Structural and Functional Brain Changes Associated with Mindfulness Meditation

Plasticity of the brain:

Contrary to previous beliefs that many centers in the brain and neural connectivity have the capacity to change structurally and functionally only occur in children, recent research confirms that brain changes (either positively or negatively based on experience and the environment a person raised) also possible during adult life.  Meditation-derived changes are a good example of such “plasticity of the brain;” the capability and the capacity of the brain to adapt. Regular practice of meditation favorably improves the structure and the higher-functions of the brain. 

We can exploit this unique capacity of plasticity of the human brain to adapt and modulate our cerebral centers, particularly the prefrontal cortex and areas such as the hippocampal regions, by transmitting constant positive signals generated through mindfulness and other meditative practices. 

Regular meditation practices facilitate positive changes in the brain that are associated with improvement of inner peace, calmness, compassion, less reactivity, more rational thinking and a better ability to solve problems. Data from recent scientific studies have demonstrated the capability and capacity of the brain to adapt through the maintenance of mindfulness and regular practices of meditation.

What brain changes are expected in chronic stresses vs. maintenance of mindfulness:

Improved structure and functions of the brain among longer-term meditators were reported in the results from several neuroscience centers in the United States that compared data from computed tomography (CT) scans, magnetic resonance imaging (MRI), and functional MRI (fMRI) obtained from meditators and non-meditators. These areas of improvement included but were not limited to memory, tolerance and compassion, understanding, and reactions, which allowed the meditators to make better decisions. 

Above-mentioned data suggest that longer-term meditative practices promote path for structural and functional changes in human brain, which until recent years, we thought is not possible in adults. Engaging in unwholesome activities; experiencing constant anger, envy, or stress (one-time or frequent exposure); and being subjected to other “mental irritants” and disorders, such as psychosis or chronic depression, can lead to negative changes in the brain. Examples of these, such as post-traumatic stress disorder (PTSD), are discussed in the next article.  

Key structural changes associated with mindful meditation:

MRI brain scans have demonstrated that among those who practice mindfulness practices long term experience a reduction in the size of the “stress centers,” particularly the amygdala, which is the reactive center in the brain that fires the fight or flight responses. However, mindfulness meditation practices increase the thickness of the grey matter, which is associated with higher brain functions, such as concentration, awareness, and decision making. Such practices also lead to thickening of the hippocampus, which is associated with long-term memory in the brain that connected with cortical regions. 

Amygdala--the stress center: The amygdala is an area of the brain that is associated with emotions, fear, and acute recognition of alarming or frightening stimuli. The latter could also arise from signals that are generated internally (repeated reflections of unpleasant experiences, imaginary threats or dangerous situations) arising from current external signals that mimic previous experiences (albeit milder or not actually real), such as occurs in those with PTSD.  

While the gray matter content (hence, the size) of amygdala reduce in regular meditators, it increases in those with PTSD. Enhancements of the “stress center” (amygdala), continues to generate barrages of signals that interact with other centers on the limbic system, including the hypothalamus that is connected to the pituitary gland, which modulate stress-hormone releases. 

Mindfulness activities pave the path for neuroplastic changes in cortico-limbic circuits. In addition to to shrinkage of amygdala, mindfulness is also associated with decreased grey matter volume in the left caudate.  These areas are associated with emotion regulation and stress. These size changes persisted, even after controlling for individual differences in study participants.  Authors of this study conducted that observed volumetric differences might explain why mindful individuals have reduced stress reactivity, and suggest new structural neurobiological pathways linking mindfulness with mental and physical health outcomes. Negative vicious cycle of signaling arising from amygdala exacerbate stress and stress-related signs and symptoms, leading to appropriate or inappropriate responses to stress.  

Specific brain areas that have been shown to change with meditation:

Recent research data suggest that in those who regularly meditate, the grey matter content is increased in the anterior cingulate cortex located behind the frontal lobe. Thickening of grey matter is a constructive change in the brain and in this case is associated with improving the functional capacity of thinking and rationality. This area of the brain is also known to control self-regulatory processes, behavioral responses, such as monitoring conflicts, and cognitive flexibility.

In addition, the grey matter content increases in the cortical regions in the prefrontal lobe, which are responsible for higher executive functions, such as emotion regulation, planning, and problem solving. Thus, the overall structural changes reported with the meditative practices are positive for human understanding, calmness, compassion, responses, and behavior. 

The grey matter content also increases in the hippocampus, a part of the limbic system that controls longer-term memory and the process of learning, in long-term meditators. In contrast, the hippocampus shrinks in people with “chronic stress,” such as those with PTSD or severe chronic depression. Modern methods of pharmacology and cognitive-based therapies can reduce the symptomatology of PTSD but not cure the disease. Thus, we are missing an important piece of action that is needed to cure those with these diseases, the Mind.

Mindfulness can also be achieved via other means, such as the practice of yoga:

In addition of the straightforward practices of mindful meditation, one could incorporate  carefully designed yoga or tai chi practices to break the cycle of lack of mindfulness, enabling one to reach a healthy mind?body connection.

Mindfulness meditation, yoga, tai chi, and other similar eastern practices bring attention to the bodies of the practitioners while keeping the mind still and silent in the present (at least during the practice), thus minimizing the mind rushing to the past or the future. It is intriguing that these healthy practices can be systematically incorporated as an adjunct therapy into the treatment of conditions, such as PTSD virtually at no cost, allowing to cure these disorders. 

The goals of these practices are to keep the mind in the present moment (here and now), which strengthens the mind to block anger, jealousy, unhealthy competition, the repeated revisiting of bad memories, all of which can fuel clinical breakouts of bad behavior, anger, PTSD, or severe depression.  

Improving the health of the mind and the body via mindful meditation:

With the ability to focus the mind on the present moment, children and adults have the unique opportunity to improve their ability to listen, comprehend, and react appropriately within the social- and religious-accepted means. One of the key secondary (unintended) benefits of these programs is an improvement in behaviors irrespective of the age and academic standards and the ability to focus better on whatever the person is engaged in. 

Attending mindfully also improves personal and community health and prevents diseases. As pointed out in a previous article in this series, another key benefit of practicing mindfulness is to improve listening skills. Doing so generates a positive cycle of listening, hearing, and comprehending verbal messages, which leads to better understanding and memory of instruction and minimizing errors in carrying out tasks.  

The regular practices of mindfulness, such as walking mindfully, sitting and eating, listening and communicating mindfully, and bringing the awareness to the body and the postures to activities of daily living, go beyond self to the family, community, and the environment. In addition, the broader benefits of mindfulness can be harmonized families and communities, which benefits all. In summary, practicing mindfulness increases the ability to focus and concentrate; it increases the neuronal density of the brain in critical areas, such as that mediate thinking, kindness, and peace.  

The next article examines how one could use mindfulness meditation to break the vicious cycle of chronic stress, such as post-traumatic stress disorder.

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Professor Sunil J. Wimalawansa, MD, PhD, MBA, DSc, is a physician-scientist, an educator, social entrepreneur, and a process consultant. He is a philanthropist with experience in long-term strategic planning, cost-effective investment and interventions globally for preventing non-communicable diseases. [recent charitable work]. The author has no conflicts of interest; he has received no funding for this work.