By Dr. Lance B. Eliot, the AI Trends Insider
How long can you go without sleep?
We’ve all done an all-nighter when studying for a final exam. As a software developer, you’ve likely gone several seemingly sleepless nights while trying to hit that all-important deadline for getting the software done and out the door. For most people, going for about three days without sleep is as far as they can go. Some years ago, radio stations and even TV shows had contests to see who could avoid going to sleep the longest. In some instances, there were situations such as having to stand and put your palm on a car, and whomever lasted the longest would win the car. These tests of human endurance about sleep were gradually either outlawed or were considered of such poor taste that they are rarely if ever done these days.
In 1965, there is the famous case of a 17-year-old student in high school that sought to make a new record for the longest officially recognized time without sleep. During a science fair, he managed to avoid sleep for about 11 days (a recorded 264 hours). Researchers have done similar kinds of studies and found that some can avoid sleep for around 8 to 10 days, but this is not the usual case. Furthermore, as you might guess, the subjects began to get quite irritable and difficult to deal with.
You likely know people at work that seem to get insufficient sleep and tend to exhibit various cognitive deficits or dysfunctions. Most commonly there is a gradual reduction in ability to concentrate and the mind of the sleepless person begins to wander. Motivation usually drops and the person becomes confused about what they were doing and why there were doing it. All in all, there is a definite and apparent degradation in mental processing and especially at the higher-levels of abstract reasoning and thinking.
Motor functions of the human body can also be impacted by a lack of sleep. There have been cases of drivers that got so drowsy that they reported they weren’t able to move their feet onto the brake fast enough to avoid an accident, one that they would normally have been able to avoid if they had been more fully alert. Sensory perception is often impacted by sleeplessness. People that have been deprived of sleep will sometimes hear sounds that aren’t there, or see images that aren’t there, and otherwise be unable to accurately make use of their normal sensory capabilities. There have been cases of drivers that swore they saw an animal dart in front of their car and so they swerved and got into an accident, when in fact there was no indication at all that an animal had been there and it was instead attributed to lack of sleep that the driver reported.
You can try to fight going to sleep, but the body and mind seem to inexorably force you into a state of sleeping. As the famous saying goes, you can delay sleep, but you cannot defeat it. Experiments with rats showed that by going without sleep for two weeks, the rats actually died. The experimenters kept forcing the rats to stay awake and eventually they collapsed entirely and died. There is debate about whether the sleeplessness actually caused the death, and so we won’t here deal with that acrimonious debate. The main point is that it seems like humans and indeed apparently all animals appear to need sleep.
When you think about the nature of sleep, you realize how dangerous a thing it is. While you or any animal is asleep, it is at a heightened risk of survival. You aren’t fully aware of your surroundings. You are subject to someone or something sneaking up upon you. That someone or something could readily harm you, capture you, or kill you. Many animals undertake elaborate protections when they sleep, such as burrowing into the ground or finding a secluded spot in a cave or at the top of a tree. As humans, we often close and lock the door to our bedrooms and sleep in a room that is generally a protective bubble, aiming to make sure that we aren’t readily subject to our sleeping state vulnerability.
Why would humans and animals generally have evolved in such a manner that we needed sleep, which as pointed out is a significant danger to survival. One would certainly think that over time the evolutionary forces would have led to us not needing sleep, doing so by “out surviving” those that do need sleep. Yet, sleep still persists. There must be a really, really, really good reason for sleep.
No one can say for sure why we do need sleep.
One argument is that we need sleep to give the body a chance to recover and recuperate. After a long day of effort, presumably the body is worn out. Therefore, it would seem to make sense to force the body into a state of motionless so that it could work toward fixing itself and getting ready for the next day’s efforts. If this were the case, you might ask why couldn’t we just rest. In other words, rather than entering into actual sleep, suppose we just let our body rest for a couple of hours each night. Wouldn’t that take care of the whole my-body-needs-recovery aspects?
The counter-argument is that maybe people and animals would not be careful enough to let their body rest, and so this sleep mechanism came to the forefront to force us to let our bodies rest. With the mind also going into a sleep mode, it would then force the body to have resting time. Were the mind to continue to remain active, it might overtax the body and keep the body going all the time, ultimately destroying the body. If the body gets destroyed, the mind has no place to go. Thus, the mind must enter into sleep, whether it wants to or not, in order to keep the body going by allowing the body to rest, and for which then the mind still has a means to function because the body is kept in good shape.
That’s a theory that most don’t buy into. Instead, the belief is that the mind also needs sleep. In fact, there are some camps that say that it is really only the mind that needs sleep. They assert that the body could be kept going all the time. The mind is the weak link in all of this sleep stuff. If you could keep the mind from going to sleep, the body could rest enough at times to keep going all of the time. The only reason the body goes to sleep is due to the mind going to sleep. When the mind sleeps, the body has nothing to control it, and so the body just naturally also goes into a motionless state.
I am sure that you know though that the mind does not seem to truly go to sleep. There used to be a belief that the mind went entirely dormant during sleep. The neurons and brain activity were assumed to stop. We know now that this is not the case. There is activity in the brain during sleep. Indeed, you might be aware of REM (Rapid Eye Movement), a sleep phase found in at least mammals and birds, involving rapid eye movements, low muscle movements, and the likelihood of dreams occurring.
Do animals dream? Researchers have tried to show that it seems that they do, including studies of birds that suggested they were dreaming while asleep. People often say that they dreamed last night and are sure that they dreamed, but they cannot remember the dream per se. They also will claim that it was their first dream in weeks. Generally, this is likely a false recollection. You normally are dreaming whenever you sleep. It is only that some of those dreams do you ever seem to become aware of, after having come out of sleep. There is also the chance that you believe you dreamed but in fact it is entirely made-up. You believe that dreams can be remembered and so you convince yourself that you had a dream and you claim you can remember it, when maybe you didn’t at all.
People and animals that go without sleep for a while are prone to cognitive deficits and dysfunctions. We might therefore use this as a clue about the nature of sleep. Why would we for example hallucinate once we’ve been deprived of sleep? What is going on during sleep in the mind that without sleep the mind turns toward hallucinations?
A prevailing theory about the mind during sleep is that it is reorganizing itself. Pretend for a moment that you are working in an office that has lots of filing cabinets. During the day, your in-box gets filled up, and you try to process things and move them into your out-box. Meanwhile, you are also filing the paperwork into the cabinets. You want the paperwork to be ordered in some helpful way, and perhaps you’ve opted to label the cabinets by the alphabet. You place some of your files into the cabinets marked A to D, and later on, when you need to find that paperwork, you’ll know to look in the A-D labeled cabinet to find it.
Some believe that the human brain works the same way. During wakefulness, your brain is trying to process all of the sensory input coming into the in-box, and producing output via the out-box, such as speaking or waving your arms or whatever. The brain is also filing memories as fast as it can, while you are awake. Maybe, the brain can only do so much while also needing to pay attention to the world. Perhaps, it needs some dedicated downtime to be able to properly organize memories and file them into the right places.
One reason why this theory seems plausible is that when you have dreams, it could be that a dream is really a snapshot of the filing that is going on. Things are kind of in a mess during the filing process, and the dream inadvertently arises from that mess. This explains why dreams often involve aspects that are seemingly unrelated. They were merely crisscrossing throughout the brain as they were being filed. This also explains why there is activity in the brain during sleep. It is doing (in parlance of software) garbage collection. Some stuff in the brain is being filed, some stuff is being discarded (maybe), some stuff is being transformed, some stuff is being packed or compacted, and so on.
Another fitting piece of the puzzle involves the mind gradually become cognitively dysfunctional when denied sleep. Using the garbage collection theory, we could suppose that the brain in a waking state eventually reaches a threshold that the amount of input has piled up so much that the brain can no longer properly function. It’s like an office that begins to have piles upon piles of files all over the floor and sitting on shelves. Until it all gets labeled and placed neatly into the filing cabinets, it becomes harder to use and begins to get jumbled together. Our hallucinations are a combination of the mental input spilling over and getting mixed with our normal conscious selves. The mind gets full of “garbage” that needs to be organized and transformed, but since it is being denied filing time (sleep), it does what it can in real-time to keep processing in spite of the junk mixing into everything.
After being denied sleep for an extended time, by-and-large most humans are able to return back to a normal mental state after getting so-called catch-up sleep. This again fits well with the garbage collection theory. Presumably, once the mind gets a chance to sleep, it then continues the garbage collection. It could be that the piled up trash in the mind takes an extra amount of sleep time to properly organize and get setup for normal mental processing.
A recent study on sleep found that even upside-down jellyfish sleep. This was unexpected, since they do not have a brain per se. Jellyfish make use of a decentralized network of nerve cells. Biologists say that this is the first time that an animal without a centralized nervous system has been shown to actually sleep. If the Cassiopea jellyfish really do sleep, and since they evolved from a lineage going back around 542 million years, it once again suggests that sleep is a very long time needed factor. You might wonder though that if sleep is due to the mind needing time off, do jellyfish really need time off to let their decentralized nerve cells do something? Some experts are puzzled by this and more research needs to be done.
What does this all have to do with self-driving cars?
At the Cybernetic Self-Driving Car Institute, we are making use of sleep as an AI mechanism for self-driving cars. This is a novel idea and few others are pursuing this. We explain next our rationale for why we think this has merit.
First, let’s focus on an overall argument about the nature of AI and how we will ultimately achieve AI. Some believe that the only path to true AI involves being able to ultimately mimic human intelligence. Since human intelligence appears to depend on sleep, we would presumably need to crack the code on why sleep is needed, and then either have systems that do something like sleep or actually really go to sleep in the same manner of the human mind.
Thus, if you are pursuing AI, you should also be wanting to pursue the nature of the human mind and how it works, and also therefore what sleep does and why it is seemingly so important to the human mind and presumably to the ability to think.
I’ll note that there are some AI researchers that believe we don’t need to know how the human mind works in order to achieve intelligence in machines. They say that there is more than one way to skin a cat. For them, if you can get a machine to exhibit the same characteristics as a human intelligence, then how you got there is immaterial to the matter at hand. Others say that those trying to find other means to get to intelligence are barking up a false tree and ought to get back to figuring out how human intelligence actually works.
Anyway, let’s go ahead and assume that there is a need for sleep in cognition, and therefore there might be a basis for having sleep occur in AI.
In the case of a self-driving car, what does this translate into? One perspective is that the AI of the self-driving car needs downtime to be able to process all of the inputs and processing and memories that were collected during its wakefulness state. This is in keeping with the earlier mentioned theory about the purpose of sleep in humans is for software related garbage collection. When a self-driving car is not otherwise in motion and functioning as a working car, we can use the downtime for the self-driving car to do a similar kind of systems related garbage collection.
This though admittedly is not an entirely satisfying answer, since you could presumably just add more processors and even offload processing to a remote centralized server, which then could enable the garbage collection while the self-driving car is still in an operating mode and not require actual downtime of the self-driving car.
Speaking of which, there is ongoing debate about whether or not self-driving cars are going to be operating 24×7. Your existing car tends to be “asleep” while you are not using it, meaning that it is at rest. Right now, there aren’t any smarts per se on your conventional car, so you could suggest that the body of the car is resting. In one way, though this might seem odd, it does kind of make sense in that suppose your car was operating continuously 24×7. How much could your car engine take? Is it really made to be continuously operating?
For those that are thinking that they are going to turn their self-driving car into a 24×7 ride sharing service, meaning that while the owner is not using the self-driving car that it will be driving around earning money by giving rides, we need to consider how realistic this will be. Cars are not particularly made in such a manner that it is expected they will continually be in operation. I am not saying they cannot operate continuously. I am just saying we are going to see a different pattern of when and how cars breakdown and need repairs, in comparison to how cars are operated and used today.
Getting back to the parallels between sleep in humans and the potential need for sleep in AI, there is the point already made about the role of garbage collection. For our self-driving car software, we are making use of the processors of the self-driving car when it is not being used (the self-driving car is parked, not in motion, not tasked with any direct activity; it might or might not be that the car is turned-off), essentially mimicking the sleep notion, and having the system review what it has most recently learned. This allows the self-driving car to create new approaches to driving and put into fast indexing lessons learned. During the normal driving of the self-driving car, the AI is busy with driving the car, and so this downtime can be put to handy use.
We also believe that there are more mental aspects underlying sleep than what is known or theorized currently. Using large-scale neural networks, we are simulating various hypotheses about other facets of sleep. We are exercising processing changes across the neural network to simulate sleeping like states, in terms of potentially serving to tune the mind. This is more than just filing of memories.
For self-driving cars, whether you believe that they should “sleep” or not, we can at least be spurred by the concept of sleep to leverage when the physical body (the car) is not being used. This is an opportunity to leverage the then under-utilized AI that is presumably otherwise dormant when the car is not actively engaged in motion and driving. I hope that our efforts will spur others to give due consideration to why sleep is crucial to humans and cognition, and in what ways might that be applied to AI and self-driving cars. I ask that you sleep on it.
This content is originally posted on AI Trends.