What Can Neuroscience Research Tell Us About the Meditative Brain?
This past month my daughter gave me a set of meditation CDs for mother’s day, and I have begun to put them to good use—but I have to admit that it has not been all that easy to quiet my brain and be in “a state of mind cultivated by paying attention on purpose, deeply, and without judgment to whatever arises in the present moment, either inside or outside of us.” Not one to give up easily, I have continued my 20 minutes of meditation practice daily but as a neuroscientist, I would really love to better understand what goes on in my brain during these sessions…
This sentiment seems to be shared widely by the scientific community and the public at large—there has been a growing interest in meditation practices; they are practiced in multiple forms (with and without movement); and they are used for multiple reasons including enhancing the quality of life, reducing psychological stress, and improving health outcomes. Meditation has been practiced since ancient times as a component of religious traditions and beliefs. There are, however, various styles of meditation practices; all include some training of the mind and self-induction of a mode of consciousness to realize some benefit. Walsh and Shapiro refer to meditation as a “family of self-regulation practices that focus on training attention and awareness in order to bring mental processes under greater voluntary control and thereby foster general mental well-being and development and/or specific capacities such as calm, clarity, and concentration” (2006). In the West, meditation is sometimes thought of in two broad categories: concentrative meditation and mindfulness meditation, with concentrative meditation being used interchangeably with focused attention (voluntary focusing of attention on a chosen object) and mindfulness meditation being used interchangeably with open monitoring (non-reactive monitoring of the content of experience from moment to moment).
Neuroscience research has provided a deeper understanding of how our brain works, and we now know that a well-functioning brain is essential for human mental activity and behavior. Different domains of information processing, including cognition, emotion, consciousness, and sense of self can be characterized through activation or inhibition of specific brain structures and circuits. The biologic factors associated with mindfulness meditation may include changes in brain function documented using electrophysiology, single photon emission computed tomography (SPECT), positron emission tomography (PET), and functional magnetic resonance imaging (fMRI). Recently, researchers using structural magnetic resonance and diffusion tensor imaging technology have found that people develop measurable physical changes in both gray and white matter of the brain after learning mindfulness meditation.
NCCAM researchers are exploring the associations of major pathways of cognitive processing and emotion regulation by meditative practices. Most of the research on the neuroscience of meditation has been focused on mindfulness meditation because it is reasonably well standardized and allows pre-post study within a manageable timeframe. Results from these studies suggest that meditation acts on areas of the brain involved in self awareness, attention, and emotion; long-term training can result in sustained effects but short-term training may have effects as well in helping individuals cope better with stress, negative affect, and trauma.
However, these are generally small (n) mechanistic studies in healthy subjects, and little is known of individual differences, acceptability, or differences in disease states. While brain imaging methodology continues to evolve, reproducible signals need to be aligned with meaningful behavioral mechanisms in a causal way. Larger clinical studies will have to be conducted to definitively clarify the mechanisms and pathways by which meditative strategies may impact health and identify biological measures of the impact of meditation. We also need to develop and validate better objective outcome measures of meditation practices; indices of expectancy and adherence specific to these practices; and precise criteria (processes and practices) of intervention fidelity for specific practices.
Meanwhile, I continue my daily meditation practices—striving for better concentration, self-control, and good health…