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Results for “Pain Perception”

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PubMed1997

The relationship between resting systolic blood pressure and cutaneous pain perception in cardiac patients with angina pectoris and controls.

In order to determine the influence of resting systolic blood pressure and stable angina on cutaneous pain perception, we studied 19 male cardiac patients with stable angina and 16 male controls. Pain perception was measured using a suprathreshold evaluation of pain intensity and pain unpleasantness to a series of thermal stimuli. We found that men with higher resting blood pressure had a decrease in the perception of pain intensity and pain unpleasantness. Similarly, we found that patients with stable angina perceived pain as less intense and unpleasant than controls. These differences in pain perception may be associated with different pain mechanisms: in the case of blood pressure, differences in opioid activity and baroreceptor-regulated pain systems; in the case of stable angina, patients may adapt to continued experiences of pain, altering internal frames of reference.

Analysis of Variance↗

PubMed2006

Changes of pain perception, autonomic function, and endocrine parameters during treatment of anorectic adolescents.

OBJECTIVES: The underlying mechanisms of reduced pain perception in anorexia nervosa (AN) are unknown. To gain more insight into the pathology, the authors investigated pain perception, autonomic function, and endocrine parameters before and during successful treatment of adolescent AN patients. METHOD: Heat pain perception was assessed in 15 female adolescent AN patients and matched controls. Results were correlated with autonomic and endocrine parameters (free triiodothyronine, free cortisol). Autonomic function was studied using heart rate variability and pupillary light reflex assessment. To investigate the influence of therapy on these parameters, data were obtained at three different time points. RESULTS: Heat pain thresholds were significantly increased in the acute state and decreased after weight had been regained for 6 months. Similarly, an increased parasympathetic tone was present in the acute state only. The relative amplitude of the pupillary light reflex showed a positive correlation to pain thresholds over time and predicted disease progression. In addition, the authors found a negative correlation between increased pain thresholds and low free cortisol. CONCLUSION: Increased pain thresholds are associated with increased parasympathetic tone and a hypothyroid state in AN. This may either indicate common central mechanisms or suggest a causative interaction.

Adolescent↗

PubMed2005

The effects of noxious heat, auditory stimulation, a cognitive task, and time on task on pain perception and performance accuracy in healthy volunteers: a new experimental model.

The effects of cognitive and competing sensory processing tasks on pain perception and as a function of time are only partially understood. To study these effects, we compared the simultaneous effects of noxious heat stimulation (HS), auditory stimulation (AS) (sinusoidally modulated speech-like signal, SMSLS), and a cognitive task (CT) (rate change detection of the SMSLS) on pain perception and task performance over repeated experimental runs. Sixty healthy paid volunteers were randomly assigned to four groups, one exposed to AS while performing the CT, one to HS (46 degrees C/6 min), one to AS and HS, and one to AS and HS while performing the CT. Each group performed the experimental run four times, each run for 6 min. Immediately after each run, the subjects rated pain intensity using a VAS (0-100). Two-way RM-ANOVA for analyzing pain intensities among the three heat pain groups demonstrated significant differences of VAS ratings (F(2,179) = 4.57, P = 0.019), being highest in the HS group (55 +/- 0.7SEM), followed by the AS+HS (39 +/- 6.8) and AS + HS + CT (33 +/- 0.7) groups. Post-hoc analyses revealed that group HS differed significantly from group AS + HS + CT and from group AS + HS (P < 0.05, SNK), whereas group AS+HS did not differ significantly from group AS + HS + CT. Neither pain rating, nor rate of errors on the CT varied significantly across runs. These findings point to a significant influence of competing passive sensory processing on pain perception, with the cognitive task not necessarily adding to the perception of pain. Advantages and shortcomings of the present experimental model for future pain studies are discussed.

Acoustic Stimulation↗

PubMed1992

Spatial summation in human thermal pain perception: comparison within and between dermatomes.

Spatial summation of thermal pain has recently been reported when stimulus presentations were restricted within a single dermatome. The present study examined whether the magnitude of spatial summation of human thermal pain perception would vary when stimuli were presented within vs. between adjacent dermatomes. Noxious contact heat stimuli from 43 degrees C to 51 degrees C (5 sec duration) were applied to the forearm using areas of 0.21-2.10 cm2. Subjects rated the intensity and unpleasantness of pain using visual analog scales. For stimuli from 45 degrees C to 51 degrees C, there was a significant increase in ratings with increasing stimulus area for both intensity and unpleasantness. When two thermodes were used simultaneously in adjacent dermatomes, the ratings did not differ significantly from those for the same stimulus area in a single dermatome. We conclude that spatial summation both within and between dermatomes plays a significant role in thermal pain perception across the range from threshold to tolerance.

Adult↗

PubMed1995

Evaluation of pain perception after anterior capsulotomy: a case report.

The medial prefrontal cortex has been implicated in pain perception by recent anatomical, physiological, and functional imaging data demonstrating that frontal and anterior cingulate cortices receive inputs related to nociception; neurosurgical case reports suggest that lesions involving these areas may specifically reduce the affective or emotional component of chronic intractable pain. We examined this hypothesis more closely by assessing psychophysical ratings of (1) warmth, pain intensity, and unpleasantness evoked by phasic thermal stimuli, (2) tolerance to tonic cold stimuli, and (3) perceived intensity of visual stimuli, both before and after neurosurgical lesions of the fiber tracts connecting the frontal lobes to subcortical structures. A 22-year-old male, with no history of chronic pain, underwent psychophysical testing 3 days before, 5 days after, and 6 months after receiving bilateral lesions of the anterior internal capsule (aIC), performed as treatment for obsessive-compulsive disorder. In each session, the patient rated the intensity and unpleasantness of 5-sec cutaneous heat stimuli (39-47 degrees C); pain tolerance was measured by means of a cold-pressor test (hand immersion in 1 degrees C water). The patient was able to differentially rate the intensities of heat stimuli during both pre- and postsurgical testing sessions (p < 0.001). However, he rated heat stimuli as less intense 5 days after surgery than during presurgical testing (p < 0.001), with significant decreases in both pain intensity (p < 0.005) and unpleasantness (p < 0.05). Likewise, the patient described the cold-water immersion as less painful following surgery, although his tolerance times were substantially shorter than those of the presurgical evaluation. Ratings of visual stimulus intensity did not differ across the pre- and postsurgical testing periods, suggesting that changes in pain perception were not related to attentional or cognitive deficits. Magnetic resonance imaging 5 days following surgery revealed bilateral lesions and edema centered in the aIC, with some edema in the left frontal lobe. Those 6 months later showed substantially smaller lesions involving less than half of the aIC and no edema; pain ratings and cold-water tolerance measured at that time indicated a substantial return toward the patient's presurgical values. These data suggest that blocking subcortical input to the anterior cingulate and frontal cortices reduces both the perceived intensity and the unpleasantness of noxious stimuli; reduced cold tolerance times--in the face of decreased pain perception--may reflect a disinhibition of cortical control on spinal reflexes.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗

PubMed1993

Differing reports of pain perception by different personalities in a patient with chronic pain and multiple personality disorder.

There have been several reports of patients with chronic pain (CP) and dissociative or multiple personality disorder (MPD). This report describes a patient with MPD in whom 4 different personalities reported different perceptions of pain. Psychological testing was used to confirm the diagnosis of MPD. Visual analogue scales (VAS) and the McGill Pain Questionnaire (MPQ) were used on each of the 4 personalities. Each personality completed pain drawings to indicate currently perceived pain and resulting disability, and had EMG recordings of muscle tension. These studies documented a difference in pain perception, location, and estimates of secondary functional impairment between different personalities in the same patient.

Chronic Disease↗

PubMed2003

Blood pressure but not cortisol mediates stress effects on subsequent pain perception in healthy men and women.

Research has demonstrated that exposure to acute stress may attenuate pain perception. Mechanisms of this effect in humans have not been determined. This study was conducted to determine the extent to which psychophysiological and adrenocortical responses to acute stress predict subsequent pain perception. One hundred and fifty-two healthy participants (80 women) were assigned to one of two conditions: rest followed by the cold pressor test (CPT; N=76) or stress followed by CPT (N=76). The stress protocol consisted of a public-speaking challenge. Participants rated their pain every 15 s during a 90-s hand CPT (0-4 degrees C), and they completed the short form of the McGill Pain Questionnaire. Salivary cortisol, mood, blood pressure (BP), and impedance cardiography measures were collected in both conditions. Women had lower BP and reported greater pain than men in both conditions (ps<0.01). Participants in the stress condition reported less pain during CPT than those in the rest condition (p=0.02). Regression analyses demonstrated that the stress effect on pain ratings was mediated by systolic BP level during stress; however, cortisol responses did not affect this relationship. Mood changes were independent predictors of pain. The study demonstrates that BP changes in response to stress mediate the stress-induced attenuation of pain perception.

Adult↗

PubMed2000

Blood pressure but not parental history for hypertension predicts pain perception in women.

Previous work has suggested an attenuated sensitivity to painful stimulation in hypertensive men. We recently reported that, compared with persons with negative parental history, men, but not women, with a positive history for hypertension showed attenuated pain perception. This study specifically addressed factors that predict pain perception in women, including blood pressure, parental history and mood states. Fifty-four normotensive women with positive (PH+; n = 20) or negative parental history (PH-; n = 34) for hypertension and high or low casual systolic blood pressure (BP) performed the cold pressor (CP) test. Participants rated their pain every 15 s during a 90-s hand CP (0-4 degrees C) and a 90-s post-CP rest period. Detailed mood ratings were obtained immediately before the CP test. Data were evaluated using multivariate repeated measure analyses of variance and regression analyses. PH+ and PH- women did not differ in age, height, weight, education, resting BP, or heart rate. PH+ and PH- women did not differ in pain ratings during or after the CP, or pain ratings using the McGill Pain Questionnaire (MPQ), and they did not differ in their cardiovascular responses to the CP, confirming our earlier study in a separate sample. Women with high casual systolic BP reported significantly less pain, especially after the CP (P < 0.01). MPQ total scores confirmed this finding with high BP women reporting less pain than low BP women (P < 0.05). Regression analyses confirmed these effects. Controlling for potential confounding variables did not alter these relationships. These findings suggest that in women, phenotype systolic BP may be a better predictor of hypoalgesia than parental history of hypertension.

Adult↗

PubMedDate not supplied

Clinical hypnosis modulates functional magnetic resonance imaging signal intensities and pain perception in a thermal stimulation paradigm.

OBJECTIVE: This study was designed to describe regional changes in blood oxygenation level dependent signals in functional magnetic resonance images (fMRI) elicited by thermal pain in hypnotized subjects. These signals approximately identify the neural correlates of the applied stimulation to identify neuroanatomic structures involved in the putative effects of clinical hypnosis on pain perception. METHODS: After determination of the heat pain threshold of 12 healthy volunteers, fMRI scans were performed at 1.5 Tesla by using echoplanar imaging technique during repeated painful heat stimuli. Activation of brain regions in response to thermal pain during hypnosis (using a fixation and command technique of hypnosis) was compared with responses without hypnosis. RESULTS: With hypnosis, less activation in the primary sensory cortex, the middle cingulate gyrus, precuneus, and the visual cortex was found. An increased activation was seen in the anterior basal ganglia and the left anterior cingulate cortex. There was no difference in activation within the right anterior cingulate gyrus in our fMRI studies. No activation was seen within the brainstem and thalamus under either condition. CONCLUSION: Our observations indicate that clinical hypnosis may prevent nociceptive inputs from reaching the higher cortical structures responsible for pain perception. Whether the effects of hypnosis can be explained by increased activation of the left anterior cingulate cortex and the basal ganglia as part of a possible inhibitory pathway on pain perception remains speculative given the limitations of our study design.

Brain↗

PubMed2004

Spinal prostaglandin formation and pain perception following thoracotomy: a role for cyclooxygenase-2.

STUDY OBJECTIVE: Prostaglandins (PGs) generated in the spinal cord may play a major role in pain perception. Consequently, the suppression of spinal cyclooxygenase (COX) and PG formation may contribute to the analgesic effect of nonsteroidal anti-inflammatory drugs (NSAIDs) in pain following surgery. Which isoform of COX is responsible for postsurgical pain and, consequently, should be targeted, is unclear. DESIGN: Prospective randomized blinded study. SETTING: University teaching hospital. PATIENTS: Thirty patients undergoing thoracotomy for lobectomy were recruited. INTERVENTIONS: Patients were randomized to receive the COX-2 selective inhibitor nimesulide, 100 mg orally twice daily, or ibuprofen (nonselective), 400 mg orally three times daily, in an open-label study. In addition, there was a randomized control group that received no NSAIDs. Cerebrospinal fluid (CSF) was analyzed for 6-keto-PGF(1)alpha, the principle metabolite of prostacyclin. COX-1 and COX-2 activity was determined by measuring serum thromboxane (TX) B(2) and endotoxin-induced PGE(2) generation in whole blood. MEASUREMENTS: Pain perception was measured by visual analog scores, and blinded assessment of opioid analgesic requirements and expiratory peak flow measurements were performed. RESULTS: At the doses used, nimesulide was selective for COX-2, while ibuprofen was nonselective based on serum TXB(2) levels. The mean (+/- SEM) levels of 6-keto-PGF(1)alpha in CSF increased following surgery from 32 +/- 4.9 to 127 +/- 29 pg/mL (p < 0.001), and this was suppressed by nimesulide (49 +/- 9.3 pg/mL; p = 0.0025) but not by ibuprofen (122 +/- 35 pg/mL). Pain scores (p < 0.001), morphine requirement (p = 0.0175), and the fall in peak expiratory flow rate (p < 0.001) were significantly lower in the nimesulide group. CONCLUSIONS: Increases in spinal PG synthesis after thoracotomy are repressed by a selective COX-2 inhibitor. This suggests that the inducible COX-2 mediates central PG synthesis, which may be important in the generation of pain, as the use of nimesulide also resulted in significant decreases in postoperative pain perception.

6-Ketoprostaglandin F1 alpha↗

PubMed2004

Primary and secondary vulvar vestibulitis syndrome: systemic pain perception and psychophysical characteristics.

OBJECTIVE: Women with primary and secondary vulvar vestibulitis syndrome (VVS) report similar vulvar pain symptoms; however, it is not clear whether these subsets have similar pain and psychophysical characteristics. This study evaluated systemic pain perception, cardiovascular measures, and anxiety level in women with primary and secondary VVS. STUDY DESIGN: Eighty-nine women were enrolled in the study: 44 had primary vulvar vestibulitis, 45 had secondary vulvar vestibulitis. Their anxiety level was first assessed. Then, heat pain stimuli were applied to the forearm, and pain threshold and pain scores for suprathreshold phasic (44 degrees C-48 degrees C) and tonic (46 degrees C) stimuli were assessed by visual analog scale. Finally, blood pressure was recorded using a volume clamp method before, during, and after a tonic stimulus of 1 minute at 46 degrees C. RESULTS: Women with primary vulvar vestibulitis had higher visual analog scale scores for pain perception at 46 degrees C to 48 degrees C, a higher level of trait anxiety 43.3 +/- 1.5 versus 37.8 +/- 1.5 (P=.010), an increased incidence of dysmenorrhea (chi(2) 8.9, P=.003), and lower resting blood pressure: systolic (108.6 +/- 2.1 vs 118.9 +/- 2.0 mm Hg) (P>.001) and diastolic (59.3 +/- 1.6 vs 64.2 +/- 1.5 mm Hg) (P=.038). Logistic regression revealed that dysmenorrhea and lower systolic blood pressure are associated with primary VVS. CONCLUSION: Women with primary and secondary VVS differ in their systemic pain perception and psychophysical characteristics. The impact of these findings on treatment modalities should be further evaluated.

Adult↗

PubMed2003

Effects of odors on pain perception: deciphering the roles of emotion and attention.

Emotions have been shown to alter pain perception, but the underlying mechanism is unclear since emotions also affect attention, which itself changes nociceptive transmission. We manipulated independently direction of attention and emotional state, using tasks involving heat pain and pleasant and unpleasant odors. Shifts in attention between the thermal and olfactory modalities did not alter mood or anxiety. Yet, when subjects focused attention on the pain, they perceived it as clearly more intense and somewhat more unpleasant than when they attended to the odor. In contrast, odor valence altered mood, anxiety level, and pain unpleasantness, but did not change the perception of pain intensity. Pain unpleasantness ratings correlated with mood, but not with odor valence, suggesting that emotional changes underlie the selective modulation of pain affect. These results show that emotion and attention differentially alter pain perception and thus invoke at least partially separable neural modulatory circuits.

Adolescent↗

PubMed2000

Clinical pain perception and hormone replacement therapy in postmenopausal women experiencing orofacial pain.

OBJECTIVE: The purpose of this study was to examine the magnitude of the relation between a postmenopausal woman's hormonal replacement status and clinical pain report in a sample of women experiencing orofacial pain. DESIGN: To accomplish this, pain ratings were collected during a routine chronic pain evaluation at an orofacial pain clinic from a sample of 87 postmenopausal women. RESULTS: Results of ANCOVA (controlling for pain duration) demonstrated that postmenopausal women receiving hormone replacement therapy (HRT) reported higher levels of pain than postmenopausal women not taking HRT. Numeric pain rating scales revealed large effect sizes for worst pain report (0.62), moderate differences for average (0.48) and current (0.39) pain levels, and trivial differences for least pain (0.04). Effect sizes for the McGill Pain Questionnaire indicated somewhat smaller differences (0.35-0.24) between the two groups. CONCLUSIONS: This study is among the first to examine the relation between a woman's hormonal status and clinical pain perception and is the first to investigate the role of HRT in a postmenopausal woman's orofacial pain report in a clinical treatment setting. This area of inquiry is particularly salient given the high percentage of women who choose to initiate HRT either after hysterectomy or with the onset of menopause.

Adult↗

PubMed2001

Pain perception in women with dysmenorrhea.

OBJECTIVE: To determine if systemic processing of pain differs in women with and without dysmenorrhea. METHODS: Twenty-two dysmenorrheic women and 31 nondysmenorrheic women were studied by pain threshold and supra-threshold magnitude estimation to heat stimuli, pain-evoked potentials by laser stimuli, and anxiety scores four times across their menstrual cycles. RESULTS: Significant differences were found between dysmenorrheic and nondysmenorrheic women. In all four examinations across the menstrual cycle, dysmenorrheic women had longer latencies of pain-evoked potentials (383.08 +/- 6.8 msec versus 345.05 +/- 7.0 msec, P <.001), higher magnitude estimations on visual analog scale of supra-threshold pain (83.29 +/- 2.87 versus 63.50 +/- 3.82, P <.001), and higher state anxiety scores (37.69 +/- 1.7 versus 29.20 +/- 1.9, P =.002). CONCLUSION: Women with dysmenorrhea show enhanced pain perception compared to nondysmenorrheic women. This augmentation of pain perception may be part of the development of dysmenorrhea.

Adult↗

PubMed1988

Counterstimulation and pain perception: effects of electrocutaneous vs. auditory stimulation upon cold pressor pain.

This study tested the hypothesis that distraction from a painful stimulus is best achieved by concurrent presentation of a similar stimulus. Specifically, it was hypothesized that pain perception would be interfered with, and thus reduced, when a stimulus similar to the sensory features of a painful stimulus was delivered concurrently. Subjects matched aversiveness thresholds for electrocutaneous or auditory stimulation so that both forms of stimulation could be judged to be subjectively of similar affective value. Subjects were then run in the cold pressor test for 2 min. While control subjects for each modality were not administered counterstimulation concurrently with cold pressor exposure, experimental subjects within each modality condition received concurrent counterstimulation. Magnitude estimation ratings of the aversiveness of counterstimulation were provided concurrently with cold pressor pain ratings, every 30 sec. The results indicated that, as predicted, subjects exposed to concurrent electrical stimulation produced lower pain ratings than subjects exposed to auditory stimulation and controls. In addition, a mutual interference effect between the cold pressor and the tactile counterstimulation was found: subjects also rated electrical stimulation as a less aversive than auditory stimulation over the duration of the cold pressor test.

Acoustic Stimulation↗

PubMed1997

Educating interventional radiology personnel in nonpharmacologic analgesia: effect on patients' pain perception.

RATIONALE AND OBJECTIVES: The purpose was to evaluate the effects on patients' pain perception of educating interventional radiology personnel in nonpharmacologic analgesia. MATERIALS AND METHODS: Ninety-six patients undergoing lower-extremity arteriography or percutaneous nephrostomy were asked to rate the pain they experienced during the procedure on a scale of 0 to 5 (0 = no pain, 1 = mild pain, 2 = moderate pain, 3 = severe pain, 4 = very severe pain, 5 = worst pain possible). Patients were studied at two baseline sessions (baseline 1, December 1993 to August 1994, n = 15; and baseline 2, September 1995 to January 1996, n = 11) and after the staff underwent one of two training sessions (posttraining 1, January 1995 to July 1995, n = 34; posttraining 2, January 1996 to April 1996, n = 36). Training targeted nurses and technologists and included rapport skills, correct use of language and suggestions, distraction, relaxation training, and self-hypnosis. Data were evaluated with analysis of variance for repeated measures. RESULTS: The mean pain scores reported after training were lower (1.48) and matched an "acceptable" pain score of 1.52 more closely than those reported under baseline conditions (2.54, P = .001). There was a tendency toward reduced use of intravenously administered agents for conscious sedation after training. There were no statistically significant differences in the pain scores between patients who underwent arteriography and patients who underwent nephrostomy overall (1.76 and 1.78, respectively), at baseline (2.58 and 2.43, respectively), and after staff training (1.49 and 1.42, respectively). CONCLUSION: Interventional radiology personnel trained in nonpharmacologic analgesia methods can help reduce patients' pain perception during interventional procedures.

Analgesia↗

PubMed2002

Adrenocortical and hemodynamic predictors of pain perception in men and women.

Research has demonstrated that women report more pain than men, and clinical observations suggest that attenuated adrenocortical activity is associated with high pain sensitivity. The extent to which cortisol concentrations and hemodynamics contribute to gender differences in pain sensitivity has not been investigated. Thirty-four women and 31 men performed the hand cold pressor test (CPT). Participants rated their pain every 15 s during a 90-s CPT and a 90-s post-CPT recovery period and reported pain using the McGill Pain Questionnaire (MPQ). Salivary cortisol samples and cardiovascular measures were collected prior to, during, and after the CPT. Women reported greater pain than men during and after the CPT and on the MPQ (Ps<0.01). CPT disrupted the expected diurnal decline in cortisol, as shown by a significant increase in cortisol concentration post-CPT (P<0.01) in men and women. Regression analyses revealed that pre-CPT cortisol concentrations predicted lower pain reports during and after CPT in men only (P<0.01). Systolic blood pressure (BP) and stroke volume correlated negatively with pain reports only in women (Ps<0.05). Controlling for potential confounding variables did not alter these relationships. The negative association between pre-CPT cortisol and pain perception in men and the association between BP and pain in women demonstrate different physiological predictors of pain perception in men and women.

Adult↗

PubMed1999

Pain perception, somatosensory event-related potentials and skin conductance responses to painful stimuli in high, mid, and low hypnotizable subjects: effects of differential pain reduction strategies.

In this study, pain perception, somatosensory event-related potential (SERP) and skin conductance response (SCR) changes during hypnotic suggestions of Deep Relaxation, Dissociated Imagery, Focused Analgesia, and Placebo, compared with a Waking baseline condition, were investigated. SERPs were recorded from frontal, temporal, central, and parietal scalp sites. Ten high, 9 mid, and 10 low hypnotizable right-handed women participated in the experiment. The following measures were obtained: (1) pain and distress tolerance ratings; (2) sensory and pain thresholds to biphasic electrical stimulation delivered to the right wrist; (3) reaction time and number of omitted responses; (4) N2 (280+/-11 ms) and P3 (405+/-19 ms) peak amplitudes of SERPs to target stimuli delivered using an odd-ball paradigm; (5) number of evoked SCRs and SCR amplitudes as a function of stimulus repetition. Results showed, high, mid and low hypnotizables exhibited significant reductions of reported pain and distress ratings during conditions of Deep Relaxation/Suggestion of Analgesia, Dissociated Imagery and Focused Analgesia. High hypnotizable subjects displayed significant reductions in pain and distress levels compared to mid and low hypnotizables during Dissociated Imagery, Focused Analgesia and, to a lesser degree, during Deep Relaxation. Placebo condition did not display significant differences among hypnotizability groups. High hypnotizables, compared to mid and low hypnotizables, also showed significant increases in sensory and pain thresholds during Dissociated Imagery and Focused Analgesia. High, mid, and low groups showed significant reductions in P3 peak amplitudes across all hypnosis conditions and, to a lesser degree, during Placebo. The temporal cortical region was the most sensitive in differentiating SERP responses among hypnotizability groups. On this recording area the subjects highly susceptible to hypnosis displayed significantly smaller P3 and greater N2 peaks during Focused Analgesia than did the other hypnotizable groups. In this condition highly susceptible subjects also reported the highest number of omitted responses and the shortest Reaction Times. These subjects also showed faster habituation of SCRs when compared with mid and low hypnotizables. During Dissociated Imagery and Focused Analgesia, highly hypnotizable subjects also disclosed a smaller total number of evoked SCRs than did mid and low hypnotizable subjects. The results are discussed considering possible common and different mechanisms to account for the effects of different hypnotic suggestions.

Analysis of Variance↗