Questions tagged [sleep]

For questions pertaining to the physiology and pathophysiology of sleep in humans and animals (e.g., sleep stages and their EEG patterns, sleep disturbances), along with psychological effects of sleep deprivation or fatigue.

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28
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2answers
3k views

Can you catch up on sleep over the weekend?

The lack of sleep has many negative effects associated with it. Maintained sleep deprivation results in a degraded performance over time (in this case reaction time). Assuming one needs 8 hours of ...
23
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2answers
10k views

How long do dreams last?

What is the relationship between time perceived in a dream and time in the external world? Is time running in dreams always faster than the time running in the real world? Is it ratio of real time ...
22
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1answer
832 views

Medium-term effects of polyphasic sleep on performance

Typical sleep patterns of one big block of 6 to 9 hours with no naps is usually referred to as monophasic sleep. A second natural sleep pattern is biphasic sleep which breaks up your sleep into two ...
20
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1answer
511 views

Does dream recall disturb the processes of memory consolidation?

Psychology in the time of Freud was occupied with dreams. Relaying these to one's analyst was an important part of treatment. Fast-forward to less than 100 years later, and we know so much about the ...
20
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1answer
3k views

Is there a reduction of “Brain Fog” with fewer hours of sleep?

I've heard patients who complain of "brain fog" (and fatigue) claim a reduction in "brain fog" (and more mental clarity) when they get fewer hours of sleep (usually less than 5.5 hours). Here I'd ...
19
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1answer
549 views

Does dream recall interfere with “reverse learning”? (Crick and Mitchison's theory of REM sleep)

I've recently became aware of the idea of "reverse learning" that might happen during REM sleep - the brain's attempt to eliminate pathological attractors that might appear in neural networks. The ...
17
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1answer
3k views

Do people wake up faster with inconsistent alarm sounds?

Many people have one alarm clock sound that wakes them up every morning. Is having this consistent sound the optimal way to wake someone up? Or can you startle someone faster by changing to a ...
16
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2answers
43k views

How is fasting related to insomnia?

Yesterday I started a new diet using intermittent fasting. For this reason I only ate one meal all day. I was pretty surprised how well I passed that day: I studied a lot, did some sports and ...
15
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3answers
50k views

Can sleep become addictive?

Can a person become dependent on sleeping (more than they otherwise physically need) in a way that fits the definition of addiction, in the same way some psychology professionals may describe a person ...
15
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1answer
16k views

What is the scientific term for unexpected, spontaneous dream recall?

I'm interested if there's a term for spontaneous dream recall. I will try to define the phenomenon I'm talking about. Over 10 years ago, I started to notice that I can spontaneously recall dreams, ...
15
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1answer
247 views

Do animals that sleep during the day have a different sleep architecture than those who sleep at night?

A typical hypnogram, delineating the sleep architecture for a (human) mammal looks like A distinct distribution of non-REM and REM sleep can be observed. Is this pattern of sleep cycles particular ...
14
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2answers
444 views

What factors improve mood and increase cognitive functioning when people wake up?

I'm a software engineer doing some research in order to figure out if developing some applications are worth the effort. This work is applied to computational devices including mobile devices and even ...
14
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3answers
7k views

Why do we always wake up at the climax of our dreams, even when it is an alarm that wakes us?

I know that it probably has something to do with the fact that our dreams didn't really end at the same time our alarm clock rang, our brains just make us think so for some reason.
14
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1answer
217 views

How does daily amount of sleep vary within and between healthy adults?

I'm interested in research that has employed the following or similar research design: Measure the daily amount of sleep every day for an for an extended period (e.g., more than a month) in a ...
13
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3answers
16k views

Can we smell in dreams?

I'm interested in whether people can smell in their dreams. Do people really experience smell in their dreams? For example, if I dream of smelling a flower, will I feel the smell, too? Is there any ...
12
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1answer
69k views

Why do we wake up when we die in our dreams?

A lot of people had some experience with dying in their dreams. They all confirm they remember the whole story until the precise moment of death and it is the death itself what woke them up - not ...
12
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1answer
179 views

Have there been any studies which report a positive correlation between eating certain foods and reported sleep disturbances?

This Skeptics question touched on the subject, but I'm more focused on studies that have been conducted under highly controlled circumstances, like a university sleep lab. We've all heard these old ...
12
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1answer
232 views

What defines the easiest time to get out of bed in the morning for humans?

I'm interested in sleep research, and sometimes in conversations with people the following idea gets discussed: "A person becomes aware at a certain time in the morning and feel great(while still in ...
12
votes
1answer
208 views

What is the mechanism behind unihemispheric sleep in animals?

It is known that dolphins have the ability to sleep with only one half of their brain at a time. According to this popular science source: Dolphins sleep by resting one half of their brain at a ...
11
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1answer
17k views

Do lucid dream eyemasks work?

There seems to be a few eyemasks available that claim to help the wearer achieve lucid dreaming. For example: The NovaDreamer lucid dream mask works by detecting Rapid Eye Movement (REM) while ...
11
votes
1answer
454 views

Why do we talk unconsciously while sleeping

Somniloquy is very fascinating. It is unclear what are the causes, but most of the time it is not seen as a medical condition. "Sleep talking usually occurs by itself and is most often harmless. ...
11
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1answer
1k views

How are people able to wake themselves up after a pre-specified amount of time?

Auto-suggestion seems to work. Several people I know seem to be able to tell themselves "I'll wake up after 'N' hours/minutes", and do so within a minute or two of that duration. I thought for a ...
11
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3answers
467 views

Can lucid dreaming detract from the recuperative effect of REM sleep?

Imagine you mastered lucid dreaming, so you have a lucid dream every night. You might want to use this phase to do creative work or problem solving. Would this have a negative influence on the ...
10
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1answer
129 views

Why aren't sleep measures consistently measured as mediators/moderators of cognitive performance?

Knowing that sleep quantity and quality affects cognitive performance across many domains, why aren't pre-test sleep measures or intra-test measures of arousal a standard part of all cognitive test ...
10
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1answer
242 views

What is it about the nature of slow-wave sleep that makes it difficult to awaken the sleeper?

In humans, delta wave sleep ("slow wave" sleep, stages III and IV by AASM criteria) is more common in children and becomes only a small percentage of total sleep time in adults. Cortical EEG waves ...
9
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4answers
2k views

Is it possible to become addicted to sleep deprivation?

Background: After staying awake for an entire night without sleeping medication, some individuals report feeling tired while others report feeling euphoric and at some point begin to hallucinate with ...
9
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3answers
472 views

What causes dreamers to accept dreams as reality?

I have long had interest in dreaming, and one of the defining features of ordinary dreams is that the dreamer either accepts the dream as "real life", or does not question the surroundings. Compare ...
9
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2answers
338 views

What happens in the brain when conscious awareness is changed during dreaming onset?

I've long been interested in dreaming and there's a peculiar phenomenon of the very start of the dreaming process. Different people experience it differently, but even for the same person there's ...
9
votes
1answer
217 views

Death from sleep deprivation, what physical mechanism is failing that makes one not to be alive anymore?

I have been reading on wiki about sleep deprivation it would appear that one can die without sleep... I have heard that it was used as torture method by quite a few agencies, but didn't know that one ...
9
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1answer
256 views

Can time be slowed in a lucid dream?

Lucid dreams allow a person to be conscious while dreaming. It has been reported that it's possible to control various aspects of the dream environment that are not possible during wakefulness, e.g. ...
9
votes
1answer
187 views

Can adults adapt to less sleep?

I am asking whether adults, especially in circumstances like a monastery or Zen center, can become able long-term to sleep only about 4 to 5 hours a night? So, that would mean: no children to care for,...
9
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1answer
1k views

Is there difference between a memory of a dream and memory of waking experience?

I'm very interested in dreaming and have pretty good dream recall. This makes me able to recall and distinguish hundreds of experience within my memory and label them as "dreams". I'm trying to ...
9
votes
0answers
410 views

If stimulus triggers dopamine release, can dopamine release trigger memory recall of stimulus?

Modern science of sleep is starting to lean towards a viewpoint that dopamine has an important function in dreaming, and that dopaminergic pathways - mesolimbic and mesocortical are activated during ...
9
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0answers
626 views

How much sleep is required to restore maximum cognitive functioning? [closed]

Background: Recently I have really messed up my sleep schedule due to my procrastination. The internet points to some very basic conclusions but I would like to see actual experiments on effects of ...
8
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2answers
5k views

Devices that detect when someone is falling asleep

I'm wondering what types of devices exist that can detect how close someone is to falling asleep. I have heard of several devices that may be able to do this, but I haven't been able to find very ...
8
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2answers
966 views

Is there a scientific term for when you fall asleep because you can't handle something?

I'm wondering if there is a scientific term that describes when you fall asleep or pass out after some traumatic event? This effect happens when people witness something gruesome (a friend being ...
8
votes
1answer
388 views

How effective are multiphasic sleep schedules?

Does multiphasic sleep work well enough that it can be used as a replacement for monophasic sleep? Has there been any research done on people that have used bi/polyphasic sleep for extended periods ...
8
votes
2answers
182 views

What is the sleep study that showed that a percentage of humans have a biological clock that is ~28 hours or greater?

There was an article published some years ago about a sleep study (I think from Germany) that showed about 10-20% of people (European's I think) are genetically predisposed to function on a 30-hour* ...
8
votes
1answer
795 views

What brain regions are activated when a dream is remembered?

Some people remember dreams, others don't. The same person can wake up with dream recall one day and without on other days. I know that the association between REM sleep and dreaming was initially ...
8
votes
1answer
606 views

Why is it easier to fall asleep in the dark?

I'm curious if there is any neurological mechanism that explains why falling asleep is easier in the dark. I recognize that this isn't true universally -- a phobia of darkness might make it easier to ...
7
votes
1answer
28k views

If you sleep during the day, do you need less sleep at night?

If, say, you sleep 2-3 hours during the day (in the afternoon) - Do you need less sleep at night? After all, subjects feel less tired in the evening after sleeping during day. Can sleep hours be ...
7
votes
2answers
224 views

What does daytime actigraphy reveal about an active and awake brain?

I have interest in the study of human motion ( Actigraphy), and have built a couple of smartphone apps using its principles. The apps look at gross motor activity of an individual. Up until now, most ...
7
votes
2answers
142 views

Is there any scientific data showing one can learn while sleeping?

Time is short in the days of learning for me but I like listening to lectures and case studies about code in my field. I've thought about getting a Bluetooth Sleep Headphone to possibly listen to ...
7
votes
1answer
177 views

Is mindfulness meditation an effective method to fall asleep?

It's my understanding that brain activity in the prefrontal cortex is suppressed during sleep and that mindfulness stimulates activity in that region. Based on this, it seems counterintuitive to think ...
7
votes
3answers
276 views

How to restore and maintain a healthy sleep pattern?

Background: Some people over holiday periods or weekends get into sleep patterns that involve waking up very late in the day (e.g., 1pm), and then going to bed quite late (e.g.,, 4am). Such people can ...
7
votes
1answer
522 views

Can split-brain patients sleep like whales?

Regular split-brain patients still have some remaining connection between the hemispheres, but would it be possible for their hemispheres to fall asleep independent of each other? What about when not ...
7
votes
1answer
203 views

Can one incubate on a specific idea in one's sleep?

In this question it is described that intentionally not thinking about a problem can allow the subsonscious to find an answer to the problem; this is known as incubation. I have heard and read it a ...
7
votes
2answers
211 views

What factors determine a healthy individual's required amount of sleep?

I suppose that it is well-known that different people need different amounts of sleep. I read somewhere that most people need something between 7 and 8 hours each day, though some people need only 6 ...
7
votes
2answers
4k views

Why do Spiritual people try to sleep less?

In Monasteries and other spiritual contexts, there seems to be a "rule" that sleep is wasted time, and so the usual daily schedule only allows for about 4-5 hours of sleep. This might be enough for an ...
7
votes
1answer
147 views

How much additional sleep is required to recover from a given number of hours of sleep deprivation? [duplicate]

A previous question dealt with whether it is possible to catch up on lost sleep. This question is a little different. Assume that a healthy adult has been deprived of sleep for "x" hours. How much ...