Humans have an elegant and intricate system of internal processes that help our bodies keep track of time, with exposure to sunlight, caffeine and flour all playing a part. But that is not the reason for the “jumping decision”.
Sarah Mosquera/NPR
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Sarah Mosquera/NPR
Humans have an elegant and intricate system of internal processes that help our bodies keep track of time, with exposure to sunlight, caffeine and flour all playing a part. But that is not the reason for the “jumping decision”.
Sarah Mosquera/NPR
Maybe this happens to you sometimes too;
You go to bed with some morning commitment on your mind, perhaps catching a flight or something important. You wake up the next morning and find that you beat the alarm clock just a minute or two ago.
What is going on here? Is it pure luck? Or perhaps you have some unusual ability to wake up at the same time without help?
It turns out that many people have wondered about this phenomenon over the years to Mr. Robert Stickgold.
“This is one of those problems in the study of sleep where everyone in the field seems to agree that it obviously couldn’t be true,” says Stickgold, who is a cognitive neuroscientist at Harvard Medical School and Beth Israel Deaconess Medical Center.
He also remembers Stickgold taking her to his matron, when he was already setting out in the line – greeted only with a doubtful look, and not at all sufficiently explained. “Investigators can say that we are all asleep, ‘balredash,’ which is impossible,” he said.
And Stickgold still believes there it is something to her. “This kind of accuracy has been watched by hundreds of thousands of people,” he said. “I can’t get up at 7:59 and turn off the clock before my wife wakes up.” Yes, sometimes.
Of course, humans are known to have an elegant and intricate system of internal processes that help our bodies keep time. Shaped in part by our exposure to the sun, caffeine, food, exercise, and other factors, these processes regulate our circadian rhythms throughout the roughly 24-hour cycle of day and night, and this affects when we go to sleep and wake up.
If you get enough sleep and your life is varied with circadian rhythms, you should wake up around the same time in the morning, adjusting for the time differences, says Philip Gehrman, a sleep scientist at the University of Pennsylvania.
However, this phenomenon of waking up a few minutes before your alarm doesn’t exactly explain it, especially when it’s a time that deviates from your usual schedules.
“I hear this all the time,” he said. “I think it’s a concern that it’s slow to contribute.”
Scientists are curious – with mixed results
Indeed, some scholars have looked at this puzzle over the years, with mixed results.
For example, one small, 15-person study from 1979 found that, over two nights, subjects were able to wake up within 20 minutes of the target more than half the time. The two subjects who did best were then followed for another week, but their accuracy was quickly assessed. Another small experiment asked participants to choose when to get up and concluded that about half of the spontaneous awakenings were recorded within seven minutes of the choice before falling asleep.
Other researchers have taken a more subjective approach, asking people to report whether they can wake up at any given time. In one such study, more than half of the respondents said they could do this. No, Stickgold says it’s quite possible that “like many things we do all the time, we only do it once in a while.”
OK, so the scientific evidence isn’t exactly overwhelming.
But there was one intriguing line of evidence that caught my eye, by Dr. Phyllis Zee, chief of sleep medicine at Northwestern University Feinberg School of Medicine.
Hormones play a role
In the late ’90s, a group of researchers in Germany wanted to show how waiting can stimulate what is known as the HPA axis – a complex system in the body that deals with our stress response and involves the hypothalamus, the pituitary gland. and glands.
Jan Born, one of the authors of the study, says that he knows that the level of the hormone stored in the pituitary gland, called ACTH, increases in advance of the time it will have to wake up, which in turn means that the glands release cortisol; the so-called “stress hormones” that help you wake up, among other things.
“At this point we decided to try it and it was based on a hypothesis,” said Born, who is now a professor of human neuroscience at the University of Tübingen, in Germany.
Here is what Born and his team did: They found 15 people who usually wake up around 7 or 7:30 am, put them in a sleep lab, and for three nights they took blood types.
The subjects were divided into three different groups: Five of them were told to get up at 6 am; the other 9 were decreed om; the third cohort was given a watch at 9 am, but then at the unexpected time of 6 am . they were excited
Natum says a clear difference emerged as the watch season approached.
The subjects who anticipated waking up at 6 am had a notable rise in the concentration of ACTH, about 5 am It was as if their body knew they had to get up earlier, says Born.
“This is a good response of a suitable preparatory organism”, says CACHINNO born, “because then you have enough energy to resist getting up and you can do it until you have the first coffee”.
The same rise in stress hormones before awakening was not noted in members of the group who did not plan to get up in the morning, but were surprised by the 6 am wake-up call. A third group—those assigned to wake up at 9 a.m.—didn’t have a pronounced rise in ACTH the hour before they got up (Natus says this suggests they simply see the same effect in the late morning).
Nati’s experiment didn’t actually measure whether people would wake up on their own before a predetermined time, but he says the findings raise some questions about that phenomenon. Finally, how did they know they were going to have their bodies before they were normal?
“This tells you that the system is plastic, it can adapt, by itself, to changes in time,” he said. And this also suggests that we have some ability to monitor the use of this “system”. That idea is not entirely foreign to the field of sleep research, he says.
The “scientific mystery” has yet to be solved
“It’s known that there’s a kind of mechanism in the brain that you can use at will to control your body, your brain, while you’re asleep,” says Born. Research shows that hypnotic suggestion can help someone sleep more deeply.
Zee at Northwestern says there are probably “many biological systems” that could explain why some people seem to be able to wake up at a given time without alarm clocks. It’s possible that anxiety about climbing somehow “disrupts” our internal master clock, he says.
“This paper is really cool because it shows that your brain is still working,” he says.
Of course, exactly how it works and how much you can rely on this enigmatic internal alarm system remains a big, unanswerable question. But when the researchers didn’t talk to anyone about the alarm clocks, Harvard’s Stickgold said he wasn’t ready to release the question.
“It is a true scientific mystery,” he says, “that we have a lot.” And because in many fields, when he submits to the mystery, he would be proud, because we do not know how it can be done, that which is not possible.
This story is part of NPR’s periodic science series “Finding Time – a journey through the fourth dimension to learn what makes us tick.”
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