New directions in hypnosis research: strategies for advancing the cognitive and clinical neuroscience of hypnosis

This article summarizes key advances in hypnosis research during the past two decades, including (i) clinical research supporting the efficacy of hypnosis for managing a number of clinical symptoms and conditions, (ii) research supporting the role of various divisions in the anterior cingulate and prefrontal cortices in hypnotic responding, and (iii) an emerging finding that high hypnotic suggestibility is associated with atypical brain connectivity profiles. Key recommendations for a research agenda for the next decade include the recommendations that (i) laboratory hypnosis researchers should strongly consider how they assess hypnotic suggestibility in their studies, (ii) inclusion of study participants who score in the middle range of hypnotic suggestibility, and (iii) use of expanding research designs that more clearly delineate the roles of inductions and specific suggestions. Finally, we make two specific suggestions for helping to move the field forward including (i) the use of data sharing and (ii) redirecting resources away from contrasting state and nonstate positions toward studying (a) the efficacy of hypnotic treatments for clinical conditions influenced by central nervous system processes and (b) the neurophysiological underpinnings of hypnotic phenomena. As we learn more about the neurophysiological mechanisms underlying hypnosis and suggestion, we will strengthen our knowledge of both basic brain functions and a host of different psychological functions. Highlights • Hypnosis treatments have demonstrated efficacy for a number of conditions. • Research supports the role of divisions in the anterior cingulate and prefrontal cortices in hypnotic responding. • Consideration of three study design issues could improve the impact of hypnosis research. • Researchers in the field would do well to consider developing mechanisms for data sharing. • It may be time to direct research resources away from studies that contrast state and non state models of hypnosis

Hypnotizability-dependent accuracy in the reproduction of haptically explored paths.

The study assessed differences between highly (Highs) and low hypnotizable (Lows) subjects in the blindfolded reproduction of paths connected at acute or obtuse angles. Reproduction attempts were made after path exploration performed by one finger, with or without concomitant cognitive activities (mental computation or imagery of exploring an angle larger than the explored one). The variables analyzed were: subjective experience (scores of the exploring effort, reproduction difficulty, perceived accuracy of reproduction, attention to mental computation and efficacy of imagery), exploration time, relative error in reproduction (under or overestimation) and the percentage of "successful" trials (absolute error <10°). The results showed that the subjective experience of exploration/reproduction and the exploration times are similar in Highs and Lows and that all subjects underestimate the explored angles and reproduce the acute angle more accurately than the obtuse one. Exploration of the acute angle concomitant with imagery of a larger one reduced its underestimation in both groups. Highs exhibited a larger number of successful trials after exploration of the obtuse angle, while Lows (males) decreased their relative error in the reproduction of the acute angle. In conclusion, in the more demanding condition of reproducing an obtuse angle, the Highs' reproduction was more accurate and more independent of cognitive load than that of the Lows

Is high hypnotizability a trouble in balance control?

Hypnotizability is a cognitive trait measured by standard scales and associated with peculiar physiological responses to cognitive and physical stimulations. Hypnotizability-related differences can also be observed in non-hypnotic state and in the absence of specific suggestions. In the normal bipedal stance subjects with high hypnotizability (Highs) exhibit a higher tolerance of alteration of the visual and leg/neck proprioceptive input with respect to low hypnotizable individuals (Lows). Aim of the study was to investigate whether this characteristic represents a disadvantage during highly demanding postural tasks. Sixteen Highs and 16 Lows of both genders participated in an experimental session consisting of maintaining balance while standing with open or closed eyes on a seesaw platform allowing roll movements. The results did not show significant differences between Highs and Lows in inclination area and time, with the exception of a greater ability of Highs with respect to Lows when they began the task displacing the body weight from the left to the right leg. Thus, high hypnotizability does not represent a disadvantage for balance control during highly demanding postural tasks. Together with previous studies, the present findings suggest that the Highs' postural control might shift from a very "economic", preeminently centrally driven functioning mode, characteristic of easy postural tasks, to an efficaciously periphery-controlled mode, required by difficult postural tasks

Body sway modulation by hypnotizability and gender during low and high demanding postural conditions

Item does not contain fulltextThe cognitive trait of hypnotizability, associated with the proneness to accept suggestions, exhibits several physiological correlates including the modulation of sensorimotor integration and, in particular, of postural control. In this respect, we have shown that, at eyes closure, healthy subjects with high hypnotizability scores (highs) having their feet 2 cm apart show larger and faster body sway with respect to low hypnotizable individuals (lows). The aim of the present study was to investigate whether hypnotizability modulates body sway during slightly more demanding and very difficult postural conditions such as feet together bipedal posture and one legged stance, respectively. The Center of Pressure (CoP) Area, mean Velocity, the CoP mean position (Xmean, Ymean) and its variability (SDx, SDy) in the frontal and sagittal planes were acquired in 18 highs (9 females) and 18 lows (9 females). Results showed that the previously observed lows’ smaller and slower body sway was not present any longer. Nonetheless, hypnotizability interacted with gender in the modulation of the variability of the CoP movement in the frontal plane during both the bipedal feet together posture and one legged stance, as significant gender differences were observed only among lows. In conclusion, results confirm a role of hypnotizability in sensorimotor integration and support the relevance of hypnotic assessment in clinical settings, as hypnotizability may be responsible for part of the postural variability.7 p

Hypnotizability and performance on a Prism Adaptation Test

Item does not contain fulltextThe susceptibility to hypnosis, which can be measured by scales, is not merely a cognitive trait. In fact, it is associated with a number of physiological correlates in the ordinary state of consciousness and in the absence of suggestions. The hypnotizability-related differences observed in sensorimotor integration suggested a major role of the cerebellum in the peculiar performance of healthy subjects with high scores of hypnotic susceptibility (highs). In order to provide behavioral evidence of this hypothesis, we submitted 20 highs and 21 low hypnotizable participants (lows) to the classical cerebellar Prism Adaptation Test (PAT). We found that the highs' performance was significantly less accurate and more variable than the lows' one, even though the two groups shared the same characteristics of adaptation to prismatic lenses. Although further studies are required to interpret these findings, they could account for earlier reports of hypnotizability-related differences in postural control and blink rate, as they indicate that hypnotizability influences the cerebellar control of sensorimotor integration.8 p

Preliminary evidence on the role of vestibolo- and neo-cerebellar circuits in the consolidation of spatial memory related to navigation.

To evaluate if the cerebellum takes part in the process of consolidation of the memory traces related to navigation, we tested in a Morris water maze two groups of male rats, chronically implanted for injection into the cerebellar nuclei of saline or muscimol (MU), a GABAA agonist with a transient inhibitory action. During the acquisition phase (Place test) animals were trained to find a submerged escape platform by the use of distal cues in a protocol of 8 trials/day (2 blocks of 4 trials) for 5 days, and injected immediately after. A Probe test was applied before Place test; the time spent in the area where the platform was previously located is an index of consolidation.Based on histology, MU-treated animals were sorted in: (a) dorsal dentate group (DDN) and (b) ventromedial dentate group (VMDN), in which the injected drug reached also the vestibular nuclei. In the place test, the VMDN showed versus controls (C), longer latencies in reaching the platform in the first block of each day, indicating a less efficient retention. In the probe test, C and DDN showed a gradual increase of time spent in reference quadrant up to values around 40% at day 4 while the VMDN remained around the value of 25 %, regarded as casual distribution. Results seem to exclude a role of the cerebellum trough the dentate nucleus in the process of spatial memory consolidation, at least at the time span of our protocol, and suggest that such a role could be exerted trough the vestibular system

Body sway modulation by hypnotisability and gender during low and high demanding postural conditions.

The cognitive trait of hypnotisability, associated with the proneness to accept suggestions, exhibits several physiological correlates including the modulation of sensorimotor integration and, in particular, of postural control. In this respect, we have shown that, at eyes closure, healthy subjects with high hypnotisability scores (highs) having their feet 2 cm apart show larger and faster body sway with respect to low hypnotizable individuals (lows). The aim of the present study was to investigate whether hypnotisability modulates body sway during slightly more demanding and very difficult postural conditions such as feet together bipedal posture and one legged stance, respectively. Stabilometric variables were studied: the body Centre of Pressure (CoP) Area and mean Velocity, the CoP mean position (Xmean, Ymean) and its variability (SDx, SDy) in the frontal and sagittal planes were acquired in 18 highs (9 females) and 18 lows (9 females). Results showed that the previously observed lows’ smaller and slower body sway was not present any longer. Nonetheless, hypnotisability interacted with gender in the modulation of the variability of the CoP movement in the frontal plane during both the bipedal, feet together posture and one legged stance, as significant gender differences were observed only among lows. In conclusion, results confirm a role of hypnotisability in sensorimotor integration and support the relevance of hypnotic assessment in clinical settings, as hypnotisability may be responsible for part of the postural variability

Hypnotizability- related effects of vestibular impairment on posture and locomotion

Body sway and locomotion are differentially modulated in high (highs) and low (lows) hypnotizable subjects undergoing alteration of visual and neck/leg proprioceptive inputs. The study's aim was to investigate whether partial impairment of vestibular information due to backward head extension affects postural (Study 1) and locomotor behavior (Study 2) differentially in highs and lows. Results showed that, at variance with the visual and proprioceptive modalities, vestibular inactivation did not induce major differences between the 2 groups, with the exception of improvement in walking straight across consecutive trials, which was observed only in highs. The article presents an overview of the structures and mechanisms possibly involved in the observed hypnotizability-related differences in motor control and suggests that hypnotic susceptibility might be a relevant factor in neuro-rehabilitative treatments because it accounts for part of the variability in the sensorimotor self

Hypnotizability-related effects of vestibular impairment of posture and locomotion.

Body sway and locomotion are differentially modulated in high (highs) and low (lows) hypnotizable subjects undergoing alteration of visual and neck/leg proprioceptive inputs. The study's aim was to investigate whether partial impairment of vestibular information due to backward head extension affects postural (Study 1) and locomotor behavior (Study 2) differentially in highs and lows. Results showed that, at variance with the visual and proprioceptive modalities, vestibular inactivation did not induce major differences between the 2 groups, with the exception of improvement in walking straight across consecutive trials, which was observed only in highs. The article presents an overview of the structures and mechanisms possibly involved in the observed hypnotizability-related differences in motor control and suggests that hypnotic susceptibility might be a relevant factor in neuro-rehabilitative treatments because it accounts for part of the variability in the sensorimotor self. Copyright © International Journal of Clinical and Experimental Hypnosis

Hypnotizability and sensorimotorintegration: An Italian Space Agency Project

In highly hypnotizable individuals (highs), postural control is more independent of sensory information than in low hypnotizable subjects (lows). The aim of the study was to find out whether locomotion is also less affected in highs than in lows by visual suppression and changes in the neck proprioceptive input. Eighteen highs and 20 lows were asked to walk straight ahead, blindfolded, in basal conditions (face forward), during real and imagined right/left head rotation and mental computation. Highs detected deviations from the straight trajectory better than lows. Their walking direction was more straight during basal conditions and less influenced than the lows' one by mental computation and real/imagined rotation of the head. The results confirm highs' lower dependence on sensory inputs, although this cannot be definitely attributed to a better internal representation of space or to higher behavioral automaticity