October 9, 2004
The Matrix! Vision! Reality! FERRETS!
Recently, a University of Rochester scientist sat a bunch of ferrets down in front of a TV and had them watch “The Matrix.”
That could be the whole post right there, but I got more!
It’s really interesting: He discovered that their visual cortexes worked like crazy even in the total absence of visual stimulus. (He observed this as the ferrets were watching Keanu Reeves emote. Wait, no, they were in a dark room.)
Here’s the implication:
“This means that in adults, there is a tremendous amount of real-world processing going on—80 percent—when there is nothing to process,” says Weliky. “We think that if you’ve got your eyes closed, your visual processing is pretty much at zero, and that when you open them, you’re running at 100 percent. This suggests that with your eyes closed, your visual processing is already running at 80 percent, and that opening your eyes only adds the last 20 percent. The big question here is what is the brain doing when it’s idling, because it’s obviously doing something important.”
Now, it’s well-established that what we see is not just raw visual stimulus. When my eyes register a blob of brown light, my brain quickly recognizes that blob as a ferret, based on previous experience*. The two inputs merge in my field of vision.
*And believe me… I’ve got an eye for ferrets.
That’s why optical illusions work: They screw with the relationship between image and idea, putting our eyes at odds with our brains.
But I don’t think anyone suspected that the “idea” part of vision might account for eighty percent of what we see.
But then, I also don’t think anyone suspected that small woodland creatures would identify so strongly with Neo’s quest to discover the true nature of reality.