Abstract

Obsessive-compulsive disorder (OCD) is associated with diminished quality of life and cognitive control dysfunction. Conflict adaptation is a reflection of cognitive control, and consists of the ability to detect conflict in previous trials and adjust performance on current trials. Conflict adaptation is thought to rely on interplay between the anterior cingulate cortex (ACC) and dorsolateral prefrontal cortex (dlPFC) for detecting conflict and signaling for increases in control, respectively. We hypothesized that individuals with OCD would show reduced conflict adaptation effects in response times, error rates, ACC activation, and dlPFC activation when compared with healthy control subjects. We also expected diminished conflict adaptation to be associated with poorer quality of life in those with OCD. Nineteen individuals with OCD and twenty psychiatrically-healthy controls completed a Stroop task while response times, error rates, and fMRI data were recorded. 2-Group (OCD, control) x 2-Previous Trial Congruency (congruent, incongruent), x 2-Current Trial Congruency (congruent, incongruent) ANOVAs were conducted for both behavioral and fMRI data. Indices of conflict adaptation were correlated with quality of life scores. There was a significant response time conflict adaptation effect collapsed across groups; however, there were no between-groups interactions or main effects. No error rate conflict adaptation was observed at any level of the analysis. On fMRI analyses, the dlPFC showed increased activation on incongruent relative to congruent trials collapsed across groups; however, no ACC activation differences were observed between current incongruent and congruent trials. Conflict adaptation-related activation was noted in the ACC collapsed across groups. The between-groups ANOVA revealed a significant cluster in the ACC with control participants showing greater ACC, medial prefrontal cortex, and left orbitofrontal cortex conflict adaptation activation-related activation relative to individuals with OCD. No between-groups differences were seen in the dlPFC. Conflict adaptation was not significantly related to quality of life. Individuals with OCD may use different neural processes to achieve similar behavioral results to those of healthy controls. Alternative explanations of conflict adaptation effects such as temporal learning theory are also discussed. Our hypothesized model for the ACC and dlPFC functioning as the evaluative and regulative components of cognitive control was only partly supported. ACC and dlPFC activation appeared to highlight different roles, but these roles may be independent rather than existing in a feedback loop. Although quality of life is significantly diminished in individuals with OCD, this loss of quality of life does not appear to be mediated by conflict adaptation differences.

Degree

PhD

College and Department

Family, Home, and Social Sciences; Psychology

Rights

http://lib.byu.edu/about/copyright/