Neurophysiology and neuropsychology of hypnosis

Over the last decades hypnosis, which is the oldest psychotherapy, has matured as both as a fascinating topic for scientific research and an effective technique for clinical application. Hypnosis has been defined as “a state of consciousness involving focused attention and reduced, awareness characterized by an enhanced capacity for response to suggestion” (Elkins, Barabasz, Council, & Spiegel, 2015). In recent years, hypnotherapy practices have become increasingly popular in health care and education (Thompson et al., 2019). However, the neurophysiological and neuropsychological correlates of hypnosis experience and responses have not been fully explored and the mechanisms of action are not well understood. Consequently, many of the basic questions regarding the essential nature of hypnosis remain unanswered. Many changes and advances in the field of experimental hypnosis have transformed the research landscape with new theories, new methodologies, new findings. The current Special Issue is a survey of contemporary hypnosis research. To address some of these questions and improve understanding of hypnosis, leading researchers and clinicians have been invited to contribute their perspectives, research, and recommendations for future work. In this special issue, we include six peer reviewed articles addressing topics ranging from neural correlates of hypnosis and hypnotic analgesia, hypnotizability, neuropsychology, and emerging methodologies in hypnosis research. The articles in this special issue offer critical analysis, cutting edge research, clinical perspectives, and directions for future research and clinical practice. In taking stock, why do a consistent fraction of high hypnotizable subjects in the population (15%) survive to natural selection? It seems unlikely that it may have happened just due to their proneness to accept suggestions. Santarcangelo, Carli, and Sebastiani propose an intriguing, evolutionary interpretation of the highs, characterized by the presence of stronger functional equivalence between imagery and perception, favorable cardiovascular asset (i.e., better FMD or Flow Mediated Dilation following 5 minutes occlusion and preeminent parasympathetic control of heart rate), greater cortical excitability reducing their vulnerability to the consequences of brain injuries, ability to control pain in the absence of an efficient opioid mechanism, and greater interoceptive sensitivity. The authors hypothesize that these adaptive characteristics were greatly relevant to our ancestors’ survival, and that they may have facilitated the natural selection of individuals with hypnotic susceptibility due to the proneness to accept suggestions. From an evolutionary perspective the proneness to accept suggestions could be just a side effect of other physiological features, which were instead directly relevant to survival during human evolution. The role of hypnotic suggestibility, involuntariness, pain expectation, and subjective hypnotic depth in the prediction of placebo analgesia (PA) responsiveness have been explored by De Pascalis, Scacchia, and Vecchio. This study showed that placebo analgesia treatment coupled with suggestion effects was effective in pain reduction in both waking and hypnosis conditions. During waking, higher pain reductions were correlated with higher hypnotic suggestibility, subjective experience of hypnotic depth, pain expectation, and involuntariness in PA response, with involuntariness being the unique predictor of pain AMERICAN JOURNAL OF CLINICAL HYPNOSIS 2021, VOL. 63, NO. 4, 291–293 https://doi.org/10.1080/00029157.2021.1892411