Dissociative part-dependent biopsychosocial reactions to backward masked angry and neutral faces: An fMRI study of dissociative identity disorder

Abstract

ObjectiveThe Theory of Structural Dissociation of the Personality (TSDP) proposes that dissociative identity disorder (DID) patients are fixed in traumatic memories as “Emotional Parts” (EP), but mentally avoid these as “Apparently Normal Parts” of the personality (ANP). We tested the hypotheses that ANP and EP have different biopsychosocial reactions to subliminally presented angry and neutral faces, and that actors instructed and motivated to simulate ANP and EP react differently.MethodsWomen with DID and matched healthy female actors (CON) were as ANP and EP (DIDanp, DIDep, CONanp, CONep) consecutively exposed to masked neutral and angry faces. Their brain activation was monitored using functional magnetic resonance imaging. The black-and-white dotted masks preceding and following the faces each had a centered colored dot, but in a different color. Participants were instructed to immediately press a button after a perceived color change. State anxiety was assessed after each run using the STAI-S. Final statistical analyses were conducted on 11 DID patients and 15 controls for differences in neural activity, and 13 DID patients and 15 controls for differences in behavior and psychometric measures.ResultsDifferences between ANP and EP in DID patients and between DID and CON in the two dissociative parts of the personality were generally larger for neutral than for angry faces. The longest reaction times (RTs) existed for DIDep when exposed to neutral faces. Compared to DIDanp, DIDep was associated with more activation of the parahippocampal gyrus. Following neutral faces and compared to CONep, DIDep had more activation in the brainstem, face-sensitive regions, and motor-related areas. DIDanp showed a decreased activity all over the brain in the neutral and angry face condition. There were neither significant within differences nor significant between group differences in state anxiety. CON was not able to simulate genuine ANP and EP biopsychosocially.ConclusionsDID patients have dissociative part-dependent biopsychosocial reactions to masked neutral and angry faces. As EP, they are overactivated, and as ANP underactivated. The findings support TSDP. Major clinical implications are discussed.

Dissociative identity disorder: An empirical overview

“…There was no difference in perfusion of any brain area between different identities (Şar et al, 2001). Moreover, significant functional brain imaging (PET and fMRI) differences have been found between (1) different identities in DID patients (Reinders et al, 2003(Reinders et al, , 2006Schlumpf et al, 2013) and (2) perfusion before versus perfusion during "switching" between identities in a DID patient (Tsai et al, 1999). In the PET studies by Reinders et al an "emotional" dissociative identity (associated with trauma memories), when compared to an "apparently normal" dissociative identity (numb and depersonalised from trauma memories), showed increased cerebral blood flow in the amygdala, insular cortex, and somatosensory areas in the parietal cortex and the basal ganglia, as well as certain areas in the occipital and parietal cortex and anterior cingulate and frontal areas (Reinders et al, 2003(Reinders et al, , 2006.…”

The trauma model of dissociation: Inconvenient truths and stubborn fictions. Comment on Dalenberg et al. (2012).

“…This concession moves a crucial element of the TM perspective decisively closer to the FM (Lilienfeld & Lynn, 2003). Some proponents of the TM (Reinders, Willemsen, Vos, den Boer, & Nijenhuis, 2012;Schlumpf et al, 2013) continue to claim or imply that the FM holds that individuals with DID typically role-play or fake the symptoms of this disorder consciously. In actuality, FM theorists have taken pains to emphasize that role-enactment, which flows spontaneously and is carried out with a high degree of personal involvement (Sarbin & Coe, 1972), is a more accurate description than role-playing, insofar as 1 When we use the term dissociation, we typically refer to dissociative experiences or symptoms, not to a literal splitting of different aspects of consciousness or multiple personalities.…”

Ten reasons for conceiving and classifying posttraumatic stress disorder as a dissociative disorder

“…Consistent with clinical observations, neutral faces may be threatening and ambiguous to EPs. The masked faces seem to elicit an instant search for meaning as is suggested by the activation of the temporal pole of the superior temporal gyrus, a part of a semantic system (Schlumpf et al 2013).…”

“…PTSD and DSM-5 dissociative disorders: shared functional brain abnormalities DID involves biopsychosocial differences for ANP and EP in response to trauma-related cues that are inexplicable as effects of suggestion, fantasy, and motivated role playing (Hermans et al 2006;Reinders et al 2003Reinders et al , 2006Reinders et al , 2012Schlumpf et al 2013). PTSD patients can respond to these cues with hyperarousal to the point of full-blown flashbacks, or hypoaroused depersonalization/derealization and emotional detachment (i.e., 'PTSD with dissociative symptoms').…”

“…In the case of an intrusion, one dissociative part strongly influences another dissociative part ANP: apparently normal part of the personality EP: emotional part of the personality DID: dissociative identity disorder. In Reinders et al (2003Reinders et al ( , 2006Reinders et al ( , 2012 and Schlumpf et al (2013): all women HC: mentally healthy controls HC in Reinders et al, 2012: extremely fantasy prone women HC in Schlumpf et al, 2013: female actors L: left hemisphere R: right hemisphere *Trauma memory scripts with respect to HC in Reinders et al (2012) involved the worst adverse events HC were willing to share with the investigators…”