It all seems a bit hard to believe, but then with some people you can never be sure whether they’re kidding or not. So let’s see what you think about it.
Some while back I was in hospital having a tumor removed from the back of my head. The surgeon, name of Don Jorge, had to saw out a section of skull to get at it, and after removing the Thing, which was about the size of a robin’s egg, he replaced the missing skull section with a plastic plate. I asked why not a metal plate, like my friend Jamie got when he had a similar operation last year, though that was on top of his head, but Don Jorge, a professional to his finger tips, just said he was doing me a favor, because Jamie was going to be held up at every metal detector from now on, while I could sail through.
Anyway, the next day Don Jorge told me he had to do some tests, so they wheeled me into a lab and sat me down in front of a large screen showing a picture of a green cat. I asked why a green cat, and Don Jorge said that was the only paint they had at the time, which was typical of the man. Then he unscrewed the plastic plate and pushed what he said was even narrower than a hair-fine electrode into what he said was the visual cortex, and connected the electrode to an oscilloscope, switched on a formidable box of electronic tricks, and asked me what I could see on the oscilloscope screen.
Not being able to think of anything smart to say at the time, I said I could see a green cat, though in fact all I could see was a moving bunch of spikes. Nevertheless, Don Jorge seemed satisfied with the answer, and switched off the box of tricks, detached the oscilloscope leaving the electrodes connected, and told me to come back in a couple of hours. I wasn’t all that happy about sitting around with my brain exposed to the elements, but they gave me a kind of hood to wear, so I didn’t complain.
When the time was up they wheeled me back into the lab, took off the hood and reconnected the oscilloscope, which was blank as was the big screen, which this time didn’t have a picture of a cat. Don Jorge then switched on the box of tricks, and there on the big screen was the green cat, though a bit fuzzy and a different shade of green from what I remembered. Don Jorge switched it off and asked me what i had seen on the screen. I was horrified; if he could make me see a green cat that wasn’t there, what if he could make me see a written message saying, “go kill your wife right now!”
When I calmed down a bit, I told Don Jorge what I’d seen and he was just tickled to death, so much so he was even willing to explain it. “What you have just seen is the first experiment of its kind on a human. We’ve done it before on chimpanzees, but it’s hard to get a straightforward answer out of them, and they need a lot of preliminary training. This is the first time we’ve had a patient with enough access to the visual cortex, and I couldn’t let the opportunity slip away.
I said, “congratulations, but why couldn’t you tell me what it was all about beforehand?” He looked a bit sheepish, but said, “because you might have faked it, and then it wouldn’t have been a scientific experiment.” Well, didn’t I say he was a professional?