Dissociative states and neural complexity

Recent findings indicate that neural mechanisms of consciousness are related to integration of distributed neural assemblies. This neural integration is particularly vulnerable to past stressful experiences that can lead to disintegration and dissociation of consciousness. These findings suggest that dissociation could be described as a level of neural disintegration reflecting a number of independent processes by means of neural complexity. In the present study measurement of dissociation, traumatic stress symptoms and neural complexity calculated using nonlinear analysis of EEG [during rest conditions], and electrodermal activity (EDA) [during rest and Stroop task] were performed in 52 university students (mean age 24.1). Neural complexity has been described using pointwise correlation dimension (PD2) calculated from EEG and EDA records. While no significant relationship was found between EEG complexity and dissociative symptoms, statistically significant relationship between EDA complexity and dissociative symptoms during rest, but not during the Stroop task, has been found. These results indicate that electrodermal complexity during rest may reflect a level of dissociative symptoms. (C) 2010 Elsevier Inc. All rights reserved.