So, as mentioned in my review of Rosenburg’s book, I want to talk a bit about the cases of blindsight that he discussed, because I think that there’s an issue there that Rosenburg doesn’t talk much about that is interesting.
Essentially, the case of blindsight is that these are people with specific brain damage where they lose the ability to have phenomenal experiences related to sight … which means that they can’t consciously see objects. But when they’re asked to, say, point to a yellow object, they do so successfully. But if they are asked about it, they always claim that they just guessed, despite having a success rate that can’t be explained by guessing. Rosenburg insists that they see without having a conscious experience of it, but this is a rather odd claim since it seems reasonable that what it means to see an object is to have a conscious experience of it, so what we can see is that they are aware of the colour of an object without having had a conscious experience of it … which might seem puzzling at first, but then I’ve already shown that this, in fact, can be the case. As a short summary, note that you can walk down a street or drive to work completely lost in thought, and yet you don’t generally spend your time running into people, running lights, and generally do so successfully. So we already know that we can react functionally towards things — ie be aware of them — without having to consciously see them. What these results, then, suggest is what we already knew: there is a distinct neural path from the centre of “vision” to simple awareness and to conscious experience. When my consciousness is engaged, the “consciousness” path gets blocked but the awareness path is not. This also, then, happens in cases of blindsight (and we can presume that there is a way to damage the brain so that you get neither, if it is damaged before the split).
So, problem solved, right? Well, this is still a bit puzzling, and it took me a bit to figure out why. See, for the most part we do accept that we can be aware of and react to things that we aren’t conscious of — by which I mean “had a phenomenal experience of” — because that happens all the time, as I just pointed out. But we do think that certain critical beliefs or actions are, in fact, caused by those experiences. Pointing to or even grabbing an object that we didn’t “see” isn’t an issue; again, we do it all the time. But pointing at an object because it is a certain colour is surprising, because we think that you don’t know what colour an object is without actually consciously experiencing a colour-qualia. The same thing applies to the Libet experiments: having subconscious mechanisms kick off a semi- or pseudo-random action isn’t unexpected, but having that kick off a “conscious decision” event is puzzling; in short, the RNG of the brain telling me that I made a conscious decision to press the button when I did no such thing without that being some kind of rationalization is definitely not what we’d expect. In that case, I suspect that they were in “decide to press the button” mode, at which point them acting as if they decided to do it at that moment even though it was caused by neural stimulation is not surprising, because in that scenario all that making the decision means is that you wait for the RNG to kick off telling you to do it. If they were in no way thinking about pressing a button, I would definitely expect them to react as if their wrist just moved, like we see in cases of Alien Limb Syndrome.
At any rate, it is easy to dismiss most of the examples as cases where our conscious deliberations and experiences aren’t normally expected to play a role, but being able to distinguish colour subconsciously seems a bit more of an issue. However, on reflection it should be obvious that we can do that; after all, we can still stop at red lights while driving while lost in thought. So in some sense we can indeed distinguish colours subconsciously. The question is: is there anything that we can’t do subconsciously, that we need to do consciously?
Fortunately, the blindsight cases themselves seem to suggest that there are. The subjects did not in any way remember consciously experiencing the colour of the object, and did not believe that the object was there or had a specific colour. So memory, at least, seem to follow from conscious experience. And since memory is required for reasoning, reasoning about the object and using the facts about the object to decide on future actions probably also requires that we be conscious of those facts, meaning that we have a conscious experience about them. So, again, the actions that we most introspectively think require conscious experience and knowledge seem to be the ones that we do, in fact, need conscious experience and knowledge for.
What these experiments do, in my opinion, is demonstrate that the subconscious is more powerful than we give it credit for, and so might be more influential than we think it is. However, they do not show that the conscious is ineffective or unnecessary, because even they show that for a lot of actions the conscious is still necessary … despite Rosenburg’s and others’ insistence that they show that.