:

Advances and Challenges in the Cognitive

Neuroscience of Hypnosis

William McGeown, PhD

12th December 2016

Neuroimaging of hypnotic suggestibility

and response to hypnosis

Overview

• Functional and neuroanatomical associations

with hypnotic suggestibility/waking suggestibility

– Brain regions and networks

• The effects of hypnosis

– Brain regions and networks

• Future directions

• Absorption

• Fantasy proneness

• Dissociative capacity

Correlations with hypnotic

suggestibility

• Hypnotic suggestibility scores had:

– correlation of 0.81 over a 15 year period

– correlation of 0.75 over a 25 year period

• (Piccione, Hilgard & Zimbardo, 1989)

Test-retest reliability

• Heritability hypnotic suggestibility: Twins – Morgan (1973) – correlation monozygotic twins (0.52)

– Bauman (1981) – 78.3% concordance (different levels of response to

hypnosis)

• Catechol-O-methyltransferase (COMT) gene (Val158Met

polymorphism) – Associated with modulation of dopaminergic signaling

– Hypnotic suggestibility (e.g., Litchtenberg et al., 2000; Raz et al., 2005;

Szekely et al., 2010; Bryant et al., 2013; Presciuttini et al., 2014)

• COMT (Met/Met) higher hypnotic suggestibility (if high

attentional control). – Gene-trait interaction

– Rominger et al (2014)

Genetic associations

Self-Reports

McGeown et al. (2012) Consciousness and Cognition, 21(1),100-116.

Hypnotic Induction

Presence of Hypnotic Induction

Level of Suggestibility

High suggestible Hypnotic induction

High suggestible No hypnosis

Low suggestible Hypnotic Induction

Low suggestible No hypnosis

McGeown et al. (2012) Consciousness and Cognition, 21(1),100-116.

• Behavioural associations (e.g., Absorption)

• Stability of the suggestibility scores over time

• Association with genetics (e.g., COMT gene)

• Capacity of Highs to perform cognitive/perceptual tasks

(with or without hypnosis)

• Are individual differences in response to hypnotic

suggestibility associated with variance in the

neuroanatomy/neurobiology of brain structures?

Hypnotic suggestibility

Differences in Suggestibility

Horton et al. (2004)

Voxel-based

morphometry

Kurth, Luders & Gaser (2015) Brain Mapping: An Encyclopedic Reference, 1, 345-349

Correlations: hypnotic suggestibility

and GMV (VBM)

McGeown et al (2015) Psychiatry Research: Neuroimaging, 231 (2), 151-159

Correlation with hypnotic depth

• Positive: Cluster included

left superior and medial

frontal gyri

• Negative: left insula and

superior temporal gyrus.

Correlation hypnotic

suggestibility & GMV (VBM)

Huber et al (2014)

• Temporal dependency between spatially remote

neurophysiological events (Aersten et al., 1989)

• Biswal et al. (1995) – motor cortex

• Low frequency oscillations (∼0.01–0.1 Hz)

Functional Connectivity

Correlations between “Intrinsic”

and “extrinsic” networks

Fox et al. (2005)

Intrinsic Connectivity

Networks (ICNs)

Yeo et al. (2011) Neurophysiol, 106 (3): 1125–1165.

ICNs: Default Mode Network

• Functions include: Thinking about the past and future, theory of mind operations, and moral decision making.

Buckner et al (2008)

Includes: The anterior and posterior cingulate cortex, the ventral and dorsal medial frontal cortex, the hippocampal formation, lateral temporal cortex, lateral parietal cortex and precuneus (see e.g., Buckner et al., 2008).

Executive control network – Left and right lateral fronto-parietal cortices and the dorsomedial PFC – Functions include employing focused and sustained attention and working

memory processes (Seeley et al., 2007)

Salience network Functions include:

• Sensory filtering and integration, pain, interoception, autonomic functioning, and emotional processing (Seeley et al., 2007)

• Switching between the more task relevant executive-control network and the more introspective DMN (Sridharan, Levitin, & Menon, 2008)

Executive control network

Salience network

McGeown, W. J. (2016). Hypnosis, hypnotic suggestibility, and meditation: an integrative review of the associated brain regions and networks. In A. Raz, & M. Lifshitz (Eds.), Hypnosis and Meditation: Towards an Integrative Science of Conscious Planes. (pp. 343-367)

Hypnotic Suggestibility & FC

Hoeft et al (2012) Huber et al (2014)

Significant correlation between hypnotic suggestibility and the

salience network

What are the effects of hypnosis?

– Brain regions and networks

Features that characterize hypnosis?

• Increased absorption

• Increased dissociation

• Reduced internal dialogue

• Decreased self awareness

• Deep relaxation

• How does the underlying neurophysiology change due

to hypnosis?

– How does it relate to phenomena such as these?

• Altered time sense

• Decreased volitional control

• Mental imagery

• Decreased positive affect

• Decreased negative affect

The effects of hypnosis

RESTFUL AWAKE HYPNOSIS HYPNOSIS WITH SUGGESTIONS

PAINFUL

PAINFUL PAINFUL (MORE OR LESS UNPLEASANT)

WARM (NEUTRAL)

WARM (NEUTRAL)

(Rainville et al., 1999) (Rainville et al. 2002)

Absorption (after controlling for relaxation)

Hypnotic Induction Suggestion

“Neutral” hypnosis

Relaxation Pleasant mental

imagery Enter hypnosis

Modulate pain experience

Hallucinate e.g. colour

Selective amnesia

Presence of Hypnotic Induction

Level of Suggestibility

High suggestible, Hypnotic induction

High suggestible, No hypnosis

Low suggestible, Hypnotic Induction

Low suggestible, No hypnosis

No hypnosis Hypnosis

High

Low

Design

Design

Rest

Look Grey Add Colour

Look Colour

Drain Colour

Rest

Rest

Time

McGeown et al. (2009) Consciousness and Cognition, 18(4), 848-55

Why focus on the rest periods

• Activation is unlikely to be confounded by task based

suggestions.

– Task demands are low (rest only).

– Analysis of time points that do not require response to

a suggestion (in this case, e.g., to hallucinate colour).

• Demand characteristics are minimised

– Participants would not be expected to consider this a

time period of interest for the investigation (only

instructed to rest).

Rest period analysis:

Hypnosis vs no hypnosis conditions

Lower levels of activity in the medial frontal gyri and anterior cingulate bilaterally & superior frontal gyrus bilaterally

High suggestible participants

McGeown et al. (2009) Consciousness and Cognition, 18(4), 848-55

Default Mode Network

• Hypnosis appears to be altering the anterior default mode network in the high suggestible people.

• The frontal regions associated with default mode are reduced in activation during hypnosis. – Suspension of spontaneous thought? Preparatory mode?

– Reduced distraction from internally generated stimuli?

Buckner et al (2008) McGeown et al (2009)

Rest period analysis:

Hypnosis vs no hypnosis conditions

High suggestible participants

Increase in subjective response to suggestions

Dienes and Hutton (2013) : Mediums - TMS over left DLPFC

McGeown et al. (2009) Consciousness and Cognition, 18(4), 848-55

Rest period analysis:

Effects of the hypnotic induction

Low suggestible participants

Thalamus

No significant differences in the frontal regions (medial or lateral) that were present in the high suggestible people

McGeown et al. (2009) Consciousness and Cognition, 18(4), 848-55

The effect of “neutral” hypnosis

• The effect of hypnosis was different between the Highs

and the Lows.

• In the Highs, focused deactivation occurred during

hypnosis

– Included anterior portions of the Default Mode Network

• Decreased introspection, mind-wandering?

– More lateral regions of the PFC - including the left superior frontal gyrus

• Disruption in executive functions and monitoring?

• Correlation with depth of hypnosis

DMN

Deeley et al. (2012)

No hypnosis Hypnosis

• Alterations within the medial PFC

• Increases in the occipital cortex Regional Homogeneity (ReHo) analysis – Lipari et al. (2012)

Negative correlation with functional connectivity within anterior DMN

Correlations with increased

depth of hypnosis

McGeown et al (2015) Psychiatry Research: Neuroimaging, 231 (2), 151-159

DMN (aka “Intrinsic network”)

Demertzi et al (2011)

a) Waking state b) No Hypnosis c) Hypnosis

Alert Autobiographical memories Mental imagery

Autobiographical memories Revivification

Extrinsic network

Demertzi et al (2011)

a) Normal wakefulness b) Mental imagery c) Hypnosis

• Fundamental differences appear to exist in the brains of those higher in suggestibility

– Neuroanatomy

• Associations between hypnotic suggestibility and the size of the anterior corpus callosum (Horton et al., 2004), the temporo-occipital cortex and insula (McGeown et al. 2015), and the medial PFC (Huber et al. 2014).

• Greater depth of hypnosis: Increased grey matter in the anterior default mode network (medial PFC) and salience network (ACC).

– Functional connectivity

• Expansion of the salience network to include the executive-control regions (Hoeft et al. 2012; Huber et al. 2014)

• Converging evidence that the interplay between the salience network, executive control network and default mode network, relates closely to both hypnotic suggestibility and the experience of hypnosis.

Conclusions – hypnotic

suggestibility

Conclusions - hypnosis

• Hypnotic induction in highly suggestible people (during a task)

– Visual areas (possibly associated with mental imagery)

– Anterior cingulate cortex (modulation of attention/absorption)

• Hypnotic induction (in the absence of a specific task) reduced activity in midline regions: predominantly in the anterior default mode network.

• Greater depth of hypnosis – less FC in anterior DMN (McGeown et al., 2015)

• Changes in DMN activity/FC might reflect reduced internal dialogue (personal thoughts, mind-wandering, etc.) and/or self-awareness.

• The left superior frontal gyrus is implicated in hypnosis

– Reduced activity in “neutral” hypnosis (McGeown et al., 2009)

– According to one study (Dienes & Hutton, 2013), disruption in that brain region enhanced suggestibility

– Modulation of executive functions/attentional ability/metacognitive processes.

• Understanding the basis of suggestibility/hypnotic suggestibility – Participant groupings

– With and without hypnosis

• Understand the effects of particular suggestions – Phenomenology, brain activity and functional connectivity

• Understanding the effects of different components (and combinations) of hypnotic inductions – i.e., mental imagery, relaxation, to be hypnotized

• Data-sharing

Future Directions

• Those who study hypnosis and suggestibility could develop a

neuroimaging data-sharing initiative. Upload data after publication.

– Would allow pulling of data across studies & increase statistical power.

– Zenodo (https://zenodo.org)

– Upload of experimental paradigms, software, behavioural data,

electrophysiological data, neuroimaging data. Very large datasets could

be stored elsewhere and linked to this database.

• Minimum requirements for sharing? For each participant:

– Suitable metadata e.g., demographics, characteristics, scanning

protocols

– Information on the hypnotic suggestibility scale used and the scores

(individual items + summary score)

– That the hypnotic induction be made available verbatim (with the

dataset). If different for each participant – summary of key components.

Data-sharing repository

Thank you for your attention!

• Collaborators:

– Prof Giuliana Mazzoni

– Prof Irving Kirsch

– Prof Annalena Venneri

– Dr Manila Vannucci

– Prof Paulo Nichelli

– Dr Kathrine Roberts

– Dr Lisa Foan

– Dr Luca Nocetti