Two experiments that studied the effects of hypnotic suggestions on tactile sensitivity are reported. Experiment 1 found that suggestions for anesthesia, as measured by both traditional psychophysical methods and signal detection procedures, were linearly related to hypnotizability. Experiment 2 employed the same methodologies in an application of the real-simulator paradigm to examine the effects of suggestions for both anesthesia and hyperesthesia. Significant effects of hypnotic suggestion on both sensitivity and bias were found in the anesthesia condition but not for the hyperesthesia condition. A new bias parameter, C’, indicated that much of the bias found in the initial analyses was artifactual, a function of changes in sensitivity across conditions. There were no behavioral differences between reals and simulators in any of the conditions, though analyses of postexperimental interviews suggested the 2 groups had very different phenomenal experiences.
This study investigated group hypnotizability in 167 adolescents (ages 13-17) in an inpatient behavioral healthcare setting through use of the Waterloo-Stanford Group Scale, Form C. It also investigated the influence of hypnotic inductions on group hypnotizability. Adolescents were randomly assigned to either a group session of hypnosis (n = 84) with a hypnotic induction or a comparison “no-induction” group (n = 83) that received identical suggestions without a hypnotic induction. Adolescents’ imaginative absorption and dissociation were measured to examine their influence on hypnotizability. A between-group comparison showed the induction condition had a significantly higher score than the no-induction group on both behavioral and subjective measures of hypnotizability.
The authors tested the hypothesis that hypnotic age regression produces a shift from secondary to primary thought processing in hypnotizable participants. Thirty participants were tested for hypnotizability using the Elkins Scale of Hypnotizability (EHS). Participants were exposed to a tailored hypnotic arm-levitation induction and a hypnotic suggestion to age regress to 5 years of age and to have a dream. Primary-process thinking was assessed using the Primary-Process Thinking Scale. An independent t test with 2 levels of hypnotizability (middle and high) showed high hypnotizables demonstrated higher ratings of primary thought processing than those in the middle group.
Measuring hypnotizability is an integral part of hypnosis research and also relevant for predicting the effectiveness of hypnosis-based therapies. The Elkins Hypnotizability Scale (EHS) was designed to meet the needs of modern hypnosis research and clinical practice. Reliability, validity, and normative data were explored by subjecting 230 participants to the EHS and Stanford Hypnotic Susceptibility Scale: Form C (SHSS:C). The EHS demonstrated adequate internal consistency (α = .78), its items showed good discriminating ability, and scores of the two scales were highly correlated (rho = .86). Results indicate that the EHS is a reliable and valid tool to assess hypnotizability. Further research is needed to establish its role as a surrogate for the SHSS:C.
Earlier studies have shown hypnotizability-related postural effects of visual suppression and of leg and neck proprioceptive alteration. This study completes this investigation by demonstrating the postural effects of asymmetric tactile foot stimulation in standing participants with different hypnotizability scores. During this stimulation, body sway changed in medium-to-high more than in low-to-medium hypnotizable participants. Findings support the view that high hypnotizability is associated with higher vulnerability of posture to sensory alteration; together with earlier results, they suggest a role of the cerebellum in the observed hypnotizability-related differences and prompt investigation of cerebral structures and factors potentially responsible for both the cognitive and physiological aspects of hypnotizability.
The aim of this paper is to complement the recently revised American Psychological Association definition of hypnotizability. It (a) lists a few differences in sensorimotor integration between subjects with high and low hypnotizability scores in the ordinary state of consciousness and in the absence of suggestions; (b) proposes that hypnotizability-related cerebellar peculiarities may account for them; (c) suggests that the cerebellum could also be involved in cognitive aspects of hypnotizability; (d) explains why the information derived from studies of sensorimotor and cardiovascular aspects of hypnotizability may be relevant to its definition and useful in orienting further experimental research in the field of hypnosis.
The hypothesis that beliefs about hypnosis determine the amount of psychological reactance aroused was tested. Participants were administered a measure of trait reactance to therapist directives (Therapeutic Reactance Scale; TRS), the Beliefs about Hypnotic State Questionnaire (BHSQ–R), and behavioral and subjective scales concerning hypnotic response. Hierarchical multiple regressions revealed significant interactions between BHSQ–R subscales and TRS. The findings suggest that the arousal of psychological reactance to hypnosis is determined by individuals’ trait reactance levels acting together with their interpretations of the hypnotic situation. The role of beliefs about hypnotic states as a moderator of the relationship between personality and hypnotizability was discussed.
There has been no research examining why people with disordered eating tend to be highly hypnotizable. The authors examine the hypothesis that concern for appropriateness mediates the association between hypnotizability and disordered eating. Fifty participants aged 15 to 30 completed the Eating Attitudes Test–26 (EAT–26) and the Concern for Appropriateness Scale (CAS) and were administered the Stanford Hypnotic Susceptibility Scale: Form C (SHSS:C). EAT–26 scores predicted CAS scores (β = 0.24, p < .001), CAS scores predicted SHSS:C scores (β = 0.38, p < .001), and the mediation model was significant (Sobel Test; R2 = .24, z = 2.54, p < .01). Individuals with problematic eating attitudes may tend to be more hypnotizable than those with normal eating attitudes at least in part because they are highly influenced by interpersonal messages.
Highly hypnotizable participants in the experimental condition were given a waking state suggestion that a reading not intended to be interesting would be fascinating and remarkable. Controls were given task motivational instructions, in which they were told to try to make it interesting. The suggestion had a major influence on participants’ enjoyment of the reading, though no effect was found for reading comprehension. Qualitative interviews indicated that the suggestion had a profound impact on some, especially those most responsive to hypnosis. The lack of an effect in reading comprehension may be due to large within-group variances. Findings suggest that hypnotic suggestion, when properly employed, may have a potential use in enhancing the learning capabilities of highly hypnotizable people.
Impaired attention may impede learning of adaptive skills in ADHD. While manipulations that reduce competition between attentional processes, including hypnosis, could boost learning, their feasibility in ADHD is unknown. Because hypnotic phenomena rely on attentional mechanisms, the authors aimed to assess whether stimulants could enhance hypnotizability in ADHD. In the current study, stimulant-naïve patients seeking treatment for ADHD-related symptoms were assessed with the Stanford Hypnotic Susceptibility Scale (SHSS) at baseline and during methylphenidate treatment. Methylphenidate dose and SHSS increase were negatively correlated with baseline SHSS scores. Upon reaching effective doses, mean SHSS scores increased significantly. All patients who had been poorly hypnotizable at baseline demonstrated moderate-to-high hypnotizability at follow-up. The data support methylphenidate enhancement of hypnotizability in ADHD, thus highlighting novel treatment approaches for this disabling disorder.