George Dvorsky writes:

Meditation yields a surprising number of health benefits, including stress reduction, improved attention, better memory, and even increased creativity and feelings of compassion. But how can something as simple as focusing on a single object produce such dramatic results? Here’s what the growing body of scientific evidence is telling us about meditation and how it can change the way our brains function.

Before we get started it’s worth doing a quick review of what is actually meant by meditation. The practice can take on many different forms, but the one technique that appears most beneficial, and which also happens to be among the most traditional, is called mindfulness meditation, or focused attention.

By mindfulness, practitioners are asked to focus their thoughts on one thought and one thought alone. An overarching goal is to be firmly affixed to the present moment. This typically means concentrating on the breath — observing each inhalation and exhalation — and without consideration to other thoughts. When a “stray” thought arises, the practitioner must be quick to recognize it, and then turn back to the focus of their attention. And it doesn't just have to be the breath; any single thought, like a mantra, will do.

The whole article is worth a read, but I will include my favorite part below.

My favorite part of the article is when George talks about how meditation changes the brain:

Buddhists have meditated for literally thousands of years. They’re familiar with its positive effects, including the way it works to instill the inner strength and insight required for the overarching spiritual practice; meditation, or “sitting,” is to Buddhist monks what prayer is to Christians. But instead of trying to hack into the mind of God, Buddhists are trying to hack into their own mind to harness it under control.

But it has only been in recent times that neuroscientists have been able to peer directly into the brain to see what’s going on. The advent of fMRIs and other brain scanning techniques have largely paved the way.

For example, neuroscientists observing MRI scans have learned that meditation strengthens the brain by reinforcing the connections between brain cells. A 2012 study showed that people who meditate exhibit higher levels of gyrification — the “folding” of the cerebral cortex as a result of growth, which in turn may allow the brain to process information faster. Though the research did not prove this directly, scientists suspect that gyrification is responsible for making the brain better at processing information, making decisions, forming memories, and improving attention.

Indeed, as much of the research is showing, meditation causes the brain to undergo physical changes, many of which are beneficial. Other studies, for example, have shown that meditation is linked to cortical thickness, which can result in decreased sensitivity to pain.

Or take the 2009 study with the descriptive title, “Long-term meditation is associated with increased gray matter density in the brain stem.” Neuroscientists used MRIs to compare the brains of meditators with non-meditators. The structural differences observed led the scientists to speculate that certain benefits, like improved cognitive, emotional, and immune responses, can be tied to this growth and its positive effects on breathing and heart rate (cardiorespiratory control).

The integrity of gray matter, which is a major player in the central nervous system, certainly appears to benefit. Meditation has been linked to larger hippocampal and frontal volumes of gray matter, resulting in more positive emotions, the retention of emotional stability, and more mindful behavior (heightened focus during day-to-day living). Meditation has also been shown to have neuroprotective attributes; it can diminish age-related effects on gray matter and reduce cognitive decline.

A study from earlier this year showed that meditators have a different expression of brain metabolites than healthy non-meditators, specifically those metabolites linked to anxiety and depression.

But it’s not just the physical and chemical components of the brain that’s affected by meditation. Neuroscientists have documented the way it impacts on brain activity itself. For example, meditation has been associated with decreased activity in default mode network activity and connectivity — those undesirable brain functions responsible for lapses of attention and disorders such as anxiety, ADHD — and even the buildup of beta amyloid plaques in Alzheimer’s disease.

This artwork "Theologue" by Alex Grey may not be that far off.