:
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
• 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
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
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
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
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
• 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