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16

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' dream diaries correlated strongly with REM time, suggesting that perceived dream time matches actual dream time. Although REM time is no longer considered a ...


14

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 dream is a stressful event, which causes your brain to release adrenaline. You can't sleep and have an adrenaline rush at the same time so you wake up. These ...


12

I will take a stab at this question, because lucid dreaming is somewhat of an area of expertise of mine. The first thing that you will notice as you explore the lucid dreaming is that the phenomenon is poorly recognized by modern sleep science. There are hundreds of articles that use scientific methods to study sleep disorders, like sleep apneas, restless ...


11

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 to your question about whether or not sleep hours can be accumulated in a linear fashion, the answer is strictly no, but approximately yes. To understand the ...


9

One thing worth pointing out as a very terse hint of an answer: we all know that activation of the sympathetic nervous system is often referred to as the "fight-or-flight response," but parasympathetic nervous system (PNS) activation is less commonly known as the "rest-and-digest" response...though this does appear on Wikipedia's PNS page. Eating (or maybe ...


9

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 brain activity during a lucid sleep. When he asked subjects to complete an activity, it took 50% longer to perform it in lucid sleep than in real life. This ...


8

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 did find some more recent research that addresses the question of weekend sleep recover on some parameters. Pejovic et al. found (quoting from the abstract): ...


8

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 dream occurs at the same time as the alarm going off. The second is that this doesn't actually happen; the alarm is just as likely to go off at the climax of the ...


7

I've used the Zeo (http://www.myzeo.com/sleep/). It seems to work pretty well. It tracks which stage of sleep you are using a very basic EEG. There are some details on how it operates here: http://radar.oreilly.com/2009/10/how-the-zeo-sleep-device-works.html As I said, I've used it in the past and from what I can tell, it seems to be pretty accurate, ...


7

If you are searching specific part of the brain, I think that frontal regions of cortex will be an answer(In particular, the dorsolateral prefrontal cortex which was associated with self-focused metacognitive evaluation). But, as it common in real life, becoming aware of dreaming state required coordinated work of different parts of brain. You can read this ...


7

Nocturnal lagophthalmos is the search term you're looking for. But it's less that they "can" fall asleep with their eyes open and more that they "can't" close their eyes during sleep: Nocturnal lagophthalmos is the inability to close the eyelids during sleep. Lagophthalmos is associated with exposure keratopathy, poor sleep, and persistent exposure-...


7

I'm not completely sure, but you may be referring to Syncope, a medical term which describes events such as fainting or passing out which occurs upon low blood flow to the brain. As a result it can occur when under shock or trauma or a post-effect of stress. Obviously, one would expect the opposite to happen in half the events, such as after vomiting, ...


7

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 next morning at 08:00 am ? It depends on what pharmacotherapies - per the clinical judgement of their treating physician - one may have consumed. Conceptually, we ...


7

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 to describe a detailed, associative, often bizarre dream plot. Usually, the dreamer has difficulty returning to sleep. Nightmares are common and can be a ...


7

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. This phenomenon is, at least partly, caused by thalamic gating. Thalamic gating is caused by the thalamus entering a state in which slow-wave activity disrupts ...


7

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 mode or in a severely depressed mode. This is because the group of neural circuits that function to create consciousness (ref 1, 2, 3) does not die when we are ...


6

Theoretical perspective: No. I don't think so. From a cognitive information processing perspective, I would hypothesise that declarative learning of new facts would not occur while sleeping. Of course, learning declarative facts while awake, but in bed (e.g., when going to sleep or when waking up in the morning) is possible, and sleep is important in ...


6

It has been theorized that it has to do with "visualizing" dreams, but the movements themselves are by virtue of the pattern of electrical activity as the waves travel between the Pons (in the brainstem), Geniculate nuclei (in the thalamus), and Occipital lobe. From PGO Waves PGO waves and REM sleep PGO waves are an integral part of rapid eye ...


6

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 what does and doesn't work. Each app also provides a lot more helpful features for better sleep. Turn off bright lights within an hour before going to bed. Your ...


6

Can caffeine replace sleep? The simple answer here is no. The easiest way to explain why is to dip our toes into the mechanism by which caffeine works. In a nutshell, a large part of what you perceive as drowsiness is caused by adenosine building up in adenosine receptors. The longer you stay awake (and the more active you are to a degree), the more ...


6

**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 found mentioned a study based on this, but failed to link properly. The below link is the empirical evidence. Mindfulness Meditation and Improvement in Sleep ...


6

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 stages and REM ( this happens several times during a typical sleeping session) and each phase brings corresponding highs and lows of the aforementioned chemicals. ...


5

Also, in Oliver Sack's The Man Who Mistook His For His Wife, the author and famous neurologist reports a case about a man who dreamed he had the olfactory powers of a dog; however, when he awoke, he still retained his heightened sense of smell and furthermore could prove it to the nurses. Any experience that one has in waking life can be recapitulated ...


5

Free-running circadian periods were estimated to vary from 13 to 65 hours in normal subjects according to a 1979 study by R.A. Wever. This paper was referenced in a more recent article regarding the circadian pacemaker (Czeisler et al., 1999). I could not access the Wever article directly to assess quality. However, the Czeisler article takes issue with the ...


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