Uncomfortably numb: new evidence for suppressed emotional reactivity in response to body-threats in those predisposed to sub-clinical dissociative experiences

ABSTRACT

Introduction: Depersonalisation and derealisation disorders refer to feelings of detachment and dissociation from one’s “self” or surroundings. A reduced sense of self (or “presence”) and emotional “numbness” is thought to be mediated by aberrant emotional processing due to biases in self-referent multi-sensory integration. This emotional “numbing” is often accompanied by suppressed autonomic arousal to emotionally salient stimuli.

Methods: 118 participants completed the Cambridge Depersonalisation scale [Sierra, & Berrios, 2000. The Cambridge Depersonalisation Scale: A new instrument for the measurement of depersonalisation. Psychiatry Research, 93, 153–164)] as an index of dissociative anomalous experience. Participants took part in a novel “Implied Body-Threat Illusion” task; a pantomimed injection procedure conducted directly onto their real body (hand). Objective psychophysiological data were recorded via standardised threat-related skin conductance responses and finger temperature measures.

Results: Individuals predisposed to depersonalisation/derealisation revealed suppressed skin conductance responses towards the pantomimed body-threat. Although the task revealed a reliable reduction in finger temperature as a fear response, this reduction was not reliably associated with measures of dissociative experience.

Conclusions: The present findings significantly extend previous research by revealing emotional suppression via a more direct body-threat task, even for sub-clinical groups. The findings are discussed within probabilistic and predictive coding frameworks of multi-sensory integration underlying a coherent sense of self.

KEYWORDS:

• Dissociation
• depersonalisation/derealisation
• anomalous experience
• embodiment
• skin conductance responses

Acknowledgement

We thank the Foundation for their generous support. The study complied fully with ethical guidance (ERN_15-0384).

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1. Oswald (1959) did investigate emotional responses to electric shocks – participants described being more dissociated at the time of the more extreme shocks. However, this current task differs significantly in that participants see the threat unfolding before them, have direct visual/tactile evidence of the threat taking place, and have been screened for latent predisposition to depersonalisation/derealisation type experiences.

2. Note, the syringe was fitted with a spring loaded retractable needle. As the needle was pressed up against the skin it retracted into the body of the syringe yet gave the strong perceptual effect of entering the limb.

3. Approximately 10% of control/healthy populations and 25% of psychopathic populations are considered non-responders/hypo-responsive if a certain degree of SCR responsiveness is not displayed (see Dawson et al., 2007).

4. Note – habituation effects were not the primary focus of this study. Utilising a three threat procedure merely allowed us to take a cursory look at this additional factor.

5. The increase in the frequency of NS-SCRs is thought to be associated with negatively tuned emotions (anxiety, fear, apprehension: Nikula, 1991; see also Boucsein, 2012; Dawson et al., 2007) though the increase in amplitudes of NS-SCRs is not as clearly associated with such cognitions. We report it here for completeness.

Additional information

Funding

The present study was funded by a Bursary grant from the Bial Foundation [#15/14] awarded to the principal investigator (JJB) and was carried out in the Selective Attention and Awareness Laboratory (SAAL), in the School of Psychology, University of Birmingham.