I've been thinking a lot recently about how our brain works. Naturally I have more questions than answers, but the most compelling thing I've learned recently is that the cerebral cortex (the seat of most higher level functions, such as language and vision recognition) is very flexible. In fact, current research shows quite strongly that the brain matter governing one sense -- hearing, say -- is identical to that governing another sense -- vision, say. The difference in make-up and density of neurons is entirely a result of differing sensory inputs rather than speciliazation for the given task at hand. For example, researchers have rewired ferret brains so that the inputs from the optic nerve are go to where auditory senses normally enter (note that in humans, at least, optical input passes first through the thalamus before reaching the first layer of visual cerebral cortex, V1). I know, I know -- poor ferrets. But the ferrets see just fine . The cerebral cortex is just a giant, flexible pattern recognition "machine"! Notably, higher level intra-sense associative areas don't really care what the underlying sense are that they're correlating. They simply correlate!
OK, so ferrets cerebral cortexes are general pattern recognition machines. Is this true of humans, too. Yes! In one interesting study scientists placed a device on blind peoples' tongues that received inputs from a crude camera and turned the camera input into a grid of pressures on the tongue that indicated intensity of light by the amount of pressure. In a relatively short time subjects were able to play rock, paper, scissors, reach for doorknobs, and etc. Why? Because the asociative areas [see mosquito, feel mosquito, oh it's the same mosquito] of the brain don't care where the inputs come from. They just try to match patterns. This is true all up and down the cortical hierarchy.
Key point: many people, sadly, think of the brain in terms of functional areas. For example, scientists have identified certain areas of the brain (in the visual cortex) that trigger when we see images of movie stars (as I recall they used Angelina Jolie, among others), and news articles frequently report when new functional areas of the brain (language, vision, hunger) are mapped. This is because brain scans are very high resolution but not dynamic. That is, they give great spatial detail but terrible time sequence detail. This is unfortunate. Time delays and correlation are a (the?) key component of sensory association and higher level thought. Functional location is unimportant, as evidenced by the poor lobotomized ferrets.
