The Effect of Predisposing Risk Factors of an Eating Disorder on Response Inhibition and Working Memory: An Event-Related Potentials Study

摘要

A novel investigation was undertaken to assess the effect of a predisposition to an eating disorder on P3a and P3b event-related potentials. Previous research has suggested the P3a and the P3b are reliable markers of inhibitory control and working memory updating, respectively. An opportunity sample of 12 female participants was obtained with mean age of 22.42 (SD = 2.61). Participants completed the Eating Disorder Inventory – 3 assessing their predisposition to an eating disorder along with scores on the included subscales. Response inhibition and working memory was measured using the 3 Stimulus Oddball Task. This task elicits a P3a component in response to novel infrequently presented stimuli and the P3b component in the response to expected infrequent stimuli. Findings showed no evidence of an interaction between an overall predisposition to an eating disorder and P3a and P3b activations. However, results ascertained a significant positive correlation between Body Dissatisfaction scores and the P3a amplitudes. Individuals with a high score on body dissatisfaction scale showed greater activation towards the frontal region than those with a low score during the executive component task, i.e. the greater the score the greater hyperactivity in the frontal area of the brain during response inhibition. With regards to the working memory component, no significant effects were found. Although head maps for body dissatisfaction scores and working memory illustrated that there was a wider spread of activation for the high body dissatisfaction group, rather than concentrated activations in the parietal region.The implications of such results in respect to compensatory activations, the inability to ignore and possible dopamine involvement are discussed.