Information processing and laterality in posttraumatic stress disorder: Quantitative EEG asymmetry and the relationship between abnormalities and clinical symptoms

Proposal details

Title: Information processing and laterality in posttraumatic stress disorder: Quantitative EEG asymmetry and the relationship between abnormalities and clinical symptoms
Research Area(s): PTSD and other Anxiety Disorders
Background: Research using the working memory model in the verbal domain has demonstrated that people with PTSD have an abnormality of memory related to the traumatic material which is manifest clinically as disturbed concentration and a diminished ability to encode and retrieve information. Recent evidence using PET has provided preliminary evidence of abnormal fronto-parietal synchrony values in sufferers of PTSD. The interpretation of the data suggest that the intrusive recollections remain highly sensitive to cues and influence the organisational patterns of cortical and subcortical functional integration.
Aims: The primary aim of the proposed study is to investigate whether there is any relationship between EEG interhemispheric and intrahemispheric asymmetry measures and scoring on cognitive tests assessing verbal and visuospatial function in PTSD individuals compared to matched controls. A second aim of the study is to examine the EEG frequency band and power values in order to determine whether the group differences in EEG asymmetry are associated with the clinical symptoms of dissociation in PTSD. A third aim of the study is to investigate the effects of a treatment intervention in a subgroup from the PTSD population in order to determine whether there is a relationship between treatment and behavioural, global and cognitive functions.
Method: The proposed data analyses will examine EEG interhemispheric and intrahemispheric asymmetry in sufferers of PTSD and assess whether there is any relationship between asymmetry and scoring on cognitive tests for verbal and visuospatial function, clinical parameters and treatment intervention. Absolute EEG amplitude, in the alpha, beta, delta, and theta frequency bands will be analysed. Measures will include EEG resting activity for eyes open and eyes closed. Power values will be calculated as relative power between intrahemispheric and homologous interhemispheric electrode pairings. The proposed data analyses will compare and contrast the correlations between EEG power measures (absolute power and relative power) and EEG network measures (coherence and phase delay) and behavioural measures.