Complex role of hypnotizability in the cognitive control of pain

This opinion article deals with the role of hypnotizability in the efficacy of the suggestions of analgesia for the cognitive control of pain and of its physiological correlates

Visuospatial imagery in healthy individuals with different hypnotizability levels

Hypnotizability is a psychophysiological trait associated with morpho-functional brain differences. Since also cerebellar peculiarities have been reported in individuals with different hypnotizability levels and the cerebellar function is relevant to spatial imagery, the present study was aimed at investigating possible hypnotizability-related differences in the ability of spatial imagery. Highly (highs, N=31), low (lows, N=17) and medium (mediums, N=16) hypnotizable participants (classified by Stanford Hypnotic Susceptibility Scale, form A) of both genders were submitted to a test of mental rotation, which requires the integrity of both executive and cerebellar structures. In order to disentangle the role of the cerebellum from that of executive circuits as much as possible, visuospatial and verbal working memory tests, which mainly reflect executive processes, were also performed. Healthy highs exhibited higher scores of mental rotation ability compared to mediums in the absence of significant differences in visual-spatial and verbal working memory. Lows reported intermediate scores not significantly different from both highs’ and mediums’. Different cognitive strategies were observed in the three groups as the correlations between mental rotation, visuospatial and verbal working memory were different in highs, mediums and lows. In conclusion, present findings represent the first report of hypnotizability-related differences in a mental rotation task, which is relevant to several cognitive functions

Imagined and Actual Movements with and without Suggestions for anesthesia in Subjects with Different Hypnotizability

Background: Hypnotizability is a psychophysiological trait associated with several differences including the level of functional equivalence (FE) between imagery and perception, i.e., the similarity of the cortical activations and network configurations associated with each of them. FE is stronger in high hypnotizability individuals (highs) than low hypnotizable participants (lows). In this framework, this study investigates the correlation between electroencephalogram (EEG) of imagined arm/hand movements (MI) and of actual movements performed in the absence of suggestions (M) and in the presence of suggestions of arm/hand anesthesia (MA) in highs and lows. Methods: The EEG alpha (8–12 Hz) and beta (13–25 Hz) absolute power, classically associated with movement preparation and execution, were studied in 18 highs and 17 lows classified according to the Stanford Hypnotic Susceptibility Scale, form A. EEG was recorded during M, MI, and MA. The subjective reports of imagery and the duration of movements were also studied. Results: The duration of movements did not differ between highs and lows. Highs reported better imagery during MI, greater perceived influence of the suggestion of anesthesia during MA, and lower cognitive efforts than lows for both tasks. In line with earlier studies, the spectral analysis did not reveal significant restructuring of the cortical activity during tasks in highs, whereas lows showed cortical changes during MI and MA indicating that they were able to mentally simulate movements and to accept suggestions for anesthesia during voluntary movement, despite their low hypnotizability scores. Conclusions: The present study indicates that unusual psychophysiological characteristics can differ in the response of individuals to suggestions

Interoceptive accuracy as a function of hypnotizability

This study aimed to measure the interoceptive accuracy (IA) of individuals with high (highs), medium (mediums), and low hypnotizability (lows) through the heartbeat-counting task during 3 relaxation trials. Participants completed the Multidimensional Assessment of Interoceptive Awareness (MAIA), ECG and skin conductance (SC) were monitored, and the experienced difficulty in counting was reported. Results showed similar counting difficulty and number of actual heartbeats in highs, mediums, and lows. SC decreased in highs during all trials, in mediums and lows only in the third trial. IA measured as [1 - (vertical bar recorded heartbeats-counted heartbeats vertical bar)/recorded heartbeats] was negatively correlated with hypnotizability and not correlated with interoceptive sensitivity (IS) measured by MAIA scales. Among mediums, IA was higher in males than in females

Is hypnotic assessment relevant to neurology?

: Studies conducted in healthy subjects have clearly shown that different hypnotic susceptibility, which is measured by scales, is associated with different functional equivalence between imagery and perception/action (FE), cortical excitability, and information processing. Of note, physiological differences among individuals with high (highs), medium (mediums), and low hypnotizability scores (lows) have been observed in the ordinary state of consciousness, thus independently from the induction of the hypnotic state, and in the absence of specific suggestions. The potential role of hypnotic assessment and its relevance to neurological diseases have not been fully explored. While current knowledge and therapies allow a better survival rate, there is a constant need to optimize rehabilitation treatments and quality of life. The aim of this paper is to provide an overview of hypnotizability-related features and, specifically, to discuss the hypothesis that the stronger FE, the different mode of information processing, and the greater proneness to control pain and the activity of the immune system observed in individuals with medium-to-high hypnotizability scores have potential applications to neurology. Current evidence of the outcome of treatments based on hypnotic induction and suggestions administration is not consistent, mainly owing to the small sample size in clinical trials and inadequate control groups. We propose that hypnotic assessment may be feasible in clinical routine and give additional cues into the treatment and rehabilitation of neurological diseases