Posted 09.23.2020 | by AMRA
Meditation practice reportedly affects the gray (cell bodies) and white matter (axons) of the brain. However, cross-sectional studies comparing meditators to non-meditators are inconclusive, while many longitudinal studies employ multiple meditation techniques. This makes it difficult to pinpoint the meditation practices responsible for specific brain changes.
Lenhart et al. [Behavior Brain Research] tested for brain changes in gray and white matter in meditation-naïve adults who completed a seven-week focused-attention meditation training.
The researchers studied 27 meditation-naïve adult Austrian participants (63% female; average age=43 years) who attended all fourteen 45-minute sessions of a seven-week focused-attention meditation training program. The program taught a breath-body-mind centered raja yoga method that involved elements of focused attention to breathing (pranayama) and retraction of the senses (pratyahara). The training also required 15-30 minutes of daily home practice.
Participants underwent magnetic resonance imaging (MRI) before and after the training program. They also completed a pre- and post-training self-report assessment of anxiety symptoms. Gray matter volume changes were assessed using whole-brain voxel-based morphometry, and white matter integrity changes were assessed using fractional anisotropy.
Results showed significant gray matter volume increases in the anterior insula, inferior frontal gyrus, superior frontal gyrus, caudate nucleus, and right cerebellum after the intervention. Significant gray matter volume decreases were detected in inferior parietal lobe, superior and middle temporal gyri, inferior frontal gyrus, medial prefrontal cortex, parahippocampal gyrus, and posterior cingulate cortex.
White matter showed increased integrity in the right basal ganglia, right hippocampus, and supraventricular region after the intervention.
The sample had a significant decrease in anxiety after the intervention, and decreases in anxiety were significantly associated with gray matter volume changes in the right-mid cingulate cortex, posterior cingulate cortex, and medial prefrontal cortices.
The study shows that intensive focused-attention meditation practice is associated with both gray and white matter changes in the brain. The researchers hypothesized these changes reflect how focused meditation reorganizes the fronto-insular brain regions responsible for sustained attention, self-control, and self-awareness.
The study is limited by the lack of a comparison group controlling for the socializing effects of a group-based intervention and other skills requiring intense focus for a similar amount of time.
Lenhart, L., Steiger, R., Waibel, M., Mangesius, S., Grams, A. E., Singewald, N., & Gizewski, E. R. (2020). Cortical reorganization processes in meditation naïve participants induced by 7 weeks focused attention meditation training. Behavioural Brain Research, 395, 112828.