If an object like a thrown ball or a car is heading towards us, we know that we can react and take effective avoidance strategies very quickly. How do the neurons in our brains manage to work so fast to determine the trajectory and decide what is the best avoidance strategy? It is clearly automatic and not done by our conscious brains.
A recent study, the conclusions of which are summarized in this article, sheds some light on how the brain manages to rapidly do all the complicated calculations needed in such situations. The authors of the study state that “One interesting aspect of the computation is that it appears to be about the same as what other people have found in flies and beetles, suggesting that evolution solved this problem once, at least a few hundred million years ago.”
That makes sense. The ability to react quickly to avoid sudden dangers would undoubtedly be a useful survival skill that likely became hard-wired in the brain a long time ago.
The abstract of the article titled Hierarchical processing of complex motion along the primate dorsal visual pathway that appeared in the Proceedings of the National Academy of Sciences is openly available but the text of the full article is available only with a subscription.
That is interesting. As a non-scientist, I’ve always wondered how it is animals like insects can have such complex behaviors with so little apparent conscious intelligence.
Aren’t flies able to react at a split second timing? Almost before the event that they’re reacting to actually happens?
Katherine, I think it only seems that way from our perspective. A significant amount of a fly’s quick reactions (I think) comes from their small size. The electrical impulses simply don’t have as far to travel relative to even the signals from, say your elbow to fingers. I’m not sure what the lag is, based on the combination of chemical and electrical impulses, but I suspect (and seem to recall reading about it long ago) that it’s very dependent on size.
It also, in the case of flies, depends on the direction the danger is coming from. The way it’s hard wired, flies react in a certain ‘pre-programmed’ way that one can take advantage of when trying to catch/kill a fly.
Have you ever noticed how much easier it seems to kill a fly with a swatter than with your hand? There’s a couple reasons for that: 1) the swatter is travelling slightly faster due to the arc of the reach; 2) (the bigger factor) your muscles work against you and automatically slow your hand to reduce the impact speed when striking a hard surface. (This is something that takes a fair amount of training to overcome in martial arts, which is why I’m very familiar with it.)
I had read that we humans have a reptilian brain, but this is the first time I have read that we have a beetle brain, too. Humbles one, doesn’t it?
Try this:
http://www.zoology.de/vwitte/work/arbeit.htm
http://ngm.nationalgeographic.com/2007/07/swarms/miller-text