Frog

Milner and Goodale discuss various animals whose perception of the world is less integrated than ours. In the 1960s, David Ingle rewired the nervous systems of some frogs by means of surgery (he was aided by the fact that frog nervous system regenerate unusually well). By crossing some wires in the brain, he was able to produce a frog that snapped a prey to its left when the prey was really to its right, and vice versa. It saw prey in a left-right reversed way. But this rewiring of part of the visual system did not affect all of the frog’s visual behavior. The frogs behaved normally when they were using vision to get around a barrier. They behaved as if some parts of the visual world were reversed, and other parts were normal. Here in Milner and Goddale’s comment:

“So what id these rewired frogs “see”? there is no sensible answer to this. The question only makes sense if you believe that the brain has a single visual representation of th outide world that governs all of an animal’s behavior. Ingle’s experiments reveal that this cannot possibly be true.”

Once you accept that a frog does not have a unified representation of the world, and instead has a number of separate streams that handle different kinds of sensing, there is no need to ask what the frog sees: in Milner and Goodale’s words, “the puzzle disappears.” ~ Page 89