It is now possible to examine the meditating brain in ways that were unthinkable a generation ago. New, advanced techniques like functional magnetic resonance imaging (fMRI) have made it possible to investigate what goes on in the living, human brain during meditation. By scanning the brains of people while they meditate, researchers can actually visualize ongoing mental activity in the brain as it occurs.
A robust finding across a number of studies and different meditation techniques, including Acem Meditation, is that areas of the brain cortex associated with attention are active during meditation. Thus, subregions within the foremost part of the brain, the prefrontal cortex, are activated while we meditate. This brain region is crucial for our higher mental functions, and is much more developed in humans than in other mammals. A main task of the prefrontal cortex is to organize our thoughts in meaningful sequences, giving priority to aspects that are beneficial to us in the future. Also, emotional subregions of the prefrontal cortex, like the anterior cingulate cortex, seem to be specifically activated in the meditating brain. One study of Acem Meditation suggests that a small area in the lower part of the prefrontal cortex (called BA47) is specifically active during effortless or nondirective meditation, as opposed to concentrative practices.
Several parts of the cortex seem to interact in what researchers call the “default mode network” when we allow seemingly random episodic thoughts to wander freely. Interestingly, it seems that different types of meditation techniques may diverge with respect to facilitating such random mind wandering during meditation. Some forms of mindfulness meditation seem to reduce default mode network activation, while other forms of meditation facilitate it. Though this issue is still unresolved, the question of default mode network activation might prove to distinguish between techniques that assist in “turning off” worrying thoughts and techniques that may assist in reworking, processing, and adapting emotional thought content, as in Acem Meditation.
Lastly, some investigators have demonstrated that meditation may in fact stimulate brain plasticity, by causing a modest growth of brain cortex thickness in some areas of the brain associated with, e.g., attention, bodily awareness, and sensory processing. There are indications that this type of brain plasticity may counteract or slow down age-related thinning of the cortex.
"There are now robust findings concerning the effect of meditation on the brain," says Svend Davanger, MD PhD, Professor of Neuroscience at the University of Oslo. He has published scientific studies on brain activity during Acem Meditation.