Tuesday, October 21, 2003

...wherein we consider humans, homing pigeons, and a lonely chameleon:

As I drive or ride back and forth on my commute every day, I have realized that how we perceive the space through which we drive is quite different from our perception of space through which we walk.

Consider the following: when you walk from home to, for example, the park, you have a mental map much like the following:

HOME <===a=====b=====c===> PARK

It doesn't matter which direction you are going, a-b-c or c-b-a. You usually have a good sense of where you are along the whole route.

Compare this to driving, which I would map more this way:

HOME >--a---b---c---> PARK >--d---e---f---> HOME

(HOME on both ends is the same place, and the routes driven are physically the same).

While driving we are usually only looking in one direction (ahead). Even if spot 'a' corresponds to spot 'f', 'b' to 'e', and 'c' to 'd', these spots often seem like different places, because we are usually looking only in the direction of travel. I have this realization when for some reason I have to turn around in my seat, and I have the "ohhh, that's where this is" feeling when I make the mental connection that point 'a' is actually the same as point 'f'.

When we are walking, we are more likely to look around, and get a more complete picture of the space through which we are passing. Of course, there are bound to be sections of a path where we always look in the direction we are walking. That's why it's easy to get lost on some trails, and especially easy to get lost when you are off-trail.

Where's this all headed? Well, I began to think about how much this is related to our field of view, and that immediately made me wonder if creatures with 360 degree fields of view have very different mental maps, since they are always seeing both where they are going and where they have been at the same time. There are a lot of birds that have binocular vision in front and behind. Do they have a much better sense of orientation in part due to this?

What about a chameleon, with independent eyes? Does it have better or worse records for getting lost?

...mad scientist sets up homing experiment with frosted contact lenses. Drivers, pedestrians, owls, hummingbirds and one chameleon protest.