Examining implicit cognition in people with seizures

Background: An estimated 15-30% of individuals referred to epilepsy clinics are diagnosed with non-epileptic attack disorder (NEAD). NEAD is a well-known clinical problem which poses diagnostic and therapeutic challenges to neurological and psychological professionals (Gates & Erdahl, 1993). There are multiple theories on the mechanisms that underlie non-epileptic seizures; however there is limited empirical support for these. The development of implicit cognition has attracted much attention in the last few decades but has yet to be developed in the context of seizure research. This thesis aimed to offer a novel perspective on the psychological mechanisms underlying NEAD by examining implicit and explicit self-esteem and anxiety in people with seizures. It also explored the relationship of these constructs with experiential avoidance and seizure frequency. Methodology: 86 participants were recruited and completed a series of self-report questionnaires. The Rosenberg self-esteem questionnaire was used to measure explicit self-esteem. Spielberger’s State-Trait Anxiety Inventory was used to assess explicit anxiety. The Patient Health Questionnaire-15 was utilised to estimate somatic symptoms. The Multi-dimensional Experiential Avoidance Questionnaire was used to examine differences in avoidance. Finally they were administered two versions of the Implicit Relational Assessment Procedure (IRAPAnxiety; IRAP-Self-esteem) to examine implicit self-esteem and anxiety. Results: Analysis of Variance (ANOVAs) found no significant differences in implicit self-esteem and anxiety between the NEAD, epilepsy or non-clinical control groups. However, the NEAD group reported a significantly lower explicit self-esteem, higher avoidance and more somatic symptoms than their epilepsy counterparts. Although the NEAD and epilepsy groups reported high levels of anxiety, only the 3 NEAD group differed significantly from controls. The NEAD group had significantly larger implicit-explicit discrepancies for both anxiety and self-esteem, with explicit and discrepant scores correlating with self-reported avoidance and seizure frequency. A logistical regression model using explicit self-esteem, experiential avoidance and somatisation correctly classified 84.9% of individuals with seizures. However, the implicit measures did not add anything to the model. Conclusions: There are several interpretations for the implicit-explicit discrepancies observed. One suggestion is the high implicit low explicit profile reflects ‘damaged’ self-esteem, which can be understood more fully in context of events preceding seizure onset as well as the corollaries of diagnosis. Other authors have suggested that this profile reflects an unstable self-image, understood from early parenting and attachment perspectives. Given the correlation with discrepant scores it is possible that avoidance and seizures serve to reduce dissonance between implicit and explicit cognition. These findings support various psychological models of NEAD and offer a rationale for a range of psychological treatments that target avoidant behaviour patterns as well as deliberate evaluations that are within a person’s awareness.