Page 28 - PIECES OF THE PUZZLE Eline Vissia

CHAPTER 1
and the posterior associative cortices in the representation of these different states of consciousness. In another study (Reinders et al. 2006), the different personality states were associated with different brain activation patterns when confronted with trauma-related cues. The cortical multimodal posterior association areas (PAA), the subcortical amygdala and subparts of the dorsal striatum were described to be involved in the psychopathology of DID. Their findings were unrelated to fantasy proneness (Reinders et al. 2012), since neither high nor low fantasy prone mentally healthy simulating controls were able to enact the psychophysiological and neural activation patterns of the authentic dissociative personality states.
In response to subliminally presented neutral and angry faces, Schlumpf et al. (2013) found abnormal reaction times for EP (equivalent of TPS), but not for ANP (equivalent of NPS), and EP activated different brain areas including in the parahippocampal gyrus, the brainstem, face-sensitive regions, and motor-related areas. Furthermore, Schlumpf et al. (2014) compared ANP and EP on resting state measures and found that ANP showed elevated perfusion in bilateral thalamus. Compared with ANP, EP had increased perfusion in the dorsomedial prefrontal cortex, primary somatosensory cortex, and motor- related areas. In both studies, patterns could not be mimicked by ANP and EP simulating healthy controls. Others (Mathew, Jack & West 1985) found hyperperfusion in the right temporal cortex in a single case study in a DID patient. Two uncontrolled resting state studies also found the involvement of the temporal lobe of the brain in DID (Saxe et al. 1992, Sheehan, Thurber & Sewall 2006) and two controlled studies, that included the largest sample of 21 DID patients in studies into DID using brain imaging techniques to date (Sar et al. 2001, Sar, Unal & Ozturk 2007) found bilateral frontal perfusion differences between patients and controls. The latter results are consistent with a neurodevelopmental model for DID proposed by Forrest (2001), underlining deficient functionality of the orbitofrontal region in the brain. The orbitofrontal lobe has been hypothesized to be affected by early trauma (Dorahy et al. 2014).
Findings from the majority of the above described studies have indicated the involvement of the frontal, parietal and temporal cortices and the hippocampus and striatum in the neuropsychopathology of DID.
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