MGH Martinos Center for Biomedical Imaging 2016 | Page 25

new insights into the brain Meditation Can Improve Emotional Learning Diffusion tensor imaging reveals the associated structural changes in the brain Sara Lazar and colleagues at the MGH Martinos Center had shown that training in mindfulness meditation produces measurable, lasting changes in areas of the brain associated with memory, compassion and stress—that is, changes in the amygdala and in hippocampal gray matter density. And in doing so they had offered evidence for the neurological benefits of mindfulness. But they still weren’t certain of the exact behavioral significance of these changes. So in a more recent set of experiments, they set out to learn more. One of the ways in which mindfulness is thought to promote mental health is through changes in ‘emotional learning’: the process by which highly emotional stimuli can influence learning new information. Psychologists can assess this in subjects using a classical fear conditioning paradigm. To dive deeper into the changes they had observed, Lazar and her team applied this paradigm to study the impact of an eight-week Mindfulness-Based Stress Reduction (MBSR) course on emotional learning. Fear conditioning was particularly relevant to a study of mindfulness. “We specifically chose fear conditioning because an important aspect of meditation practice is to not turn away from unpleasantness, but rather to allow yourself to experience it without reactivity,” said La- © Can Stock Photo / paulprescott72 zar, an Assistant Professor of Psychology at Harvard Medical School and an affiliated faculty member in the Martinos Center. “Therefore we reasoned that meditation practice might influence classical fear conditioning. Furthermore, this is both an emotional task and a learning task, and thus engages both the amygdala and hippocampus.” emotion regulation. They found that changes in uncinate fasciculus correlated with change in conditioning, which suggests that mindfulness does in fact contribute to the maintenance of the sensitivity of emotional responses, and furthermore points to an underlying neural plasticity with respect to this. Other authors of the study include The investigators reported some of the Center’s Britta Holzel, Tim their findings in June 2016 in the Gard, Douglas Greve and Mohamjournal Frontiers in Behavioral Neu- med Milad. roscience. As part of the study, they looked at the plasticity of white matter during the paradigms—in particular, of white matter in the uncinate fasciculus, one of the primary white matter tracts associated with