I read a couple of interesting articles on Scientific American today…
Left brain, right brain
The first was on how or why – and more interestingly, when – specialization evolved between functions of the left and right hemispheres of the brain. Apparently, even in the first vertebrates, one side of the brain would be more active than the other in certain types of situations. That’s one or two hundred times longer ago than the beginnings of hominid life. Normal, routine activity and perception would belong to the left brain, and recognition and response to unexpected circumstances to the right – and these patterns may have led to speech, facial recognition, and our asymmetrical tendency toward right-handedness. (Curious: the article says that right-handedness shows up in a number of other species, from other primates to whales.)
Not everything was new, but there were interesting examples that back up the distinction between the left and right brains. Note: many animals react more strongly to predators in their left field of vision (right brain) than in their right (left brain), and humans tend to respond to a threat more quickly with their left hand than their right. Also, regarding reasons for specialization to be favored by natural selection, chickens with lateral processing (specialization) were able to multitask better and/or faster than chickens whose “left” and “right” brain specialization had been compromised (whose brains were ambidextrous, in effect).
I’ve been used to thinking of “left brain” – “right brain” talk as half imagined; we’re pretty adaptable beings, after all, besides which, I usually hear the distinction used by people who just want to say that they particularly like either artsy stuff or mathy stuff. So, nice article.
Are crazy dreams good for us?
The other article was on theories as to the reasons why we dream, and why our dreams are so, well, weird. We know our brains are more active during REM sleep, and one theory is that dreaming is sort of like a screensaver. It’s a workout – keeps certain parts of our brains active while others are restored, maybe. But why are our dreams so visual, yet so lacking in sound and smell? Well, someone awake in the dark couldn’t see well anyway – so perhaps visual stimulation in dreams leaves us less vulnerable than would auditory or olfactory stimuli, to which the darkness when we sleep is irrelevant. And maybe those recurring nightmares of being chased, or of falling, or of being attacked are a way of simulating threats – giving us a chance to ‘practice’ responding to threats in relative safety.
What I don’t get, though, is this: supposedly, dreaming can aid us in problem solving. There’s a nice anecdote about a study participant who was struggling with one of a set of puzzles given to her to work on before she went to sleep. She fell asleep frustrated, and in a dream saw the problem in a much more visual, metaphorical scene, which allowed her to see the solution. I have no trouble believing this story; intuition itself can be trained, I am convinced, and that seems to lend itself to the thought that we can process problems through dreaming (and certainly in a very different way than when we are awake!). And it seems familiar, too, like this kind of thing has happened to me. Probably it was during those late nights of paper-writing during my first semester of philosophy classes. But there’s no explanation here for a question that burns much stronger than just what dreams do: how, exactly, does this happen? How do dreams work?