Meditation, in one form or another, has been practiced since ancient times. However, it’s only been recently that scientists have begun to investigate these practices that were once considered to be the sole domain of religion and spirituality. However, as evidence of the benefits of meditation amassed, scientific interest in the topic has grown. 

Among other questions, scientists have shown an interest in what happens in the brain when one meditates, and whether there are permanent changes in the brain as a result of ongoing practice. 

Because there are a vast number of different types of meditation, it might not seem like we’d be able to talk about them collectively. Some forms of meditation, such as mindfulness and insight meditation, have been studied a great deal, while others (e.g. esoteric practices of obscure or secretive lineages) haven’t been studied at all. It’s true that it would be wrong to assume insights from the study of specific forms of meditation apply universally. On the other hand, the defining trait of meditation in its varied forms is relaxed focus. The meditator relaxes to reduce the agitation of the mind, and then directs his or her awareness to some “object” or topic of thought.  To a large extent, the different practices result from the different objects to which the mind is directed. The object used to anchor one’s attention could be breath, bodily sensations, a mantra or sound, a mandala or image, a visualization, a thought, a question, or it could even be the flow of thoughts and images through one’s mind, directly. 

So, what happens when one meditates? 

1. The neural pathways for focus are strengthened: Directing one’s attention toward some object builds capacity to hold one’s attention. At first, one is constantly finding that one’s mind has wandered and one is no longer conscious of the practice, but one keeps steering the mind back on course. That act of returning the awareness builds up those attention circuits. So, instead of feeling disappointed that one’s mind wanders so readily, recognize that the act of switching one’s attention back builds a stronger mind — similar to the way in which repetitively lifting a weight or taking steps builds stronger muscles. 

There’s a concept called neuroplasticity that refers to the brain’s ability to change itself depending upon the nature and frequency of firing down neural pathways. The brain changes because the routes for nerve signals that are used heavily become bigger and faster. (This is a major reason why when we practice an activity we get more skillful at it, and why when we tell ourselves we’re terrible, we stay terrible.) The strengthening of neural pathways is how meditation can make long-term changes to the brain. Harvard scientists found that it only takes about eight weeks for these changes to become observable. 

2. The state of brainwaves changes: Brainwaves are electromagnetic waves that results from the activity of neurons in the brain. Brainwaves are classed into five groups by frequency range (waves per second,) and the waves that dominate at any moment can tell scientists something about a person’s state of mind.  

From fastest to slowest the brainwave classes are: Gamma waves (seen during simultaneous processing in multiple brain areas as well as during flashes of insight); Beta waves (seen in active thinking, such as during conversation or problem solving); Alpha waves (seen during reflective mental activity); Theta waves (seen while daydreaming or in trance states such as “highway hypnosis”); Delta waves (seen during the deep and dreamless phase of sleep) 

During meditation, individuals usually display more activity in the alpha and theta ranges than the beta waves associated with active waking consciousness. This reflects the mind becoming more tranquil. Advanced meditators have been shown to display another interesting change. Monks frequently experienced long periods of gamma activity, and, when they did compassion meditation, this gamma activity strengthened further. For most of us, gamma waves come only in bursts when we are processing multiple streams of different sensory information or if one is in the midst of an epiphany.  Scientists don’t yet know why high-level meditators show this tendency, or what purpose it serves, but it’s a strong indication that intense meditation practice leaves its mark in the brain.

3. Reduced reactivity in the amygdala, which (among other things) takes the attention in fearful directions: Just as researchers have seen that the brain’s grey matter associated with attention, learning, and cognition centers grows thicker in meditators, they’ve also noticed a shrinkage involving the amygdala. It’s easy to over-simplify the amygdala. It’s been called the “fear center” and is often villainized in popular accounts. However, the amygdala does play a role in learning fear by drawing one’s attention to items which are thought fear-worthy.  This is a fine thing up to a point, but it can be overactive. Shrinkage of grey matter doesn’t sound like a good thing, but when one considers that this shrinkage results from less firing of neurons in response to fear or anxiety, it reflects a positive change in levels of emotional stability. 

4. Increased activity in the empathy and compassion centers of the brain: The Temporo-Parietal Junction (TPJ) is involved with what psychologists have called “theory of mind” (ToM.) ToM refers to one’s ability to distinguish one’s own mental state from those of others. The ability to intuit what another person is thinking or feeling allows one to have empathy and compassion. It’s often true that we aren’t as good at seeing the point of view of another person as we think. We often project our own thoughts and feelings onto others — and often not with the best results. Given the amount of misery that results from not being able to see other’s point of view, this benefit of meditation is no small thing. 

Conclusion:

While there is still much to be learned about what happens in the brain during meditation, a remarkable body of scientific study has been produced and interest has been growing.  Because so many benefits have been observed, the medical, business, and governmental sectors have all taken a keen interest in what might be gained through these ancient practices.

Citations:

Goleman, D. & Davidson R. 2017. “The Science of Meditation.” London: Penguin Books

Hernández, Sergio Elías et al. “Increased Grey Matter Associated with Long-Term Sahaja Yoga Meditation: A Voxel-Based Morphometry Study.” PloS one vol. 11,3 e0150757. 3 Mar. 2016, doi:10.1371/journal.pone.0150757

Hölzel, Britta K et al. “Mindfulness practice leads to increases in regional brain gray matter density.” Psychiatry research vol. 191,1 (2011): 36-43. doi:10.1016/j.pscychresns.2010.08.006