Interaction between Neuroanatomical and Psychological Changes after Mindfulness-Based Training

Several cross-sectional studies have documented neuroanatomical changes in individuals with a long history of meditation, while a few evidences are available about the interaction between neuroanatomical and psychological changes even during brief exposure to meditation. Here we analyzed several morphometric indexes at both cortical and subcortical brain level, as well as multiple psychological dimensions, before and after a brief -8 weeks- Mindfulness Based Stress Reduction (MBSR) training program, in a group of 23 meditation naïve-subjects compared to age-gender matched subjects. We found a significant cortical thickness increase in the right insula and the somatosensory cortex of MBSR trainees, coupled with a significant reduction of several psychological indices related to worry, state anxiety, depression and alexithymia. Most importantly, an interesting correlation between the increase in right insula thickness and the decrease in alexithymia levels during the MBSR training were observed. Moreover, a multivariate pattern classification approach allowed to identify a cluster of regions more responsive to MBSR training across subjects. Taken together, these findings documented the significant impact of a brief MBSR training on brain structures, as well as stressing the idea of MBSR as a valuable tool for alexithymia modulation, also originally providing a plausible neurobiological evidence of a major role of right insula into mediating the observed psychological changes

Groups demographics and psychological changes after MBSR.

<p><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0108359#pone-0108359-t001" target="_blank">Table 1</a> shows demographic data and pre (t0) – post (t1) MBSR changes in psychological dimensions of both groups of participants. P-values refer to a repeated measure ANCOVA (p<.05).</p><p>Groups demographics and psychological changes after MBSR.</p

Optimized morphovolumetric analysis results.

<p><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0108359#pone-0108359-t002" target="_blank">Table 2</a> reports anatomical clusters of increased cortical thickness values after MBSR exposure. Voxel count, MNI coordinates and peak F-values are reported. Results referred to paired t-statistics obtained using a multiple comparisons correction based on a Montecarlo simulation with a corrected p<.05.</p><p>Optimized morphovolumetric analysis results.</p

Pre-Post MBSR thickness comparisons and correlation between psychological and morphometric results.

<p>Panel A reports insula and somatosensory cortex average cortical thickness values for both groups, calculated before and after the MBSR/wait-list periods. Significant pre-post differences for MBSR group participants obtained using a repeated measures ANOVA model are reported. Scatterplot in panel B refers to the significant inverse correlation between the pre-post MBSR change in insula cortical thickness (y axis) and participants alexithymia level (x axis) (ΔBrain/ΔPsy index, z-scores, MBSR group R² = .45, wait-list group R² = .012).</p

Morphometric changes after MBSR.

<p>Panels A, B, C and D show the results of voxel-wise cortical thickness comparison between MBSR trainees and control-group participants (repeated measures ANCOVA, p<.05, Montecarlo correction for multiple comparisons; individual VBCT masks), with clusters of increased thickness plotted on a reference T1-weighted image in MNI space and radiological convention. Specifically, panels A and C show axial, coronal and sagittal views of right somatosensory cluster, while B and D show the cluster located in the right insula.</p