Tuesday, March 24, 2015

Our Understanding of the Brain is even more Incomplete than We Thought

As the only stage in an NDE that involves perceiving the physical rather than the spiritual world, an out-of-body experience has the most potential to convince skeptics. If you could prove that someone saw or heard things that brain science says they could not have seen or heard, you would have, at the very least, evidence that our understanding of the brain is even more incomplete than we thought, and at most, a sign that a conscious mind can exist apart from a living body.

As a result, reports of veridical perception have a totemic significance among NDErs. One of the most celebrated is the story of “Maria,” a migrant worker who had an NDE during a cardiac arrest at a hospital in Seattle in 1977. She later told her social worker that while doctors were resuscitating her, she found herself floating outside the hospital building and saw a tennis shoe on a third-floor window ledge, which she described in some detail. The social worker went to the window Maria had indicated, and not only found the shoe but said that the way it was placed meant there was no way Maria could have seen all the details she described from inside her hospital room.

That social worker, Kimberly Clark Sharp, is now a bubbly 60-something with a shock of frizzy hair who acted as my informal press officer during the conference. She and her story are an IANDS institution; I heard several people refer to “the case of Maria’s shoe” or just “the tennis-shoe case.” But while Maria’s shoe certainly makes for a compelling story, it’s thin on the evidential side. A few years after being treated, Maria disappeared, and nobody was able to track her down to further confirm her story.

A case with a lot more evidence is that of Pam Reynolds, a singer-songwriter. In 1991 Reynolds, then 35, underwent surgery to remove a huge aneurysm at the base of her brain. Worried that the aneurysm might burst and kill her during the operation, her surgeon opted for the radical move of “hypothermic cardiac arrest”—chilling her body to 60 degrees Fahrenheit, stopping her heart, and draining the blood from her head. The cooling would prevent her cells from dying while deprived of oxygen. When the doctors restarted her heart and warmed her body back up, she would, in effect, be rebooted.

About a Dozen Prospective Studies have been Published in Recent Years

Of those books, probably the single best overview is The Handbook of Near-Death Experiences: Thirty Years of Investigation, an anthology published in 2009. As The Handbook outlines, by 2005 dozens of studies involving nearly 3,500 subjects who reported having had NDEs had become material for some 600 scholarly articles. Many of these articles are in the Journal of Near-Death Studies, the IANDS house journal—which, the association proudly notes, is peer-reviewed. But many others are in mainstream medical publications. A search in February on PubMed, a database that is maintained by the National Library of Medicine (and that doesn’t include the IANDS journal in its index), turned up 240 papers mentioning near-death experiences.

Most of the NDE studies have been retrospective, meaning the researchers looked for people who’d had such an experience to come forward and be interviewed. That poses a couple of problems, scientifically speaking. It means the subjects were self-selecting, so they might not be representative. For instance, people who’d had scary NDEs might have been less eager to tell their stories than people who’d had uplifting ones. (One of the arguments you hear for why NDEs are not hallucinations of the dying brain is that so many of the stories contain similar features; but it’s notable that, while some studies indeed report only the well-known positive experiences, unpleasant NDEs account for a combined 23 percent of reports across a dozen different studies. They get far less attention, and certainly don’t seem to sell nearly as many books.) Most of the interviews took place years after the fact, so memories might have been faulty. And most important, retrospective studies make it pretty much impossible to obtain reliable data on what was actually happening to the subjects’ bodies and brains while they felt their souls were elsewhere.

About a dozen prospective studies have been published, several of them in recent years. In these, researchers typically arrange for every consenting patient who survives a specific medical emergency (such as a cardiac arrest) at a hospital to be interviewed as soon as possible thereafter. The patients are asked open-ended questions about what, if anything, they experienced while doctors were trying to revive them. If they report anything unusual, the researchers check their medical records and the accounts of people who treated them, looking for things that might explain the experience or show that their brain was shut down at the relevant time. All told, these studies have collected the near-death experiences of just under 300 people.

The goal for those who believe the mind really does leave the body is to find a verified case of what one prominent researcher has termed “apparently nonphysical veridical perception”—in other words, having an experience during which you see or hear things you otherwise couldn’t have perceived that are later confirmed to have actually happened. (Veridical means “not illusory.”) An out-of-body experience is only one of the 16 possible elements of a near-death experience on the Greyson scale, and the proportion of experiencers who report having had one varies widely from one study to another.