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Health and medicine
Course: Health and medicine > Unit 9
Lesson 3: Sleep and consciousnessDreaming
Created by Carole Yue.
Want to join the conversation?
- What other animals dream? All mammals? Lizards? Fish? Birds?(16 votes)
- It's hard to say, because we can't ask them. We do know that some other mammals, like dogs, do dream. We know we dreams occur whenever we sleep, and since animals sleep, there is no reason to think any animal doesn't dream when they sleep.(16 votes)
- why we can't remember our dreams?(2 votes)
- We can remember our dreams. Certain triggers in conscious experience can lead to remembering a dream partially or, in some people, fully.
Why we repress those memories, by default, is probably for our own sanities.(7 votes)
- Do we dream the first time we sleep, like right after we're born?(4 votes)
- It depends on what you mean by dreaming. For a baby, I seriously doubt it will have dreams like flying in the sky or swimming in the sea but perhaps it may have some primal form of this. What I do know is that as we grow older and learn more things, our dreams may get subconsciously influenced by our knowledge and environment. That is why it would make sense for a 50 year old man to, perhaps, dream about owning a supercar but this wouldn't make sense for a baby.(2 votes)
- Why does time seem to go fast when we sleep? I would go to sleep and then about 2 seconds later I'm awake and it's 11 AM. Also, is deja vu related to dreaming? i would remember something in my dream and a day later the scene in my dream would actually happen in real life.(3 votes)
- Time goes by so fast when we sleep because we do not have the opportunity to look at the time as frequent as we can as when we are awake. Thus we did not witness the interval of events as we are sound asleep. We're pretty much in a "coma" being mostly unaware of what's going on.(3 votes)
- I noticed in this video you didn't mention anything about lucid dreaming, that is where you are aware you dreaming while you are dreaming. I lucid dream very frequently. I even know how to induce lucid dreaming by testing to see if I'm in a dream. What is the cause of lucid dreaming and why are some people able to do it and not others?(3 votes)
- Fascinating question! Dreaming only happens in REM sleep, so maybe people who spend less time in REM sleep are less likely to have lucid dreams. Or maybe there are different "intensities" of REM sleep and the lucid dreamers' brainwaves speed up more than the other dreamers' brainwaves.(2 votes)
- Can you remember dreams?(3 votes)
- Yes, definitely. Especially if you use a dream journal and write down your dreams first thing in the morning, when you are most likely to remember them(2 votes)
- I thought that dreams wear just a jumble of memories and thoughts. Is there any scientific evidence to support this theory?(2 votes)
- It's thought that the brain categorizes information, events, thoughts, and other information while you sleep, but that's just one more theory. Brain waste is removed and ATP is generated during sleep. This Scientific American article excerpt might interest you: http://www.scientificamerican.com/article/what-is-dreaming-and-what-does-it-tell-us-about-memory-excerpt/(3 votes)
- Do people who are born blind dream? I mean if they don't know what the real world looks like, what would they dream of?(2 votes)
- People who are blind by birth dream with their other senses, mostly hearing and to a lesser extent, touch, taste and smell. People with later-onset blindness can also have visual dreams.(2 votes)
- I sometimes have dreams about things and then they happen, is there a meaning to them!?(2 votes)
- this my friend is called deja vu there no real explanation for these thing we just now the have been proven just not scientificallly(1 vote)
- Sometimes I dream about something, then I forget the dream, then something happens that I thought happened in my dream even though it didn't. Why does that happen?(2 votes)
Video transcript
Voiceover: Do you
remember your last dream? Maybe it was really nice, maybe scary, maybe just a little weird. Maybe you don't even remember dreaming. Everybody does dream, [bearing] any brain damage and you dream every
night during REM sleep. Sometimes you dream during non-REM sleep but those dreams aren't
as vivid or memorable. You can usually tell
that someone's dreaming because their eyes are moving rapidly underneath their closed lids. If you were to look at
an EEG of their brain it would look almost like they're awake. Even though their body is
completely non-responsive and mostly paralyzed. Most dreams last about five
to 20 minutes at a time and they don't seem to be localized in any one part of the brain. If you remember your
dreams when you wake up, you might remember that some
pretty strange things happened even though they probably
didn't seem that weird when you were in the dream. One reason that we don't realize how strange dreams are until we wake up is that during REM sleep, activity in our prefrontal
cortex is decreased. That's the part of the brain responsible for logical
thinking and planning, so if it's not very active then we wouldn't be aware
of things in our dreams that defy logic like fooling around, or animals talking to you, or something. No one really knows why dreams occur but there are plenty
of different theories. The most popularized one
is Sigmund Freud's idea that dreams are unconscious
thoughts and desires that need to be interpreted. There's very little science
to really support this idea. Even within evolutionary psychology there are lot of other theories
about why people dream. Some evolutionary psychologist think that it allows us to simulate threats so that we're better prepared
for them in the real world. Some think that it helps us solve problems by thinking about them in
an altered biochemical state and still other evolutionary
psychologists think that dreaming is just a byproduct
of our neural development and serve no real purpose at all. Even within one school of thought there are multiple theories
about why dreams occur. You can imagine how
many there are over all in all of psychology
and all philosophy too. Just to give you an idea of some of the range of dream theories, I'll tell you about a couple others. Some psychologist think
that the combination of conscious and unconscious elements that occurs during dreaming helps our brain maintain flexibility, enabling us to learn and be
creative when we're awake. Still others think that
dreaming helps our brain sort of clean up by
sweeping away some thoughts and incorporating others
into long term memory which is a process called consolidation. There definitely does seem to be some link between memory and sleep. People who learn something and then sleep tend to do better than people who learn and/or then deprived of sleep. The role of REM sleep and
dreaming in particular is unclear. Another theory is that
dreaming helps our brains repair and recuperate by preserving and developing neural pathways. One reason people think this might be true is that in infants
who are constantly developing new neural networks and growing spend most of their time in the REM stage. As might be particularly helpful for them. Given the number of theories out there you should feel free to
come up with your own ideas. Regardless of why dreams occur, we know that they do and
it can be kind of fun, if a little scary to see
what our brains come up with when we're not quite in control.