- realize some benefit, or
- for the mind to simply acknowledge its content without becoming identified with that content.
The term meditation refers to a broad variety of practices that includes techniques designed to promote relaxation, build internal energy or life force ("qi" in Chinese medecine, "prana" for yogis, etc.) and develop compassion, love, patience, generosity, and forgiveness.
A particularly ambitious form of meditation aims at effortlessly sustained single-pointed concentration meant to enable its practitioner to enjoy an indestructible sense of well-being while engaging in any life activity.
One of the limbs of yoga is meditation. Yoga introduces you to meditation techniques, such as how to focus on your breath and disengage from your thoughts. We often picture yoga practice as being only the “asanas” (the postures) and think that those very bendy postures represents yoga, whereas meditation is an integral part of the yoga practice.
It's taken the development of modern technologies like functional MRI screening to give scientists a glimpse of how yogic practices like asana and meditation affect the brain. It seems that long-term practitioners see changes in brain structure that correlate with their being less reactive and less emotionally explosive. Scientists at the University of Wisconsin have shown that meditation increases the activity of the left prefrontal cortex—the area of the brain that's associated with positive moods, equanimity, and emotional resilience. In other words, meditating regularly may help you weather life's ups and downs with greater ease and feel happier in your daily life.
Researchers are in the earliest stages of examining whether yogic practices could also help stave off age-related cognitive decline. Indeed, research has shown that parts of the cerebral cortex—an area of the brain associated with cognitive processing that becomes thinner with age—tend to be thicker in long-term meditators, suggesting that meditation could be a factor in preventing age-related thinning.
Asana and pranayama (breathing exercices) probably improve immune function, but, so far, meditation has the strongest scientific support in this area. It appears to have a beneficial effect on the functioning of the immune system, boosting it when needed (for example, raising antibody levels in response to a vaccine) and lowering it when needed (for instance, mitigating an inappropriately aggressive immune function in an autoimmune disease like psoriasis).