Yeah, I saw Inception. Brilliant movie, no doubt; the only problem was the dreams did not really feel like dreams. They felt too rational, and too well organized - not the surreal kinda ones we get. But still, it kicked ass. But really, how much do our dreams contribute to thoughts? Dreams are basically the subconscious manifesting itself into a semiconscious state. I have thought of them more as a TV show - where our thoughts form the show, a jumbled variety that is edited and directed by the conscious brain. I find them fascinating. BTW, isn't it a weird feeling thinking about thoughts? and even dreams? It's a out-of-mind-watching-the-mind kind of thing. Anyway, research so far hasn't found the reason we dream, or what role dreams play in memory. We have hypotheses though. I think we need to understand sleep and memory formation to better understand dreams. Why do we sleep? It is quite sad that we still can't answer even this question. The mind is shrouded in so much mystery, you gotta love neuroscience!
There seem to be conflicting opinions regarding why we actually sleep. One camp goes to say that sleep has a vital restorative function in the body. The opposite camp says that sleep is just a way of conserving energy, when there is no physiological need to stay awake. Though the first view appears reasonable, they really don't have much in terms of supporting facts except behavior in humans. As far as humans go, we know that if we were to go sleepless a few days, we do not function well, to put it mildly. There are plenty of movies to vouch for that- think the machinist (Personally, I have never stayed awake for more than 48 hours- I just need my sleep. But I have heard people say they go sleepless for up to a week. If I went sleepless on one night, the next day I feel a kind of lightness in being but a strange weight in my brain that seems to crush in-happens for a few minutes. wonder if anyone else feels that way. What happens in reality sometimes feels dreamy and disconnected; and while I do doze off, I go into extremely dreamy sleep. anyway... moving on...) But is that the status quo, for all other animals too? Do we really need sleep so much, or is it just that we have become so used to it?
It apparently is quite tough to study sleep in animals. Apart from the obvious reason that you can't ask them if they had nightmares the previous night when they wander in grouchy at your doorstep demanding food, electrophysiological recordings of activity are not really indicative of actual sleep occurring. It is believed that whales and dolphins don't really sleep. They go into a unihemispheric sleep, where they doze off one brain half at a time. However, even during this "sleep", they keep moving and can respond to stimuli. But unlike other mammals, they do not require both hemispheres of the brain to carry out metabolic functions either- one is sufficient, and therefore, it is possible that there is a reduction in metabolic activity when one side sleeps... for a detailed argument saying sleep is necessary, see this open source article: http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.0060216&annotationId=info:doi/10.1371/annotation/47c75a12-8a0b-491d-89f9-383f70a0eed7 (I came to this after reading this article http://neuroskeptic.blogspot.com/2009/09/why-do-we-sleep.html)
If you look in the comments of the PLoS paper, there is an interesting hypothesis that says evolutionarily, sleep was primary and activity was secondary. Over time, activity has increased, and sleep decreased.
So, going back, there is a hypothesis that as we sleep, long term memories get formed. One of the functions of sleep is probably in the consolidation of thoughts and experiences into memories. Dreams are probably by-products of this process. There is an article going along these lines which discusses these in relation to cortisol, a stress hormone. http://learnmem.cshlp.org/content/11/6/671.full
The authors in conclusion write this interesting piece:
"In addition to telling us something about the contributions hippocampal and neocortical circuits make to episodic memory, to the consolidation of episodic and semantic memory, and to the content of dreams, our proposal suggests some intriguing possibilities about creativity and the generation of novel thoughts. One stage of consolidation likely involves the integration of information with pre-existing knowledge and the linking of distant but related concepts. We dream when we become aware of these activated traces, which are often fragmented images and sounds coupled with motor activity. Similar to memories created under stress, these fragments are immediately subjected to a process of narrative smoothing, and the result is typically a story that is often confabulatory, quite bizarre, but possibly also creative.
Although it is true that accurate recall is adaptive in many cases, there may nonetheless be a positive side to a process that produces fragmentation—both during wake and during sleep. All new ideas are based upon previously stored information. These fragments, or pieces and patches of knowledge, are bound into representations that we use to recall information about personal experience and to help us understand and act in the world. When these bonds are weakened, this information can be recombined, either in dreams or misremembered episodes—perhaps resulting in a process leading us down unusual paths to creative insights and new ideas." Payne and Nadel, 2004. Sleep, dreams, and memory consolidation: The role of the stress hormone cortisol.
Pretty neat, I think.
So now, coming back to Inception, it’s time for spoilers.
I think there is a flaw in the story. Entering a person’s dream and using it as a vehicle to the subconscious to plant a thought sounds cool, but I don’t think it’s plausible. One, the person is still dreaming, and it doesn’t really fit into actual thought process. How do you account for a thought that is generated within a dream? Does it ever happen? However, they do agree in the movie that a brand new idea is not manufactured. It is built on previous thoughts; after all, it’s our interpretation of these thoughts that adds the uniqueness. Two, the fact that he doesn’t have to remember this when he wakes up. Given, it is going to be tough to forget a dream like THAT, but how many dreams do we actually remember? Atleast I don’t remember much, and I do know people who recite stories from dreams… anyway, it’s a movie I would definitely watch again and figure out the loopholes.
