We often hear about how mindfulness meditation reduces stress, or, in other words, makes us more stress-resilient. And we also often hear about how this process supposedly takes place. One explanation is that meditation helps us focus on the present moment and not be taken away by anxiety-inducing thoughts. Another is that it allows us to approach thoughts, present situations, or future scenarios in a non-judgmental way—basically, to accept thoughts and situations as they are, without associating them with negative emotional content. Whatever the case may be, the more interesting and robust explanation of the meditation-stress reduction connection is to be sought at the level of the brain and body. By looking at the brain—especially parts of the brain that process emotion and anxiety—one can have a direct window into the biological mechanism that links mindfulness with stress reduction.
Thankfully, neuroscience research has looked at this connection. But before we get into the latest literature on the topic, it’s important to canvass some basic brain science. When we think of fear and anxiety in the context of neuroscience, we immediately think of the amygdala. Located in the middle of the head, behind the eyes, this infamous pea-sized brain structure is known to be involved in emotion processing and memory. Specifically, it’s known to be heavily active in the processing of negative emotions, especially fear and anxiety. In stressful situations, one expects heightened amygdala activity, leading to distress signals that activate the fight-or-flight response.
But does this mean that amygdala activity alone is associated with stress/anxiety? Of course not. Things are a bit more complicated than that, and in addition to the obvious role of hormones during the stress response, amygdala activation is thought to be coupled with activation in the anterior cingulate cortex (ACC). When there is a pattern of co-activation of brain areas, these areas are said to be “functionally connected”.
In a recent paper published in Social Cognitive and Affective Neuroscience, Taren and colleagues (2015) monitored the functional connectivity between the amygdala and ACC as a marker of stress levels. They took 35 unemployed and stressed community adults, and split them into two groups. The first group underwent an intensive 3-day mindfulness meditation program, while the second went through a relaxation training intervention. The mindfulness group practiced body scan awareness, mindful walking and eating, etc, and were encouraged by an instructor to develop more mindful attitudes like letting go of judgments and expectations, and cultivating self-care, patience, and so on. The relaxation group practiced similar behavioral exercises—like stretching and walking—but in a relaxed, rather than mindful way.
The results of the study supported the authors’ hypothesis that mindfulness meditation decreases perceived stress through a mechanism that reduces amygdala-ACC functional connectivity. The mindfulness group displayed decreased amygdala-ACC connectivity by the end of the 3-day training, while the relaxation group showed no such decrease. Interestingly, this decrease in connectivity was coupled with reduced stress biomarkers—in this case, reduced HPA-axis activity. This further strengthens the finding that mindfulness meditation reduces stress.
The study should come as good news for those of us with high levels of stress. By practicing mindfulness meditation, it’s possible to decrease the co-activated firing of the amygdala and ACC, thereby reducing perceived stress. It’s important to note, though, that the study did not look at whether mindfulness can prevent stress-related disease, and the authors suggest that this should be the work of future research. There is reason, though, to think that meditation may reduce stress-related diseases. The logic is simple: we know that stress is associated with poor psychological and physical health outcomes, and if meditation reduces stress, it can potentially prevent the occurrence of such diseases. We’ll have to sit back and wait to see if that’s true.
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