Skepticism about Phenomenal Unification

In the last post, I described the binding and unification problems. I defined the unification problem as the problem of explaining how it is that certain features which we perceive get unified into a single phenomenal percept. I took it for granted that some features such as color and shape are bound together and that we know this.

There is something strange about these assumptions.  If it is true that some of the features that we perceive are presented to us in the form of unified percepts, why should we know it?

Let’s suppose that in order to really know about phenomenal unification, instead of merely believing correctly or incorrectly, we must have a faculty of introspection that is sensitive to the difference. In other words, the fact that we do experience phenomenal unification must play some role in explaining why it is that we believe that we do. (There are other possible explanations – we might, for instance, say that the belief that the experiences are unified serves to unify them. This would allow introspection to be accurate by default. Or else we might say that correct belief about our experiences are justified for free. Neither of these alternatives strikes me as very satisfying.)

If we do demand that knowledge requires sensitivity, we have two possibilities to consider. Either we know about phenomenal unification because we have a faculty of introspection which was selected in our evolutionary past to provide us with correct views about phenomenal unification. Or else, we know about phenomenal unification because we have a faculty of introspection which was selected for providing us with correct views about our experiences more generally, and the mechanisms that it relies on happen to also make us sensitive to phenomenal unification.

The first possibility seems implausible. Why should the ability to know which experiences were unified have helped our ancestors to survive? If they were mistaken about what they experienced, and thought that they had separate shape experiences and color experiences, it probably wouldn’t have affected their ability to hunt or attract mates. After all, what they experienced and what they were capable of detecting wouldn’t have changed.  Just what they believed about their experiences.

The second possibility also seems implausible. We don’t at present know how introspection works. However, given what we do know about sensory processing in the brain, I think that it is a fairly safe bet that whatever might explain phenomenal unification is would be rather idiosyncratic. The same mechanisms that explain how we know anything about our experiences will not also explain how we know about phenomenal unification. If this is right, then our sensitivity to unification cannot be a side effect of our capacity for introspection more generally.

As a result, I find myself to be somewhat skeptical about the true extent of phenomenal unification. It sure seems like my experiences are unified in certain ways, and not unified in others, but I am not sure why I should think that these seemings are accurate.