Measuring brain waves during meditation is a fairly new development, as scientists try to discover why meditation works to improve stress and increase physical and emotional well-being. Modern scientific techniques such as fMRI and EEG have been used to see what happens in the body while people meditate. One function that has been measured is brain wave activity during meditation.
From the Daily Mind:
In EEG (electroencephalograph) studies, brainwaves of different frequencies are measured, and many found an increase in these following brainwaves:
Alpha Waves: Healthy alpha wave production supports mental resourcefulness, better mental coordination, and improves the general sense of relaxation and weariness. Many believe alpha waves are the bridges between consciousness and unconsciousness. Meditation synchronizes alpha activity between the four regions of the brain: left, right, anterior, and posterior, which positively correlates with creativity.
The most common brain waves seen during meditation, alpha waves are increased in the posterior parts of the brain during meditation – much more than during simple relaxation. They characterize wakeful rest. It is a sign of deep relaxation, but does not mean that the mind is void. Alpha waves promote changes in the nervous system to calm it, resulting in lower blood pressure and heart rate, lower stress hormones, and a calm mind.
Theta Waves: Theta waves come in strong bursts in long-term meditators who report a peaceful, drifting, and pleasant experience at the time. These waves enhance creativity, intuition, and daydreaming. It is also a storage area for memories, emotions, and sensations. Theta waves are strong during any sort of spiritual focus and they reflect the state between wakefulness and sleep.
Theta waves likely originate from a relaxed attention to inner experiences. This is the significant difference between meditation and simple relaxation. Increased theta waves occur more frequently in highly experienced meditators. Theta waves are said to help open the “third eye” for meditators, through which they gain illumination wisdom.
Beta Waves: When the EEG shows bursts of Beta waves, experienced meditators report an approach of yogic ecstasy or a state of intense concentration sometimes accompanied by an acceleration of heart rate. Beta waves can increase mental ability, focus, and alertness.
Beta waves occur when reflecting actively over a particular issue. Fewer beta waves are present during meditation and rest, indicating that you “step away” from problem solving during meditation.
Delta waves are characteristic of sleep, and few delta waves are seen during meditation except in cases of very deep meditation by experienced practitioners. Increasing delta waves will cause a decrease in the stress-producing hormone, Cortisol.
Scientists have discovered that the meditator’s mind is physically different from one who doesn’t meditate. Meditation not only changes how the brain functions in the short term, but findings show it might possibly produce long-term changes. By studying such functions as “People who come to attend seminars and meetings are often under pressure and tired either because of long journeys or work based stress. If they are to take on-board new information they must first make room for it.” - and finding positive results – scientists are opening the doors for meditation to be taken seriously as a means to change one’s physical and emotional well-being.