Binding Problem

The binding problem is one of a number of terms at the interface between neuroscience and philosophy which suffer from being used in several different ways, often in a context that does not explicitly indicate which way the term is being used. Of the many possible usages, two common versions may be useful anchor points. Firstly, there is the practical issue of how brains segregate elements in complex patterns of data. This can be illustrated by the question "When I see a blue square and a yellow circle, what neural mechanisms ensure that the sensing of blue is coupled to that of a square shape and that of yellow is coupled to that of a circle?" Secondly, there is the more fundamental problem of "how the unity of conscious perception is brought about by the distributed activities of the central nervous system." The first question is a difficult but conventional question within physical science that could equally be applied to a mechanical computer or any complex system with an input and output. The second question is metaphysical in the sense that the "unity of conscious perception" may be an idea outside physical science that requires a metaphysical or ontological underpinning, of the sort on which physics is generally agnostic. Thus "unity" in this sense has no physical meaning, but it does have a crucial meaning in subjective experience.

These two meanings of "binding problem" can be found in a well-defined form, chiefly in the neuroscience and philosophy literature respectively. However, there are also many instances where the two issues are conflated in ways that are difficult to be sure about. Perhaps the clearest exposition of the second meaning comes in William James's Principles of Psychology where he refers to it as the combination problem.