I'm going to rely very heavily on the radiolab radio cast of this, cuz I think it's great and they are geniuses. Also, it'll provide some focus. This is meant to be an overview and if feel I need to add something and go back, I will add something and go back. This isn't brainiac mansion.
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Ok, first of all, I'm going to assume that dreams don't not serve a purpose.. errr.. I think there is a purpose to dreams and dreaming. Evolution doesn't tend to do things for fun, and I think there must be some sort of connection from sleeping and dreaming to the grand scheme of things evolutionarily.
So, let's start at the beginning; sleep. Why do we need to sleep? All mammals do it. All known animals actually do it.. cockroaches too. And it's not a voluntary thing; sleep will be forced upon you at some point whether you like it or not. Sort of analogous to Shakespeare describing sleep as death. He also described orgasms as death* so... you know Shakespeare!
*A recent study of brain activation patterns using PET give some support to the experience of an orgasm as a small death:
Anyway, back on topic. We now know this is very far from the truth. Sleep is not death, it's not even the opposite of awake. Our brain is still working hard as we sleep, going through cycles of different types of activity."To some degree, the present results seem to be in accordance with this notion, because female orgasm is associated with decreased blood flow in the orbitofrontal cortex, a part of the brain that is crucial for behavioural control."[1]
I'm not going to go through or define these cycles cuz I think they're not important for this overall current examination, but maybe another time cuz it is interesting.*
*As a quick aside one of my favourite Northern Exposure episodes, Ursa Minor, involves Chris, the dj guy, making a sleep contraption that fits on to his head like goggles. In the goggles there are motion sensors that read his eye movements. When his eyes move as he sleeps, this indicates REM sleep (err, Rapid Eye Movement), which coincides with our dream cycle. Anyway, these motion sensors, when they detect eye movement would set off blinking red lights onto Chris' eyelids. He trained himself (and apparently it's pretty easy to do - there's software out there now that will help you, and yes, there's an app for that) to recognize the flashing red lights in his sleep, and those lights would cue him that he was in a dream, and hence provide the opportunity for lucid dreaming. Really, really awesome.
Ok, so yeah, there is a ton of brain activity when we sleep, we know that. I'm sure you've also heard that dolphins only sleep with one half of their brains at a time. Because they are conscious breathers (they need to actively think about breathing) and because they breathe air (and not through the water), the need to stay relatively awake and at the surface of the water as they "sleep". So, half their brains show classic sleep brainwave patterns for a few minutes while the other half shows classic awake patterns, and then vice versa (this will flip back and forth) as they lie like logs on the surface of the water. Uni-hemispheric sleep. Also, of note, they end up sleeping eight hours a day. Most aquatic mammals do this, but other animals do this as well.
For example, ducks are really interesting.
They tend to sleep in rows, like let's say five to a row. The inner three centred ducks all sleep with their eyes closed, but the outer most ducks sleep with ONE EYE OPEN. I bet you can guess which eye too.. yeah, the outer eye. They, the outer ducks, have even been observed to rotate their bodies 180 degrees as they sleep to allow for the other side of their brain to sleep! How cool is that. (link you need a subscription, but if anyone really wants to read the article and doesn't have a subscription, let me know and I'll just forward it to you. Alternatively, Scientific American back issues to 1993 are available on this torrent)
Now, this brings up an interesting evolutionary adaptation. We haven't really looked at why we need to sleep yet but, because we do, certain adaptation have evolved in animals because of the potential fear of predation.
Sleeping is dangerous. For dolphins, they don't want to drown. For ducks, there are always foxes and wolves. Lizards do this too. In lizard sleep studies, the introduction of a snake into the room overnight brought on the exact same one eye open sleep behaviour.
Uni-hemispheric sleep. Aquatic mammals have it. Birds, avians have it. Reptiles have it. But we, and all terrestrial mammals don't.
Following evolution, it figures we lost it somewhere along the way. To recap, sleep is necessary (we don't know yet why), but because it is, there are certain predatorary dangers involved. We may at times feel unsafe and insecure, for good evolutionary reason only hopefully, while we sleep.
So, the theory goes that the first terrestrial mammals were big hole diggers, and dug themselves underground to sleep, where they were safe and in the dark. They hid in caves, etc... Finally, safely hidden away from predation, the evolution and ability to sleep with both eyes closed developed/evolved. Not sure about the exact theory, but the simple idea is this: predation risk. If you feel safe and there is little risk of being killed, you can sleep easier. The obvious benefit is that you are then awake longer with both sides of your brain working.
How does this translate to humans? Well, there are sleep studies that people in novel sleeping environments (sleeping on a friend's couch for example, or a hotel for the first night) tend to have less deep sleep brainwaves. There is evidence that the sleep isn't as good, and that we are more alert sleepers when in novel environments. Buried deep in our reptile brain is some sort of predator alert system. A sort of fear radar when uncomfortable with our surroundings. Pretty neat stuff here. Evolutionarily, anxiety will translate into your sleep.
Alright. So, we've established that sleep is dangerous, evolutionarily, and that it can rightly cause us anxiety. If there was some way to circumvent it, wouldn't nature have allowed that/put pressure on that to happen? Or is there a requirement, an essential benefit to sleep that is so crucial to ALL our lives that these benefits outweigh the potential for death? Basically, what I'm asking here is why do we need to sleep.
Well, I couldn't find any Canadian numbers (surprise, surprise) but let's take a look at the 40+ million Americans, about 15% of the population, who can't sleep.
What happens when you don't sleep? You feel tired. Why do we feel tired? I mean, what happens chemically in our brains and bodies?
Dr. Allan Pack is perhaps the leading sleep biologist (he's up for a lifetime achievement award this year). He has been looking at sleep at the cellular level, and one of the things he’s found over and over and over — shown in mice, shown in rats, shown in the fruit fly — is that certain cells in all those different types of animals, when they are sleep-deprived, is that you don’t get proteins properly folding.
This is a phenomenon called the unfolded protein response. This is basically your worst nightmare (sorry, couldn't resist). Why do you need proteins to “properly fold”? Well, you’re made of proteins. Proteins are the essence of you. If your proteins are misshapen, if they’re not folded properly, if they don’t have the right three-dimensional structure, they start accumulating inside the cell, broken. Then these unfolded proteins can start to aggregate together and form clumps inside the cell and essentially clog it up, slow it down, and it’s really quite toxic. Clumpiness equals tiredness!
But when you get sleep, a group of "cleaner-uppers" go through your cells and removed these misshapen proteins so that, in effect, sleep is a housemaid, just in the hotel of you.
(This upcoming paragraph gets a bit technical, so skip it if you like; it's not essential.) Specifically, our body's unfolded protein response (UPR) are these "cleaner-uppers"(haha, "technical"), and they have two primary goals: (i) initially to restore normal function of the cell by first halting protein translation and (ii) activating the signaling pathways that lead to increasing the production of molecular chaperones involved in protein folding. If these objectives are not achieved within a certain time lapse or the disruption is prolonged, the UPR aims to initiate programmed cell death (apoptosis).
Honestly, there are no simple pictures of the UPR system. Seriously. If there were, I would put one here.
Blah, blah, blah... Ok, so what does this all mean? Well, sleep activates the clean up system and is really the main point here. Because not only are these cleaner uppers really really essential at preventing cancer, among other things, there is a theory that these cleaner-uppers could translate into learning.
DUH-DUHNNNNN!
Ok, so anyone who's played an instrument knows the score here, so to speak. You're practicing this one difficult section, or this one difficult drum rhythm, and you just can't get it... you keep on trying and trying until you finally give up for the night. You just can't nail it down.
So, you go to sleep.
Then, the next day, what inevitably happens is that you wake up, inevitably, and you go to the instrument and you try again. And what happens? You get it. You get that difficult parsing, or you get that rhythm down cold. Why? What happens?
Dr. Giulio Tunoni believes this is what happens as you sleep. Sleep helps you remember, by forgetting.
He believes that the space in your brain, what you can learn in a day is limited. And every experience you have in one day takes up space. Every experience uses up a little of what you have, and not only that, all these experiences interact with eachother and start to confuse themselves. Just talk to someone who's sleep deprived. They don't make sense, jumble up words and thoughts, can't concerntrate on immediate information, etc.. So the brain records and tries to learn/incorporate everything, whether you want to or not.
Experiences stick with us, having breakfast, talking to your mom, speaking with co-workers, even reading this; it all forces your brain to make new connections. I mean, think about it. Just the simple fact that you can remember what you read at the beginning of this sentence is proof that there have been new connections formed in your brain. Your brain is being reshaped. I am reshaping your brain right now!!! Ok, sorry, enough of that.
Ok, so now. You sit down with your cello or drum kit for two hours at the end of the day, and you start to play. Because you're concentrating more, perhaps you're making even more connections. Physical movements, proprioception, timings, memorizing. Everytime you do it all makes new connections in the brain.
The same thing with studying or learning. Everytime you think about something, you form new connections. If you think about something intensely, with emotion, the connections formed are going to be stronger and more numerous.
All of these synaptic connections are made during the day, and by the time you're ready for sleep, there is a giant mess in your brain! This is one argument not to have arguments at night, btw! Anyway, this is where sleep comes in, in Dr. Giulio Tunoni's opinion.
Sleep is like your housemaid, once again. Only, perhaps not in the way you think. The brain won't come through and pick and choose which connections should stay and which should go. It simply does an electronic sweep of EVERYTHING. Waves of electrical activity, starting at the back of your head, kind of like slow oscillations, 1000 times a night, will flow over your brain, and ALL of those synaptic connections will get just a little bit weaker. Again, it does not pick and choose which connections get stronger or weaker; this wave of electrical activity weakens all connections.
So, what does that mean? Well, the things you concentrated on most out of your day -- the things you spent the most time on, the things that had a strong emotional impact on you, that thing you couldn't get out of your head all day -- these things are the only things that will survive the general sweep.
Now, come next day, when you pick up that instrument, voila, you got it. Why? Because only those stronger connections survived. Even though they are weaker than last night, they are the only connections that survived. Moreover, because you practice the next day, you think about it the next day, these connections will once again start to strengthen. See the gradual pattern here? The connections that have survived the previous night are heard better because the background has become more silent, in a relative sense.
Once you start thinking about something over and over again, especially day after day, these connections are getting extremely strong. This is the reason (or at least the theory) behind learned behaviours and learning in general.
Of note, the brain learns both good and bad behaviours indifferently, cleans them all equally at night where only the strongest survive. If those behaviours are repeated the next day, they are just bound to get stronger. It really is a great system of reinforcement and temporary space usage!
Learning seems like the process of erosion. The things left standing the next day have an opportunity to be built up upon again.
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Ok, so, we've discussed the evolution of sleep and why we need to sleep. Now, why do we dream and what do they mean!
Friedrich August Kekulé von Stradonitz, if you haven't heard of him, was the dude who came up with the idea of the benzene molecule being in the shape of a ring in his dreams.
"...I was sitting writing on my textbook, but the work did not progress; my thoughts were elsewhere. I turned my chair to the fire and dozed. Again the atoms were gamboling before my eyes. This time the smaller groups kept modestly in the background. My mental eye, rendered more acute by the repeated visions of the kind, could now distinguish larger structures of manifold conformation; long rows sometimes more closely fitted together all twining and twisting in snake-like motion. But look! What was that? One of the snakes had seized hold of its own tail, and the form whirled mockingly before my eyes. As if by a flash of lightning I awoke; and this time also I spent the rest of the night in working out the consequences of the hypothesis."
Ok,... not sure where that takes us. But think about it, it is possible that that is true, as weird as that sounds. I mean, just a few nights ago I had a dream of cottage cheese and gummy worms existing together as a desired, commercially available breakfast food. Weird stuff does tend to happen in dreams.
The stuff that you experienced the day before certainly does have the potential to enter your dreams. Think about playing Tetris. If you played Tetris as a kid and you didn't dream about it that night then you're lying. Even in daydreams, or just before bed, Tetris pieces were dancing on your eyelids.
And funnily enough, someone tested just that. Bob Stickgold of Harvard University sat subjects down in a room, made them play tetris for a good amount of time, then got them to sleep in a sleep lab, and then woke them up during their REM sleep and 60% of his subjects were dreaming about Tetris! Ok.. so, makes sense right!.. I mean, it's a pretty big deal, but whatever; it really isn't the whole answer right? I mean, sure we can dream about what we just experienced; no brainer.
Now here is where Matt Wilson comes into the picture. He studies brain waves from dreaming rats. He hooks the rats up to neural signal monitors and outputs these things, both audio and visual, for recording. What he did was during the day he sent these rats through a maze, and recorded their neuronal activity. Then at night, as they slept, he again recorded their neuronal activity. Guess what he found.
Yeah, they matched up. They matched up so well in fact that Matt Wilson was actually able to start to tell when the rats were running in their dreams, when the rats were stationary in their dreams, and when and where the rats were in the maze in their dreams. He started to be able to interpret, based on the lining up of the prior day's events, what the rats were dreaming about.
Specifically, when the rats ran through the maze during the day, let's say it took them 1 minute, they displayed a characteristic neuronal (fingerprint) message during that 1 minute. Well, that exact firing was again acheived while they slept, and Matt was able to line these up and interpret them! The rat was effectively re-running it's maze from earlier in the day. Matt has gotten so good at decoding the neuronal signatures that he can now just listen to the brainwaves, and without looking at the rats, he knows what they were doing.*
*Aside: remember this little fact, cuz it's gonna come up in a post a few days from now. Basically, Matt discovered how to read neuron activity, brain waves and thoughts in GREAT detail by comparing unknown wave patterns with known ones and experiences.
Ok, that is pretty great in and of itself, but, it gets better.
Now, at this point Matt put the rats through two different mazes, let's call them Maze #1 and Maze #2. He found that yes the rats dreamt that they were running in Maze #1 and dreamt separately that they were running in Maze #2 at different times in their REM sleep. But, he also found that the rats would in essence 're-mix' the mazes, and produce new patterns with parts of Maze #1 and parts of Maze #2. So, the implication is that the rat began to invent new mazes.
Sleep therefore seems like the opportunity to basically run through the events of the day and put them together in ways that may not have actually occurred while the animals were awake.
Now, isn't this what learning is?.. or, at least this synthesis is a part of learning? You take two things that are seemingly unrelated, figure out the connections between them, find out the hidden rules and figure out the undiscovered rules that will allow us to create something new and significant that could help us in the future.
Dreaming seems to allow us the opportunity to try out new possibilities and connections that were inhibited by consciousness in the waking hours. Some things end up making sense, some thing don't. But, when it does work, that, my dear, is a new connection and is learning. If it makes sense (even emotionally) and you thought about it, it has the potential to be reinforced.
Ok, so how does the brain decide what to try to connect? As in, what does the brain decide to put into a dream and what to leave out of a dream?
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People don't really have dreams about word processing, about surfing the net, about reading a text book. These are debatably things we do the majority of the time during the day, right? So, why aren't these the things in our dreams? Bob Stickgold, the Tetris dude, has a hunch.
Instead of having his subjects play Tetris, he now had a group play "Alpine Racer 2".
A full body game. Also, a stressful type of game. Stickgold has the theory that as you go through your day, your brain will put a sticky note on memories with emotional content and involvement. The brain will flag those things that are significantly involving and that are important to be able to bring them up afterward in dreams. Then, all the brain has to do while in REM is go back and grab sticky notes.
Stickgold had his test subjests play AR 2 during the day, put them to sleep in a sleep lab, then woke them up after about 2 minutes of sleep and found that about 40% reported dreaming about skiing. Like, right away it seems the brain starts thinking about and processing the days events, the sticky notes.
Then, he let his test subjects sleep a little longer; he didn't wake them until 2 hours into their sleep. After sleeping for two hours, he found almost no replay of the sticky events at all. The replays seems to have dissolved... into a re-mix. He started to get reports like "I was sliding down a hill", or "Rolling".. or "skateboarding".. or, "doing yoga on a ski slope"... So, as the dream goes on the brain seems to start to free associate.
What do I have in my past (so the brain may think) in all my other significant memories that seems to fit thematically or schematically with this major event from today. Sometimes weird stuff happens, sometimes things seem to make sense.
Dreaming then, seems like a time when you can work on the problems you have, allow your brain to start free associating these major significant events in your life, pull them apart, mash them together, and see if any of these almost random connections of important events that you normally wouldn't make during the day, make sense.
Hence, Friedrich August Kekulé von Stradonitz's benzene-snake ring. And my cottage cheese-gummy worm breakfast delight. (I actually woke up the next morning and opened up my container of cottage cheese expecting there to be gummy worms. I was disappointed and I may have been half-asleep.)
Meh, you win some, you lose some. Just gotta keep dreaming it seems like. And reinforcing certain thoughts and dreams during the day to keep them learned! Cool how the mechanisms describing the theory and the practice match up.
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So, take home messages:
Sleep is really important. Crucially important. It helps you clear your mind, quite literally, of unimportant thoughts and connections, jumbled ideas, and jumbled, broken clumped proteins. It's evolutionarily binding; no animal goes without this stuff. It is fundamental to survival and to learning. However, there is a fear of predation element involved, and hence the push and pull of evolution. Because most animals need to spend a third of their day sleeping, it seems like a pretty importnat thing.
Dreaming seems to be a free association of important emotional events. The longer you sleep, the more free association with past events takes place. However, this is probably a good thing as new connections can and will be formed, and eventually reinforced if thought about significantly and sufficiently throughout the next day. If they are garbage associations, they may not be thought about again. However, my cottage cheese-gummy worm idea is obviously not a garbage idea, so I will obviously continue to have this seed grow stronger and more salient in my mind, day after day, night after night, whether I like it (lucky I like it) or not.
Also, sleep and dreaming are both like housemaids looking after different parts of your brain. The sleep houemaid is responsible for removing clumps,the dream housemaid is responsible for eroding synapses and memories.
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Here's Sloan - Keep on Thinkin', from the totally underrated Navy Blues.
Also, of note in this clip, Rufus Wainwright and Martha Wainwright cooking with Sloan?!?! Awesome. I'm not even being cool; they are actually cooking.
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