Explanations for near-death experiences and the aftereffects can be classified into two groups: traditional paradigms and new paradigms.
Persinger (1983) and Blanke & Mohr (2005) based their research studies on the theory that out-of-body experiences can be induced by stimulating the right temporoparietal junction (TPJ) of the brain, the area where information from the thalamus, limbic system, visual, auditory and somatosensory systems are integrated. Britton & Bootzin, (2004) describe electrical stimulation of the nearby angular gyrus as being able to create a feeling of another presence.
Glaucoma with severe loss of peripheral vision can produce tunnel vision. Patients who have schizophrenia, Alzheimer’s or Parkinson’s disease can have hallucination and see visions or hear voices others cannot experience. Low oxygen levels have been hypothesized to cause tunnel vision and changes in light experiences (Blackmore, 1996); Mobbs & Watt, 2011; Whinnery and Whinnery, 1990).
Endogenous opioids and endorphins released during the time of death have been said to cause the wonderful euphoric feelings (Molina, 2003; Jansen, 2001).
Most of these theories have not held up for two main reasons. Not everyone who has an NDE is oxygen deprived and not all patients who are oxygen deprived near death have these experiences. Research has also shown it is rare for research subjects who have NDEs to have a history of mental illness, Alzheimer’s or Parkinson’s disease or diseases that impact the temporoparietal junction or the angular gyrus.
Also the most common transpersonal experiences are the ADCs. The individuals to whom they occur are not close to death, they are grieving. These experiences definitely cannot be explained by lack of oxygen, endorphins or endogenous opioids.
Evolving new paradigms
The heart of the new paradigm explaining these occurrences lies in the study of consciousness. The theory that consciousness is separate from the physical brain is at the nucleus of a new area of research (Carter, 2010). The neuroscientists are deeply involved in this non materialistic and non reductionistic explanation of consciousness. These transpersonal experiences, particularly the NDE, can exist without brain function or some bodily alteration that allows these experiences.
Eban Alexander, a neurosurgeon and an NDE skeptic before his own NDE is now a major proponent of the ability of consciousness to exist separate from the brain. He suffered from a life threatening meningitis that caused his seven day coma. During that time he had diffuse cortical damage with global neocortical involvement. He had only a small change of surviving. From his training he would have said no one with that history would have remembered anything during his coma. He did remember enough to write 20,000 words about his experience in this presumably unconscious state (Alexander, 2012).
This is consistent with Lawrence’s (1997) study of experiences of unconscious patients. Out of 111 patients who were interview, only 27% had not recollection of any experience. Even someone who had been pronounced dead, whose doctor had signed a death certificate, recovered and remembered some occurrences.
Part of the quest for a new understanding of consciousness is the development of a new journal, Neuro-Quantology, an interdisciplinary journal of neuroscience and physics.