Document Type

Thesis

Date of Degree Completion

Fall 2016

Degree Name

Master of Science (MS)

Department

Experimental Psychology

Committee Chair

Susan Lonborg, PhD

Second Committee Member

Kara Gabriel, PhD

Third Committee Member

Terrence Schwartz, PhD

Fourth Committee Member

Mary Radeke, PhD

Abstract

This study was conducted to investigate whether the number of traumatic events an individual has previously experienced influences that individual’s physiological and psychological reactions when exposed to a negative affective stimulus followed by a mindfulness-based stress reduction (MBSR) intervention. Twenty-eight participants were placed into intact quasi-experimental groups based on their scores on the Traumatic Life Events Questionnaire (TLEQ). The negative affective stimulus consisted of a series of photos bearing negative affective valence. The photos were selected from the International Affective Picture System (IAPS), and paralleled the areas of trauma exposure evaluated by the TLEQ. All participants were exposed to the same negative affective stimulus, but were randomly assigned to either the MBSR intervention or the inert control intervention. Alpha wave amplitude, as measured by EEG, and heart rate were assessed at three different times throughout the protocol. Participants’ self-reported negative affect was also measured at those same three times using the Positive and Negative Affect Schedule (PANAS). Since only half the sample (n = 14) consistently produced oscillations in the alpha range, parametric statistical tests were not performed on the EEG data. Separate ANOVAs were performed on both the heart rate and PANAS data. A significant interaction effect of the trauma group and intervention condition on overall heart rate was detected. Within the low trauma group, only, heart rate was significantly lower when exposed to the control condition compared to treatment. Time, overall, was found to have a significant effect on negative scale PANAS scores. Significant differences were found between baseline and the end of the intervention, as well as between the end of the photos and the end of the intervention. Significant differences were also found over time between the intervention conditions; scores differed significantly at all three time points within the treatment condition, only. No significant differences were found within the control condition over time.