Electronic Theses and Dissertations

Date of Award


Document Type


Degree Name

Ph.D. in Psychology



First Advisor

Kelly G. Wilson

Second Advisor

Allison Burkette

Third Advisor

John Young

Relational Format



Individuals with commonly diagnosed psychological disorders often apply self-labels that have a negative effect on behavior. In Acceptance and Commitment Therapy, defusion exercises are designed to de-emphasize the literal interpretation of thoughts (such as self-labels) so that behavior is less controlled by verbal rules and more sensitive to direct interaction with the environment. Although existing self-report measures sensitive to changes in believability are an important step in establishing the utility of defusion interventions, it is also worthwhile to develop behavioral markers of fusion/defusion with self-referential content. The matching-to-sample (MTS) task, commonly used in basic behavioral research, examines the ability of participants to relate different stimuli. Performance on this task can demonstrate whether relating stimuli is disrupted by one's learning history, making it a potentially useful paradigm for assessing cognitive fusion. Results of the current study offer preliminary evidence for the utility of the MTS procedure in detecting disrupted responding when stimulus classes are incompatible with learning history. Participants in the fusion condition made more errors on the self-relevant classes compared to the neutral class, whereas those in the defusion condition shorelatively equal responding regardless of class type. Evidence of enhanced transfer of stimulus functions (facilitated acquisition) was not found in the current study. If the effects are improved and replicated, the MTS task has potential as a behavioral marker of fusion in the context of evaluative self-referential labels.


Emphasis: Clinical Psychology

Included in

Psychology Commons



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