Cognitive-Affective Neural Plasticity following Active-Controlled Mindfulness Intervention

Summary

A six-week randomized trial compared mindfulness training to an active control condition in healthy adults. Both groups improved on a response-inhibition task, but only the mindfulness group showed reduced emotional conflict on an affective Stroop task. The mindfulness group also showed greater dorsolateral prefrontal cortex activity during executive processing, suggesting increased use of top-down control. No overall group differences emerged for negative affect-related reaction times or brain responses. However, participants who practiced mindfulness the most showed improved response inhibition and greater recruitment of dorsal anterior cingulate cortex, medial prefrontal cortex, and right anterior insula during negative-valence processing. The findings indicate that mindfulness training engages distinct neural mechanisms at progressive stages and that optimal application may depend on context.

Study at a glance

Abstract

Mindfulness meditation is a set of attention-based, regulatory, and self-inquiry training regimes. Although the impact of mindfulness training (MT) on self-regulation is well established, the neural mechanisms supporting such plasticity are poorly understood. MT is thought to act through interoceptive salience and attentional control mechanisms, but until now conflicting evidence from behavioral and neural measures renders difficult distinguishing their respective roles. To resolve this question we conducted a fully randomized 6 week longitudinal trial of MT, explicitly controlling for cognitive and treatment effects with an active-control group. We measured behavioral metacognition and whole-brain blood oxygenation level-dependent (BOLD) signals using functional MRI during an affective Stroop task before and after intervention in healthy human subjects. Although both groups improved significantly on a response-inhibition task, only the MT group showed reduced affective Stroop conflict. Moreover, the MT group displayed greater dorsolateral prefrontal cortex responses during executive processing, consistent with increased recruitment of top-down mechanisms to resolve conflict. In contrast, we did not observe overall group-by-time interactions on negative affect-related reaction times or BOLD responses. However, only participants with the greatest amount of MT practice showed improvements in response inhibition and increased recruitment of dorsal anterior cingulate cortex, medial prefrontal cortex, and right anterior insula during negative valence processing. Our findings highlight the importance of active control in MT research, indicate unique neural mechanisms for progressive stages of mindfulness training, and suggest that optimal application of MT may differ depending on context, contrary to a one-size-fits-all approach.