The mechanisms of mindfulness meditation

Can you imagine staying two weeks in a house in the middle of nowhere, surrounded by people you are not allowed to talk to, where your daily task is being aware of the present moment, by paying attention, on purpose, in a non-judgmental manner? That’s what I experienced at a mindfulness meditation retreat. No phone, no books, no writing… It was challenging, but definitely an eye-opening experience. We sometimes feel so caught in thoughts that we are not really conscious of them and the harm they may do to us and to those around us.

Mindfulness is noticing how all phenomena arise, whether thoughts or physical sensations, and after a while, go away. This can help us be more aware of our mental patterns and therefore change them. Aside from retreats, one can also develop mindfulness with the help of a meditation course or an app. Meditation has been found to induce positive changes in attentional skills, emotion regulation, stress reduction, and relationships [1]. Moreover, it is used as a tool for treating anxiety and depression [2], among other disorders. What are the psychological and neural mechanisms behind such results? Follow my experiences at the retreat to learn more about them.

    1. ATTENTION

      At the retreat, we were instructed to sit down, close our eyes, and focus on our breath. If you try this yourself, you may realize that, after a few breaths, your mind is somewhere else. Gently go back to your breath. After a short while, your mind may start wandering again. This loop is repeated over and over throughout a typical meditation session. This has interesting neural correlates [3]: when your focus is on your breath, your central executive network, involved in cognitive functions such as attention, is more active. Suddenly, your mind starts wandering – that’s when your default mode network has become more active, since it’s related to reflecting about oneself or others, remembering the past or imagining the future. After a while, your salience network becomes active. This network is involved in detecting salient stimuli, which is key in task monitoring. This way, you realize that you’re not doing what you’re supposed to do, and you shift your attention back to your breath.

      With practice, as it happened as the days in the retreat passed by, your attention gets better. Your mind is less likely to get lost in thoughts, and when that occurs, you realize it faster. Indeed, experienced meditators show better performance and faster reaction times than non-meditators in several tasks involving attention, and have structural changes in areas related to attention, such as a greater cortical thickness in the dorsal anterior cingulate cortex, part of the salience network [4].

        2. BODY AWARENESS

          Besides sitting meditation, we also practiced walking meditation, moving slowly and noticing the small events that take place at each step: bringing the heel up, lifting the foot, moving the foot, touching the ground, putting the whole foot on the ground. Whenever other bodily sensations (like itchiness, heat, or pain) come into consciousness, you may stop walking and focus on those sensations as objectively as possible: without reacting to it, just observing it. This also trains attention, because you experience mind wandering in a similar way to sitting meditation, but you additionally train body awareness and acceptance. Meditators who have practiced in a similar way have greater activation in the insula (involved in interoceptive awareness) and secondary somatosensory cortex (relevant for processing exteroceptive events) than non-meditators when focusing on their momentary experience. A greater cortical thickness in the insula and in the temporo-parietal junction has also been found in meditators. The latter is a crucial structure for mediating the first-person perspective of bodily states  [4].

            3. EMOTION REGULATION

              Having to follow rules at the retreat was not always easy and I sometimes experienced anger when confronted with things I didn’t like. While trying to follow the instructions of mindfully observing my body as well as my mental states, I would turn the attention inwards whenever I felt angry and would try to find this anger. But each time I was about to find it, I discovered that it had somehow dissolved. As the retreat progressed, I felt less emotionally reactive (fewer automatic reactions, and faster return to emotional baseline after reactivity), and my mood increased. This has been shown in studies, where meditators have less startle response and faster decrease in skin conductance in response to aversive stimuli, as well as increases in left prefrontal activity (related to the experience of positive emotions) [4].

              One reason why emotions tend to go away when observed mindfully could be that our mind needs to constantly repeat the reasons for why we should be angry in order to sustain an emotion for a long time (for example, to be angry for hours). But when you mindfully observe your thoughts without reinforcing them, they tend to lose strength much in the same way that a fire burns out if you stop adding wood to it. Moreover, you begin to observe your emotions more objectively by being more mindful about your physical sensations, since physiological events also play a crucial role in emotions. This allows you to feel more relaxed and less reactive.

              Finally, emotional nonreactivity can also be linked to classical conditioning. Let’s say there’s a person that reminds you of someone from your past with whom you had a bad experience. Whenever you see this person or think about them, your mind starts feeling agitated, and you find yourself overreacting to their words. By mindfully observing your emotional response instead of letting it control your behavior, this association between such a person and that bad experience starts to weaken. Such an extinction process can also be clearly experienced when faced with two very common sensations that often create agitation in our mind: addiction and pain.

              At the retreat, we were not allowed to eat after noon, but at 6 p.m. we were offered a piece of chocolate. On the first few days, my meditation before 6 p.m. was usually not calm – I continuously craved the chocolate. Of course, it didn’t make much sense to think about the chocolate, I would have the opportunity to eat it anyway. This reminded me of a talk from the Neuroscience of Mindfulness Conference, which took place in June 2019 in Madrid. Judson Brewer from Brown University explained how to break bad habits including craving food by being mindful of the craving and the reward sensation. (You can also watch his TED talk, “A simple way to break a bad habit” online.) On the one hand, I tried to be mindful of the craving by observing my thoughts and my salivation, and they slowly decreased. On the other hand, I tried extinguishing the conditioning by eating mindfully as well. The chocolate was sweet, so I acknowledged the sweetness. It was pleasant, so I acknowledged the pleasantness. I could observe my sensations with curiosity, without clinging on to them. This way, the reward that created the craving was extinguished to some extent, and even though I could still enjoy the chocolate, the negative feelings associated with the craving were gone.

              After sitting cross-legged for a while, I would start feeling some pain, and of course, I didn’t like it. Two common strategies to deal with unpleasant sensations are (1) changing the condition that creates it (in this case, changing body posture) or (2) mentally avoiding the unpleasant sensation (for example, thinking about something else). To develop mindfulness, however, you may try the opposite: observe your pain and acknowledge that there is pain. I found my mind trying everything to avoid having to face the pain, but in the end, I took the courage and started observing the sensation of pain itself. Slowly, I noticed the pain dissolving into neutral subtle sensations. Again, this reminded me of a talk at the Neuroscience of Mindfulness Conference given by Sara Lazar from Harvard Medical School. She explained that meditators rate pain with the same intensity as non-meditators but with less unpleasantness, and have a reduced activity in the lateral prefrontal cortex when confronted with a painful stimulus. This region is related to cognitive control including inhibition of pain perception, which is indeed diminished by having a nonjudgmental and accepting attitude towards the present experiences [5]. Accordingly, I could observe the painful sensation, but since I didn’t link it to a negative connotation, it lost much of its unpleasantness.

                4. THE SELF

                  Shifting the perspective from “my pain” to “just neutral subtle sensations” implies more than just pain relief. It also signified a change in perspective on my self. A core concept in Buddhist psychology is that the sense of self is an illusion. It is a product of ongoing mental processes that make us experience a self as being the one who inhabits the body, thinks the thoughts, is the agent of actions, and has free will. By mindfully observing all experiences, including thoughts, arise and pass, you realize that the sense of self arises from a succession of little events that create the illusion of a static entity. With this understanding, our habits of craving and aversion get uprooted, which results in an increase in well-being and in compassion towards others.

                  This change in perspective gets built up by mindfulness practice, until a drastic de-identification with the sense of self occurs. Although little empirical research has been done on this radical deconstruction of the self, the default mode network of the brain could be a neural correlate, since it gets activated when reflecting about ourselves. It has repeatedly been shown to become less activated in meditators than in non-meditators, both during meditation and at rest, although this is usually attributed to the fact that meditators are generally lost in thoughts less often. Higher activation of the insula and the secondary somatosensory cortex, also found in meditators, could also be related to the body being perceived more objectively [4].

                  This classification of the mechanisms of mindfulness meditation into four components (attention, body awareness, emotion regulation, and the self) has been proposed by Hoelzel et. al [4]. Despite this differentiation, it should be kept in mind that such elements are highly integrated, as they put it: “An increased awareness of the body’s response to an emotional stimulus might thus lead to greater awareness of one’s own emotional life; in turn, an awareness of one’s emotions is a precondition for being able to regulate those emotions. […] Greater internal awareness might replace the previous, narrative form of self-reference.” On the other hand, identifying the different components might help to better understand how the clinical population can benefit from mindfulness practice. For example, “strengthening attention regulation might be most beneficial for patients suffering from attention deficit disorders, while […] patients with mood disorders, anxiety disorders, borderline personality disorder, or aggression might benefit from improved emotion regulation.” In short, mindfulness meditation, including the different techniques, each with their own focus such as awareness of breath or of walking, can lead to valuable changes in a number of psychological aspects. The increasing empirical evidence about how these changes occur can support and guide the application of mindfulness interventions in the general public and clinical population.

                  REFERENCES

                  1. Sedlmeier, P., et al. (2012). The psychological effects of meditation: A meta-analysis. Psychological Bulletin, 138(6), 1139–1171.
                  2. Hofmann, S. G., et al. (2010). The effect of mindfulness-based therapy on anxiety and depression: A meta-analytic review. Journal of consulting and clinical psychology, 78(2), 169–183.
                  3. Hasenkamp, W., et al. (2012). Mind wandering and attention during focused meditation: A fine-grained temporal analysis of fluctuating cognitive states. NeuroImage, 59(1), 750–760.
                  4. Hölzel, B. K., et al. (2011). How Does Mindfulness Meditation Work? Proposing Mechanisms of Action From a Conceptual and Neural Perspective. Perspectives on Psychological Science, 6(6), 537–559.
                  5. Gard, T., et al. (2012). Pain Attenuation through Mindfulness is Associated with Decreased Cognitive Control and Increased Sensory Processing in the Brain. Cerebral Cortex, 22(11), 2692–2702.

                  Erola Pons is currently a GTC Master’s student in Neural and Behavioral Sciences.


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