Meditation encompasses a family of complex practices that include mindfulness meditation, mantra meditation, yoga, tai chi, and chi gong. Of these practices, mindfulness meditation is one of the most popular. Jon Kabat-Zinn, a scientist who helped popularize mindfulness in the West, defines mindfulness as “awareness that arises through paying attention, on purpose, in the present moment, non-judgmentally.” In the context of the broader scientific research community, mindfulness generally refers to a self-regulated attentional state focused on present moment experiences, emphasizing curiosity, openness, and acceptance.
Reported benefits of meditation practice include more focused attention, relaxation, positive shifts in mood, enhanced self-awareness, and overall improved health and well-being. For this reason, mindfulness meditation has received a great deal of attention in neuroscience over the past two decades. The question that many scientists have been trying to address is: what does meditation really do to the brain to bring all these positive effects? To answer it, a multidisciplinary field called contemplative neuroscience was born, and it is rapidly growing. Contemplative neuroscience investigates the underlying neural mechanism of ancient meditation practices, together with their clinical, psychological, and neurological manifestations, to explore the neuroscientific evidence of meditation.
The human brain is a fascinating and powerful machine. It contains between 80 to 100 billion cells – called neurons – that communicate with each other through hundreds of trillions of synapses. Over the past ten years, several neuroimaging and observational studies have explored changes in brain morphology and function following mindfulness meditation. Meditation’s effects on the brain can be divided into two categories, called state changes and trait changes. State changes are alterations in brain activity during the act of meditation, while trait changes are alterations observed as an outcome of long-term practice. The most widely used techniques to assess these changes are electroencephalography (EEG) and functional magnetic resonance imaging (fMRI).
Studies have shown benefits against an array of conditions, both physical and mental, including irritable bowel syndrome, fibromyalgia, psoriasis, anxiety, depression, and post-traumatic stress disorder. Some of those findings have been questioned because the studies had small sample sizes or faulted experimental design. However, it is clear that for a number of key areas – including depression, chronic pain, and anxiety – well-designed and well-run studies have undoubtedly shown benefits for patients engaging in a mindfulness meditation program, with effects similar to other existing treatments.
A very useful tool to collect strong scientific evidence is called meta-analysis, and it is the analysis of data pooled from many different studies. Some of the strongest neuroscientific evidence to date for the positive health benefits of meditation come from two meta-analyses of meditation research. The first meta-analysis of 47 clinical trials with 3,515 participants in total found that people participating in mindfulness meditation programs experienced less anxiety, depression, and pain. The second meta-analysis of 163 studies found evidence that meditation practice is associated with reduced negative emotions and neuroticism. Even more interestingly, the impact of meditation was comparable to the impact of behavioral treatments and psychotherapy on patients.
Because of the increasing popularity of mindfulness meditation and mounting evidence that meditation has wide-ranging and measurable effects on many aspects of health, neuroscientists too are becoming interested in understanding the biological mechanisms that underlie these effects in the brain. A systematic meta-analysis, including 21 neuroimaging studies, examined the brains of more than 300 experienced meditators and found fascinating results. It revealed that there are eight specific regions of the brain which appeared regularly changed in experienced meditators. These eight regions are the rostrolateral prefrontal cortex, the sensory cortices, the insular cortex, the hippocampus, the anterior cingulate cortex, the mid-cingulate cortex, the superior longitudinal fasciculus, and the corpus callosum. But, beyond their complicated-sounding names, let’s see what these regions are responsible for and how they change in response to meditation. In response to consistent mediation practice, the study found that all these areas changed in terms of density and thickness of the brain tissue, especially the white matter fibers. The rostrolateral prefrontal cortex is a region of the brain that is linked with a greater awareness of the thinking process, the processing of complex, abstract information, and introspection. The sensory cortices and insular cortex are the parts of the brain that are the main cortical hubs for tactile information, like touch, pain, body awareness, and conscious proprioception. The hippocampus is a structure involved in the formation of memory as well as facilitating emotional responses. The anterior cingulate cortex and mid-cingulate cortex are connected with self-control, regulation of emotions, as well as attention. The superior longitudinal fasciculus and corpus callosum are what is called white matter tracts. These areas communicate between and within the hemispheres of the brain. Therefore, we can see how meditation involves multiple aspects of brain function and facilitates neuroplasticity and connectivity in specific brain areas related, amongst others, to emotion and attention regulation, a very promising insight for contemplative neuroscience.
To conclude, it is clear that meditation has a profound impact on neurological function, in addition to exhibiting other biological effects. Contemplative neuroscience research has shown that through the active and intentional shaping of our brains (neuroplasticity), we can promote and cultivate well-being. Well-being is a complex phenomenon related to various factors, including cultural differences, socioeconomic status, health, the quality of interpersonal relations, and specific psychological processes. Clinical research suggests that an ability to distance oneself and observe the ongoing internal train of thoughts plays a vital role in psychological well-being, and this is where mindfulness meditation becomes crucial, even in the absence of particular medical issues. Additionally, engaging in mindfulness meditation practice is promising in terms of treatment of clinical disorders such as depression and anxiety. Recent and emerging data indicate that the practice of meditation may also alter non-neuronal biological systems such as pain processing and energy metabolism, indicating a genuinely holistic mind-body impact from a relatively simple, cost-free therapeutic strategy. While the field of research into meditation and its substantial effects on the human brain and body is still developing, the data we have so far support a prominent role for meditative practice in a wide range of medical conditions and overall well-being.
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Arianna Ferrini is a postdoctoral research fellow at University College London (UK) and a freelance scientific writer and illustrator. She holds a PhD in Tissue Engineering and Regenerative Medicine from Imperial College London (UK) and an MSc in Medical and Pharmaceutical Biotechnology from the University of Florence (Italy). She’s an avid reader, a nature lover and a wanna-be ukulele player.