Are near-death experiences trustworthy glimpses into an afterlife? OK, I'm a skeptic. I have a problem with research of any kind claiming this or that truth solely on the basis of anecdotes and subjective reports.

Let me explain. Dr. Raymond Moody in 1975 published a controversial piece about life after life titled, understandably enough, "Life After Life," based upon subjective reports of individuals who "came back to life" after having been pronounced clinically dead. A series of related books followed in 1977, 1988, 1989, 1991, 1993, 1999, 2001 and 2010, all proclaiming on the basis of subjective reports from those returning from clinical death that there was some form of "after-death" existence. He also founded and now heads the Dr. John Dee Memorial Theater of the Mind, a research institute in Alabama where people can experience an altered state of consciousness with the intention of invoking apparitions of the dead. One of the methods used to obtain this altered state is crystallomancy, or "mirror gazing" (for which he was admitted by his family into a psychiatric hospital). He has also researched past life regression and believes that he personally has had nine past lives.

And then we have Stafford Betty, a professor of religious studies at Cal State Bakersfield, who last year published his own work in this space about similar "existence after death" phenomena to local fanfare and acclaim ("Why society needs belief in an afterlife," Community Voices, Sept. 28, 2011).

Let's look at the life after death thing closely.

Question: At what point does death occur? The medical answer has varied greatly over time. Many conventions have been used to denote the moment of death, among others the cessation of breathing, cessation of heartbeat, fixing of the pupil, cessation of whole and deep brain electrical activity, rigor mortis. But the more closely medical science looked at death, it began to be seen that it was not a singular moment-in-time thing, but a sometimes prolonged continuum and series of bodily occurrences that do not necessarily follow a defined sequence, and do not necessarily end in death. The sentinel events were at times found to be suspendible, even spontaneously reversing, and reversible with the right emergency interventions. To conclusively denote death, many hospitals now require multiple EEGs, separated widely in time, under exacting conditions.

So where does that leave us? With a phenomenon lacking an exact moment-in-time definition, which creates a monster of a problem for existence-after-death enthusiasts. The process of dying involves the slow-motion cessation of life sustaining bioelectrical activities. As the brain winds down its functioning, moving into deep unconsciousness then possibly death, there is no doubt that those who move into the earlier phases of it and return describe similar sensory phenomena: hearing sounds such as buzzing; a feeling of peace and painlessness; having an out-of-body experience; a feeling of traveling through a tunnel; a feeling of rising into the heavens; seeing people -- often dead relatives; seeing a bright light and meeting a spiritual guide or being such as God; seeing a review of one's life; feeling a reluctance to return to life.

These things signify little more than the brain is going through a variety of bioelectrical changes. Changes that may eventuate in death, deeply suspended unconsciousness, or a return to full consciousness. To complicate matters, these dreamy sensory phenomena occur not uncommonly in everyday sleep and dreaming, deep day-dreaming, dissociative states, psychosis, chemically induced hallucinosis and gas anesthesia So the proof of life after life points as well to sleeping, dreaming, daydreaming, dissociating under stress or trauma, psychosis, hallucinosis and undergoing surgery. Or having died and returned. Take your pick.

With proof that nonspecific, one cannot make a case for anything much less for returning from death's portal with reports of life on the other side. One would hope for something more specific or evidence more convincing than what's been served up so far.

So call me doubting Thomas. It would be convincing to find a documented return-to-life case that had met all the sentinel criteria of death, including rigor mortis. Now that would be a person worth listening to.

Brik McDill, Ph.D., of Tehachapi has spent 40 years in private practice in clinical and forensic psychology. Community Voices is an expanded commentary of 650 to 700 words.