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What is the real reason we sleep?

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41–50 of 94 posts

Re: What is the real reason we sleep?

#41
Very relevant PubMed article many of you will undoubtedly find interesting: "Partial sleep in the context of augmentation of brain function."

Abstract: Inability to solve complex problems or errors in decision making is often attributed to poor brain processing, and raises the issue of brain augmentation. Investigation of neuronal activity in the cerebral cortex in the sleep-wake cycle offers insights into the mechanisms underlying the reduction in mental abilities for complex problem solving. Some cortical areas may transit into a sleep state while an organism is still awake. Such local sleep would reduce behavioral ability in the tasks for which the sleeping areas are crucial. The studies of this phenomenon have indicated that local sleep develops in high order cortical areas. This is why complex problem solving is mostly affected by local sleep, and prevention of local sleep might be a potential way of augmentation of brain function. For this approach to brain augmentation not to entail negative consequences for the organism, it is necessary to understand the functional role of sleep. Our studies have given an unexpected answer to this question. It was shown that cortical areas that process signals from extero- and proprioreceptors during wakefulness, switch to the processing of interoceptive information during sleep. It became clear that during sleep all "computational power" of the brain is directed to the restoration of the vital functions of internal organs. These results explain the logic behind the initiation of total and local sleep. Indeed, a mismatch between the current parameters of any visceral system and the genetically determined normal range would provide the feeling of tiredness, or sleep pressure. If an environmental situation allows falling asleep, the organism would transit to a normal total sleep in all cortical areas. However, if it is impossible to go to sleep immediately, partial sleep may develop in some cortical areas in the still behaviorally awake organism. This local sleep may reduce both the "intellectual power" and the restorative function of sleep for visceral organs.

https://www.ncbi.nlm.nih.gov/pubmed/24822040

Re: What is the real reason we sleep?

#44
post #24

I remember watching this TED talk a couple years ago which stuck with me, though am not 100% sure on its validity. http://www.ted.com/talks/jeff_iliff_one_more_reason_to_get_a... The theory being that sleep was a way to clear out waste from the brain during normal operation, due to the lymphatic system not extending to the brain, it has to put itself into "sleep mode" to drain the waste. This might explain why memory…

It's already in the article:

"Neuroscientists discovered a previously unrecognised network of vessels in the brain that flush out the fluids between brain cells: the “glymphatic system”."

Re: What is the real reason we sleep?

#45

Earlier quoted context omitted.

Probably related. Mammals dream, and we humans experience time in dreams much faster than the actual passage of time. Dreaming is likely the same mechanism as 'experience replay' used in AI reinforcement learning. We're just training our neutral networks using minibatches of our experiences from our waking hours.

"Likely" is not the word I would go for. "according to my wild guess" is a more accurate term.

I've heard it before and it's not their wild guess but a seriously discussed idea. It's just that it's hard to set up experiments to test these sort of ideas.

Re: What is the real reason we sleep?

#46

Earlier quoted context omitted.

Note that sleep apnea can also lead to oxygen depletion, so it could be difficult to discern which of those symptoms were caused by brain damage from lack of oxygen vs. sleep deprivation.

It's mostly sleep deprivation though. I graduated with a 3.7 from a top 5 school in CS after I was treated. My apnea was SEVERE before treatment: 30 apneas per hour. I doubt I had any brain damage, though my study only recorded a min SpO2 of 90%.

Before CPAP, How many times do you actually remember waking up in middle of night?

Re: What is the real reason we sleep?

#47
post #26

Earlier quoted context omitted.

We can't all be plants and fungus.

Why? I think it is possible for life to evolve on a planet with only plants and fungus. Plants have been pretty successful down here on Earth, and I think most of them don't need animals for their survival (except flowers?).

Flowers don't necessarily need animal life either, though it does help. Wind can pollinate.

Re: What is the real reason we sleep?

#48
post #21

What if the question was phrased as what is the real reason we wake up and dedicate some conscious time for our mind? Surely, because in the physical world we live we need to arrange for some time to deal with the unavoidable practical things such as finding food and shelter. Then, after a long enough period of this activity focused on these very tangible, physical and physiological constraints we can finally say we…

Isn't that basically what the scientist asks in the last paragraph?

> “What about this hypothesis: sleep was the first state of life and it was from sleep that wakefulness emerged,” says Walker. “I think it’s probably a ridiculous hypothesis – but it’s also not entirely unreasonable.”

Re: What is the real reason we sleep?

#49

I tend to believe it's tied quite closely to memory and emotional states. I had very bad sleep apnea that was untreated, and for the time that it was untreated my memories are extremely vague compared to most. I also had very high anxiety which is completely gone now. Now that I use a machine to sleep my memory is sharp again. I also eat much less now, so I believe that calories were a way the body would attempt to c…

Interesting that you had the similar experience to mine – I had years of depression, panic attacks, and anxiety that vanished virtually overnight with sleep apnea treatment.

I don't use a machine though, just a brace.

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