How Meditation-related Changes in the Brain Affect Our Behavior?

Nowadays, it is rare to meet a person who is not practicing, has not tried, or at least heard of meditation. According to social media and various meditation gurus, it would seem that meditation can solve all of the problems of the modern world: stress, obesity, financial difficulty, insomnia, and anxiety, and cure various diseases, such as depression or cancer. But at the same time, mindfulness is still considered by many to be a very esoteric practice, associated with shamanism, chakra opening, or some other voodoo pseudoscience practice. Mindfulness is seen as something that is very 'unscientific'.

But what do science and peer-reviewed research articles say about meditation? This is the second article in a series called “Science of Meditation” where I describe the science behind meditation on how it affects our brain, body, behavior, and health. In the first article, we explored what happens in your brain when you meditate.

When applying one or another practice or intervention, it is useful to know which parts of the brain it affects, in order to understand whether the intervention is effective, how it works and how long the effect lasts.

However, it should not be forgotten that even the repeated movement of the little finger changes the structure and activity of the brain (for example, the part of the cerebral cortex responsible for the movements of the little finger). Anything we do (and especially repeatedly) changes the brain. This is the well-known neuroplasticity of the brain. Thus, structural and functional studies alone are not enough to understand the effects of meditation on our body, they need to be linked to observable changes in our state, behavior, and well-being caused by the intervention.

Therefore, in this article we explore how meditation related changes in the brain translate into our behavior with examples on stress, pain and sadness.

Meditation shapes our response to stress

One study showed that even a short meditation practice helps to better regulate emotional responses to negative stimuli, or stressors, due to altered brain activity in two brain regions – prefrontal cortex and amygdala.

The amygdala, amongst other functions, plays a prominent role in coordinating emotional responses such as fear, anxiety, aggression, and stress. Greater activity in the amygdala is associated with higher levels of stress and emotional reactivity. Meanwhile, the prefrontal cortex is our cognitive control center and therefore is responsible for impulse inhibition, prospective memory, planning, and decision-making. The prefrontal cortex has anatomical connections to many brain parts, including the amygdala, and can “supervise” them - increase or decrease their activity.

In the study, 46 people were shown neutral, positive, or negative pictures (stress trigger) while being in a functional magnetic resonance imaging (fMRI) scanner which measures brain activity in different brain regions, the amygdala, and prefrontal cortex in this case. Several seconds before the pictures appeared, a symbol was shown indicating what to expect - a negative, a positive, or a neutral picture. Half of the people were instructed to use mindfulness meditation practices while waiting for the picture to appear after the symbol, the remaining control group was told to simply wait for the picture and experience it.

When looking at negative pictures, the amygdala of the mindfulness meditation group was significantly less activated than the control group. This suggests that meditation is associated with lower emotional reactivity and potentially lower stress experiences during and after negative stimuli. Interestingly, during the anticipation phase, after seeing the symbol but before seeing the picture itself, the mindfulness meditation group showed significantly greater activity in the prefrontal cortex than the control group.

This could mean that while waiting for a negative stimulus (expecting something bad or unpleasant), mindfulness meditation engages the prefrontal cortex, which in turn "supervises" the amygdala and inhibits its activity thereby lowering emotional reactivity. Similar results were observed in another study in which mindfulness meditation was associated with lower levels of amygdala activity when viewing positive pictures as well. This may seem like a negative or unwanted result, but it is most likely related to one of the principles of meditation - not reacting to and identifying with our emotions but rather observing them neutrally.

Meditation softens our perception of pain

Meditation can also provide pain relieving, or analgesic, effects. A 2015 study showed that mindfulness meditation can reduce the experienced intensity and unpleasantness of pain specifically through activation of brain regions related to active mental control of pain experience or simply put - the power of thought.

In this study, participant’s brains were scanned in an fMRI scanner while their hand received a painful heat stimulus (heat was low enough not to cause burns, but high enough to cause unpleasantness/pain). The participants were free to remove their hands from the stimulus at any given time point. All subjects were separated into 4 groups: 1) placebo (fake painkillers), 2) a "sham meditation" (participants were told to sit with a teacher and close their eyes while taking deep breaths), 3) a relaxing activity (listening to an audiobook) and 4) a proper mindfulness meditation practice.

The results showed that although all interventions reduced pain perception compared to control (doing nothing) and placebo, mindfulness meditation had the greatest pain-relieving effect. Also, mindfulness meditation activates completely different parts of the brain than a placebo, indicating that the mechanism of action of mindfulness meditation is not the same as a placebo.

Meditation changes our response to sadness

A study by researchers from University of Toronto investigated how mindfulness meditation affects our response to sadness. Study participants watched film clips that were either neutral or provoked sadness while their brain activity was measured in an fMRI scanner. There were two groups – mindfulness meditation and control.

Sadness activated brain areas that were characteristic of cognitive elaboration, increased self-focus, and ruminative problem-solving that would be typical of reappraisal processes. Yet researchers found that the meditation group demonstrated less neural reactivity to sadness provocation than the control group. Moreover, the mindfulness meditation group showed higher activity in brain regions associated with increased interoceptive awareness and empathy and decreased activity in brain regions associated with rumination (overthinking), autobiographical memory retrieval, self-referential processing, and language areas.

As such, according to the authors “By balancing participants' regulatory responses to sadness with coordinated monitoring of less valenced and more sensory visceral information, mindfulness may represent one neural path for reducing affective reactivity and disorder vulnerability.”. Simply put – meditation practitioners are not as carried away by their sadness as non-meditators and therefore might be more resilient to sadness-related mental disorders.

One of the central cornerstones of meditation is that we can observe emotions without becoming too entangled in them. Research shows that meditation-related changes in the brain affect us in a way that we are more stress resilient, are not as affected by pain, and are not carried away by our sadness. The following article in this article series on meditation will explore how meditation affects our body – our stress hormones, immune system, glucose control, and more.