The sudden blare from my oxygen monitor jerked me from sleep again. I replaced the fickle sensor that had fallen from my index finger, silencing the din. The hospital was quiet. No footsteps came running. If I’d actually been suffocating in my airtight cage, would anyone have noticed? I readjusted the uncomfortable tube that pumped a continuous stream of nitrogen into my nostrils and went back to sleep. Just a few more weeks in this plastic prison and I would be free.Desperation had driven me to this point. I was determined not to return to the soul-eating life of a cubicle serf, so, unemployed and grasping for tuition money, I’d become a Craigslist whore, selling my services to slick marketers wielding surveys and hawking focus groups. As bills piled up, I found myself eyeing medical studies, debating, literally, how much my health was worth. I made a few ground rules: no experimental drugs, no sleep deprivation longer than 48 hours, and no rectal thermometers.
Fortunately, medical studies that pay well come in two varieties: high-risk and high-maintenance. They involve a lot of danger, a lot of time, or both. While danger was out for me, I had nothing but time, so when I stumbled across a month-long study at a Boston hospital that only required sleeping soundly, I knew I’d found what I was looking for.
The principal investigator was an affable doctor named Grant Gilroy.* In his rolling bass he explained the purpose, methods, and hazards of the experiment, speaking slowly and using small words, apparently accustomed to the burnouts and dropouts that frequent sleep labs.
“We’re studying sleep apnea,” he said. “Do you know what that is?”
“It’s a condition where you stop breathing while you’re asleep. It’s usually obese men who get it,” I answered.
“Right. We’re going to try to recreate the condition in you, so we can see how a lack of oxygen affects an otherwise healthy subject.”
“You’re going to make me stop breathing while I’m asleep?”
“Sort of.”
“Sounds good.”
Some people, usually very overweight men, are unable to regulate their breathing while asleep. Intake of breath is irregular, and they can sometimes go for two minutes or more between breaths. The relationship between the resulting oxygen deprivation, or hypoxia, and the metabolic and cognitive impairments that some sleep apnea patients suffer from isn’t well understood. I was to aid in the understanding. My compensation: $3,400. I was sold.
The setup for the experiment was elaborate. For 33 consecutive nights I would report to the hospital at 9 p.m., where I would be zipped up inside an airtight plastic tent. An electric pump would force oxygen out of the tent, making the atmosphere within resemble the air at the top of a mountain—Mt. Rainier specifically, an altitude of 15,000 feet. At the same time, I’d wear a tube leaking benign but unbreathable nitrogen directly into my nostrils. Every two minutes, a hit of oxygen would puff through the tube, simulating a sleep apnea patient’s occasional breaths. I was also fitted with an oxygen monitor, which would sound an alarm if the oxygen saturation level in my blood dropped below 70 percent of normal. I’d spend nine hours sleeping, then be free during the day. On ten days sprinkled throughout the month, I’d be subject to a battery of physical and cognitive tests designed to determine any changes in my metabolism, blood pressure, memory, nervous system response, or sleep habits. But first, I’d need to spend a night sleep-deprived while performing cognitive tests inside an MRI scanner.
