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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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29 votes
2 answers
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 ...
Steven Jeuris's user avatar
  • 3,523
24 votes
2 answers
11k 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 ...
Deep-est Shah's user avatar
23 votes
1 answer
930 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 ...
Artem Kaznatcheev's user avatar
20 votes
1 answer
578 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 ...
Chuck Sherrington's user avatar
20 votes
1 answer
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 ...
Bradford's user avatar
  • 301
19 votes
1 answer
608 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 ...
Alex Stone's user avatar
  • 9,390
18 votes
1 answer
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 ...
JoJo's user avatar
  • 675
16 votes
3 answers
15k 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.
rodrigochousal's user avatar
16 votes
1 answer
279 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 ...
Chuck Sherrington's user avatar
15 votes
2 answers
47k 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 ...
Jon's user avatar
  • 253
15 votes
3 answers
51k 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 ...
Nicole's user avatar
  • 259
15 votes
1 answer
24k 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, ...
Alex Stone's user avatar
  • 9,390
14 votes
2 answers
476 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 ...
bmartins's user avatar
  • 243
14 votes
1 answer
229 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 ...
Jeromy Anglim's user avatar
13 votes
3 answers
25k 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 ...
user avatar
12 votes
1 answer
111k 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 ...
vojta's user avatar
  • 223
12 votes
1 answer
192 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 ...
Chuck Sherrington's user avatar
12 votes
1 answer
254 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 ...
Alex Stone's user avatar
  • 9,390
12 votes
1 answer
258 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 ...
Chuck Sherrington's user avatar
11 votes
1 answer
25k 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 ...
Douglas S. Stones's user avatar
11 votes
2 answers
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 ...
Everyone's user avatar
  • 419
11 votes
1 answer
582 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. ...
SiXUlm's user avatar
  • 211
11 votes
3 answers
579 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 ...
draks ...'s user avatar
  • 1,828
10 votes
3 answers
657 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 ...
Alex Stone's user avatar
  • 9,390
9 votes
2 answers
201 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* ...
Garrett Fogerlie's user avatar
9 votes
2 answers
365 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 ...
Alex Stone's user avatar
  • 9,390
9 votes
1 answer
134 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 ...
stowler's user avatar
  • 91
9 votes
1 answer
262 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 ...
Matas Vaitkevicius's user avatar
9 votes
1 answer
499 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. ...
Justas's user avatar
  • 1,537
9 votes
1 answer
256 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 ...
Chuck Sherrington's user avatar
9 votes
1 answer
222 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,...
user avatar
9 votes
0 answers
508 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 ...
Alex Stone's user avatar
  • 9,390
8 votes
4 answers
5k 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 ...
Josh's user avatar
  • 5,390
8 votes
2 answers
6k 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 ...
Azmisov's user avatar
  • 183
8 votes
1 answer
45k 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 ...
user avatar
8 votes
1 answer
495 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 ...
Oliver's user avatar
  • 173
8 votes
1 answer
925 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 ...
Alex Stone's user avatar
  • 9,390
8 votes
1 answer
642 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 ...
Josh's user avatar
  • 5,904
8 votes
1 answer
307 views

Sleep deprivation and task performance

Case: In case of an adult, the average adult sleep time required is 7.5 to 8 hours. Suppose the person (aged between 23-29) has slept only 6 hours, or less than the average time (7.5 to 8 hours). ...
New one's user avatar
  • 333
8 votes
1 answer
2k 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 ...
Alex Stone's user avatar
  • 9,390
8 votes
1 answer
165 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 ...
user avatar
7 votes
2 answers
238 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 ...
Alex Stone's user avatar
  • 9,390
7 votes
2 answers
1k 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 ...
user avatar
7 votes
2 answers
181 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 ...
Gʀɪᴍ's user avatar
  • 171
7 votes
1 answer
199 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 ...
Wuschelbeutel Kartoffelhuhn's user avatar
7 votes
3 answers
304 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 ...
Oliver's user avatar
  • 173
7 votes
1 answer
235 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 ...
Anubhav's user avatar
  • 179
7 votes
2 answers
245 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 ...
J. Doe's user avatar
  • 71
7 votes
2 answers
6k 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 ...
user avatar
7 votes
1 answer
1k views

What is the difference between drug withdrawal and sleep deprivation effects?

Personal sleep-deprivation study: Recently, I posed a question that I'm sure many people find tough already: "Do I really need to sleep?", and so I tested myself, I spent two days without sleeping. ...
Enoque Duarte's user avatar