by Mary Roach
Normally I object to strangers beaming force fields into my brain. But Michael Persinger has a university post and his papers are published in mainstream medical journals. How dangerous could it be? I’ve been pondering this in the back of the cab on my way to the university. The driver, a graduate of Laurentian, asks what sort of work I’m doing there. I tell him I’m visiting Michael Persinger. He swivels to look at me. “Strange guy. I heard he’s totally nocturnal, eh? And he keeps rats.”
It would seem that in Sudbury, Ontario, Michael Persinger is more famous than the Big Nickel. He is assuredly more interesting. “They say he mows his lawn in a three-piece suit.”
Dr. Persinger is not at the lab to greet me. I’m told he’ll be arriving later, after I’ve filled out some personality inventories, part of the protocol for whichever experiment my data will become part of. A research assistant seats me at a table just inside the door, and there I remain, for the next half hour, checking True and False boxes. I have been taken aboard a space ship. I sometimes tease animals. I certainly feel useless at times. There is something wrong with my mind.
I can’t imagine the sort of personality that would check True for some of these statements. Or maybe I can. I mow the lawn in a suit. I like rats.
The lab assistant gets up to run an errand. For some reason, she locks the door as she leaves. I sit awhile. I get up and pace. A table against one wall is stacked with plastic storage containers, each holding two large chunks of brain preserved in a clear liquid. Fascinating, I think, and then I notice the labels on the lids: “Sean and Kristy.” “Michelle and Holly.” “Brent and Derek.” On any other evening, I’d have assumed that these were the students who dissected the brains. On any other evening, it would not cross my mind that Sean and Kristy might BE THE BRAINS IN THE CONTAINER.
The door opens behind me. It’s a man in a three-piece suit. The suit is black, with pinstripes and a watch fob. Dr. Persinger, trim and white-haired and seemingly sane, introduces himself. Before he even sits down, he begins to scan my answer sheets. He seems in a hurry to get me into the chamber. I tell him I’d like to ask some questions first. He says that’s fine and that we’ll walk over to the Colony Room and talk there. I picture dark wood paneling, trustees conversing in hushed tones.
Dr. Persinger unlocks an ordinary-looking door on the other end of the building. Inside are two long walls of cages and a corresponding wall of smell: Colony, as in rats. But the rodents aren’t a hobby, as the cabdriver had made it sound; they’re subjects in various experiments on the beneficial effects of EMFs. (Persinger believes certain kinds of EMFs can be helpful in treating conditions as widely varying as depression and multiple sclerosis.) He tells me he returns several times during the night to make adjustments and gather data, often going to bed around four. Hence the reputation as a nocturnal being.
While he attends to his rats, Persinger gives me the lowdown on the haunt theory. Why would a certain type of electromagnetic field make one hear things or sense a presence? What’s the mechanism? The answer hinges on the fact that exposure to electromagnetic fields lowers melatonin levels. Melatonin, he explains, is an anti-convulsive; if you have less of it in your system, your brain—in particular, your right temporal lobe—will be more prone to tiny epileptic-esque microseizures and the subtle hallucinations these seizures can cause. Persinger adds that the emotions of bereavement produce stress hormones that may serve to raise the likelihood of these microseizures even further.
Persinger isn’t the only researcher to have examined the link between spirituality and tiny seizures in the temporal lobe. In a 2002 Psychological Reports study of 242 undergraduate volunteers, scores on a ninety-eight-item spirituality assessment were significantly predictive of scores on a questionnaire that assessed a cluster of symptoms of complex partial epilepsy, including hallucinations, fear, and a sense of detachment from one’s body. Also known as temporal lobe epilepsy, this condition often goes undiagnosed. Without a medical explanation for these mystifying experiences, patients may interpret them as spiritual events and adjust their belief systems accordingly.
It would seem that Persinger has the whole ghost business neatly sewn up. It’s true that people with naturally occurring microseizures—e.g., sufferers of complex partial epilepsy—often have hallucinations. It’s also true that EMF exposure dampens the body’s natural production of melatonin. This has been shown in rats and in dairy cows housed inside a “bovine exposure chamber” at the McGill University Dairy Cattle Complex* in Quebec.
The results of Persinger’s lab work suggest that you can indeed evoke that haunted feeling in a lab using EMFs. Of the approximately one thousand people who have had Persinger’s signature electromagnetic bursts applied to their right temporal lobes, eighty percent, he says, have felt a presence. In 2002, he published a paper on lab-generated hauntings in the Journal of Nervous and Mental Disease. Forty-eight university students were exposed to complex one microTesla electromagnetic fields either over the left temporal lobe or the right, or both. A fourth group received sham pulsations. Those whose right brains were exposed were more likely to report feeling fear and sensing a presence than were left hemisphere or sham exposures. Disappointingly, no other researchers have replicated Persinger’s work.
THE SOUNDPROOF chamber where Persinger haunts his guests is about as big as a freight elevator. It appears to have been decorated circa 1970; the floor is covered with yellow and brown shag carpeting, and the subject chair is padded with a messy drape of cheap Mexican blankets. I half expect someone to pass me a bong.
Linda St-Pierre, the lab manager, is sticking EEG leads to my scalp. While she does this, I ask Persinger about a statement he made in one of his papers: “Although these results suggest that these apparitions are an artifact of an extreme state-dependence, the possibility that they are associated with transient, altered thresholds in the ability to detect normally indiscriminable stimuli cannot be excluded.” Could the “normally indiscriminable stimuli” he’s speaking of be generated by someone dead? In other words, is it possible that—rather than prompting hallucinations—certain electromagnetic field patterns enhance people’s ability to sense some sort of genuine paranormal impulse or entity?
Persinger acknowledges that both explanations are possible. It could be that people are being physically affected by the electromagnetic fields and then applying their own cultural overlay (“Ghost!”) to explain the experience, and it could also be that people—at least some of them—are suddenly, as a result of the field’s effect on their brain, able to pick up, as Persinger puts it, “actual information that’s in the environment.” Persinger thinks the latter is likely. “Particularly,” he says, “in places where people experience the same thing again and again.” Before I arrived, I had thought Persinger was a skeptic, a debunker, but clearly he’s not.
As he talks, Persinger ties a worn paisley scarf around my head to secure the EEG leads. He says he’s been using it for years. He pauses. “Wouldn’t it be funny if it turned out that all along, it was the scarf?” Persinger slides an orange Skidoo helmet down over the scarf. Glued to the outside of the helmet are eight small electromagnets, which will deliver the milliseconds-long pulses to my brain. Persinger assures me that the exposure level is no higher than that of a hair dryer. It’s the pattern of the signal—its complexity—that matters. Then he shuts off the lights and backs out the doorway.
“Ready?”
No. “Yes.”
The door shuts with a heavy, whispering clumpf, like a space-station air lock. Five minutes pass. I want to feel a presence, but mostly I just feel absence: of sound, of light, of the eerie effects I’d hoped for. If you’ve ever waited quietly in the dark before a surprise party begins, then you know what I’m experiencing right now. I worry that I’m going to disappoint Dr. Persinger, much as I’m disappointing myself. I certainly feel useless at times. There is something wrong with my mind.
Toward the end of the session, I begin to see and hear some things
. Glimpses of faces, utterances that flash through my conscious mind so quickly I can’t remember them a second later. At one point, I hear a police car off in the distance—the repeated whoop-whoops that signal a driver to pull over.
After it’s over, Dr. Persinger comes into the chamber and sits down on an ottoman to interview me about my experiences. I interrupt him. “Did you hear the police siren?”
“No.”
“I did. From over in that direction.”
Persinger looks up from his notepad. “This is a soundproof room.”
Ah. Then I must have been drifting off to sleep.
“You’re labeling,” says Dr. Persinger. “Don’t label.” He gets up to retrieve my EEG printout. He flips through page after page of taut, insistent scratchings. “You weren’t drifting off to sleep. Not even close.”
Whatever it was and as real as it seemed, it wasn’t something I’d interpret as a paranormal phenomenon. About five years ago, for a period of several months, I would occasionally be awakened in the night by someone knocking loudly and insistently at either the front or the back door. So clear and so convincing were the knocks that the first time it happened I got out of bed, put on my bathrobe, and stumbled to the door, greatly amusing my husband, Ed, who was in the living room reading. No one was there. There had been no knocks. That had seemed spookier than this, but maybe it’s the context: sitting expectantly in a lab versus lying alone in bed late at night.
Persinger says that based on my answers to the questionnaires, I’m left-hemispherically dominant. I’m a “least responder.” For comparison, he hands me a sheet of paper with passages from transcripts of the sessions of highly responsive, right-hemispherically dominant types:
“I felt a presence behind me and then along my left side….”
“I began to feel the presence of people, but I could not see them; they were along my sides. They were colourless, grey-looking people. I know I was in the chamber but it was very real.”
Most impressive, to me at least, was the response of paranormal researcher-turned-skeptic Susan Blackmore, who visited Persinger well into her skeptical years, for a New Scientist article: “I felt something get hold of my leg and pull it, distort it, and drag it up the wall.”
It’s possible that the reason I’ve never experienced a ghostly presence is that my temporal lobes aren’t wired for it. It could well be that the main difference between skeptics (Susan Blackmore notwithstanding) and believers is the neural structure they were born with. But the question still remains: Are these people whose EMF-influenced brains alert them to “presences” picking up something real that the rest of us can’t pick up, or are they hallucinating? Here again, we must end with the Big Shrug, a statue of which is being erected on the lawn outside my office.
*When I got home, I wrote to the Dairy Cattle Complex researcher, Javier Burchard, and asked him if the cows ever behaved as though there were an invisible presence in the chamber. He replied that he’d never seen any behavior that was so abnormal as to cause him “to pursue research in that direction.” This suggested to me that he had in fact seen cows behaving in a mildly abnormal manner, so I wrote back again and encouraged him to pass along any anecdotes. I clearly sounded like I had a dairy cattle complex of my own. “I’m sorry,” came the exasperated reply. “But I cannot give you any cow story.”
10
Listening to Casper
A psychoacoustics expert sets up camp
in England’s haunted spots
SIR FULKE GREVILLE lived in Warwick Castle from 1605 until 1628, the year he was stabbed by his disgruntled manservant Ralph.* The murder happened in London, but Sir Fulke’s ghost, in the manner of certain lost but persevering pets, found its way back to the castle. I’m guessing it got a lift from the Tussaud Group, the wax museum people, who bought the castle in 1978 and installed a Fulke-inspired production number called “Warwick Ghosts—Alive!” (“unsuitable for anyone of a nervous disposition”).
Sir Fulke is Coventry’s most famous ghost and certainly its highest-grossing, but not, to my mind, its most intriguing. For that you must visit the home of chartered engineer and psychoacoustics researcher Vic Tandy. Tandy, who teaches at Coventry University, is a big middle-aged guy with a goofball grin and glasses with heavy lenses that tend to pull the frames slightly off-kilter on one side or the other. He fits my stereotype of an engineer so well that when I hear him say things like “I have a second-level in aikido” and “I’m also a magician,” I have to stop myself from going, Really? We are sitting in Tandy’s living room with his wife Lynne and their son Paul, who has a stall at the local market selling rubber dog doo—and probably, knowing this family, a Ph.D. and a Heisman Trophy.
Tandy’s ghost story takes place twenty-some years ago, at a nearby factory that manufactured life-support systems. Tandy designed the company’s products and he put in a lot of overtime. One night as he returned to his lab from a coffee break, the cleaner barreled past him with a stricken look. “She told me there was a ghost in there. She said she’d been feeling uneasy, as though someone was in there with her, and then this gray thing appeared in the corner of her eye, and she took off running.”
Tandy’s first guess was that an anesthetic bottle was leaking, and the fumes were causing the cleaner to hallucinate. Everything checked out fine, so he put it down to, as they say at Warwick Castle, a nervous disposition. The next night, though, working late again, Tandy began to feel strange himself. “I felt my hackles go up.”* Again, Tandy suspected fumes. He wondered whether someone had left the stopper off the tricoethylene, which his lab mates used for degreasing machine parts. “That wasn’t it, so I thought, Right. I’ll go have a coffee. I came back in. Same thing.” Again with the hackles. “Then I see this gray object around to the side of me. I would say I was projecting a form onto it, trying to make sense of it, but… it had arms and legs at one point. I turned to look at it and it disappeared. The following day I was going in for a fencing competition—”
“Really?”
“Yeah. So anyway, I’d brought my foil in to fix it. I’d put it in the vise and gone over to my desk, and when I turned back, it was moving on its own. Aaaaaa!” I don’t know how to spell the sound Tandy just made. Imagine an opera singer being garroted at the crescendo of an aria. What he means is, it scared the bejeebers out of him. But only for a moment. “I thought, No, no, come on, there has to be a reason for this.”
Ever the engineer, Tandy set out to find the answer. Had the cleaner come in at this juncture, she would not have been reassured about the safety and normalcy of her place of employment. She would have found Vic Tandy on his hands and knees, sliding a fencing weapon slowly across the linoleum. Every few seconds, he’d stop to jot notes on a pad. By watching for where the blade started to vibrate, he could measure the peaks and troughs of the sound wave he suspected might be his ghost and pinpoint the frequency. (When sound pressure waves hit an object, they cause it to vibrate; if the object is an eardrum, the brain reads these vibrations—a certain range of them, anyway—as sound.)
Tandy’s suspicion was that his ghost was the product of inaudible, low-frequency sound waves—infrasound. Indeed, when he set up his measuring equipment in the lab, he found a sharp peak at nineteen hertz. (Infrasound runs from zero to twenty hertz.) If the source is powerful enough, infrasound can, in addition to setting fencing foils aquiver, engender all manner of mysterious-seeming phenomena. Unbeknownst to audience members, infrasound pulses were sent out at certain points during a piano concert at Liverpool’s Metropolitan Cathedral in September 2002. It was at these points that concertgoers reported—via a questionnaire distributed before the concert began—a variety of physical effects, such as tingling on the back of the neck and “strange feelings in the stomach,” as well as an intensification of their emotions.
Infrasound has also been reported to cause vision irregularities: sometimes blurring, sometimes a vibrating visual field. The eyeball, Tandy explains to me, has a resonant f
requency of nineteen hertz. Meaning that in the presence of a standing nineteen-hertz infrasound wave, your eye would start to vibrate along with the waves. This is similar to the effect of a powerful operatic voice on a wineglass: When the voice—created by pressure waves from vibrating vocal cords—hits on the resonant frequency of glass, the glass in turn begins to vibrate and may, if the note is held, even shatter.
Tandy explains that peripheral vision is extremely sensitive to movement, a helpful adaptation for dealing with predators that sneak up on you from the side. “If your eyeball is dithering, the sides—the peripheral vision—are where it’s going to register.” The blurry gray ghost in the edge of the cleaner’s vision could have resulted from just such a dither.
Next Tandy went off in pursuit of the source. He found it in the basement. “The maintenance people had replaced an exhaust fan,” he says. “I think they made it themselves. Huge, huge amount of unneeded energy. I mean, it was quite surprising the fan wasn’t standing still and the building going ’round it.”
All of this got Vic Tandy thinking. What if he were to visit some of England’s purportedly haunted spots and take some sound readings? What if the feelings people report when they think they’ve been in the presence of spirits are in fact the effects of infrasound? The more he thought about it, the more sense it made. Old buildings have thicker, more solid walls, which resonate better. And old abandoned castles and cellars often have no furniture or curtains to absorb sound waves. Infrasound would also help explain why reports of ghosts are often localized—why people sense a presence in just one part of a room. Infrasound tends to “pool”—it registers strongly in the spots where the peaks and troughs of sound waves overlap, and disappears where peak and trough cancel each other out. Tandy even has an infrasound-based explanation for why people sometimes feel cold in the presence of what they take to be a ghost. Infrasound can activate the fight-or-flight response, and part of that response is a curtailing of blood to the extremities. Hence the chills (and the racing heart and thus, it stands to reason, the unease).
