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Could Meditation Modulate the Neurobiology of Learning Not to Fear?

Principal Investigators:

Mohammed R. Milad, Ph.D., Assistant Professor of Psychiatry, Massachusetts General Hospital and Harvard Medical School
Britta K. Hölzel, Ph.D., Postdoctoral Fellow, Lazar Lab, Massachusetts General Hospital and Harvard Medical School

It is well-established that the practice of mindfulness meditation leads to improvements in mental health and well-being and the cultivation of positive emotions. However, the neural mechanisms of these improvements are largely unknown. A few recent studies suggest that mindfulness meditation impacts the structure and function of the ventromedial prefrontal cortex, the hippocampus, and the amygdala. Interestingly, recent studies have shown that these regions are part of a brain circuit that is critical for the extinction of conditioned fear responses, and for the retention of fear extinction memory. Building on the overlap of these regions and on conceptual considerations, the project investigates whether mindfulness meditation could influence one's capacity to retain the memory of fear extinction. Meditation-naïve participants will be randomized to either a mindfulness-meditation based training or an active control training that controls for all mindfulness-unspecific components. Participants will undergo a fear conditioning, extinction and extinction recall protocol in an MRI scanner before and after the trainings. We hypothesize that participants who have practiced mindfulness meditation will show greater improvements in fear extinction memory after the course, and that these improvements will be correlated with anatomical and functional changes in the brain regions of interest. Improvements in fear extinction memory will also be related to improvements in self-reported psychological well-being. Merging the fields of an ancient spiritual tradition and a fundamental learning mechanism, the project investigates the underlying neural mechanisms of a practice for the enhancement of mental health and well-being.


Mohammed R. Milad obtained his Ph.D. in Behavioral Neuroscience at Ponce School of Medicine in Puerto Rico in which he examined the neural mechanisms of fear inhibition in rodents using single-unit recordings in awake animals. His findings revealed that the ventromedial prefrontal cortex (vmPFC) was involved in the consolidation of safety memory and in the inhibition of conditioned fear responses. Dr. Milad decided to translate his findings from rat into the human brain. As such, for his post-doctoral training, he joined the Department of Psychiatry at Harvard Medical School (HMS) and Massachusetts General Hospital (MGH) under the supervision of Dr. Scott Rauch to examine the neurobiology of fear inhibition in the human brain using functional MRI.

Through his recent work, Dr. Milad has identified a network of brain regions, including the vmPFC to be critical for fear inhibition in the human brain. Currently, Dr. Milad is an Assistant Professor of Psychiatry at MGH-HMS. He continues to conduct translation research that is primarily focused on understanding how fear inhibition can be strengthened, which could have substantial clinical implications.

Britta K. Hölzel holds a Ph.D. in Psychology and currently works as a Research Fellow at the Psychiatry Department at Massachusetts General Hospital (MGH), Harvard Medical School. For her Ph.D. thesis, she conducted two MRI studies comparing experienced mindfulness meditators to non-meditators, investigating the anatomical and functional neural differences between the groups. As a postdoctoral fellow in the lab of Sara Lazar, she is involved in anatomical and functional MRI studies with meditators and yoga practitioners. She is currently the PI on a longitudinal study investigating the effects of MBSR on healthy participants' emotion regulation with a paradigm that induces social threat. Dr. Hölzel was previously a Contract Lecturer in the Department of Biological Psychology at Frankfurt University and in the Department of Clinical and Biological Psychology at Giessen University, where she taught classes on Experimental Psychology, Clinical Psychology and yoga/ meditation classes. She has practiced meditation and yoga for over ten years, giving her an inside perspective on the phenomena she studies. She is also an MBSR instructor and teaches classes to healthy and patient populations. Dr. Hölzel has been awarded a Career Development Award by the European Commission, which will cover her salary until February 2012.

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