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“ I can ’ t tell whether it ’ s my hand ” : a pilot study of the neurophenomenology of body representation during the rubber hand illusion in trauma-related disorders

View Article: PubMed Central - PubMed

ABSTRACT

Background: Early traumatic experiences are thought to be causal factors in the development of trauma-related dissociative experiences, including depersonalization and derealization. The rubber hand illusion (RHI), a well-known paradigm that measures multi-sensorial integration of a rubber hand into one’s own body representation, has been used to investigate alterations in the experience of body ownership and of body representation. Critically, however, it has never been studied in individuals with trauma-related disorders.

Objective: To investigate body representation distortions occurring in trauma-related disorders in response to the RHI.

Method: The RHI was administered to three individuals with the dissociative subtype of posttraumatic stress disorder (PTSD), and subjective, behavioral, cardiovascular and skin conductance responses were recorded.

Results: Participants’ subjective experiences of the RHI were differentiated and complex. The illusion was induced following both synchronous and asynchronous brushing and variably evoked subjective distress, depersonalization and derealization experiences, tonic immobility, increased physiological arousal and flashbacks.

Conclusions: The present findings point towards the RHI as a strong provocation stimulus that elicits individual patterns of symptom presentation, including experiences of distress and dissociation, in individuals with trauma-related disorders, including the dissociative subtype of PTSD.

Highlights of the article: The rubber hand illusion (RHI) elicits distress, tonic immobility, depersonalization and derealization, and autonomic responses in individuals with trauma-related disorders, including the dissociative subtype of posttraumatic stress disorder (PTSD).

Highlights of the article: RHI effects related to body misrepresentation may trigger altered experiences related to body ownership.

Highlights of the article: The RHI represents a promising paradigm for studying the neurophenomenology of body distortion in individuals experiencing trauma-related altered states of consciousness (TRASC).

No MeSH data available.


Related in: MedlinePlus

Answers from all three case report subjects to the nine-question post-trial questionnaire administered following each asynchronous and synchronous trial. Each question is evaluated on a Likert scale spanning from – 3 (complete disagreement) and+3 (complete agreement). The first three questions assess the illusion effect, whereas the last six serve as control questions. This plot reveals that all subjects endorsed the subjective perception of the illusion following the synchronous trial, whereas only Stephanie endorsed the perception of the illusion following the asynchronous trial. It is important to note that for both Stephanie and Dawn, the asynchronous trial was performed first and the synchronous trial second, whereas for Michelle, the order was reversed.
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Figure 0001: Answers from all three case report subjects to the nine-question post-trial questionnaire administered following each asynchronous and synchronous trial. Each question is evaluated on a Likert scale spanning from – 3 (complete disagreement) and+3 (complete agreement). The first three questions assess the illusion effect, whereas the last six serve as control questions. This plot reveals that all subjects endorsed the subjective perception of the illusion following the synchronous trial, whereas only Stephanie endorsed the perception of the illusion following the asynchronous trial. It is important to note that for both Stephanie and Dawn, the asynchronous trial was performed first and the synchronous trial second, whereas for Michelle, the order was reversed.

Mentions: Prior to each trial, the box was covered with a flat lid, and a ruler (in centimeters) was placed on the lid. The participant was then asked to report the number on the ruler that corresponded to her perceived index finger (Burin et al., 2015). This procedure was repeated six times, changing randomly the position of the ruler each time. The same exercise was performed after the trial to determine proprioceptive drift (see Fig. 2 for pre- and post-trial individual proprioceptive drift). The absolute drift was obtained by subtracting the average post-trial estimations from the average pre-trial estimations for each subject (Botvinick & Cohen, 1998). A nine-item questionnaire created from Botvinick and Cohen’s (1998) original RHI study was administered verbally to the patient after each trial to identify the subjective perception of the illusion (see individual scores in Fig. 1). The DSS and the PCL-5 were administered before and after each trial to assess state dissociative symptoms.


“ I can ’ t tell whether it ’ s my hand ” : a pilot study of the neurophenomenology of body representation during the rubber hand illusion in trauma-related disorders
Answers from all three case report subjects to the nine-question post-trial questionnaire administered following each asynchronous and synchronous trial. Each question is evaluated on a Likert scale spanning from – 3 (complete disagreement) and+3 (complete agreement). The first three questions assess the illusion effect, whereas the last six serve as control questions. This plot reveals that all subjects endorsed the subjective perception of the illusion following the synchronous trial, whereas only Stephanie endorsed the perception of the illusion following the asynchronous trial. It is important to note that for both Stephanie and Dawn, the asynchronous trial was performed first and the synchronous trial second, whereas for Michelle, the order was reversed.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5120383&req=5

Figure 0001: Answers from all three case report subjects to the nine-question post-trial questionnaire administered following each asynchronous and synchronous trial. Each question is evaluated on a Likert scale spanning from – 3 (complete disagreement) and+3 (complete agreement). The first three questions assess the illusion effect, whereas the last six serve as control questions. This plot reveals that all subjects endorsed the subjective perception of the illusion following the synchronous trial, whereas only Stephanie endorsed the perception of the illusion following the asynchronous trial. It is important to note that for both Stephanie and Dawn, the asynchronous trial was performed first and the synchronous trial second, whereas for Michelle, the order was reversed.
Mentions: Prior to each trial, the box was covered with a flat lid, and a ruler (in centimeters) was placed on the lid. The participant was then asked to report the number on the ruler that corresponded to her perceived index finger (Burin et al., 2015). This procedure was repeated six times, changing randomly the position of the ruler each time. The same exercise was performed after the trial to determine proprioceptive drift (see Fig. 2 for pre- and post-trial individual proprioceptive drift). The absolute drift was obtained by subtracting the average post-trial estimations from the average pre-trial estimations for each subject (Botvinick & Cohen, 1998). A nine-item questionnaire created from Botvinick and Cohen’s (1998) original RHI study was administered verbally to the patient after each trial to identify the subjective perception of the illusion (see individual scores in Fig. 1). The DSS and the PCL-5 were administered before and after each trial to assess state dissociative symptoms.

View Article: PubMed Central - PubMed

ABSTRACT

Background: Early traumatic experiences are thought to be causal factors in the development of trauma-related dissociative experiences, including depersonalization and derealization. The rubber hand illusion (RHI), a well-known paradigm that measures multi-sensorial integration of a rubber hand into one’s own body representation, has been used to investigate alterations in the experience of body ownership and of body representation. Critically, however, it has never been studied in individuals with trauma-related disorders.

Objective: To investigate body representation distortions occurring in trauma-related disorders in response to the RHI.

Method: The RHI was administered to three individuals with the dissociative subtype of posttraumatic stress disorder (PTSD), and subjective, behavioral, cardiovascular and skin conductance responses were recorded.

Results: Participants’ subjective experiences of the RHI were differentiated and complex. The illusion was induced following both synchronous and asynchronous brushing and variably evoked subjective distress, depersonalization and derealization experiences, tonic immobility, increased physiological arousal and flashbacks.

Conclusions: The present findings point towards the RHI as a strong provocation stimulus that elicits individual patterns of symptom presentation, including experiences of distress and dissociation, in individuals with trauma-related disorders, including the dissociative subtype of PTSD.

Highlights of the article: The rubber hand illusion (RHI) elicits distress, tonic immobility, depersonalization and derealization, and autonomic responses in individuals with trauma-related disorders, including the dissociative subtype of posttraumatic stress disorder (PTSD).

Highlights of the article: RHI effects related to body misrepresentation may trigger altered experiences related to body ownership.

Highlights of the article: The RHI represents a promising paradigm for studying the neurophenomenology of body distortion in individuals experiencing trauma-related altered states of consciousness (TRASC).

No MeSH data available.


Related in: MedlinePlus