The phenomenon of near-death experience could be due to the tendency of the brain to blur the line between wakefulness and sleep, suggests a new study.
Until now, why some people see bright light, have extraordinary sensations or feel detached from their body when they are in death bed has remained a mystery. The present research highlights that it might have a physiological base, occurring due to a blend of sleep and wake states. While neurologists feel that the phenomenon is far to complicated to be studied scientifically, others view it as an evidence of life after death.
From the study, researchers have found that individuals who have near death experiences were more likely to experience another phenomenon, called as REM intrusion, where aspects of the dream state of sleep spill over into wakefulness. Infact in the present study, 60% of the 55 study participants had experienced REM intrusion.
Such individuals for example experience auditory / visual hallucinations or feel paralyzed as they fall asleep or awaken. The authors hence suggest that the arousal system of the brain could predispose some people to experience both near-death experience and REM intrusion. REM intrusions and near-death experiences share certain common features.
As the visual centres in the brain are highly active during REM sleep, occurrence of REM intrusion could promote the visions of light and a sensation of 'being dead', eventually simulating a near-death experience.
It is also believed that stimulation of the vagus nerve that connects the brain stem to the lungs, heart and intestines could be responsible for near-death experience phenomenon. Consistent with the above hypothesis, increased activity of the vagus nerve is known to be associated with the fight or flight response, seen in dangerous situations.
This brain arousal system also regulates alertness and attention during waking hours, in addition to sensitizing an individual to dangerous situations. Although the study has yielded certain important clues about near-death experience as a physiological phenomenon, the authors have concluded that it might not be the complete explanation for the same.
He has further stated that the above results should not distract people from the meaning they have learnt from their experiences. 'My work is spiritually neutral. Research can only look at how the brain contributes to near-death experience, and not why the phenomenon occurs. The 'why' can't be addressed by scientific inquiry,' commented senior researcher Nelson about his work.