greater increase (y dB).
Results: 1. Drawings were at same developmental level for both alters. 2. Adult alter was less accurate in cutting than child alter. All cuttings made by child’s left hand were superior to those made by right hand; all cuttings made by adult’s right hand were superior to those made by her left hand. The child was more accurate when cutting with left hand; adult was more accurate when cutting with right hand. Difference in dexterity between alters was statistically significant. 3. Dichotic listening: child showed a small right ear advantage; adult showed a large right ear advantage. The child’s small REA resulted from a shift from left to right ear report at the highest level of task difficulty; at the lower levels of difficulty (1-3 digit pairs) she showed a left ear advantage.
On music test the child more accurately identified melodies presented to her left ear and adult more accurately identified melodies presented to her right ear. In summary, on the lateralized tests the two personalities differed significantly with the child performing the tasks better on the left side and the adult performing them better on the right side.
Her explanation is that the results indicate a difference in hemisphericity, i.e. the preferential use of one hemisphere over the other. When one or the other personality is in control, the corresponding hemisphere is more active and controls processing. As Kinsbourne (1973) has shown, the more active hemisphere draws the subject’s attention to the contralateral side of space. Control is most visible in the side of greater manual preference and dexterity. The change in personality reflects a switch in hemispheric control.
In the dichotic tests, each personality requested that the volume be decreased on the side which subsequently performed better, suggesting that the differential activity of the hemispheres increased the perceptual salience of the stimuli contralateral to the active hemisphere which was perceived as increased volume. … That the child began the verbal test with a LEA but shifted to a REA when the task load increased suggests conflict between the hemisphere that is in control of the personality (right) and the hemisphere that is specialized to do the task (left). It suggests that when the task is simple and cognitively undemanding, the subject’s preferred mode of processing (hemisphericity), and thus the corresponding hemisphere, controls behavior. However, when a task becomes more cognitively demanding, the hemisphere specialized to do the processing takes control. Similar performance on this task has been observed in commissurotomy subjects (Henninger-Pechstedt, 1986, 1989) and learning disabled boys (Henninger & Bloch, in preparation).
The adult’s chance level of performance in the left ear on the musical dichotic test, when compared to that of the child who identified 3/4 of the left ear melodies, suggests that the adult’s dominance involves suppression of the right hemisphere. It suggests that personality changes are modulated by the degree of callosal suppression produced by one hemisphere over the other.
She mentions only one study (Burrows, Collison & Dennerstein, 1979–in Proceedings of the 8th International Congress of Hypnosis and Psychosomatic Medicine, Melbourne, Australia)–indicating that the more hypnotizable a person is, the greater the relative difference in hemispheric activation while performing hemispheric specific tasks.
She suggests that her results suggest that shifts in hemisphericity involve both a redistribution of attentional resources and callosal suppression. The shift in the child’s ear advantage as the task load increased suggests that perceptual advantages in laterality tests reflect effects due to both hemisphericity and hemispheric specialization. IN most laterality experiments perceptual differences due to hemispheric specialization are confounded with those due to hemisphericity. Experiments need to be designed in which these effects can be deconfounded.
There are no data on callosal function in persons with MPD, and the shift in ear advantage as difficulty increases suggests possible atypical callosal function in patients with MPD.
Although the commissurotomy model informs these results, there are areas in which it does not fit the data. In the callosally disconnected patient, each hemisphere may be unaware of the perception and cognition of the other hemisphere, but the patient is not amnesic for the behaviors. When he or she observes contradictory behavior in him/herself, he/she tries to interpret it. No commissurotomy patient manifests multiple personalities and none changes personality when he or she changes from operating his/her right to left hand. Most patients with MPD have more than two personalities which does not fit the commissurotomy model. This woman has six or more. Perhaps the initial two personalities are lateralized to opposite hemispheres and additional personalities align within this primary subdivision. Co-consciousness between personalities might indicate co-existence in the same hemisphere. Lastly, in a person with intact commissures, laterality differences reflect changes in the balance of brain activity between the two hemispheres, not the exclusive use of one. Shifts in consciousness in MPD patients may utilize the corpus callosum. It is likely that the inhibition of processing and suppression of awareness observed in this study are functions of the patient’s intact corpus callosum.
It is proposed that early severe trauma in some cases leads to the development of an extreme form of hemisphericity, marked by conditional handedness, as a means of escaping the emotional pain. Whether early trauma influences the development of ambilaterality or whether people born predisposed to bilateral representation of function are better able to use disassociation as a means of coping with abuse is an important question for further research to investigate.
Hughes, Dureen J.; Melville, Norbert T. (1990). Changes in brainwave activity during trance channeling: A pilot study. Journal of Transpersonal Psychology, 22, 175-189.

Authors studied 10 people known trance channels–all had been channeling for more than one year. Used an anthropological field method. Electrode was placed only on left occipital (O1) area, referenced to left ear. Calculated difference between each S’s pre- trance and trance EEG beta percentages, for alpha and theta percentages also.
Basically, the pre-trance versus trance sums of differences scores were greater than the post-trance versus trance sums of different scores for each of the three frequency bands–indicating a residual of the trance state. There were large, statistically significant increases in amount and percentage of beta, alpha and theta brainwave activity, and some suggestion of a pattern. The large amount of beta differentiates these Ss from what has been observed with meditators (increases in alpha and theta). Among the Subjects, large amounts of beta activity were recorded continuously throughout the trance period and were coupled with large amounts of high amplitude alpha and theta (relative to the pre- and post-trance states).
The authors compare these results to older hypnosis literature. They conclude that the trance channeling state may be a distinctive state characterized by a particular EEG profile that differs from that found in certain meditative states, hypnotic states, various pathological states, or the waking states of the trance channel Subjects who participated in the study. Authors also liken the differences seen between trance and non-trance states of these Subjects to the differences seen for different alter personalities among people diagnosed with Multiple Personality Disorder.
DISCUSSION. The foregoing research suggests that the trance channeling state, as measured in the current study, is characterized by large, statistically significant increases in amount and percentage of beta, alpha and theta brainwave activity. There appear to be definite neurophysiological correlates to the trance channeling state, and furthermore there is some evidence that these correlates may be patterned. This pattern might be provisionally compared to those associated with other altered states of consciousness.

Alexieva, A.; Nicolov, N.A. (1989). Brain mechanisms in classical conditioning. Behavioral and Brain Sciences, 12, 137.

This is a Commentary on article by J. S. Turkkan (1989), Classical Conditioning: The new hegemony. In Behavioral and Brain Sciences.
Commentators note that the objective of the target article is to show how current thinking about Pavlovian conditioning differs substantially from the historical view; also that this has been recently emphasized by Rescorla (1988). Commentators note that the neural pathways and neural mechanisms involved in Pavlovian conditioning are of great interest and are investigated by many neuroscientists all over the world (Grigoryan & Tchilingaryan 1988; Kositsyn N.S. & Dorochov 1986; Onifer & Durkovic 1988; Storzhuk 1986: Vartanyan & Pirrgov 1986). Commentators also note the work of Ramachandran & Pearce (1987) and Uryvaev Yu.V. et al. (1988).
They express the opinion that Turkkan’s review affords a thorough description and interpretation not only of basic data and new conceptual views, but also of certain key notions in the modern theories of Pavlovian associative learning.

Bick, C. H. (1989). An EEG-mapping study of ‘laughing’: Coherence and brain dominances. International Journal of Neuroscience, 47, 31-40.

Laughter is triggered by pleasurable psychoemotional stimuli and may have healing potential. According to split-brain studies, psychoemotional stimuli are bound up with emotional activity in the right side of the brain. This suggested the idea of studying laughter generated by different sources with regard to electrical brain activity in the right and left hemispheres. This study first used subjects in normal consciousness and with laughter under hypnosis to study the neurophysiological processes connected with laughter.

De Pascalis, Vilfredo; Marucci, Francesco S.; Penna, Pietronilla M. (1989). 40-Hz EEG asymmetry during recall of emotional events in waking and hypnosis: Differences between low and high hypnotizables. International Journal of Psychophysiology, 7, 85-96.

Sixteen high and thirteen low hypnotizability women, who had participated in our previous study (De Pascalis et al., 1987), were enrolled in a hypnotic session. After the hypnotic induction they were requested to recollect 2 positive and 2 negative personal life experiences. IN our previous study subjects performed similar tasks in a waking-state. Hypnotizability was evaluated the first time with the HGSHS and, a second time, individually, with the Stanford C. The State Trait Anxiety Inventory, Maudsley Personality Inventory, and Tellegen Absorption Scale were administered. Upper-trapezius electromyogram (EMG) and bilateral electroencephalogram (EEG) activities within the 35-45 Hz band were recorded. Self-report rating scores for vividness of visual imagery and emotional feeling of the material recalled were evaluated. The 40-Hz EEG amplitude and the left and right hemisphere 40-Hz EEG densities were obtained.
The data collected in hypnosis were compared with those in the waking-state. High hypnotizables, while they were in hypnosis, showed an increase of 40-Hz EEG density during emotional recall compared with rest periods. In contrast, low hypnotizables, after hypnotic induction, showed no density during emotional recall compared with rest periods. In contrast, low hypnotizables, after hypnotic induction, showed no density change during tasks compared to the rest conditions. Different hemispheric trends were found between groups. Highs showed an increase of 40-Hz EEG density over both hemispheres during positive emotions and a density increase in the right and a density reduction in the left during negative ones. This hemispheric trend was found in waking and hypnotic conditions although in the hypnotic condition more pronounced hemispheric patterns were observed. The Tellegen Absorption Scale was found positively related to hypnotizability and with the level of 40-Hz density increase on the right hemisphere during emotional tasks. High hypnotizables, with respect to the lows, were able to access affects more readily. They also showed a greater hemispheric specificity in waking and hypnotic conditions.
Hall, H.; Minnes, L. (1989). Psychological modulation of auditory responses. International Journal of Psychosomatics, 36 (1-4), 59-63.

Psychological modulation of auditory response, the effects of imagery and suggestion on auditory thresholds were examined in naive subjects. After a hypnosis-like induction, the subjects, who were not aware of the purpose of the study, were asked to generate and maintain a specific set of images before, during, and after which their auditory thresholds were tested. Following the imagery, which represented cooling and vasoconstriction in the cochlea, audiograms revealed a temporary auditory threshold shift (TTS) in the experimental group only. This TTS pattern was similar to that produced by exposure to loud noise. Information carried in the image is suggested as the basis for the observed auditory changes. Although a hypnosis-like induction was employed, the subjects’ level of hypnotizability did not appear to be related to the findings.

Holroyd, Jean; Hill, Alexis (1989). Pushing the limits of recovery: Hypnotherapy with a stroke patient. International Journal of Clinical and Experimental Hypnosis, 37, 189-191.

Hypnotherapy was used to assist recovery of left arm function following stroke in a 66-year-old woman. Treatment protocol is described, and results are discussed in terms of how hypnosis may facilitate voluntary motor movement. Recent literature on cortical changes in hypnosis and motor improvement during hypnosis is discussed in relation to the present results.

The patient was 6 months post-stroke and physicians did not expect much additional improvement. She improved despite the fact that she measured as a low hypnotizable on the Stanford Scale, Form C. However, she appeared very absorbed in the hypnotic imagery, and she was highly motivated and exhibited much hope or positive expectation. Also, the author notes that “remarkable improvements in brain functioning have been reported through the use of sophisticated behavioral technology,” (p. 124), as in the use of EEG biofeedback to treat untractable seizures (Sterman & Lanz, 1981).
In rehabilitation cases, hypnotic dissociation may enhance pain control during the performance of exercises; more vivid hypnotic imagery may facilitate mental rehearsal of movements; attitudes may be reframed using hypnotic suggestion; and focusing attention on bodily sensations may be enhanced with hypnosis. Hypnosis also may improve expectancy, reduce anxiety, increase hope, provide general relaxation (reducing involuntary spasticity), increase cerebral blood flow, or in other ways promote healing.
Research by Pajntar, Roskar, & Vodovnik (1985) has demonstrated improved motor response during hypnosis for patients with hemiparesis. They attributed EMG changes under hypnosis “to a facilitory influx from supraspinal motor centers. They hypothesized that new motor units of paretic muscles were being activated or that there was an increased recruitment of the motor units already active, and they suggested that relaxation of the spastic antagonist muscle permits the paralyzed muscle to move” (p. 125).

Borgens, Richard B. (1988). Stimulation of neuronal regeneration and development by steady electrical fields. In Waxman, S. G. (Ed.), Functional recovery in neurological disease (47, pp. 547-564). New York: Raven Press.

At the end of the review, author notes that a combination of electromyography and computer modeling of agonist-antagonist, flexor-extensor muscle contraction patterns in the functional body parts of hemiparetic patients, artificially imposed on the paralyzed portions of the body using repetitive electrical stimulation to effect more normal movement, sometimes leads to functional recovery. Such recovery has been observed in some chronic cases of paralysis associated with head injury, stroke, and cerebral palsy. These clinical observations challenge the way we should view paralysis in general. Perhaps there are many redundant pathways in the CNS that will support certain kinds of functional return in the absence of the original pathways destroyed by trauma. Perhaps CNS-associated paralysis is a problem, at least in part, of too much competing signal in spared pathways, not one of impoverished signal. Can use of these neuronal pathways be entrained or retrained? Is the return of function in patients who experience repetitive functional electrical stimulation due to a reorganization within the CNS? These are exciting questions whose answers will possibly lead to our ability to further modify the plasticity of the brain and spinal cord.
[This would fit with the inhibition model of hypnosis, and with the high theta power findings during hypnosis, the implication being that hypnosis facilitates filtering out non-essential competing stimuli.]
De Pascalis, Vilfredo; Silveri, Alessandra; Palumbo, Giovanni (1988). EEG asymmetry during covert mental activity and its relationship with hypnotizability. International Journal of Clinical and Experimental Hypnosis, 36, 38-52.

Parietal-occipital EEG was recorded bilaterally while 20 high and 20 low hypnotizable Ss performed, in the eyes-closed condition, 2 covert right-hemisphere tasks (visual long-term memory and fantasy) and 2 covert left-hemisphere tasks (multiplication and verbal long-term memory). Ss were not, however, hypnotized during any aspect of the psychophysiological testing. After each task, Ss rated orally their degree of involvement in the tasks. The integrated amplitude alpha, the alpha density, and the alpha ratio as a measure of hemispheric asymmetry, were evaluated. Finally, the proportion of relatively greater right activation periods during right-hemisphere tasks minus the analogous proportion during left-hemisphere tasks was used as index of hemispheric specificity. The high hypnotizable Ss showed significantly higher alpha amplitude than the low hypnotizables; the alpha amplitude was correlated with hypnotizability, while the alpha density was not. The alpha amplitude of the right hemisphere during right- hemisphere tasks was significantly lower than the same amplitude during left-hemisphere tasks, while no significant differences related to task-type were detected in the left hemisphere. The pattern of task-effect on alpha ratio scores was the same as that on alpha amplitudes. Verbal and multiplication ratings were related to the alpha ratio, imaginative- visual memory ratings were not. No differences in hemispheric specificity between high and low hypnotizable Ss were found to exist, and no relationship between hypnotizability and hemispheric specificity was observed.

The authors review the literature on differences between the two hemispheres’ involvement during hemisphere-specialized tasks. The ratio between left- and right- hemisphere alpha amplitudes has been shown to be a reliable measure of hemisphere lateralization as a function of task demands (Amochaev & Salamy, 1979).
They also review the literature on EEG asymmetry and hypnotizability. Most investigations used tasks with a problem solving component, whereas this study used “a covert numeric task and other covert self-generated tasks in which the range of cognitive activities resembled natural thinking” (p. 40).
Purposes of this research were “to investigate whether (a) the amount of alpha in EEG is correlated with hypnotizability, (b) high hypnotizable Ss would reveal higher hemispheric specificities during covert mental tasks than low hypnotizable Ss, and (c) verbal-numeric tasks involve more left-hemisphere activation and imaginative-visual tasks more right-hemisphere activation” (p. 40).
The subjects were 40 women (from an original pool of 71), aged 19-23, with no previous experience using hypnosis. To minimize the possible effects of expectation, hypnosis was not mentioned in the invitation to participate in research. All subjects were tested first with the Harvard Group Scale of Hypnotic Susceptibility, then with the Stanford Scale of Hypnotic Susceptibility (SHSS:C). The SHSS:C was used to select 20 high hypnotizables (defined as having a score 1 standard deviation above the group mean of 6.51) and 20 low hypnotizables (with scores 1 standard deviation below the group mean). The mean score for highs was 10.05 (S.D. = .88) and mean score for lows was 2.75 (S.D. = 1.49).
Although subjects were selected on the basis of their measured hypnotizability, hypnosis was not used during the investigation’s psychophysiological testing. However, they were required to relax and keep eyes closed during trials on the tasks. After each trial, the subjects rated their involvement in the task.
Tasks used for this research were: 1. Visual long-term memory. Ss were asked to recall from memory pictures, places, faces, or visual scenes that were in a movie, but not scenes with a negative content. 2. Fantasy. Ss were requested to fantasize about something new that they like (nothing from past experience, and nothing sexual). 3. Multiplication. Ss were asked to multiply 2 serially, as, 2 x 2 = 4, x 2 – 8, etc., and to do it verbally without visual representation. 4. Verbal long-term memory. Ss were requested to think of some poem, speech, or other verbal material that they could recall from memory, and to repeat it mentally, to themselves.
Results can be summarized as follows.
Hypnotizability correlated .38 and .35 with right alpha amplitude and left alpha amplitude during baseline (statistically significant).
There was a significant association between alpha density and hypnotizability, when the group was divided at the median on density. (Alpha density = the time periods in which the alpha was present over the 6-second epochs accumulated during each 1-minute period which preceded the tasks). This association may be seen in the Table that follows:
SHSS:C Alpha Density Low High
+ 6 13
– 14 7
Chi Square = 3.61, p <.05 There was a significant interaction between type of task (verbal-numeric, imaginative-visual memory) and hemisphere, which was attributable to changes in alpha amplitudes in right hemisphere, according to tasks. "Alpha amplitude of the right hemisphere during right-hemisphere tasks was significantly lower than during left- hemisphere tasks, while no significant differences were detected in the left hemisphere as a result of the differences between left- and right-hemisphere tasks" (p. 44) Alpha ratio = (Right-hemisphere alpha - Left-hemisphere alpha) / (Right- hemisphere alpha + Left-hemisphere alpha) exhibited the same pattern as for alpha amplitudes. The ANOVA 2 (high/low) x 2 (right tasks/left tasks) repeated measures on alpha ratio revealed a significant main effect for tasks, and a significant interaction between right-left tasks and hypnotizability. "During right-hemisphere tasks there were no significant differences (p <.5) [sic] in alpha ratio between high and low hypnotizable groups, while during the multiplication task, the low hypnotizable Ss evidenced a higher mean alpha ratio (p <.05) than the high hypnotizable group (.08 & .04, respectively); identical ratios were found during verbal tasks" (p. 45). Task involvement was expected to be positively related with left-hemisphere tasks, but negatively related to right-hemisphere tasks (i.e. greater subjective involvement in the task would be associated with more negative alpha ratios, showing a bias towards right- hemisphere activation. "Verbal ratings were substantially related to alpha ratios (rho = 0.82; p <.01), and multiplication ratings moderately related to alpha ratios (rho = 0.31; p <.05); visual memory and fantasy ratings were not related to alpha ratios (r = -.04 & r = - .18, respectively)" (p. 45). Hemispheric specificity was defined as the proportion of greater relative right- hemisphere activation periods during right-hemisphere tasks minus the analogous proportion during left-hemisphere tasks. The authors did an analysis to "verify whether the task rating moderates the hemispheric specificity (i.e., the level of subjective involvement in a task is related to the level of hemispheric lateralization, while S is carrying it out)" (p. 46). They concluded that hypnotizability (SHSS:C) is not significantly related to Ss' hemispheric specificity. In the discussion, the authors present a Table summarizing the results of similar investigations. They mention that the alpha-hypnotizability relationship may depend on which alpha variable is taken into account, or whether eyes-open/closed is varied. They conclude that the different methodological procedures render any comparison of results across studies very difficult. They note that there was a significant correlation between alpha amplitude and hypnotizability even though Ss did not know in advance that hypnosis would be part of the experiment (the hypothesis proposed by Dumas, 1977, to account for this type of correlation). "One possible explanation of these data might lie in a different level of arousal in the high and low hypnotizable Ss: the high hypnotizable Ss might have been simply more relaxed than the lows. "Nevertheless, his explanation must be taken with caution. The study of Paskewitz and M. T. Orne (1973), in fact, pointed out that in dark-adapted Ss, the relaxation condition does not produce increases of alpha activity. In a further study, contrary to previous reports, M. T. Orne and Paskewitz (1974) also found that a reduction in alpha activity is not a necessary consequence of apprehension or heightened arousal. Thus, it is not yet clear whether a decrease in anxiety tends to cause an increase in alpha density and vice versa" (p. 48). DeBenedittis, Giuseppe; Sironi, Vittorio A. (1988). Arousal effects of electrical deep brain stimulation in hypnosis. International Journal of Clinical and Experimental Hypnosis, 36, 96-106. In an earlier study, DeBenedittis and Sironi (1986) demonstrated that during depth EEG studies, electrophysiological correlates of hypnotic behavior emphasize the role of the limbic system in mediating the trance experience. In the case of a young man who was affected by medically resistant temporal lobe epilepsy and who was a potential candidate for surgical treatment, diagnostic depth EEG in hypnotic and non- hypnotic conditions offered a unique opportunity to stimulate limbic structures. This permitted an evaluation of the subjective and behavioral responses, as well as of the electrophysiological correlates. During hypnosis, repeated stimulations of the left and the right amygdala produced arousal from the hypnotic state each time, whereas the stimulation of other cerebral structures (e.g., temporal neocortex, Ammon's horn) or pseudostimulations were ineffective on the hypnotic state. These data represent the first experimental, controlled evidence of the amygdala's effects on the arousal from the hypnotic state in man, thus suggesting that hypnotic behavior is mediated, at least in part, by a dynamic balance of antagonizing effects of discrete limbic structures--the amygdala and the hippocampus. NOTES: The patient was a 30-year-old man who had suffered from medically resistant psychomotor temporal lobe epilepsy since age 7; a diagnostic EEG showed right temporal seizure focus, concomitant with independent, contralateral, temporal spiking abnormalities. Hypnotizability was measured at 6 on the SHSS:C; the patient was given two training sessions in hypnosis, with suggestions for "dissociation, rehearsal and reframing of spontaneous seizure events, desensitization of their negative emotional impact, and amnesia" (p. 99). Electrodes were implanted in deep cerebral structures (amygdala, Ammon's horn) and corresponding superficial areas of temporal cortex, with confirmation of placement by X-ray. Two weeks later the patient's brain was stimulated on two consecutive days, first in the waking state (Session 1) and then in hypnosis (Session 2). (Antiepileptic medication was discontinued three days before the stimulation sessions.) False (placebo) stimulations were randomly provided along with the true stimulations. The false (placebo) stimulations did not result in subjective or behavioral changes in either the waking or the hypnosis condition. In the waking condition, a psychomotor seizure was produced by stimulation of Right amygdala and Left Ammon's horn; stimulation of Left amygdala evoked only the aura patient usually had before a seizure, or a brief lapse of consciousness. Stimulating the temporal neocortex did not evoke seizure activity. In the hypnosis condition, arousal from hypnosis into the waking condition occurred with stimulation of amygdala (either Right or Left). Stimulation of the temporal neocortex or of the Right Ammon's horn did not arouse the patient. Stimulation of Left Ammon's horn led to abortive seizures, such that it could not be determined whether the hypnotic state had been interrupted. Stimulating the Right amygdala "triggered a psychomotor attack similar to that recorded during the waking stimulation, but with reduced emotional involvement" (p. 100). For the Left Ammon's horn, "waking stimulation always induced clinical seizures with prolonged after-discharge, whereas hypnotic stimulation evoked only abortive seizures, without after-discharge" (p. 100). In their Discussion, the authors note that animal experimental literature suggests that stimulation of the cortico-medial amygdala facilitates arousal functions, of the baso- lateral amygdala diminishes arousal and produces sleep, and lesions of the amygdala lead to 'amygdala hangover' (Weiskrantz, 1956). "The animal with amygdala destruction appears tame and placid, with reduced social reactivity, insensitive to environmental changes and reluctant to initiate new behavior, unless highly motivated (Isaacson, 1976)" (p. 101-102). In contrast, the animal research on hippocampus suggests it is involved in inhibitory functions (Isaacson, 1976), and may be the 'internal inhibitor' theorized by Pavlov (1955) to be responsible for animal hypnosis. With lesions, animals are more willing to undertake new behaviors, less inactive, less distractible during goal-oriented behavior (Isaacson, 1976). "Moreover, normal hippocampograms show typical, slow (theta) synchronous activity opposed to the arousal desynchronized activity of the electroencephalogram. During hypnosis, desynchronization of the normal, slow activity of the hippocampal Ammon's horn has been registered as compared with the waking hippocampogram, opposite to the slow synchronous activity of the amygdala" (p. 102). The authors note that their results are at variance with the finding by Crasilneck et al. (1956) that their patient, during brain surgery for an epileptogenic focus, aroused from hypnosis each time they stimulated the hippocampus. They explain the discrepancy as due to the fact that the hippocampus was not simply stimulated, but in fact there was 'coagulation' of a hippocampal vessel each time. Quoting from Crasilneck et al. "'The patient did not complain of pain during this [brain] excision [in hypnosis] except on one noteworthy occasion, when a blood vessel of the hippocampal region was being coagulated. The patient suddenly awoke from the hypnotic trance ... She was immediately rehypnotized. ... The surgeon then purposefully 'restimulated' the same region of the hippocampus. Once again, the patient abruptly awakened from trance... [p. 1607].'To the present authors, the description appears misleading and responsible for subsequent misinterpretation of the observation. Because on the first occasion the hypnotic arousal effect followed 'coagulation' of the hippocampal region, it may be assumed that 'restimulation' is a misnomer for repeated coagulation. From this it may be inferred that the arousal effect observed by Crasilneck et al. (1956) could probably be ascribed to a hippocampal microlesion rather than to hippocampal stimulation. This could explain the apparent discrepancy" (p. 104). Gabel, Stewart (1988). The right hemisphere in imagery, hypnosis, rapid eye movement sleep, and dreaming: Empirical studies and tentative conclusions. Journal of Nervous and Mental Disease, 176, 323-331. Reviews studies that have addressed the issue of whether there is an increased activation or efficiency of right-hemispheric processes during imagery, hypnosis, REM sleep, and dreaming. Evidence strongly supports the notion of increased right- hemispheric activation in simple imaginal or visual states during usual consciousness. There are also studies supporting this view of REM sleep, dreaming, and hypnotic phenomena. It is concluded, however, that the lack of adequate studies, contradictory or negative findings, and moderating variables (e.g., task difficulty, cognitive style) make it difficult to draw definitive conclusions concerning right-hemispheric processes. Hawkins, Russell; Le Page, Keith (1988). Hypnotic analgesia and reflex inhibition. Australian Journal of Clinical and Experimental Hypnosis, 16, 133-139. The major change in thinking about models of analgesia over the last decade or so may be seen as a shift away from the earlier emphasis on a one-way afferent transmission sequence. Analgesia was effected, according to the older models, by a simple blocking of afferent impulses at some level (as achieved by local anaesthesia). Recent models suggest that there are at least two CNS analgesia control systems, each operating via an active mechanism for the inhibition of nociception which includes reciprocal _efferent_ impulses able to respond to input from lower centres by sending control signals which modify their output. One CNS analgesia system has now been quite well described. This "opiate" analgesia system has proved to be naloxone reversible and seems to be mediated by reciprocal pathways between brain stem structures and the dorsal horn and trigeminal caudalis. This is not likely to be the system responsible for all cases of hypnotic analgesia, since the common experience of continued awareness of some elements of a normally painful stimulus, in spite of a freedom from pain, implicates a higher level involvement such as input from the prefrontal cortex. NOTES: The authors present a surgery case (of a cystoscopy and urethrotomy performed under hypnotic analgesia, with a highly hypnotizable patient) as an illustration of their position. The patient grimaced when the urethrotome was inserted into the urethra and dilated, but she denied discomfort and did not exhibit a reflex adduction of the thighs that is often observed even under standard general anaesthesia. She had spontaneous amnesia for the entire surgery. Later, under hypnosis, the patient could remember "discomfort and a sharp pain" which lasted for "seconds, if that" (p. 134). The authors refer to Melzack and Wall's (1965) gate control theory as well as Hilgard's (1973) neodissociation interpretation of pain reduction in hypnosis. They review research by Hardy and Leichnetz (1981) with monkeys, in which they "traced the projections of the periaqueductal gray (PAG) to determine the extent of any possible cortical involvement in the endogenous analgesic system. Their work showed that the prefrontal cortex was the principal source of projections to the PAG" (p. 136). They quote the latter as writing that, "Patients who have had prefrontal lobotomies for relief of chronic pain report that while they still feel the pain they are no longer bothered by it ... the prefrontal cortex by virtue of its projections to the PAG may play a role in modulating nociception at the spinal level" (Hardy & Leichnetz, 1981, p. 99). "Hardy and Leichnetz have also suggested that there may be more than one analgesic system within the CNS. The first system is a naloxone-reversible mechanism which can be activated by opiates (presumably both endogenous and exogenous) and by acupuncture. Since hypnotic analgesia has shown itself not to be naloxone-reversible (Goldstein & Hilgard, 1975) it may have little to do with the opiate reception analgesia system. Instead the mechanism of hypnotic analgesia may lie in Hardy and Leichnetz's second system which is sensitive to affective and cognitive influences" (pp. 136-137). The authors include a review of the work by Mayer and Price (1976) which established the importance of brain stem structures in analgesia, especially for eliciting stimulation-produced analgesia. They cite Mayer and Price as drawing a distinction between "analgesia achieved by incapacitating a component in a pain transmission system or by activating a pain inhibition system" (p. 137). They also report that Mayer and Price conclude that stimulation-produced analgesia does not result from a "functional lesion" in the brain stem, but results from stimulation of a pain-inhibiting mechanism, suggesting the dorsal horn and trigeminal nucleus caudalis may be involved. This would be consistent with the inhibition of spinal reflexes (the adductor reflex) observed in their urethrotomy case, and the spinal reflex to nociception has also been reported by Finer (1974). "The concomitant inhibition of reflexes in humans during hypnotic analgesia can be interpreted as evidence that nociception is probably not ascending to the cerebral cortex and that therefore the source of analgesia can be localized to the brain stem areas. It may be the case, however, that the locus of effect of hypnotic analgesia is not uniform across cases and may be identified by the overall pattern of subjective reports and physiological responses. Hypnotic analgesia may be experienced in more than one way subjectively and these differences may be attributable to differing underlying physiological mechanisms. On some occasions the relevant body part may be experienced as totally anaesthetised and all sensation (not only painful sensation) may be lost. This experience matches well with a brain stem involvement, which presumably inhibits any further afferent action. On other occasions, however, and more commonly, patients are still aware of a variety of sensations, which might include pressure in the case of childbirth or even cutting in the case of surgery, but these sensations are not described as painful. This is reminiscent of the effect of frontal lobotomy and it is tempting to focus on the frontal lobe as the locus of hypnotic analgesia effects in such instances" (p. 138). Hobson, J. Allan (1988). The dreaming brain. New York: Basic Books. NOTES: _Hypnosis and Sleep_ Ramon y Cajal and Freud shared an interest in hypnosis, as an experimental method of inducing an altered state of consciousness, introducing dynamic principles into both neurology and psychiatry (rather than simply static descriptions). The author contrasts the hypnosis "artificially altered state of consciousness" with sleep as a "naturally altered state of consciousness, asking whether similar rules govern the transition of state change in both cases. He notes that induction of both states involve rhythmic stimulation and eye fixation, and both may facilitate gaining control over brain-stem centers implicated in conscious-state regulation. "The brain stem is the nightly battleground of warring neuronal factions, and REM sleep and dreaming are the result of temporary domination of one neuronal population over another. Victorious is a troop of reticular-formation neurons concentrated mainly in the pontine portion of the brain stem; owing to their fusillades of firing in association with REM-sleep events, these pontine reticular neurons are likely to play the executive role in the generation of REM sleep and dreaming. Sharing the white flag of temporary surrender is a population of aminergic neurons located in the locus ceruleus, the raphe nuclei, and the peribrachial regions of the anterior pontine brain stem; hardly a shot is fired by this neuronal phalanx during REM sleep. By virtue of this cease-fire, these aminergic neurons are likely to play a permissive role in the generation of REM sleep" (p. 183). The Reciprocal-Interaction Model suggests that "the continuous competition between the excitatory reticular neurons and the inhibitory aminergic neurons is the basic physiological process underlying sleep-cycle alternation" (p. 184). Neurotransmitters (aminergic for inhibition, cholinergic for excitation) are implicated as well. The width of the brain stem correlates with sleep-cycle. The brain seems to "undergo a periodic shift in neurotransmitter ration, from a predominantly aminergic mode in waking to a predominantly cholinergic mode during REM sleep" (p. 192). Thus, there is a major shift in metabolic orientation as we change from waking externally generated information and action to REM-sleep internally generated information and suppressed action. The author proposes an activation-synthesis hypothesis to account for dreaming and envisions the brain as a "Dream Machine." "The recognition that the brain is switched on periodically during sleep answers the question of where dreaming comes from: it is simply the awareness that is normal to an auto-activated brain-mind. This causal inference is continued in the term _activation_ in the new dream theory's title. The question of why dreams are paradoxically both coherent and strange is in turn suggested by the term _synthesis_ , which denotes the best possible fit of intrinsically inchoate data produced by the auto-activated brain-mind. "The original dream theory thus had two parts: activation, provided by the brain stem; and synthesis, provided by the forebrain, especially the cortex and those subcortical regions concerned with memory. The physiology that is now in hand best supports the first part of the theory; much more work needs to be done on the synthetic aspects of the process. But I now add a third major component to the theory, the concept of _node switching_ , which accounts for the _differences_ in the way the activated fore-brain synthesizes information in dreaming (compared with waking): for the twin paradoxes of dream bizarreness and insight failure (where the system has lost self-reference as well as its orientation to the outside world) and for dream forgetting" (p. 204). The author assumes a formal isomorphism between subjective (dream report) and objective (brain activity) levels of investigation. Thus, the report of experiencing visual images in dreams implicates the brain's visual system. In terms of psychophysiology, Hobson proposes that "the on-off switch for dream mentation is the reciprocal-interacting neuronal populations comprising the aminergic neurons and the reticular neurons of the brain stem" (p. 205). For sleep (and dreaming) to be maintained, stimulation from the outside world must be minimized. This is accomplished in at least two ways. There is active inhibition of nerves at the pre-synaptic level (e.g. by depolarization by signals coming from the brain stem; Pompeiano, 1978) so that the nerves are less efficient in transmitting information from the environment, as there is less neurotransmitter available. Secondly, there is competition among higher levels of sensory and associative circuits, so that they ignore incoming signals (or incorporate them into internally generated dreaming activity). Hobson refers to these mechanisms as the sensory input blockade. Hobson also describes the motor output blockade, which prevents us from taking actions based on dream content. There seems to be inhibition of motor-command neurons in the brainstem and spinal cord. When dreams arise, there seems to be brain activation as evidenced by PGO (Pons, lateral Geniculate, Occipital cortex) waves originating in the brain stem. They are found in association with REM sleep and go via independent pathways to both visual and association cortex. "According to the activation-synthesis hypothesis of dreaming, the now auto-activated, disconnected, and auto-stimulated brain-mind processes these signals and interprets them in terms of information stored in memory" (p. 207). Hobson states that the activation-synthesis hypothesis can account for five aspects of dreaming: visual and motor hallucinations, the acceptance of these hallucinations as 'real', bizarre spatial and temporal distortion, strong emotions, and amnesia for the events after waking up. The experiences of dreams are accepted as real because there is no concomitant external input. Jones, Lynette A. (1988). Motor illusions: What do they reveal about proprioception. Psychological Bulletin, 103 (1), 72-86. Five illusions involving distortions in the perception of limb position, movement, and weight are described in the context of their contribution to understanding the sensory processes involved in proprioception. In particular, these illusions demonstrate that the position sense representation of the body and the awareness of limb movement results from the cross-calibration of visual and proprioceptive signals. Studies of the vibration illusion and phantom-limb phenomenon indicate that the perception of limb movement and position are encoded independently and can be dissociated. Postural aftereffects and the illusions of movement induced by vibration highlight the remarkable lability of this sense of limb position, which is a necessary feature for congruence between the spatial senses. Finally, I discuss the role of corollary discharges in the central processing of afferent information with respect to the size-weight and vibration illusions. Kingsbury, Steven J. (1988). Hypnosis in the treatment of posttraumatic stress disorder: An isomorphic intervention. American Journal of Clinical Hypnosis, 31, 81-90.