Restful Alertness

What is it?

There is a state of high relaxation during the Vihangam Yoga meditation meaning that the person is not anxious or tensed. There is a high alertness during the meditation, which means he can react efficiently to the task on which he is concentrating. There is state of consciousness which is difficult to interpret scientifically

How did we measure it – 192 Channel Quantitative EEG Study

192 channel EEG was recorded using Neurofax EEG-1100 system (Nihon Kohden) with a time constant 0.1 sec. and a high frequency filter of 120 Hz. EEG was recorded for 15 minutes before and after the meditation and 30-60 minutes during the meditation in the same sitting, with the meditator maintaining the same posture through out the recording (Figs. 1 and 2). A Vihangam Yoga practitioner with 192 electrodes placed on his head, being recorded in a computer (behind him) while meditating and a 3-D simulation diagram of electrode placement  

Quantitative analysis of EEG

VihanagmYoga Power spectrum values showed an significant decrease in delta and theta power and an increase in alpha power across all the regions, predominantly over the frontal region during meditation. Intra-hemispheric coherence showed an increase in the alpha band and a reduction in the delta and theta bands during meditation. While the interhemispheric coherence showed a similar trend but the coherence in the alpha band remained less during meditation than pre- and post-meditation  

Evidence – Restfulness

Power of Alpha waves – Relaxed State: A person can be relaxed upto 5 times during Vihangam Yoga meditation. Graphs depicting the power of Alpha waves before, during and after meditation for 3 person taken for study.  

Evidence – Alertness

Alpha Wave Coherence – Alertness: A person is more alert during Vihangam Yoga meditation. Graphs depicting the Alpha Wave Coherence before, during and after meditation for 3 person taken for study.  


Cahn, B. R. & Polich, J. (2006).Meditation States and Traits: EEG, ERP, and Neuroimaging Studies. Psychological Bulletin, 132, 2, 180-211 Travis, F., & Wallace, R. K. (1999). Autonomic and EEG patterns during eyes-closed rest and transcendental meditation (TM) practice: The basis for a neural model of TM practice. Consciousness and Cognition, 8,302-318. Aftanas, L. I., & Golocheikine, S. A. (2002). Non-linear dynamic complexity of the human EEG during meditation. Neuroscience Letters, 330,143-146.  


Dr. Mohammad Zia Ul Haq; Senior Resident; Centre for Cognitive Neurosciences; Central Institute of Psychiatry, Ranchi, India-834006 Ph: +919234687231; Fax: +916512233668 Email: and