Sustained modulation of emotion-related fibers after 8 weeks of mindfulness-based stress reduction training

An 8-week mindfulness-based stress reduction (MBSR) program enables novices to learn and practice mindfulness meditation. A longitudinal study design has been used in prior research to investigate the effect of short-term mindfulness meditation training on brain structures. Many studies have demonstrated microstructural changes in the white matter by comparing baseline measurements with measurements obtained immediately after short-term meditation training. However, these studies did not clarify the evolution of the modulated microstructures several months after mindfulness meditation practice is discontinued. Therefore, in this study, we recruited 13 novice practitioners and administered an 8-week MBSR training program. We extended the span of the longitudinal study by adding a third measurement taken approximately 6 months after the second time point. Diffusion indices derived from diffusion spectrum imaging were used to quantify the temporal changes in modulation across three time points. The analysis identified four tract bundles that were significantly modulated after the 8-week MBSR training program, namely the callosal fibers connecting the bilateral amygdalae and bilateral hippocampi, right thalamic radiation of the auditory nerve, and right uncinate fasciculus. At the third time point, at which the participants had discontinued practice for approximately 6 months, the diffusion indices of the four tract bundles still presented a significant difference compared with the baseline. Our results indicate that the modulation of microstructural properties of the white matter tract induced by the 8-week MBSR program was sustained after completion of the program and support that neuroplasticity in brain connection persists after the discontinuation of meditation training.