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.
“The cost of losing consciousness to survival is astronomical,”
"This means we can confidently reject one of the simplest theories of sleep: that we drift off simply because we have nothing better to do."
> “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.”
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?).
That's kinda circular, given that plants and fungi are examples of evolved life :)
You are correct that plants don't strictly need help with pollination (they simply release their spores to the wind/current and hope they land on a receptive partner), however the odds of a succesful pollination decrease sharply as the number of competing plants in an area increase.
In my (uneducated) view, in a scenario where all life is stationary (rooted to the ground, hur hur), you are much more likely to find monocultures -- where most plants can interbreed -- or more species using asexual reproduction.
"Sleep problems may increase risk for developing particular mental illnesses, as well as result from such disorders." - http://www.health.harvard.edu/newsletter_article/Sleep-and-m... (2009)
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 counter act the lack of rest.
These are just my thoughts, I honestly don't have any scientific background on it. Just my own experiences.
Common symptoms of sleep apnea are if you're regularly tired without apparent reason or experience a reduced ability to concentrate during daytime, or if your surrounding complains that you snore loudly.
I don't use a machine though, just a brace.
I doubt I had any brain damage, though my study only recorded a min SpO2 of 90%.
I didn't have to use CPAP to treat it though, so other people's experiences might be different.
I suspect that it's an artifact of the Earth having a day-night cycle at all. Imagine the very first organisms on earth. One is always wakeful, and spends all of its awake time hunting for food. During the earth's night cycle, hunting for food is harder - it's colder, so smell molecules travel more slowly. It's darker, so you can't see food as well. The organism has to work harder to gain the same calories compared to during the day. If there's another organism that goes into a low-energy state during the night, it exchanges the risk of being killed for food during the night with the lower energy budget of not needing to be active at night. Even if a particular organism gets eaten, it's a net positive for the species, and these organisms can outcompete the wakeful organisms.
Then, as sleepfulness becomes part of the successful energy budget of early organisms, you can further optimise nighttime activities - organisms that do brain garbage collecting during the night can do so more efficiently than organisms that also sleep but do continuous garbage collecting. Because sleep was the optimal strategy for primitive organisms, fitting recovery into sleep becomes selectively chosen for.
The only way to prove this, though, would to find a planet that has no day/night cycle, and see if those organisms have any sleep behavior.
Deep sea hydrothermal vents provide this experiment on Earth. While the ecosystems are not completely isolated from our sun based ones, they are pretty insolated from it. Of course, to actually prove this you would need multiple, independent, evolutions of life with a day/night cycle and multiple evolutions without one.
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 is usually better after a good night's sleep, and also the cause of dreams - which is just misfiring of neurons while the waste is being cleared.
"Neuroscientists discovered a previously unrecognised network of vessels in the brain that flush out the fluids between brain cells: the “glymphatic system”."
Our "real" bodies (minds) need some downtime from the game.
So this explains why real AI will never happen: This reality is not where our consciousness lies.
Would make sense with the learning connection and memory.
Under this model the next obvious question is why it takes so long to reset the brain's state. Maybe it can be done faster.
Anyone got any recommendations on lay-person books on sleep/subconscious?
And, as usual, REM sleep steals the show. Probably because of that funky acronym, and that's when we tend to have movie-like dreams. Wake people up at the right time in slow-wave sleep and they'll report 'dreams' that are just sounds or flashes of light.
Bonus factoid: you can wake most people up from even deep sleep by calling their name a few times. When I was a 'sleep technician', that's how I used to wake people up when I had to fix a sensor - much more gentle than physically touching or shaking them.
It's a bit disappointing that journalists are still peddling the "sleep is a great big mystery" angle. And also that the article is arguing that there must be one particular reason why we sleep. There isn't one reason why we respirate, one reason why we digest, or one reason why we circulate - why should there be one reason why we sleep?
one reason why we respirate
To replenish the oxygen in our blood.
one reason why we digest
To extract energy from our food.
one reason why we circulate
To distribute nutrients around the body.
Simplified as those answers may be, they're not wrong FAFAIK, they're incomplete. Do we have such a single not-completely-wrong answer for why we sleep?
Then compare to the article, a bit of long-form journalism rather than throw-away summary lines, which opens with the statement that there's one crucial reason for sleep and we don't know it.
For instance, it deals with the internal world of our body, maintaining and dealing with issues as they happen. It's responsible for releasing chemicals to get a desirable action from our 'conscious' self. It gives us rashes in an attempt to change its environment.
I haven't thought about this too much, but in the very least, I think it's an interesting thought experiment. Has anyone actually tested that our 'unconscious' is indeed unconscious?
There was a PBS Nova episode on sleep many years ago. It showed people who never sleep. They are rare but they exist and have been studied extensively. They do have down-time where they rest for hours, but they never fall asleep. If this was any other show than Nova I'd call bullshit.
Animals in studies seem to die after around 30 days (which I think is longer than any scientifically verified claim made by a human?), and also may even have microsleeps prevented, depending on the experiment.
Humans may also have some rudimentary system of "local sleep". Some other animals have much more sophisticated systems. Basically, parts of your brain might "sleep" and become inactive temporarily, while others are still functioning. I don't think there's any hard evidence of this in humans yet, though.
Also, the longer you stay up, the less aware and cognizant you are, so you might even doze off for an hour or so and not actually realize or remember it. I imagine the people Nova reported on were studied and confirmed not to have actually napped, but it probably does apply to many people who give personal anecdotes of staying up for more than a week.
The only cases of a human truly "never sleeping" are from fatal familial insomnia, I think, and it is as fatal as it sounds like.
So, I suspect if an experiment really kept a human up for a month and prevented microsleep, they'd also die. Even if they didn't die as a direct result, their immune system would be so compromised that they'd probably die from a pathogen pretty quickly.
Also, fatal familial insomnia is a thing, so we have a pretty good idea of what happens when people are deprived of sleep for too long.
According to wikipedia: The ICSD-R states that 85–90% of the general population grind their teeth to a degree at some point during their life, although only 5% will develop a clinical condition.
Of course, we sleep because we evolved from other forms that already slept!
The understanding of sleep isn't complete without taking into account why animals sleep.
Sleep could have gotten more complicated during evolution; acquiring new functions.