This thesis set out to investigate the role of dissociation in the human response to traumatic events. The overarching aim was to determine if different forms of exposure to trauma are related to an individual's ability to employ dissociations in experience to self-regulate emotional responses. The role of individual differences in the related personality traits of absorption, fantasy proneness, and imagery ability in generating trance-like dissociations of experience are examined by combining trait questionnaire measures with state measures of the phenomenology of trance, a condition characterised by dissociations in experience. Findings are applied to investigate the role of dissociation in the relationship between recollections of childhood trauma and adults' emotional responses (e.g., skin conductance and heart rate variability) to images of traumatic events. Finally, the dissociation-related neural processes implementing affective self-regulation in trauma exposed adults are examined in an experimental electroencephalographic study. Study 1 examined the structure of experience while responding to a standardised trance induction. Exploratory factor analysis on the Phenomenology of Consciousness Inventory (PCI) determined five factors of trance experience named Altered Awareness, Negative Affect, Self-Control, Positive Affect, and Imagery.