Cerebral responses in anticipation of painful stimulation and while coping with it were investigated in a ‘fakir’ and 12 male volunteers. Experiment 1 consisted of 3 periods of 40 trials each. During period 1, subjects heard one of two acoustic warning stimuli of 6 sec duration signaling that either an aversive noise or a neutral tone would be presented at S1 offset. During period 2, subjects were asked to use any technique for coping with pain that they had ever found to be successful. During period 3, the neutral S2 was presented simultaneously with a weak electric shock and the aversive noise was presented simultaneously with a strong, painful shock, again under pain coping instructions. EEG activity within the theta band increased in anticipation of aversive events. Theta peak was most prominent in the fakir’s EEG. A negative slow potential shift during the S1-S2 interval was generally more pronounced in anticipation of the aversive events than the neutral ones, even though no overt motor response was required. Negativity tended to increase across the three periods, opposite to the usually observed diminution. In Experiment 2, all subjects self-administered 21 strong shock-noise presentations. The fakir again showed more theta power and more pronounced EEG negativity after stimulus delivery compared with control subjects. Contrary to the controls, self-administration of shocks evoked a larger skin conductance response in the fakir than warned external application.
NOTES
A published case study by Pelletier (1977) reported EEG theta enhancement during pain control states, which were maintained by EEG feedback of alpha and theta bands. That author concluded that EEG theta was necessary for the control of pain psychologically.
The authors of this article measured slow brain potentials (SBPs) and vertical eye movements (VEMs). Principal components analysis of the EEG wave forms found three components: theta (4-5.6 c/sec), alpha band (9-10 c/sec) and high frequencies (above 14.4 c/sec) plus harmonics loading in frequencies of 3.2-4.5 c/sec, 7.5-9, and above 15 c/sec.
Alpha “decreased over periods in the parietal record and was virtually absent in the fakir’s EEG during period 3” (p. 301). The fakir had a lot of non-sinusoidal, especially square wave, activity.
“Very pronounced negativity was recorded preceding the aversive S2, greater than under neutral stimulus conditions …. This difference was most pronounced at the vertex … The late negativity increased over periods in control subjects … especially in anticipation of the aversive S2 … . This contrasts with the usually observed decrease of SBP components over trials. As is shown in Figure 2, the PCA [principal components analysis] yielded two components for the 2.0 sec S2 interval, a positive deflection, which can be assigned to the P300 complex (here not reported), and a negative deflection, labeled post- imperative negative variation. … This negative component increased over periods, being more pronounced in response to the aversive stimulation … with increasing differentiation over period …” (p. 302-303).
The fakir undertook an elaborate self hypnosis or trance induction to achieve analgesia that he had previously demonstrated in the laboratory (thrusting 4 unsterilized metal spikes into his abdomen, tongue, and neck without bleeding). This included “long- continued fixation on a point above the eye-brows. Blank facial expression, staring eyes, and a very low rate of eye-blinks indicated a trance-like state (periods without eye-blinks more than 30 min)” (p. 299). During the experiment itself, the fakir showed few ocular movements during the second and third periods. He also demonstrated large skin conductance responses, recorded from the second phalanges of the index and middle fingers of the left hand, to the aversive S1.
Experiment 2 was designed to emulate the self-administered aversive stimulation that the fakir routinely undertook, by having the volunteer Ss hold a switch that they pressed twice/minute, giving themselves a mild shock and an aversive noise. (These were the same aversive stimuli as were used in Experiment 1.) There were 21 self-paced button presses.
Three additional measures were taken: 1. Bereitschaftspotential (BP) – the mean negative shift during the 0.3 sec interval prior to the motor response of pressing the switch 2. Postimperative component (PINV) – the mean negative shift 0.9 to 1.9 sec after stimulus onset, i.e. elicited by closing the microswitch 3. Skin conductance response (SCR) – maximum change in skin conductance level during five second interval after the motor response of pressing the switch.
The fakir, but not the control Ss, showed a pronounced precentral PINV on each single trial of Experiment 2. He also showed pronounced SCRs (indicating autonomic arousal), which was even greater than the SCRs of control Ss. His subjective pain rating was 1 in Experiment 1 (compared with 6.4 for controls) but 8 during Experiment 2 (compared with 5.7 for controls), on a scale of 1 to 10 maximum. Thus the fakir’s pain increased from Experiment 1 to 2, while for many volunteer Ss it decreased 2 or 3 points. When interviewed, he said that “intention and motor commands prevented the fakir from getting into ‘trance’ satisfactorily. Consequently, he reported to have experienced the aversive stimuli as more painful than in experiment 1. Thus it might be that the observed PINV indicates the noncontingency between the demand for coping and the failure to cope or the discrepancy between expected control and presently experienced control” (p. 307).
In their Discussion, the authors speculate that control of pain such as can be achieved by the fakir may involve dissociation of higher (possibly thalamic and cortical) and lower (reticular formation) arousal structures. Their observation of slow brain potentials (theta) recorded in anticipation of painful or aversive stimuli is in agreement with earlier published studies. However their observation of increasing negativity in anticipation of aversive stimuli is in contrast to previous research findings, in which diminution of negativity is generally observed.
Both the fakir and subjects showed a post-stimulus negative shift in response to the S2; this has been “observed in normal subjects under conditions of change from controllable to uncontrollable aversive stimuli… and/or from obvious response- consequence contingencies to unpredictable control over the S2… PINVs were associated with an unexpected change in contingency or the inability to resolve ambiguity. Since a relationship was found between PINV amplitude and subjective ratings or experienced aversiveness of the painful stimulation, it may be speculated that obvious failure in coping with pain (i.e. more experienced pain) together with the requirement to cope (induced by instructions and experimental setting, giving rise to increased expectancy for control), produced a PINV (and probably feelings of uncontrollability together with a state of reactance and frustration) in the present experiments. In accordance with this point of view, it is of particular interest that only the fakir showed a more pronounced PINV in experiment 2, in which subjects delivered the painful stimuli to themselves. A postexperimental interview revealed that intention and motor commands prevented the fakir from getting into ‘trance’ satisfactorily” (p. 307).
1981
Blum, Gerald S.; Nash, John; Jansen, Robert D.; Barbour, John S. (1981, June). Posthypnotic attenuation of a visual illusion as reflected in perceptual reports and cortical event-related potentials. Academic Psychology Bulletin, 3, 251-271.
Highly selected and trained hypnotic subjects, capable of ablating portions of visual stimuli from conscious awareness, showed varying degrees of ability to attenuate the Titchener-Ebbinghaus circles illusion post-hypnotically under a negative visual hallucination instruction. The presence or absence of such inhibitory skill, inferred from perceptual reports, was differentially reflected in changes in cortical event-related potentials not typically associated with shifts in selective attention. These findings point to the cognitive operation of a distinctive mechanism of selective inattention.
NOTES
Blum et al. postulate an inhibitory mechanism of the central nervous system with stages of amplification and attenuation. They suggest that individual differences in inhibitory skill may be improved with practice even for very skilled Subjects. They studied this type of inhibition using a visual illusion (the Titchener-Ebbinghaus circles) because the neural locus of such illusions is thought to be more central in the nervous system rather than at the level of the retina.
Experiment 1. Three Ss trained in using hypnosis viewed stimuli in waking and posthypnotic negative visual hallucination (NVH) conditions. All three had previously passed a negative hallucination item (not seeing a playing card of three such cards placed on a table). Training included practice sessions applying NVH to the experimental stimuli. S1 reported immediate success; S2 experienced some initial difficulty (“I have a feeling something’s there”) but then reported success; S3 required a couple of long practice sessions.
The classic Titchener-Ebbinghaus illusion stimuli were used. Stimuli were ten slides with drawings of a standard 17-mm-diameter black circle on the left and a comparison black circle on the right. The black circle on the right was either 14, 15, 16, 17, or 18 mm in diameter, skewed intentionally around 17, to compensate for the proportion of smaller and larger judgments applied to the comparison figure in relation to the standard. One black comparison figure was surrounded by seven 15-mm diameter white circles; the other by seven 10 mm diameter white circles. The key drawings were both black circles of 17 mm. The second set of five drawings, used as a control, contained the same black circles but lacked outer rings of white circles.
The Subject was to state whether the black circle on the right appeared larger, smaller, or the same as the standard black circle on the left. Slides were shown for 4 seconds each, with 6 seconds in between slides.
Alternating blocks of trials were given under baseline (B) condition and a posthypnotically programmed negative hallucination condition (NVH). In the NVH condition, “the rings of white circles surrounding the standard and comparison black inner circles were ‘ablated’ from consciousness. The observers were amnesic in the waking state for their prior hypnotic instructions and were cued in advance of a block of trials simply by the phrases ‘This will be a mixed series’ (referring to B, in which the stimuli appeared as they really were, some with outer rings of white circles present and others not), or ‘This will be a black only series’ (referring to NVH, in which all stimuli appeared to the observer as black circles only, whether the outer rings were physically present or not)” (pp. 254- 255). Sessions were spread out over 8-12 months for each observer, interspersed with a variety of other experiments.
In one session the Experimenters used a selective attention instruction, with Ss given posthypnotic suggestions to regulate their cognitive arousal to a peak of mental alertness and concentration (+AA) and focus on the inner black circles but not to negatively hallucinate the outer white circles.
Although all three Ss showed the illusion effect, they varied in ability to attenuate the illusion when negative visual hallucination suggestions were given. “S1 showed a very greatly reduced frequency of reports in the illusory direction under the NVH condition, a less marked reduction under +AA concentration, and no reduction at all under a waking instruction to ignore the outer circles; S2 revealed a moderate but significant reduction under NVH but not under +AA; S3 gave no evidence of attenuation in either condition” (p. 258). The response times for the two more successful Ss (1 and 2) with the 17 mm stimuli under NVH conditions were not different when the outer circles were either present or absent.
Experiment 2. The next year S1 and S2 returned but S3 was no longer available as a Subject; S4 and S5 were added and trained in hypnosis skills. EEG evoked response potentials (ERPs) were recorded while Ss made size judgments as in Experiment 1. Averaged ERPs for each block of 100 stimulus presentations were obtained for the first 500 milliseconds following stimulus onset. Judges blind to the experimental conditions evaluated the ERP records.
All Subjects experienced the Titchener-Ebbinghaus illusion, but again there were individual differences in ability to attenuate the illusion: S1 was the most successful; S2 gave significantly fewer responses in the larger category under NVH than B conditions; and both S1 and S2 improved attenuation performance over the previous year. S4 fell between S1 and S2 in ability; S5 was unable to attenuate the illusion in the NVH condition.
Results. “All three observers whose perceptual reports indicated some attenuation of the visual illusion during the NVH condition also showed a consistent reduction of the P2-N2 amplitude during NVH” (p. 262) at the Occipital sites. Median amplitude reduction was 36%, 40%, and 36% for S1, S2, and S4; only 7% for S5. There were no similar reductions for the other electrode sites, though “enhancement of P2-N2 amplitudes occurred in the lateral prefrontal and frontal areas in the two most successful individuals, S1 and S4” (p. 263). There was also a lag in N2 peak latencies for the three best subjects. The Experimenters noted that the N2 peak occurred 50 msec later in the frontal and prefrontal areas than in the occipital area.
In their Discussion, the authors express the view that it is not likely that faking could have occurred, for several reasons: 1. The Subjects were trained to report honestly, and they often had reported failures to experience hypnotic phenomena suggested during training sessions. 2. The task elicited rapid responses, usually in less than 2 seconds, to 10 different slides in randomized blocks of 100 trials, which would make self monitoring of responses extremely difficult. 3. Subjects exhibited a consistency of responses over experimental sessions that were widely separated in time, making conscious or unconscious deception unlikely. 4. The finding of no difference in latency between 17 mm stimuli with and without outer rings of white circles supports an interpretation of reliable reporting. 5. Differences in ERP data between the B and NVH conditions were obtained only for those Ss who successfully attenuated the illusion.
The authors also state, “In terms of our conceptual model of the mind, inhibitory skill is attributable to the capacity for invoking inhibitory action earlier in the sequence as signals are processed through stages of amplification and attenuation en route to consciousness (Blum & Barbour, 1979). In the NVH condition of the present task, first- stage attenuation … [Subject 1] … occurs in time to negate the illusion as well as preventing conscious awareness of the outer white circles, second-stage attenuation takes place too late to disrupt the illusion but still in time to keep the outer circles from consciousness” (p. 265). Note that the unsuccessful Subject 5 had the highest score on the screening hypnotizability tests. The variation among very high hypnotizables casts doubt on the practice of grouping Ss who score between 9 and 12 on the SHSS. “It is perhaps not surprising that many previous hypnotic studies involving alterations in such subtle phenomena as visual illusions have yielded negative results.” p. 266.
N.B. None of the Ss was able to eliminate the illusion under a strong waking instruction to ignore the outer circles while judging the inner black ones. “These different results for AA and NVH instructions pinpoint the contrast between selective attention (+AA) and selective inattention (NVH)” (p. 266).
The ERP changes seen in occipital and frontal areas were in opposite directions. Thus “the data suggest an effect which seems to parallel both investment of attention (increases in late components over frontal cortex) and withdrawal of attention (relative decreases in late components over occipital cortex). This parallel leads us to speculate that our occipital decreases may have been due to active inhibition of information-processing in the occipital regions, and that the late component enhancement over frontal areas may have been due to the mobilization of resources in these areas necessary to accomplish the tonic inhibition of visual input. … Activity in the frontal cortex apparently ‘programs’ inhibition on the specific sensory nuclei of the thalamus, in a modality specific and topographical way, accomplishing gating of sensory information to primary sensory cortex” (p. 268).
Chen, Andrew C.; Dworkin, Samual F.; Bloomquist, Dale S. (1981). Cortical power spectrum analysis of hypnotic pain control in surgery. International Journal of Neuroscience, 13, 127-136.
Cortical power spectrum (CPS) of brain potentials was recorded from the scalp between prefrontal and parietal regions in both right hemisphere (RH) and left hemisphere (LH). A pattern of laterality shift in CPS occurred at different stages during an extensive oral surgery, performed under hypnosis, in a young female patient. Video and audio recordings as well as psychophysiological recordings were obtained through the following 6 stages: Baseline, Hypnosis, Surgery (1 hr, no cortical recording), Immediate Postsurgery Procedure, Hypnotic Re-experience, Hypnotic Rest, and Posthypnotic Baseline. Indications of anxiety and pain scores were reported in writing by the patient through verbal command by the hypnotist. In each stage, 10 min of CPS (10 spectrum/stage, 8 epochs/spectrum, 6 seconds/epoch) were analyzed by a PDP-11 computer. The results of CPS analysis demonstrated significant large total power reduction at different stages. There was significant correlation between both hemispheres at baseline, but dissociation of hemispheric power output occurred during hypnosis stages. LH was more dominant than RH during baseline and presurgery hypnosis, but both were leveled- off immediately following the surgery procedure. However, RH became more dominant during all postsurgery hypnosis stages. Interestingly, this pattern shifted back to the original relationship during the posthypnotic baseline stage. Specific changes of spectral power in theta and alpha of EEG activities in both hemispheres also occurred in conjunction with hypnosis.
NOTES
Subject was a 25 year old woman, described as only medium in hypnotizability. She scored 3 on the 5-point Stanford Hypnotic Clinical Scale, 7 on the 12-point Stanford Hypnotic Susceptibility Scale, and 3 on up-gaze, between 2 and 3 on eye roll, on the Spiegel eye roll test.
The principal hypnotic approach was a suggestion of dissociation, i.e. that the patient “experience herself swimming freely and powerfully, in a deep cold mountain lake, pre-occupied with the intensity of the blue-black color of the water, the shimmering of light from above, and the possibilities of exploration of rock formations, caves, etc. It was suggested that while she was experiencing the exhilaration and strenuous stimulation of the cold water and the vigorous exercise, an ‘observing-self’ would remain on the shore, watching and ensuring that no harm would come to the person. The suggestion was reinforced that any stimulation experienced was experienced in the body, not in the person” (p. 129).
The patient was trained in inductions and dissociation first in the therapist’s office, then with two sessions in the research laboratory (where tooth pulp stimulation pain thresholds were measured), and then two sessions in the hospital dental operatory.
The results of the computerized CPS were analyzed by hemispheres. “Large reductions in total power occurred at different stages associated with hypnosis and these reductions in power output of the CPS showed significant left-right differences” (p. 130).
“The total energy output of LH [left hemisphere] continued to diminish as hypnosis continued by as much as 80% of baseline value, while RH [right hemisphere] power output tended to be stabilized from the initial hypnosis recording stage until the awake baseline stage” (p. 130).
“Those stages involving hypnosis were characterized by dominant RH energy output in the alpha spectrum. …
“Alpha output for the LH decreased an average of 65% between awake baseline levels and postsurgery hypnosis stages, while RH alpha only decreased approximately 50% of resting levels. This resulted in a relative shift of alpha output which was approximately equal in both hemispheres prior to surgery, to a 2:1 shift in favor of RH alpha output as hypnosis progressed. This differential shift in laterality of alpha was reversed when the subject awakened from hypnosis.
“Of interest was the observation that total power reductions and laterality shifts associated with hypnosis were not altered by the profound instrumentation of surgery and postoperative pain, nor were observed laterality shifts affected by hypnotic suggestions aimed at recreating the surgical experience (see Stage 5)” (p. 130).
During the experiment when the investigators used hypnotic suggestion to recreate the surgical experience, LH output continued to diminish while RH output did not change, making the LH-RH contrast highly significant. “This suggests that the RH is active during deep stages of hypnosis and can remain so despite hypnotic suggestions which are presumed to be intensely aversive” (p. 131).
In their Discussion, the authors reinforced the conclusion that overall cortical functioning is reduced during hypnosis, and that the left cerebral hemisphere shows a greater reduction than the right. They discuss the increased theta density in RH and LH during the postsurgery hypnosis stage in terms of reports that theta is associated with altered states of consciousness (Tebecis et al., 1975; Ulett et al., 1972; Anad, China, & Singh, 1961; Banquet, 1973; Kasamatsu & Hirai, 1966; Wallace, 1970) and with cognitive tasks like mental arithmetic (Dolce et al., 1974).
The authors note that their results are congruent with Hilgard’s neodissociation theory of hypnosis, and add that since their suggestions were dissociative in nature rather than of local anesthesia, the EEG may reflect the brain physiology of dissociation.
Finally, they comment on the implications for pain neurophysiology. “The total power changes and shifting patterns in laterality of cortical functioning observed more closely tracked the hypnosis experience than the pain experience; this is, in fact, a very puzzling issue. It appears on the face of it that the EEG measurements recorded are not reflective of EEG-related pain phenomenology despite the strenuous and invasive surgical procedures used. The observations that overall power output continued to decrease during the several hypnosis stages after strenuous surgery and then increased as the patient came out of hypnosis makes reasonable the possibility that _hypnosis_ has some functional brain correlates; we cannot conclude from the present cortical power spectrum analysis that any brain correlates of surgical _pain_ were revealed. We are well aware that EEG recordings were not available during actual surgery itself, because of artifacts resulting from head movements, etc. Nevertheless, it can be fairly claimed that recordings obtained immediately after such oral surgery of one hour duration, could reasonably be expected to be associated with a person in pain. But, both by verbal report and available objective data, any surgically induced traumatic pain was of brief duration under hypnosis” (p. 135).
Karlin, Robert; Goldstein, Leonide; Cohen, Allen (1981, October). A shift to the right: EEG during hypnotic induction. [Paper] Presented at the annual meeting of the Society for Clinical and Experimental Hypnosis, Portland, OR.
Bilateral electroencephalographic activity was recorded from temporal and occipital sites during a resting baseline and hypnotic induction periods. Results indicated that highly hypnotizable subjects showed a shift to greater right hemisphere activation when the hypnotic induction period was compared to the resting baseline period. This was not the case for the less hypnotizable subjects. This study replicates the recent findings of MacLeod-Morgan (1982).
1980
Barabasz, Arreed F. (1980). EEG alpha, skin conductance and hypnotizability in Antarctica. International Journal of Clinical and Experimental Hypnosis, 63-74.
On the basis of alternative hypotheses in the literature, 9 invited Ss undergoing wintering-over isolation at Scott Base, Antarctica, were tested for EEG alpha and hypnotizability. 8-channels of EEG, bipolar skin conductance (SC) and hypnotizability data were collected at Scott Base prior to and following the wintering-over isolation. Significant increases in alpha density and hypnotizability were found in Ss following isolation. The previously reported relationship between simple eyes closed alpha density and hypnotizability was not found prior to isolation; however, this correlation approached significance following isolation. The possible influence of psychophysiological arousability on baseline EEG alpha records was considered. Correction of EEG records using SC indices of arousal resulted in a significant correlation between EEG alpha and hypnotizability following isolation. A tendency toward significance was evident in the pre-isolation, SC corrected, correlation. The significant influence of environment on EEG alpha and hypnotizability is discussed as is the use of SC arousal indices to enhance EEG alpha/hypnotizability correlations.
Karlin, Robert; Morgan, Donald; Goldstein, Leonide (1980). Hypnotic analgesia: A preliminary investigation of quantitated hemispheric EEG and attentional correlates. Journal of Abnormal Psychology, 39 (4), 591-594.
The effects of hypnotically induced analgesia were studied in six subjects rated as moderately hypnotizable and five subjects rated as highly hypnotizable. Subjective pain reports and electroencephalographic (EEG) activation were recorded during 1-minute periods of cold-pressor stimulation. Both groups of subjects reported decreased pain during hypnosis, but the decrease was greater for the highly hypnotizable group. During hypnotic analgesia, immersion of either the right or the left hand in ice water was correlated with contralateral EEG activation for moderately hypnotizable but not for highly hypnotizable subjects (p <.05). Lack of contralateral shift was correlated for the whole sample (p<.05) and within groups (p = .05) with success on an attentional task related by previous research to hypnotizability as well as with reports of reduced pain (p <.05). NOTES A previous study shows hypnotizability predicts ability to allocate attention selectively (to selectively increase and decrease the salience of stimuli. This study shows hypnotizability also is related to ability to control cortical activation from a pain stimulus, so that pain is not [subjectively] experienced. The test of ability to attend selectively (in waking state) correlated with the [expected contralateral] cortical activation .58. Thus highs have attentional skills not as evident among mediums or lows. Whether these are amplified by hypnosis is another question. Rizzo, Paolo Andrea; Amabile, Giuseppe; Fiumara, Romano; Caporali, Manlio; Pierelli, Francesco; Spadaro, Maria; Zanasi, Marco; Morocutti, Cristoforo (1980). Brain slow potentials and hypnosis. Biological Psychiatry, 499-506. SUMMARY Contingent negative variation behavior was studied in 12 voluntary normal subjects in basal conditions and in the hypnotic trance state under different emotional suggestions. A CNV voltage decrease and the appearance of a PINV were observed in the hypnotic state. Furthermore 12 nonhypnotizable control subjects were tested under the same experimental conditions and no CNV modification was found" (p. 505). 1978 Lehrer, Paul M. (1978). Psychophysiological effects of progressive relaxation in anxiety neurotic patients and of progressive relaxation and alpha feedback in nonpatients. Journal of Consulting and Clinical Psychology, 46 (3), 389-404. Gave 10 anxiety neurotic patients 4 sessions of individual instruction in progressive relaxation; 10 patients served as waiting list controls. 10 nonpatients were assigned to each of the same conditions, and an additional 10 nonpatients were given 4 sessions of alpha feedback. Nonpatients showed more psychophysiological habituation over sessions than patients in response to hearing 5 very loud tones and to a reaction time task. Patients, however, showed greater physiological response to relaxation than did nonpatients. After relaxation, the autonomic responses of the patients resembled those of the nonpatients. The effects of relaxation were more pronounced in measures of physiological reactivity than in measures of physiological activity. Defensive reflexes yielded to orienting reflexes more readily in nonpatients than in patients. There was also a tendency for progressive relaxation to generalize to autonomic functions more than alpha feedback. Parwatikar, Sadashiv D.; Brown, Marjorie S.; Stern, John A.; Ulett, George A.; Sletten, Ivan S. (1978). Acupuncture, hypnosis and experimental pain - I. Study with volunteers. Acupuncture and Electro-Therapeutic Research: International Journal, 3, 161-190. An experiment was designed to evaluate the protective effects of different agents - acupuncture, hypnosis, Morphine, aspirin, Diazepam and placebo - upon experimentally-induced pain in humans. Twenty normal, healthy volunteers were subjected to cold water and tourniquet- induced pain and the protective effects of 35 minutes of hypnotic suggestion, electro- stimulation of both acupuncture points and non-acupuncture points, 10 mg/kg of Morphine, 5 grains of aspirin, 10 mg of Diazepam and a mild sugar placebo were evaluated. Data was collected on subjective evaluation of pain, EKG, EEG, respiration, skin temperature, peripheral vascular activity and EMG. A special study was also done to evaluate the effects of all the above agents on the somatosensory evoked potentials and EEG. The data were further analyzed on the basis of hypnotic susceptibility of the volunteers. The results indicated: 1) Hypnosis, acupuncture at specific sites with electrical stimulation and Morphine Sulphate had about the same reduction in experimental pain. 2) Hypnosis produced different effects from those resulting from acupuncture stimulation on EEG. 3) Acupuncture stimulation in specific loci resulted in a latency increase in the early secondary response on somatosensory evoked potential. 4) Cold water pain was remarkably reduced after true acupuncture point stimulation. 5) Tourniquet (ischemic) pain was reduced by both hypnosis and true acupuncture site stimulation. 6) Skin temperature was significantly reduced on the side of acupuncture points (true) stimulation. 1977 Crosson, B.; Meinz, R.; Laur, E.; Williams, D.; Andreychuk, T. (1977). EEG alpha training, hypnotic susceptibility, and baseline techniques. International Journal of Clinical and Experimental Hypnosis, 25, 348-360. 3 alpha feedback sessions of 40 minutes were administered after a similar baseline period without feedback to 12 Ss high in hypnotic susceptibility and 12 Ss low in hypnotic susceptibility. Hypnotic susceptibility was not a significant dimension in alpha feedback training and previously reported relationship between alpha density and hypnotic susceptibility were not generally found. Evidence did support the efficacy of the current baseline procedure over others more commonly used. The possibility under certain conditions of there being a relationship between hypnotic susceptibility and alpha density and theoretical considerations in recording baseline are discussed. Fisher, R. (1977). On flashback and hypnotic recall. International Journal of Clinical and Experimental Hypnosis, 217-235. This essay deals with both the intra-individual and inter-individual varieties of arousal state-bound experiences. The former are labelled as "flashbacks" while the latter embrace the great fantasms and repetitive schemes, the ever re-written plots and images of literature, art, and religion. Flashbacks are both arousal-state and stage (i.e., set and setting) bound experiences. Flashback and hypnotic recall differ only in the ways by which they are induced. Induction methods should be distinguished from induced states on the hyperaroused perception-hallucination and hypoaroused eprception-meditation continuum. Flashbackers may be characterized by their (a) variability on perceptual-behavioral tasks; (b) tendency to minimize (or reduce) sensory input; (c) high resting heart rates; (d) hypnotizability; and, hence (e) preferential right-cerebral-hemispheric cognition; and (f) a display of EEG-alpha dominance in the resting, waking state. Pelletier, K. R.; Peper, E. (1977). Developing a biofeedback model: Alpha EEG feedback as a means for pain control. International Journal of Clinical and Experimental Hypnosis, 25, 361-371. 3 adept meditators voluntarily inserted steel needles into their bodies while physiological measures (EEG, EMG, GSR, EKG, and respiration) were recorded. Although each adept used a different passive attention technique, none reported pain. During the insertion, 2 of the 3 Ss increased their alpha EEG activity. The role of alpha EEG and its relationship to pain control is discussed. NOTES The three adepts studied were: (1) RCT, a 34 yr old Ecuadorian who had "demonstrated control over pain by placing bicycle spokes through his body, being suspended from hooks inserted under his shoulder blades, and walking through fire -- all without reported pain or observed damage to his skin;" (2) JSL, a 31 yr old Korean karate expert, who "suspended a 25-pound bucket of water from a sharpened spoke placed through a fold of skin on his forearm;" and (3) JS, a 50-yr old Dutch meditator who had "demonstrated pain and bleeding contol" (pp. 363-365). "RCT, JSL, and JS each remarked that pain is principally fear of and attention to pain, and they maintained that anyone can learn to control pain through relaxation and passive attention" (p. 367). Both JS and RCT had increased alpha EEG activity during piercing, whereas JSL showed no increase. The authors suggest that "the karate expert practiced a very focused meditation, during which he mentally saw and felt the ki energy as a point, while RCT and JS employed passive attention and did not attend to the body stimuli. Thus, it is possible for physiological measurements to reflect strategies used in dissociation of pain perception, and that the quality of pain perception is altered if S is at either extreme of focused or unfocused conscious attention" (p. 368). "We hypothesize that, for nonadepts, alpha EEG training without alpha blocking to stimuli could become a distraction technique whereby S again could learn self-control and competence as he becomes more successful in controlling his EEG" (p. 369). 1976 Cooper, Leslie M.; London, Perry (1976). Children's hypnotic susceptibility, personality, and EEG patterns. International Journal of Clinical and Experimental Hypnosis, 24, 140-148. 19 boys and 16 girls, aged 7 to 16, were given the EEG and then the Children's Hypnotic Susceptibility Scale, while a parent watched. About 1 week later, after some separate tests and interviews, each child was given a puzzle to solve in the parent's presence, while Es recorded offers and requests for help. Hypnotic susceptibility was positively correlated with the alpha duration with eyes open, but not with eyes closed. Both susceptibility and alpha duratino tended to be negatively correlated with age. Highly susceptible children tended to wait longer than low susceptibles before asking parents for help with the puzzle, and their parents tended to be more strict, anxious, and impatient than did the parents of low susceptible children. London, Perry (1976). Kidding around with hypnosis. International Journal of Clinical and Experimental Hypnosis, 24 (2), 105-121. This paper reviews a long term research project relating hypnotic susceptibility to performance and personality variables. Several experiments indicated that people who are low in hypnotic susceptibility try harder than high susceptibles for maximum performances on strength, endurance, psychomotor coordination, and cognitive tests, though high susceptibles are generally more pleased with their own performances. Other experiments indicated that people of high hypnotic susceptibility have slower brain- wave patterns under relaxed, nonhypnotic conditions, than do low susceptibles. These findings, together with a third set of findings on the developmental character of hypnotic susceptibility, led to the theory that hypnotic susceptibility and brain-wave patterns are both inversely correlated with achievement motivation and with its developmental roots in childhood independence training. An elaborate research program was initiated to investigate the hypothesized relationships. 1975 Melzack, Ronald; Perry, Campbell (1975). Self-regulation of pain: The use of alpha-feedback and hypnotic training for the control of chronic pain. Experimental Neurology, 46, 452-469. Patients suffering chronic pain of pathological origin received alpha- feedback training methods in association with prior hypnotic training. Changes in the intensity and quality of pain were measured with the McGill Pain Questionnaire. The combined procedures produced a substantial decrease in pain (by 33% or greater) in 58% of the patients during the training sessions. Both the sensory and affective dimensions of the pain were diminished. The EEG records indicated that the majority of patients learned to increase their alpha output during the training sessions. In contrast, patients who received the alpha training alone reported no decreases in pain even though they showed increases in alpha output. Patients who received hypnotic training alone also produced increased EEG alpha during the training sessions and showed substantial (though not statistically significant) decreases in pain. The results demonstrate that chronic, pathological pain can be reduced in a significant number of patients by means of a combination of alpha-feedback training, hypnotic training, and placebo effects. It is concluded, however, that the contribution of the alpha training procedure to pain relief is not due to increased EEG alpha as such but, rather, to the distraction of attention, suggestion, relaxation, and sense of control over pain which are an integral part of the procedure. NOTES The study employed 24 patients with variety of pains, divided into 3 groups randomly: hypnosis alpha/biofeedback combined procedures - the only group which decreased group mean of pain significantly. Hypnosis - 50% of patients showed decrease in pain Combined Treatment - 50% " " " " " " Alpha/biofeedback - None " " " " " " All patients demonstrated higher alpha levels; the authors inferred it was due to relaxation, distraction, a sense of control over pain, or direct suggestion itself. 1975 Saletu, B.; Saletu, M.; Brown, M.; Stern, J.; Sletten, I.; Ulett, G. (1975). Hypno-analgesia and acupuncture analgesia: A neurophysiological reality?. Neuropsychobiology, 1, 218-242. The effects of hypnosis, acupuncture and analgesic drugs on the subjective experience of pain and on objective neurophysiological parameters were investigated. Pain was produced by brief electric stimuli on the wrist. Pain challengers were: hypnosis (induced by two different video tapes), acupuncture (at specific and unspecific loci, with and without electrical stimulation of the needles), morphine and ketamine. Evaluation of clinical parameters included the subjective experience of pain intensity, blood pressure, pulse, temperature, psychosomatic symptoms and side effects. Neurophysiological parameters consisted of the quantitatively analyzed EEG and somatosensory evoked potential (SEP). Pain was significantly reduced by hypnosis, morphine and ketamine, but not during the control session. Of the four acupuncture techniques, only electro- acupuncture at specific loci significantly decreased pain. The EEG changes during hypnosis were dependent on the wording of the suggestion and were characterized by an increase of slow and a decrease of fast waves. Acupuncture induced just the opposite changes, which were most significant when needles were inserted at traditional specific sites and stimulated electrically. The evoked potential findings suggested that ketamine attenuates pain in the thalamo-cortical pathways, while hypnosis, acupuncture and morphine induce analgesia at the later CNS stage of stimulus processing. Finally some clinical-neurophysiological correlations were explored. 1974 London, Perry; Cooper, Leslie M.; Engstrom, D. R. (1974). Increasing hypnotic susceptibility by brain wave feedback. Journal of Abnormal Psychology, 83 (5), 554-560. Presents a reanalysis of earlier studies by D. R. Engstrom et al (1970) as well as additional findings which show that successful training to increase alpha rhythm duration raises people''s hypnotic susceptibility. Ss in the previous studies were 30 volunteers who had low to moderate hypnotic susceptibility and low alpha production. It was found, subsequent to publication, that some Ss had had previous exposure to alpha training. When they were eliminated in reanalysis, the previous findings were still confirmed; alpha training was more effective for experimental than for control Ss, and hypnotic susceptibility accordingly increased more among experimentals than among controls. In addition, base-rate alpha production in each training session was correlated with feedback alpha output among experimental Ss but not among controls. (24 ref) (PsycINFO Database Record (c) 2002 APA, all rights reserved) 1972 Kratochvil, Stanislav; Macdonald, Hugh (1972). Sleep in hypnosis: A pilot EEG study. American Journal of Clinical Hypnosis, 15 (1), 29-37. Six highly susceptible Ss were hypnotized and allowed to sleep in the laboratory during the night. Hypnotic rapport was tested after each of two awakenings, and simple suggestions were also administered in different stages of sleep. After awakening, hypnotic rapport was still present. In sleep, the Ss did not react to suggestions in stages 3 and 4. They sometimes reacted in stage 2, but usually woke up either during listening or during responding to the suggestion. In stage REM the Ss usually responded well to the suggestions; they sometimes woke up and sometimes not. The results are taken as a proof that hypnosis can continue after periods of sleep which occur during hypnosis. The question whether hypnosis and sleep can occur simultaneously or only alternately is discussed. ATTEMPTED TO CONFIRM THE FINDINGS OF A. G. HAMMER AND W. J. ARKINS (SEE 39:1) OF SIGNIFICANTLY GREATER IMPROVEMENT IN HYPNOTIC PERFORMANCE AS A RESULT OF 11-CPS INTERMITTENT PHOTIC STIMULATION THAN WITH FREQUENCIES OUTSIDE THE RANGE OF EEG ALPHA ACTIVITY. USING THE BRAIN WAVE SYNCHRONIZER, 3 GROUPS OF SS WERE GIVEN STIMULATION AT 5, 11, AND 30 CPS. TESTS OF HYPNOTIC PERFORMANCE WERE MADE DURING AND IMMEDIATELY AFTER STIMULATION, AND A WEEK OR MORE LATER. NO EVIDENCE OF FREQUENCY-SPECIFIC EFFECT WAS OBTAINED, AND THE ORIGINAL FINDING WAS NOT CONFIRMED. (SPANISH + GERMAN SUMMARIES) (PsycINFO Database Record (c) 2002 APA, all rights reserved) 1967 Dittborn, J. M.; O'Connell, D. N. (1967). Behavioral sleep, physiological sleep and hypnotizability. International Journal of Clinical and Experimental Hypnosis, 15, 181-188. A SLEEP-INDUCTION PROCEDURE REQUIRING MANUAL RESPONSE TO A REPETITIVE AUDITORY SIGNAL WAS ADMINISTERED TO 52 SS WHO HAD CLEAR ALPHA ACTIVITY IN THEIR WAKING EEG AND WHOSE HYPNOTIZABILITY WAS KNOWN. THE OCCURRENCE OF SLEEP WAS DEFINED BY PHYSIOLOGICAL, BEHAVIORAL, AND SUBJECTIVE CRITERIA. NEITHER THE TENDENCY TO DEVELOP EEG SLEEP NOR THE ABILITY OF SOME SS TO RESPOND WHILE IN EEG SLEEP WAS RELATED TO HYPNOTIZABILITY. HYPNOTIZABILITY WAS RELATED TO A TYPE OF DISSOCIATION BETWEEN EEG SLEEP AND BOTH BEHAVIORAL AND SUBJECTIVE SLEEP SHOWN BY 5 SS, ALL HIGHLY HYPNOTIZABLE. (SPANISH + GERMAN SUMMARIES) (PsycINFO Database Record (c) 2002 APA, all rights reserved) 1964 Domhoff, Bill (1964). Night dreams and hypnotic dreams: Is there evidence that they are different?. International Journal of Clinical and Experimental Hypnosis, 12, 3, 159-168. The evidence against equating night dreams and hypnotic dreams is reviewed in the light of 2 developments in dream research--Dement and Kleitman''s (1957a; 1957b) physiological and behavioral indicators of dreaming and Hall''s (1951; 1963) quantitative studies of dream content. It is concluded that: the equivalence of the EEG patterns of the hypnotic trance and the "dream" stage of sleep (Stage I) cannot be ruled out; the psychologically-important question of content differences between night and hypnotic dreams has never been examined in a controlled, quantitative manner. (48 ref.) (PsycINFO Database Record (c) 2002 APA, all rights reserved) 1960 Diamant, J.; Dufek, M.; Hoskovec, J.; Kristof, M.; Pekarek, V.; Roth, B.; Velek, M. (1960). An electroencephalographic study of the waking state and hypnosis with particular reference to subclinical manifestations of sleep activity. International Journal of Clinical and Experimental Hypnosis, 8, 199-212. (Author''s Conclusions) EEG records have been investigated in 10 patients in a waking state and under hypnosis. It was shown that no differences existed between these two states in terms of EEG. EEG signs of decreased wakefulness can be demonstrated in some of the patients, but these were also present without hypnosis. This latter effect appears to be subclinical sleep activity (Roth), frequently seen particularly in neurosis. Reactibility to external stimuli under hypnosis was also, in most cases, equivalent to reactions in the waking state. The authors incline to the view that EEG data does not support the concept that the nature of hypnosis and sleep is qualitatively the same. Roberts, Donald R. (1960). An electrophysiological theory of hypnosis. International Journal of Clinical and Experimental Hypnosis, 8, 43-55. It is theorized that general hypnosis is brought about by an electrical blockage between the brain stem reticular formation and the specific-sensory, parasensory, and coordinate neuronal channels; the selective activity of brain rhythms of the delta frequency is proposed as a possible mechanism of inhibition. (50 ref.) From Psyc Abstracts 36:02:2II43R. (PsycINFO Database Record (c) 2002 APA, all rights reserved) 1959 Kroger, William S.; Schneider, Sidney A. (1959). An electronic aid for hypnotic induction: A preliminary report. International Journal of Clinical and Experimental Hypnosis, 7, 93-98. NOTES The BWS or brain wave synchronizer is "an instrument specifically designed to induce various levels of hypnosis by subliminal and photic stimulation of the brain waves" (p. 93). It was developed after noticing that radar operators on ships sometimes fell into deep hypnotic states while watching signals on a radar screen. It has been used with 2500 subjects, 200 of whom were receiving pre-natal training for childbirth under hypnosis. "For the first five minutes there is a gradual increase in the number of subjects who enter deep hypnosis. At this level, a figure of 50% reach the deep state" (p. 95). The instructions given were, "Concentrate on the center of the instrument. When your eyes become tired and heavy, as they will, just let them close and feel yourself going deeper and deeper into a relaxed state." It is acknowledged that this procedure worked when Ss expected to experience hypnosis; the rate of deep hypnosis increased as the expectancy of hypnosis increased. "Deep hypnosis in individual inductions reached 80% under the following conditions: A. Synchronizer on 5 minutes B. Expectation Level of 50 [on a scale in which 100 represented having seen demonstrations of conventional hypnosis and an explanation of what the instrument would do]" (p. 97). EFFORT/ENDURANCE 1999 Kirsch, Irving; Burgess, Cheryl A.; Braffman, Wayne (1999). Attentional resources in hypnotic responding. International Journal of Clinical and Experimental Hypnosis, 47 (3), 175-191. Theories of hypnotic responding differ regarding attentional processes. Predictions derived from neodissociation, dissociation control, response set, and ironic process theory were tested by administering suggestions with and without cognitive load to high suggestible participants and low suggestible simulators. Cognitive load interfered with responses to ideomotor and cognitive suggestions but not with responses to challenge suggestions. The effect of cognitive load on suggested amnesia depended on the assessment of that response. Although cognitive load decreased recall on the amnesia trial, it did so even more on recall trials before the amnesia suggestion was given and after it was canceled. These data indicate that attentional effort is required for both recall and memory suppression. Under conditions of low cognitive load, simulators displayed less recall than did nonsimulating participants during suggested amnesia, and they reported smaller subjective responses to ideomotor and challenge suggestions. 1998 King, Brenda J.; Council, James R. (1998). Intentionality during hypnosis: An ironic process analysis. International Journal of Clinical and Experimental Hypnosis, 46 (3), 295-313. Two studies were completed to test whether resonding to hypnotic suggestions requires intentional effort. Hypnotic suggestions for amnesia were used as an analog of thought suppression, and Wegner's model of ironic processing was applied to hypnotic responding. In the first study, participants were required to maintain suggested amnesia while performing a cancellation task with and without a cognitive load. The second study required suppression of thoughts of a favorite car, once with "blank-mind" instructions and then with a suggestion for amnesia. The results of these studies indicate that dissociated control theory provides the best explanation for hypnotic responding in one subset of highly hypnotizable participants, whereas more intentional responding provides the best explanation for others. NOTES "In a well-known study, Wegner (1994) asked participants not to think of a white bear. This led participants to think of white bears, whereas there had been no such thoughts prior to the request. Wegner suggested that such ironic effects stem from two complementary processes involved in the self-control of mental states. The first is an effortful operating process that seeks to maintain the desired state of mind (free of white bears). The second is an automatic and effortless monitoring process that searches for evidence of failure of intentional control (points out any white bear thoughts), so that corrective action can be taken. According to Wegner, a cognitive load will increase ironic effects, because reduced cognitive cpacity may allow the monitoring process to supplant the operating process and make the person more sensitive to mental processes that are opposite of those that are intended" (p. 297). 1992 Mittleman, K. D.; Doubt, T. J.; Gravitz, Melvin A. (1992). Influence of self-induced hypnosis on thermal responses during immersion in 25 degrees C water. Aviation, Space & Environmental Medicine, 63, 689-695. The efficacy of self-induced posthypnotic suggestion to improve thermogenic responses to head-out immersion in 25 degrees C water was evaluated in 12 males. An online computerized system permitted the change in body heat storage to be used as the independent variable and immersion time as the dependent variable. Two one- hour hypnotic training sessions were used. There were no differences in rates of heat production, heat loss, mean skin temperature, or rectal temperature between control and hypnotic immersions. Individual hypnotic susceptibility scores did not correlation with changes in thermal status. Ratings of perceived exertion during exercise were similar for both immersions, but perceived sensation of cold was lower during the second rest period of the hypnotic immersion. Three subjects used images of warm environments during their hypnotic immersion and lost heat at a faster rate than during control immersions. These results indicate that brief hypnotic training did not enhance the thermogenic response to cool water immersion. 1986 Pereira, Robert Peter (1986, July). The role of organismic involvement in hypnotic emotional behavior (Dissertation, Wayne State University). Dissertation Abstracts International, 47 (1), 385-B. (Order No. DA8605027 "Two hundred college undergraduates were pretested via the Harvard Group Scale of Hypnotic Susceptibility: Form A. Fifty subjects scoring in the range 7-12 were designated as Reals, while 25 subjects scoring in the range 0-4 were designated as Simulators. Reals and Simulators were given differential instructions before the administration of a second hypnotic induction procedure, which was accompanied by a task in which subjects were asked to relive each of three emotional experiences, i.e., fear, anger, and happiness. Reals were given instructions encouraging cooperation, while Simulators were instructed to try to convince a group of experienced hypnotists that they were deeply hypnotized, when, in fact, they would not be. "Physiological, overt-behavioral, and cognitive measures taken either during or following the relived-emotions task served as indices of Sarbin's organismic involvement construct. A post-experimental measure of the realness of subjects' relived emotional experience was regressed on these organismic indices in order to test Sarbin's assumption of a positive linear relationship between organismic involvement and belief-in imaginings, using data from the Real group only. Results indicated that, across all three emotions, the linear composite of organismic indices shared statistically significant amounts of variance with the criterion of experiential realness. Obtained amounts of shared variance ranged from 22% (during anger) to 55% (during happiness). These findings were interpreted as offering clear and robust support for Sarbin's theory of hypnosis. Suggestions for further research were offered. "The question of Real-Simulator differences was explored through several multivariate analyses of variance and covariance, using the organismic indices as dependent variables. These analyses were performed on the original sample of Reals and Simulators, and on two subsamples of Reals/Highs and Simulators/Lows which were created through the use of pre- and/or post-experimental exclusion criteria. Reals/Highs showed statistically higher levels of effort than did Simulators/Lows during all three emotions, as well as higher levels of skin conductance and finger temperature during anger. These findings were interpreted as being of theoretical and practical significance. Multiple replications of the physiological findings were recommended in order to assess the extent to which the skin conductance and finger temperature variables might be used in practical, i.e., forensic contexts" (p. 385-B). 1980 Pajntar, Marjan; Jeglic, Anton; Stefancic, Martin; Vodovnik, Lojze (1980). Improvements of motor response by means of hypnosis in patients with peripheral nerve lesions. International Journal of Clinical and Experimental Hypnosis, 28 (1), 16-26. In order to accelerate rehabilitation of patients with peripheral nerve lesions, hypnosis was employed to encourage them voluntarily to move those muscles with weak re-innervation and to achieve the best possible activity of the affected muscle groups. By measuring muscle force and endurance and by observing the electrical activity of the affected muscles, it was found that the activity of the affected muscles was much better while patients were in hypnosis than when they were in the waking state. The patients were able to contract even paretic muscles having only weak re-innervation with such strength, that clinically perceptible contraction of the muscles and movement of paretic extremities occurred. Such early and improved activation is very important for prevention of much permanent damage. 55 male Ss were assigned to 5 groups: control, hypnosis alone, motivation alone, low susceptible hypnosis with motivation, or high susceptible hypnosis with motivation. Ss performed 2 runs on a treadmill to their maximum capacity, as measured by oxygen consumption, blood lactate concentration, and respiratory quotient. Groups involving hypnosis performed in the posthypnotic state. A significant increase in endurance performance was revealed in the motivation alone Ss and in high susceptible hypnosis Ss who were given motivational suggestions. Maximum ventilation was significantly increased in high susceptible hypnosis Ss when compared with control Ss and significant increases in blood lactate concentrations were revealed when the high susceptible hypnosis Ss were compared with low susceptible hypnosis and motivation alone Ss. The reasons for the changes in metabolic variables are discussed. Findings demonstrated that in achieving greater endurance performance, motivational suggestions alone are as effective as identical suggestions given to high susceptible Ss. 1964 Levitt, Eugene E.; Brady, J. P. (1964). Muscular endurance under hypnosis and in the motivated waking state. International Journal of Clinical and Experimental Hypnosis, 12, 21-27.