Sleep medicine wasn’t seriously studied until the early 20th century, when Dr. Nathaniel Kleitman began examining the sleep-wake cycle. Yet it’s seen a staggering amount of progress in the following years.

We know about everything from the ins and outs of circadian rhythms to REM sleep disorders, parasomnias to periodic limb movement, as well as any number of other such conditions. More staggering is that there are courses of treatment and an every-increasing body of knowledge for nearly every one.

A field of study cannot see such major strides without a fair share of intrepid scientists (citizen or professional) who, for better or worse, were unafraid to push the limits of research. As such, we gathered some of the more bizarre sleep studies, from a man who kept himself up for 200 hours to a doctor who diagnosed and studied his own stroke.

Who says the science of sleep is a bore?

1) Sleeping Is for the Dogs

Two of the earliest sleep studies would probably never get funding today — and for good reason. In 1894, Russian physician Maria Manaseina kept four puppies awake through forced walking and handling. Just, you know, to see what happened. What happened was they died; the first after 96 hours, the last after 143. Manaseina then repeated the experiment with six puppies, which also all died. Her work led her to the conclusion that sleep is more important than food.

One year later, scientists at the University of Iowa conducted the first controlled study of sleep deprivation. They kept three young men awake for ninety hours, conducting periodic tests of performance and cognition. The results are pretty run-of-the-mill — they fared pretty well after the first night, and started getting wonky after the second — but notable nonetheless, if only because no puppies were harmed. One of the patients reported intense hallucinations after the second night, which the study’s author later recounted:

The subject complained that the floor was covered with a greasy-looking, molecular layer of rapidly moving or oscillating particles. Often this layer was a foot above the floor and parallel with it and caused the subject trouble in walking, as he would try to step up on it. Later the air was full of these dancing particles which developed into swarms of little bodies like gnats, but colored red, purple or black. The subject would climb upon a chair to brush them from about the gas jet or stealthily try to touch an imaginary fly on the table with his finger. These phenomena did not move with movements of the eye and appeared to be true hallucinations… they entirely disappeared after sleep.

When the experiment was over, the subjects slept so deeply that even electric shocks couldn’t wake them.

2) “My Fingernails Taste Terribly Bitter”

1942 was a big year for science: the Manhattan Project began, Stephen Hawking was born and Professor Lawrence Leshan performed his historic nail-biter sleep experiment.

Leshan’s subjects were a group of young boys, all chronic nail-nibblers; the setting, a camp cabin in upstate New York; the goal, to modify their behavior through sleep learning. As the boys slept, Leshan stood above them and incanted the phrase “My fingernails taste terribly bitter.”

It was hard, grueling work, but someone had to do it — especially since his trusty phonograph had broken five weeks into the experiment and Leshan didn’t want to scrap the experiment. After examining subjects’ nails at summer’s end, Leshan determined that 40 percent were cured.

A later attempt to replicate the experiment, however, resulted in a 0 percent success rate, and suggested that Leshan’s subjects probably weren’t fully asleep.

3) Peter Tripp’s Weird Trip

In 1959 radio DJ Peter Tripp conducted a one-man sleep study, keeping himself awake for 200 hours to benefit the March of Dimes. As Tripp took stimulants and spun records in Times Square, a pair of psychologists monitored him in shifts to ensure he didn’t endanger himself — or, at least, endanger himself any further. At the time it was a groundbreaking peek into the effects of sleep deprivation: 100 hours in, Tripp couldn’t perform simple math problems or remember the alphabet. After 120 hours he started hallucinating. According to Thomas Bartlett in the New York Times:

He saw mice and kittens scampering around the makeshift studio. He was convinced that his shoes were full of spiders. He thought a desk drawer was on fire. When a man in a dark overcoat showed up, Tripp imagined him to be an undertaker and ran terrified into the street. He had to be dragged back inside.

When the marathon was over, Tripp went to bed, slept for 13 hours, woke up and read the paper — just like any other day.

4) Driving Under the influence

Dr. Ewen Cameron gained wide attention in the 1950s and early 60s for his newfangled schizophrenia treatment: “psychic driving.” Basically, he had his patients wear headphones for long stretches of time, playing looped messages he hoped would — wait for it — drive new ways of thinking into the psyche. He forced this treatment on hundreds of patients at the Allan Memorial Clinic in Montreal, including many who didn’t even have schizophrenia.

In some cases the recordings were as tame as “People like you and need you. You have confidence in yourself.” In other cases Cameron would sedate people and play this message as they slept: “When you see a paper, you want to pick it up.”

Afterward, he took them to gym, where a sheet of paper lay on the floor; Hobson claimed many patients immediately went to pick it up. Apparently correlation implied causation back in the 50s.

Things got really weird when the CIA found out about Cameron’s work, and gave him money to continue it. When they decided it was all a bust, Cameron admitted he’d taken “a ten year trip down the wrong road.”

5) Underground Knowledge

In 1962, French geologist Michel Siffre spent two months isolated in a freezing subglacial cave in order to figure out how humans respond to extended solitary confinement — a question with broad ramifications in the Cold War. Siffre took no clocks and made no effort to mark time. He called his research assistants, stationed at the surface, whenever he awoke, ate and went to bed.

They were not allowed to call him, however, as that might tip him off as to what time it was outside.

They discovered that humans have an internal clock: Siffre unwittingly maintained a regular sleep schedule and a 24.5-hour day. Yet he perceived time as passing much slower than it did. Whenever he called his team, they conducted a simple psychological test: Siffre had to count from one to 120, one digit per second. It took him five minutes to count to two minutes. Even more bizarrely, when he emerged from the cave on September 14th, he was certain it was August 20th.

“My psychological time,” Siffre recalled, “had compressed by a factor of two.”

In 1972, NASA sponsored a second experiment, this time for six months in a much warmer cave in Texas. The results were surprising. Though he maintained a 24.5-hour day for the first month, after that his sleep cycles grew inconsistent — he had days as short as 18 hours and as long as 52.

Why the discrepancies? Siffre still has no idea.

“It’s the problem of psychological time,” he said. “It’s the problem of humans. What is time? We don’t know?”

6) Choose Your Own Stroke

In 2001, noted sleep scientist J. Allan Hobson stumbled upon an unprecedented research opportunity: the chance to document his own stroke. Vacationing in Monte Carlo, Hobson fell nauseous, lost his balance, and felt as though he were drowning in his own saliva. He recognized the symptoms of a stroke in his lateral medullary brain stem (duh), a self-diagnosis swiftly confirmed by his physicians.

They told Hobson he had a classic case of Wallenberger Syndrome, but he soon observed a rather un-classic symptom: complete insomnia. Hobson couldn’t sleep for ten days, suffering vivid hallucinations, which he dictated to his wife. As he later recalled:

During the whole 10-day period, I could visually perceive, immediately upon closing my eyes, a vault over my supine body, which resembled the bottom of a swimming pool, its surface aqua, white, or beige. Less often, it resembled engraved obsidian or a sort of gauze of ice or glass crystals. The most fully realized human images that I “perceived” were of my wife, featuring her lower body, and (most amusingly) of a Peter Pan-like version of a colleague, Robert Stickgold, and two fairies enjoying a bedtime story. Stickgold is a senior collaborator in my lab who does have a pixielike playfulness. While visual disturbances are not uncommon in Wallenberg’s syndrome, they have only been reported as occurring while awake and with the eyes open. Mine were behind closed eyes.

It was not until his 38th day of hospitalization that Hobson had his first full dream: He and his wife were again on vacation, during which she explained at great length her intent to cheat on him. Hobson recalled the dream in atypical detail, which he took as evidence that the stroke had physically altered the way he dreams.

Like any good scientist, he later reproduced the experiment — if unintentionally — by suffering a cardiovascular collapse that led to even more prolonged insomnia.

By Seth Simons, Van Winkle’s

This article originally published by Van Winkle’s, vanwinkles.com, the editorial division of Casper Sleep;