Friday, May 20, 2011

The Neuroscience of Meditation

Dr. Shock M.D., Ph.D.
Science of meditation: "Functional MRI shows how Mindfulness Meditation changes decision-making process" (freakingscience blog).

Meditation is different from either rest or sleep. It’s a wakeful hypometabolic state with lowered sympathetic activity as opposed to the fight and flight reactions that requires an active sympathetic system.

Parasympathetic activity is increased, which is important for relaxation and rest. This increase is characterized by reduced heart rate, lower systolic blood pressure, lower oxygen metabolism, and an increase in skin resistance.

So it is not only a rest state, but also physiological relaxation related to stress relief.

What is the effect of meditation on the brain?
During meditation not only general relaxation is experienced but also a reduction of mental activity and positive affect [emotion or feeling].

During meditation the reduced mental activity is modified by increased activation of networks of internalized attention. These trigger activity in regions that mediate positive emotions.

Activity in networks related to external attention and irrelevant processes are decreased.

The networks activated for internal attention and positive mood are mainly located in the frontal and subcortical brain regions. More specifically, this positive affect increases the activity in the left prefrontal and limbic region of the brain.

The internal focused attention is thought to originate in an activation of frontal and thalamic region of the brain. There is also some evidence that experienced meditators show these activations and deactivations to a greater extent than novice meditators.

In conclusion, there is converging evidence that fronto-parietal and fronto-limbic brain networks seem to be activated in the attention practices that lead to meditation, presumably reflecting processes of internalized sustained attention and emotion regulation.

It should be kept in mind that these findings relate to meditation in general.

Different kinds of meditation can result in slightly different activation and deactivation patterns. Different brain activation networks can thus be activated by different meditation traditions.

These findings mostly result from comparison of small groups of experienced meditators compared to novices.

Rubia, K. (2009). The neurobiology of Meditation and its clinical effectiveness in psychiatric disorders Biological Psychology, 82 (1), 1-11 DOI: 10.1016/j.biopsycho.2009.04.003