Changes In Stress After Meditation

For a thousand years, people have reported feeling better by meditating but there has never been a systematic study that quantified stress and how much stress changes as a direct result of meditation until now.

U.S. Army Research Laboratory researchers spent a year collaborating with a team of scientists from the University of North Texas to develop a new data processing technique that uses heart rate variability as a sensor to monitor the state of the brain. Their findings are reported in a paper published in the June edition of Frontiers in Physiology.

Healthy heartbeats have irregularities built into them with a slight random variation occurring in the time interval between successive beats. The sinus node, or the heart's natural pacemaker, receives signals from the autonomic or involuntary portion of the nervous system, which has two major branches: the parasympathetic, whose stimulation decreases the firing rate of the sinus node, and the sympathetic, whose stimulation increases the firing rate. These two branches produce a continual tug-of-war that generates fluctuations in the heart rate of healthy individuals.

Heart rate variability provides a window through which we can observe the heart's ability to respond to external disturbances, such as stress, said Dr. Bruce West, the Army's senior research scientist for mathematics.

He said it turns out that the HRV time series is very sensitive to changes in the physiological state of the brain and the new data processing system, called dynamic subordination technique, can quantify the changes in HRV and relate these directly to brain activity, such as produced by meditation. Thus, the DST has quantified the level of stress reduction produced by meditation and offers the potential to quantify such things as the inability to concentrate and sustain focus, impatience, impulsiveness and other dysfunctional properties that severely limit a soldier's ability to do his job.

Stress modulates the autonomic nervous system signals, which in turn disrupts normal HRV and therefore the stress level can be detected by processing HRV time series.

Through a new method of processing HRV time series data, the researchers developed a way to measure the change in the level of stress provided by meditation. This measure assigns a number to the level of variability of heartbeat interval time series before and during meditation. This number indicates precisely how much stress is alleviated by control of the heart-brain coupling through meditation. (MORE)

Source: Science Daily