The biological process characterized by reversible unconsciousness, unresponsiveness to external stimuli and motor passivity.

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59 views

Involuntary twitches and apnoea during early phases of sleep

I assume most people either experienced or have seen people with the following phenomenon: in the early phases of sleep sometimes involuntary twitches occur that usually accompany the pause of ...
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0answers
17 views

Why do body parts sometimes get a itching and tingling feeling when falling asleep?

Just before I fall asleep I sometimes experience an itchy and stinging feeling in my body parts. It can be that the nose or neck suddenly start to itch or a tingling stinging feeling in the legs. ...
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2answers
9k views

Do humans sneeze or cough in their sleep?

As far as I know, I've never seen anyone sneeze or cough while they're sleeping. Google wasn't very helpful either; a lot of contradicting claims. So the questions remains: do humans sneeze or cough ...
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2answers
116 views

Is it possible for a human to wake up in a wrong way?

There's an old folk saying that goes like "He got out of bed on a wrong foot" - to indicate that the person's day is going poorly because of the way that person woke up. Is it is possible for a human ...
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0answers
56 views

Why do I see dreams upon closing my eyes?

I know it is widely accepted that dreams happen during the REM period of sleep, which occures after some considerable time from going asleep. Thus my question is: why am I seeing dreams, should I just ...
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0answers
28 views

Are mind and body really independent when falling asleep?

I have been researching dreaming for many years and often see a theory posed that the mind and body are actually independent in regards to the sleep process. In other words, the body doesn't know for ...
7
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1answer
33 views

Behavioral change in dolphins during different hemispheres activity periods?

It is known that dolphins never sleep in the sense that we do, instead they have one hemisphere of the brain sleeping while the other one is awake. I wonder, do they show observable changes in ...
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0answers
26 views

Immediate Early Genes during sleep

In Neuroscience 3rd ed by Bear et al. on page 607, immediate early genes are described as related to changing synaptic strength, yet have decreased expression during sleep. The explanation given is ...
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1answer
51 views

What factors affect the likelihood of auditory stimuli causing arousal during sleep?

I've noticed that the sound of water drops makes me wake up from sleep but other more strong sounds don't make me wake up. I can't find anything about this. The only reason I can think of is maybe ...
8
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1answer
105 views

What senses are active while sleeping?

During sleep, our body activity decreases. I am wondering on the extent of the lowering of this activity regarding our five senses. Clearly, the sense of touch is still very efficient since shaking a ...
0
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1answer
46 views

Is it true that some organs “sleep” at certain times of the day and does this affect dieting or when to take medicine?

Is it true that some organs (such as the liver or the intestines) are less active at certain times of the day, regardless of whether the individual is awake or not?
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1answer
73 views

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

After a week of too little sleep, I slept about 12 hours last night to "catch up". It made me wonder: what is happening physically that signals that I'm done sleeping, or conversely, that I need to ...
6
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1answer
61 views

Chickens roosting, is it sleep or torpor?

At night when they roost, do chickens experience a state of sleep (meaning do they move from NREM1 to NREM2, NREM3 and REM) or are they in a state of torpor (reduced metabolic rate and decreased ...
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1answer
102 views

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

It is well known that sleep deprivation causes considerable discomfort in humans (and has even used as a form of torture), but nevertheless there have been people who went through protracted sleep ...
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0answers
27 views

How much does sleeping correlate with daily activity?

I'm a very lazy person. I spend most of my time in a chair, at a computer; I eat more than three meals a day. I don't do any sport, at all. What I want to know is: why do I need to sleep 8-12 hours ...
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vote
1answer
64 views

Does physical exercise following lack of sleep increase the risk of sudden cardiac death (SCD)?

Is there any scientific evidence supporting the hypothesis that physical exercise following lack of sleep increases the risk of sudden cardiac death (SCD)? The only relevant research I could find is: ...
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0answers
19 views

Dawn simulation - does color change affect waking up?

just curious. Are there any works or research results related to the influence of light color used for dawn simulation? I mean those wake-up lights which try to simulate dawn to make waking up better ...
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3answers
940 views

How are our senses dimmed during sleep?

Our senses are not as sensitive during sleep compared to wake. There is an arousal threshold during sleep that only when it is overcome will it wake a person up. My question is how is this arousal ...
2
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3answers
77 views

Is the quality of sleep dependent on sleep duration?

I've been facing this lately, where I will wake up in the middle of the night after sleeping for perhaps 2-3 hours and be wide awake, but when I go back to sleep, I wake up more tired than before. ...
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0answers
50 views

TV's so loud when I turn over

Scenario: I'm about to fall asleep with the T.V. on. Having completely forgotten that it was, no longer even hearing it, just before falling asleep I turn over with a 'fresh' ear and it's blaring. If ...
6
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2answers
233 views

Why sleep? No, actually, why wake?

I was just reading the sleep threads, and I wondered, why is the body so constructed so that sleep is necessary? (Is it just a design error?) But then, how do things come to be awake at all? How did ...
41
votes
2answers
7k views

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

I was thinking yesterday about insects (as there was a spider in the house, and I couldn't help but think of anything else, even though they aren't insects), and I started to wonder if ants sleep? ...
7
votes
1answer
104 views

What are the effects of sleep deprivation?

Having recently pulled an "all-nighter" while trying to fix a fatal bug in our release code, I started thinking of any health risks that I might have. What are the adverse effects of staying up for ...
13
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1answer
706 views

What light intensity starts melatonin release in humans?

I'm interested in whether any studies have determined the intensity of light at eye level that starts melatonin release in humans. I know that: melatonin release is suppressed by blue light with ...
7
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1answer
277 views

Do non-human animals suffer from insomnia?

And how do we know whether they do or not? § If sleep is a physiological need, it seems weird that we become unable to fulfill on demand even in the absence of any obvious physical issues. We would ...
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2answers
183 views

How would the human body adjust to sleep times if we were to live in a place with different day lengths?

You sleep at night and are active during the day that's how things work for humans, but theoretically if a human whose parents lived on earth were to be born in another planet resembling earth but the ...
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1answer
82 views

Does tea have its effect if you have a sleep after drinking it?

If I drink tea, then go to sleep for a while, when I wake up, will the effect of tea still be on me (the refreshing effect)? Does it depend on the duration of sleep?
6
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1answer
124 views

Which part of human eyes is getting tired?

It's a thing of common sense that if you read, drive or look at computer screen for too long your eyes will get tired. They burn, itch and try to close all the time. But I was wondering which part(s) ...
3
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1answer
273 views

Where do butterflies sleep?

Do butterflies (insects) sleep, and if so, where?? I have googled for information but didn't get an exact answer.
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0answers
62 views

Is there a correlation between brain size and amount of sleep? [closed]

As far as we know, sleep seems to be the part of the daily cycle when executive functions are resting and memories are fortifying. Many, but not all, of the functions that become dysfunctional upon ...
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3answers
2k views

Why do our eyes close when we sleep?

Why do our eyes close when we sleep? Is it to relax our eye muscles? How can it be explained from an evolutionary point of view?
6
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1answer
3k views

What causes adenosine build up in the brain when awake?

Adenosine is an important hormone in sleep regulation. It is postulated that when a person is awake, there is a build up of adenosine in the brain, which inhibits the neurons in the brain, and ...
6
votes
1answer
368 views

Why do people sleep with their eyes open?

It's a fact that some people sleep with their eyes open, but why does that happen? Is it normal behavior, not a symptom of any sort of disorder? Are there any (dis)advantages to sleeping with eyes ...
14
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2answers
2k views

What causes REM atonia to be lost in sleepwalking?

I understand that in normal REM sleep the voluntary muscles are in effect paralysed in order to prevent an individual acting out their dreams. This paper indicates that there are likley to be ...
15
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2answers
359 views

Can parts of a human brain be asleep independently of each other, or vary in the times required for them to fall asleep?

I know that some birds and marine animals can continue complicated activity (swimming, flying?) while one hemisphere of their brain is asleep. I'm interested if human brain has some parts of it that ...
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0answers
70 views

Do invertebrates dream? [closed]

From Wikipedia: Studies have observed dreaming in mammals such as monkeys, dogs, cats, rats, elephants and shrews. There have also been signs of dreaming in birds and reptiles. Have there ...
2
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4answers
200 views

Why do the humans become sleepy after meals?

I don't know about all the mankind, but I know enough people, who becomes sleepy after their meals. Also, I'm not sure, what kind of food do they consume, but I personally get sleepy almost from any ...
6
votes
1answer
203 views

What causes Paresthesia (Pins and Needles) at a cellular level?

I've looked it up in plenty of places like the Wikipedia page and such, and it is clear that the most common cause of Paresthesia is either a fair amount of pressure on a specific patch of skin ...
2
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2answers
331 views

Do brain cells shrink during REM sleep or a lucid dream?

In this BBC news article a study shows that during sleep brain cells shrink to open up the gaps between neurons and allow fluid to wash the brain clean. But do the cells shrink and undergo the whole ...
4
votes
1answer
169 views

Does playing music during sleep actually suppress rather than rouse the brain?

I've long been interested in the effect of music/sound on dreaming, and even built 2 apps that play music during REM period. Now I'm looking at this article about FMRI studies of a sleeping brain, and ...
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0answers
33 views

Is there a homeostatic setpoint for number of hours of sleep required by a human?

I've heard this TED.com talk about dieting and it mentions that there's a very definitive setpoint within the human brain about how much a human should weight. The speaker mentions that after as much ...
2
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1answer
67 views

Can cerebrospinal fluid deliver nutrients/drugs to neurons during sleep?

I'm looking at this article on the possible mechanism of detoxifying brain during sleep using cerebrospinal fluid. It states that at night, the space between neurons may allow better (up to 20x) ...
5
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2answers
99 views

The least complex animals with ability to dream

People can dream, dogs can dream, cats probably too when they are sleeping. What about other creatures? Can a bird dream? Do rats have dreams? Are there any studies about that kind of thing? What ...
4
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2answers
296 views

Melatonin production - requires nighttime, or just full darkness?

Is melatonin properly produced in daytime sleep in full darkness? Or does it require only nighttime sleep? Additionally, what other biological implications are there, if any, to daytime sleeping? ...
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0answers
51 views

What is the cause of singularity in phase response curve of human sleep and bright light?

I have no background in science as I am a computer programmer, but I am trying to get information on phase response curves, human sleep and exposure to bright light as I am trying to get to grips with ...
6
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0answers
111 views

Does Lucid Dreaming decrease the regenerative effect of sleep?

After watching this SciShow video on sleep, I wonder about lucid dreaming. Specifically: Does lucid dreaming and associated directed agency within Lucid Dreaming decrease the regenerative effect of ...
2
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2answers
581 views

Do primates other than humans have a consistent sleep schedule?

I'm doing some sleep research and would like to compare a human sleep pattern as recorded by a wrist-based actigraph with a "natural" sleep pattern, such as from apes. In an experiment like that, a ...
2
votes
2answers
312 views

What mechanism suppresses melatonin release in humans?

I'm looking at melanopsin, a photo pigment in the human eye. One of its actions is to trigger suprachiasmatic nuclei SCN to suppress melatonin release. I'm interested in learning what is the exact ...
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0answers
39 views

Does sleep duration vary for animals based on time of the year?

I'm interested in the sleep patterns of wild animals, that still use sun for controlling their biological clock. Animals entrain their biological clock to the day/night cycle using light as the ...
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3answers
176 views

How does one maintain balance sleepwalking?

Anectodal. Feel free to shoot it down. Walking is an acquired skill; As far as I'm concerned exhaustion causes disorientation. Even after waking up it sometimes takes a second or so to get balanced. ...