Investigating Normal and Pathological Variation in Memory-based Inhibition: An Examination of Worry, Thought Suppression, and Stimuli Characteristics

Dedication This dissertation is dedicated to Robert A. Brown. Your support has made my work possible. Your generosity, patience, kindness, and wisdom continue to teach me what is important in life. I hope to have the opportunity to give to others a fraction of what you have given to me. Thanks dad. This work was conducted in an effort to better understand the role that activational mechanisms in memory play in the etiology and maintenance of anxiety disorders. The affect of word stimuli characteristics, such as affective valence and semantic association with worry, on the association between inhibition and trait worry was investigated under different types of induced thought. Previous research has demonstrated that worry is associated with negative affect, and that worry may be semantically organized in memory. Based on these findings, it was hypothesized that words would be differentially inhibited in association with trait worry when worry was induced compared to neutral thought. Stimuli characteristics including the positive or negative affective valence of words, and their semantic association with common domains of worry were expected to moderate the relationship between inhibition and trait worry. In order to investigate these hypotheses, 86 undergraduate students from the University of Texas at Austin completed a series of memory tasks designed to measure vii inhibition for either negative or positive words, both associated and unassociated with worry. They underwent either idiopathic worry or neutral thought induction prior to completing each memory task, and completed questionnaires assessing trait worry and thought suppression. The findings provide partial support for the hypotheses. Higher levels of trait worry were associated with less inhibition of negative words, but more inhibition of positive words semantically associated with worry. Contrary to predictions, differential induction of worry did not affect the relationship between inhibition and trait worry. The research and clinical implications of these findings are discussed.