Hot answers tagged

17

A general model of processing stimuli suggests that when information does not provide informational value, then we gradually begin to ignore it. Such a model is consistent with the experience of many people in relation to background traffic noise when moving from a quiet to a noisy neighbourhood. I.e., the frequency with which external traffic noise enters ...


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 ...


15

I am not aware of any study that specifically addresses dream recall, but there is a growing literature about "memory reconsolidation" or "post-reactivation plasticity", the idea that memory reactivation (recall) can temporarily return a memory to a state of high fragility and susceptibility to interference, after which a process similar to consolidation ...


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 ...


13

Antonio, Nielsen and Doneri (1998) provide one assessment of self-reported prevalence of smell in dreams. To quote the abstract (my bolding): Although numerous studies have investigated the content of laboratory and home dream reports, surprisingly little is known about the prevalence of various sensory modes in dreams. 49 men and 115 women ...


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 ...


12

Particulalry short wavelengths (such a UV light) have been shown to suppress melatonin[1], a hormone that regulates sleep. The authors also show that: All subjects had an elevated cortisol level in the 90 minutes prior to onset of light exposure compared with the corresponding clock time on the previous day So there's a kind daily memory in the ...


11

The scientific concept which most closely matches your description of "brain fog" is sleep inertia. Any theories on why this may happen? First, a brief detour. Sleep is divided up into 5 stages (stages 1, 2, 3, 4, and REM). Since 2007, NREM sleep has been reclassified into stages N1, N2, N3, with N3 being a combination of the former stages 3 and 4; ...


11

Assuming there's not a neurological dysfunction underlying sleep deprivation (which is even more possible with Aspergers as sleep dysfunction is a typical comorbidity) it can simply be a learned behavior. The more you do something (whether you particularly "enjoy" it or not) the more likely you are to build it up as a habit. Procedural memory is always at ...


10

Not aware of any studies on this topic. I think this is a tricky question because of the nature of sleeping. Hypersomnia does not fit in with physiological nor psychological dependence because of the following (from the proposed DSM-V revision, but similar enough to the DSM-IV-TR) symptom: "The sleep periods are non-restorative (unrefreshing) or so ...


10

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

"Nor can I see potential for one to become psychologically dependent or addicted to sleep." I believe someone can become "psychologically dependent on sleep". I am 47 and have used sleep for 40 years to escape from life. I typically sleep 4-6 hours too much each day. I don't really physically need this sleep, since I then am often awake the next night ...


8

Disclaimer: As you have noted yourself, there aren't very many scientific researches on the topic. The only main points that I can derive are generally of blogs or sketchy speculations. As such, you are supposed to take this answer with a grain of salt. Interesting Thing of the Day notes that polyphasic sleep may make the person awake and alert but have ...


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

Measures of arousal surely do play a role in subject performance on a wide variety of cognitive tasks. Generally, scientists can safely ignore this factor as it is assumed to introduce random noise between participants. From a hypothesis testing perspective, scientists are much more worried about factors that introduce systematic bias, or factors that skew ...


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 ...


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