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61 votes
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Do ants or other insects sleep, and if so why?

A quick search on Web of Science yields "Polyphasic Wake/Sleep Episodes in the Fire Ant, Solenopsis Invicta" (Cassill et al., 2009, @Mike Taylor found an accessable copy here) as one of the first hits....
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51 votes

Does sleeping fewer hours than needed cause common cold?

There have been some studies directly linking sleep deprivation to increased risk of catching a cold ("Behaviorally Assessed Sleep and Susceptibility to the Common Cold Sleep". 2015;38:1353–9.). ...
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37 votes

Do ants or other insects sleep, and if so why?

The short answer is apparently yes. Studies on sleep in insects date back to papers published by Phil and Nellie Rau in 1916 and 1938. Hussaini et al. (2003) showed that sleep does affect memory ...
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18 votes

Does sleeping fewer hours than needed cause common cold?

A new study published in this week's journal SLEEP finds that people who sleep less than six hours are more likely to catch a cold. Researchers tracked 164 healthy men and women for a week at a time, ...
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17 votes
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Why sleep? No, actually, why wake?

Based on various comments, I've expanded this answer. Though long, I cannot cover the depth of the topic of sleep but I tried to address the issues asked in the original question while broadly ...
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11 votes
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What are the effects of sleep deprivation?

24 Hour Mark The consequences of sleep deprivation at 24 hours is comparable to the cognitive impairment of someone with a blood-alcohol content of 0.10 percent, according to a 2010 study in the ...
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10 votes

Can a lack of sleep degrade balance?

Short answer Sleep negatively impacts attention, which in turn impairs balance control in cognitively challenging situations. Background Schlesinger et al. (1998) argue that under normal conditions, ...
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9 votes
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What senses are active while sleeping?

The answer is of interest not only in sleep but also the perceptions of patients under anesthesia, comatose states, etc. Our senses aren't 'dimmed' in sleep. There is no effective way to turn off our ...
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9 votes

Why do we sleep?

We don't actually know. But these two theories are strong candidates: Sleep 'cleans' the brain of toxins. Metabolic waste products of neural activity are cleared out of the sleeping brain at a faster ...
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  • 491
8 votes

What's the worst that can happen from too much sleep deprivation? Can you die?

The short answer is: Yes. Fatal familial insomnia is a genetically passed down disease that at some random point in a carriers life will suddenly stop them from sleeping, ever, they die within 7 to ...
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8 votes

Why do some people become more aggressive when tired?

From Poor sleep as a potential causal factor in aggression and violence In most people poor sleep will not evoke actual physical aggression, but certain individuals, such as forensic psychiatric ...
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7 votes
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Biological origin of shuddering during sleep

These are called hypnic jerks, also known as hypnagogic jerks or sleep starts. They are normal part of the wake-to-sleep transition. Hypic jerks consist of non-periodic myoclonic movements, generally ...
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7 votes
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What is "integrated spindle activity" in plain English?

Integrated spindle activity is just this paper's measure of the intensity of spindles. It isn't really a term of art, there is no defined thing "integrated spindle activity," it is just a description ...
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6 votes
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Influence of eating at late night on sleep

According to Crispim et al 2011, caloric intake late at night is correlated negatively with sleep quality: We conclude that food intake during the nocturnal period is correlated with negative ...
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6 votes
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Is it possible for a human to wake up in a wrong way?

I did a quick search and found some research in this area. Sleep inertia is the technical term for feeling groggy for a while after waking up. In a review article by Patricia Tassi, Alain Muzet (...
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  • 3,045
6 votes

Which part of human eyes is getting tired?

These symptoms have a name: Computer vision syndrome. Basically our eyes are made to look at longer distances from 1-6 meters without much accommodation. Typically computer screens are located at a ...
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6 votes
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Where do butterflies sleep?

It would be better to say that they go into an inactive, low metabolic state. This low metabolic state is often driven by the temperature in the air itself; ectothermic butterflies require outside ...
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6 votes
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What's the technical difference between fainting (and being unconscious) and falling asleep (and sleeping)?

For this answer I assume that we are talking about sleep in healthy individuals as well as fainting as an isolated event without underlying disease or injury. The most common form of what we call "...
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6 votes

How does waking up from an alarm clock work?

The brain does not "shut down" during sleep. While not everything about sleeping is understood, we do know that certain areas in the brain remain active during sleep. There is a good overview on sleep ...
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  • 2,228
5 votes

What is happening physically when I get sleepy and when I wake up?

During sleep the cerebrospinal fluid clears out the waste products of brains cells. Sleep fragmentation or sleep deprivation can prevent this process, or reduce its efficiency. So I think the ...
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  • 4,450
5 votes

Why do we dream while sleeping?

Disclaimer: the shortest answer still remains we don't know...yet. Talking from the evolutionary perspective, I have found as many as 8 theories about the purpose of dreaming, some of which even ...
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5 votes
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Chickens roosting, is it sleep or torpor?

When birds sleep, they do experience NREM sleep [1]. Furthermore, Kavanau (2002) concluded that NREM has evolved in warm blooded animals [2]. Birds provide a unique opportunity to evaluate current ...
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  • 2,167
5 votes

Can adenosine be cleared?

In order to do this you would need to find a compound that does all of the following: Crosses the blood-brain barrier. Many pharmaceuticals are not able to do this. Binds strongly to, or has some ...
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  • 36.6k
5 votes
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Melatonin production, sleep, and "cyan light"; how might this finding be possible?

Melatonin production is in response to photoreceptors in the eye, in part, the same photoreceptors in rods and cones that process and transmit information about the wavelength of light (eventually) to ...
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  • 8,691
5 votes

Why do morning people have shorter biological clocks?

Circadian rhythms are entrained by light via the suprachiasmatic nucleus, a part of the brain that receives signals from special retinal ganglion cells that are directly sensitive to (mainly blue) ...
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5 votes
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What are the essential criteria for sleep in living organisms?

I take it you did not even read the article. The article quite nicely expounds on this question. The whole idea is that sleep used to be considered as a human or psychological phenomenon that could ...
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  • 5,690
5 votes

Are there any biometrics that can measure tiredness (sleepiness)?

Most of the sleep-deprivation studies I've seen measure cognitive impairment as a way of quantifying sleepiness, similar to some of the metrics taken in drug and alcohol intoxication studies. Here's a ...
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  • 4,551
5 votes

How are the receptors in the thalamus weakened/shut down during sleep?

Sleep research is a big field and the answer to your question can take many forms and fill libraries. Having said that, it is not so much inhibition of the thalamus per se, but a change in firing ...
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4 votes
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Is it true that some organs "sleep" at certain times of the day and does this affect dieting or when to take medicine?

No, this is not true. The only "organ" (if you will) that needs to "sleep" is the brain, and even then it is still quite active. The body needs to rest. When blood is needed in a prioritized manner ...
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4 votes
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Involuntary twitches and apnoea during early phases of sleep

Jerk-like muscle contractions occurring while drifting off to sleep are normal and are referred to as "sleep starts" or sleep myoclonus (National Institute of Health - NINDS). Sleep Education ...
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