Dissociative identity state-dependent working memory in dissociative identity disorder: a controlled functional magnetic resonance imaging study

[摘要] Background Memory function is at the core of the psychopathology ofdissociative identity disorder (DID), but little is known about itspsychobiological correlates.AimsThis study aims to investigate whether memory function in DIDdiffers between dissociative identity statesMethodBehavioural data and neural activation patterns were assessed in92 sessions during an n-back working memory task. Participantswere people with genuine diagnosed DID (n = 14), DID-simulatingcontrols (n = 16) and a paired control group (post-traumaticstress disorder (n = 16), healthy controls (n = 16)). Both DIDgroups participated as authentic or simulated neutral andtrauma-related identity states. Reaction times and errors ofomission were analysed with repeated measures ANOVA.Working memory neural activation (main working memoryand linear load) was investigated for effects of identity state,participant group and their interaction.ResultsIdentity state-dependent behavioural performance and neuralactivation was found. DID simulators made fewer errors ofomission than those with genuine DID. Regarding the prefrontalparietal network, main working memory in the left frontalpole and ventrolateral prefrontal cortex (Brodmann area 44)was activated in all three simulated neutral states, and in trauma-related identity states of DID simulators, but not those withgenuine DID or post-traumatic stress disorder; for linear load,trauma-related identity states of those with genuine DID did notengage the parietal regions.ConclusionsBehavioural performance and neural activation patterns relatedto working memory in DID are dependent on the dissociativeidentities involved. The narrowed consciousness of traumarelated identity states, with a proneness to re-experiencingtraumatising events, may relate to poorer working memoryfunctioning.

[学科分类] 计算机科学（综合）

[关键词] dissociative disorders;simulation;post-traumatic stress disorder;trauma;cognitive neuroscience