Scientific research shows how meditation can alter the brain to improve mental health.
There are different neural networks in the brain. The analytical network is used for solving problems. The narrative network produces mental chatter - the internal talking we do about ourselves, our past, and our future. The experiential network1 is active when a person is meditating mindfully. Too much analytical thinking causes callousness, too much mental chatter can cause or worsen anxiety and depression. Experiential thinking increases empathy, compassion and wisdom1. Mindful meditation quiets the analytical and narrative networks and stimulates the experiential network.
Permanent changes in the brain are possible because of a phenomenon called neuroplasticity - the ability of the brain to rewire itself. Whenever you do a task, the neurons involved recruit neurons away from other tasks to help strengthen the current task. When you meditate mindfully, you strengthen the experiential network. However, during the rest of the day, that strength is being recruited away by everything else you do. The way to strengthen the changes in the brain caused by meditation and maintain them over time, is to meditate for longer periods of time and meditate more often. When you are not meditating, try to be in the mindful state whenever possible. Be aware of what you are doing as you are doing it, not thinking about the past, the future, or anything else. Notice the absence of mental chatter as you do that. Everyone needs time to plan for the future, digest and understand their past, and solve the problems in their life, so you shouldn't eliminate those activities entirely, just do them deliberately at times you control rather than letting them control your mind.
1) From my web page on meditation:
Dr. Jon Kabat-Zinn is Professor of Medicine Emeritus and creator of the Stress Reduction Clinic and the Center for Mindfulness in Medicine, Health Care, and Society at the University of Massachusetts Medical School. In the transcript of a podcast on bigthink.com, he describes how meditation can quiet mental chatter made up of anxious and depressed thoughts:
If you put people in a scanner and tell them to just do nothing; just rest in the scanner; don’t do anything at all, it turns out that there’s a region in the midline of the cerebral cortex that’s known as the default mode network that just lights up, that all of a sudden gets very, very active. I mean you’re told to do nothing and then your brain starts to use up energy a lot. ... And that’s called the default mode network because when you’re told to do nothing, you default to activity in this mode and when you inquire what’s going on there, a lot of it has to do with my wondering and just daydreaming. And a lot of that has to do with the self-referencing our favorite subject, which is me of course. So we generate narratives. ... it’s also called the narrative mode network or the narrative network. And it’s the story of me.Dr. Kabat-Zinn also says the benefits of suppressing the narrative network and stimulating the experiential network with meditation leads to wiser, more empathic and more compassionate thinking in an interview at: psychcentral.com:
When you train people in MBSR, you find that another area of their cortex lights up more lateral after eight weeks of training in mindfulness. And that that area is associated with a region called the insula and that doesn’t have a linear, time-based narrative. It’s just the experiencing of the present moment in the body — breathing in, breathing out, awake, no narrative, no agenda. And the interesting thing — and this is the study — when they put people through eight weeks of MBSR, this narrative network decreases in activity and this experiential network increases in activity and they become uncoupled. So they’re no longer caught together in such a way. So this one can actually attenuate and liberate you a little bit from the constant thinking, thinking, thinking — a lot which is driven, of course, by anxiety and, "What’s wrong with me?" The story of me is often a depressing story. And a fear-based story. We’re like driving the car with the brake on, with the emergency brake on. And if we learn how to just kind of release it, everything will unfold with less strain, with less stress and with a greater sense of life unfolding rather than you’re driving through it to get to some great pot of gold at the end, which might just be your grave.
One pathway is a mid-line pathway, very akin to what is called a default mode, that seems to be functioning when nothing else is supposed to be happening — like being or mind wandering, or something like that, which is what they call the narrative network for self. So like what you tell yourself about who you are, where you’re going, how things are going, how stressed you are, how great it’s going to be in the future, how horrible it was in the past, or vice-versa, how wonderful it was in the past, or how horrible it is in the present. So it is a narrative ongoing story of me. And that occupies a certain kind of brain territory.
They showed that people who are taking the MBSR program showed activity in a whole other, more lateral ventral pathway in the cerebral cortex, again in the prefrontal cortex, which was involved with what they called experiential focus. It’s like no more story, just this. Just this moment. Just this breath. Just this unfolding. And I want to emphasize that it doesn’t mean that all of a sudden you are either disassociating or that you’re going to get really, really stupid practicing mindfulness because now you’re just in the present moment and you don’t know what’s really happening and you’ve now gone beyond thought. Not at all. I mean it’s much more an effective, wise and emotionally intelligent way to make use of one’s thoughts and emotions, but hold them in a much, much greater and more empathic, and in some sense, more compassionate and wise container, and that container embraces what I mean when I use the word mindful."