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16 votes
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How long do dreams last?

In experiments conducted in the 1950's, William C. Dement, a pioneer sleep researcher, asked subjects to write down their dream content. What he found was that the number of words in the subjects' ...
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13 votes
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Why do we wake up when we die in our dreams?

When you dream you're in REM sleep (rapid eye movement). REM sleep is only slightly more "deep" than stage 1 of non-REM which means it's not that hard to wake you up in the first place. Dying in a ...
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11 votes
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If you sleep during the day, do you need less sleep at night?

Short answer: Yes, if you sleep 2--3 hours during the day, you generally need less sleep at night. Important considerations: However, the short answer is not the full story. In particular, in answer ...
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9 votes

How long do dreams last?

I would like to bring up that there is also an opposite study about sleep duration than described in the previous answer. Daniel Erlacher at the University of Bern conducted an experiment to analyze ...
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8 votes

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

There are two possibilities. One is that we do tend to wake up more at the climax of dreams, and that somehow our dreams can sync up with external input like an alarm clock so that the climax of the ...
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8 votes
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How much sleep is needed for peak cognitive performance?

How much sleep is needed for peak cognitive performance. If some were for >example wake up one morning at 12:30 pm would a sleeping pill help obtain >better sleep required for that performance the ...
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8 votes
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Can you catch up on sleep over the weekend?

Well, to be able to answer your question affirmatively, we'd have to know all the effects of sleep deprivation, including the long term ones, and those are still are not fully accounted for. However I ...
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7 votes
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What is the cause of frequent nightmares?

Nightmares can be defined as (Pagel, 2000): ...vivid and terrifying nocturnal episodes in which the dreamer is abruptly awakened from sleep. Typically, the dreamer wakes from REM sleep and is able ...
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7 votes
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How can someone asleep recognize a very brief sound?

Short answer The auditory system remains active during sleep. Background Filtering of sensory input during sleep is a recognized phenomenon and indeed the senses are typically lulled during sleep. ...
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7 votes

Does our consciousness die when we go to sleep or fall into a coma?

Q: Does our consciousness die when we go to sleep or fall into a coma? A: No, neuroscientifically speaking, the consciousness does not die when we are sleeping or are in a coma; it is just in a sleep ...
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6 votes
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Is there a way to make oneself more sleepy?

If you google "Sleep Hacks" you'll get a lot of good answers. Start by tracking your sleep with My Sleep Bot for Android or iPhone, or Sleep101 for iPhone. This will help you know more precisely ...
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6 votes

Is it possible to become addicted to sleep deprivation?

Possibly of interest: 2011 study from Berkeley, published in the Journal of Neuroscience: Pulling an all-nighter can bring on euphoria and risky behavior: https://news.berkeley.edu/2011/03/22/pulling-...
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6 votes
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Is mindfulness meditation an effective method to fall asleep?

**Is there any empirical evidence meditation is good for sleep? ** Yes. There is. But it definitely depends on the type of meditation. Some types of meditation increase alertness. A few articles I ...
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6 votes
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Death from sleep deprivation, what physical mechanism is failing that makes one not to be alive anymore?

As far as I know REM is just brain running a simulation During sleep hormones and neurotransmitters shift in their quantities available along the phases of sleep: slow wave sleep, intermediate ...
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  • 577
5 votes
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If sleeping is related to 'saving information' you've experience, is forgetting related to more energy?

Short answer: No. Long answer: The need for sleep is not a function of information received in any meaningful sense. Memory consolidation and forgetting processes are not thought of in terms of ...
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5 votes
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What happens in the brain when conscious awareness is changed during dreaming onset?

Here is the first study with fMRI, EEG and eye-video simultaneously recorded while subjects were performing a task (Poudel et al., 2014). "fMRI analysis revealed a transient decrease in thalamic, ...
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5 votes
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Is it counter-productive to study while tired?

Yes. When studying sleep is crucial in consolidating memories. Recently a wave of research and opinion has hit around optimizing learning, sleep is always mentioned as key. To prominent authors are ...
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5 votes

Do neurons fire at a faster rate during dreaming?

In REM sleep, the EEG is remarkably similar to that of the awake state (Purves et al., 2001). Although the EEG represents the synchronized activity of many neurons in the cortex, it does give us a ...
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5 votes
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Can you Counteract the Negative Effects of Sleep Deprivation?

Nutrients have little to do with it*, it's the rest cycles that are important. Cells are messy, stumbling, statistically functional things. Periodically, a cell needs to take a break so it can ...
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5 votes
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Sleep vs. Trance

Wearing those big headphone is indirectly a way to isolate yourself from the surrounding sound. That is usually a prelude for relaxation, or meditation. (In people with audiotory disorder, or with ...
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4 votes
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What is the mechanism behind unihemispheric sleep in animals?

In general, I don't think the answers to these questions are known. This paper is a good review of unihemispheric slow-wave sleep (USWS); the section on neurophysiological mechanisms is largely ...
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  • 2,903
4 votes
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Do animals that sleep during the day have a different sleep architecture than those who sleep at night?

One study (Zhao et. al., 2010), investigating the sleep architecture of two bat species (one nocturnal, and one mixed), notes the following: C. sphinx was found to sleep predominantly throughout ...
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  • 1,517
4 votes

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

You're describing Hypnagogia. There has been some research on the EEG states during hypnagogia: To identify more precisely the nature of the EEG state which accompanies imagery in the transition ...
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  • 191
4 votes
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What brain regions are activated when a dream is remembered?

Your memory of a dream would be an autobiographical memory, which is a memory system that is based on a combination of episodic memories and semantic memories. Autobiographical memories are memories ...
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4 votes

Can split-brain patients sleep like whales?

Short answer An animal study did not reveal any effects on the synchronization of the cerebral hemispheres after callosotomy, as based on EEG recordings. When one hemisphere showed sleep patterns on ...
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4 votes

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

I'd reckon this can be due to the chance of you remembering the dream when you wake up. When your dream was mundane (i.e. emotionless), you probably have no reason to remember it - when awake. (see ...
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  • 141
4 votes

Is our sense of smell heightened when we are asleep?

Short answer The sense of smell may still be operational during sleep, but it is not enhanced. Olfactory stimuli typically will not wake you up during sleep, however. Background Olfaction and sleep ...
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4 votes

Does night-sleep-deprivation have any effect on cognitive performance?

According to this article, yes it does have various symptoms including cognitive deficiencies that make us more prone to errors and less efficient : Circadian rhythms biologically program us to ...
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4 votes

Can we interconnect with other people mentally during dreaming?

Short answer Telepathy is pseudoscience. Background I think you are referring to the phenomenon of telepathy, which can be defined as [T]he purported transmission of information from one person ...
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4 votes
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Difference between drowsiness/sedation and sleepiness

Sedation This is a forced state of drowsiness or sleep and as indicated in your Ipnos link, it will not necessarily help with drowsiness or sleepiness brought about due to problems with your ...
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