This article at IO9 reminded me of the recent discussion some of us had on philosophical zombies.
Ever heard of the philosophical zombie? It’s a philosophical concept that rarely translates into physiology – until now. A case of false color-blindness makes us wonder: What’s the difference between seeing something and knowing that you’re seeing something?
The patient in question was recovering from a stroke, and one of his complaints was a loss of color vision. His medical providers noticed he wasn’t making the same mistakes that many people with limited color vision do, and so they had him do a quick test. They showed different colors to him, and asked him to take a guess at what they were. He guessed right much of the time. They then asked how accurately he thought he was guessing. He gave an estimate of his accuracy, and that estimation shot up for the times when he guessed right.
So not only was this person seeing most colors, he knew, most of the time that he was seeing them. He just had no consciousness of the colors he was seeing. He was, in essence, a philosophical zombie when it came to color vision. Although he could behave as if he saw colors, he never, consciously did. So what do you think? Can you be a zombie, without anyone guessing that you are?
I don’t know if any of us would really be tempted to call this poor patient a p-zombie, but it does remind me of the attention schema theory of consciousness that sees it as basically a feedback mechanism, a way for the brain to summarize its current state (albeit incompletely and not always accurately) for use by the language center and other areas of the brain.
Viewed in that light, what’s damaged in this patient’s brain is probably the connection between the vision processing centers of their brain, and the module that summarizes the information. So, they see color, but can’t consciously experience the color anymore.
One thing that I do find puzzling is that they can still articulate the color when pressed to make a best guess. That means that there are enough connections to get the information to their language centers, but not necessarily through the consciousness centers. That’s weird, but reminds me of other site blindness issues I’ve read about before. These cases seem to imply that the language center isn’t totally dependent on consciousness. (Which actually isn’t too surprising given how often I shoot my mouth off without thinking.)