Graduation Year


Document Type




Degree Name

Doctor of Philosophy (Ph.D.)

Degree Granting Department


Major Professor

Geoffrey Potts, Ph.D.

Committee Member

Chad Dubé, Ph.D.

Committee Member

Liz Schotter, Ph.D.

Committee Member

Michael Brannick, Ph.D.

Committee Member

Christine Vinci, Ph.D.


Emotion, ERN, Executive, Nonjudgmental, P300


Given the increased popularity of mindfulness in both the clinical settings and the general public, it is important to understand the active mechanisms of mindfulness. Mindfulness practice (MP) involves two active components, attention regulation and acceptance of experience, being aware of the current experience as it is without evaluating the experience as positive or negative. Much research has evaluated the attention regulation component and found that MP improves high-level (effortful) attention with few reported effects on low-level (automatic) attention. It is unclear whether MP affects merely low- or high-level attention, or both, because little empirical research has examined both low- and high-level attention simultaneously. Existing mindfulness studies on acceptance have often employed emotional labeling tasks, which might not elicit reliable emotional experience as self-generate emotional events because emotional experience arising from self-generate emotional events is more relevant to the subject. The current project adopted a randomized pretest-posttest design to examine both components of mindfulness through inducing a brief 10-minute guided mindfulness intervention (MI) among participants who have no prior experience with mindfulness-related exercise. The control group listened to a 10-minute TED talk about green living. Neural indices of attention and affective reactivity were measured using event-related-potentials (ERPs), summed activity of postsynaptic potentials among a large scale of neurons. Study 1 examined whether MI affected low-level attention (indexed by P3a), high-level attention (indexed by P3b), or both. Participants completed a visual Novelty Oddball Task that captures both low- and high-level attention. Our results showed that MI improved high-level attention to a greater extent than the control condition. We were not able to evaluate the impact of MI on low-level attention because the experimental design failed to elicit a P3a component. Possible reasons are discussed in the Discussion and Limitations. Study 2 examined whether MI improves the general state of acceptance measured by self-report decentering and reduces affective reactivity to negative experience as measured by the error-related negativity (ERN) and post-error slowing (PES). Participants completed a Flanker Task, a speeded reaction time task that is prone to errors. The results demonstrated increased self-reported acceptance, but this effect was not manifested in behavioral and neural measures of affective reactivity; instead, a practice effect was revealed as indicated by faster RT and increased certainty of response. Taken together, these findings suggest that attention, but not acceptance, can be reliably altered through a brief MI. MI is more efficient than the control intervention in improving attention.