Can posthypnotic suggestion (PHS) enhance cognitive abilities? The authors tested behaviorally and with event-related potentials (ERP) if sequential learning (SL), the ability to learn statistical regularities, can be enhanced with PHS. Thirty adults were assessed with the Stanford Hypnotic Susceptibility Scale (Form C) and an auditory SL task. Before this task, half the sample received a PHS to enhance SL, and the other half received the same suggestion under normal waking state. Response times and ERPs indicated a strong effect of PHS. Compared to the control group, PHS inverted, attenuated, or left unaffected the response time SL effect in low, medium, and high hypnotizability participants, respectively. These results suggest that PHS cannot be used to enhance SL.
A new control condition called Wiki is introduced. Key themes of each test suggestion of the Stanford Hypnotic Susceptibility Scale, Form C, were matched by a corresponding extract from Wikipedia.org. The authors compared phenomenological reports of participants across 4 conditions: hypnosis split into high and low hypnotizable subgroups, music, and Wiki condition, using the Phenomenology of Consciousness Inventory. High hypnotizables undergoing hypnosis reported higher altered experience and altered states of awareness than individuals in the Wiki condition, supporting the authors’ hypothesis that the Wiki condition does not evoke an altered state of consciousness (internal dialogue, volitional control, and self-awareness did not differ). Wiki might be a viable control condition in hypnosis research given further examination.
This work was supported by the Hungarian Scientific Research Funds (OTKA 109187 and K100845).
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.
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.
Assessment of hypnotizability can provide important information for hypnosis research and practice. The Elkins Hypnotizability Scale (EHS) consists of 12 items and was developed to provide a time-efficient measure for use in both clinical and laboratory settings. The EHS has been shown to be a reliable measure with support for convergent validity with the Stanford Hypnotic Susceptibility Scale, Form C (r = .821, p < .001). The current study examined the factor structure of the EHS, which was administered to 252 adults (51.3% male; 48.7% female). Average time of administration was 25.8 minutes. Four factors selected on the basis of the best theoretical fit accounted for 63.37% of the variance. The results of this study provide an initial factor structure for the EHS.