Binding Problem, Neural Basis of

The currently dominant interpretation of brain states as symbols of the mind has it that individual neurons are elementary symbols and the brain state as a whole is correctly summarized as a list of those neurons that are active. If this interpretation was correct, the brain would not have the ability to express grouping of neurons into a hierarchy of subsymbols. When we think of several objects simultaneously, the neurons representing their various features need to be grouped according to which object they refer to, otherwise the brain would commit ‘conjunction errors,’ imagining objects with false combinations of features. Such conjunction errors are actually observed when subjects are distracted or have too little time for object inspection. This deficiency of the current interpretation is called the ‘binding problem.’ The most fundamental solution to the binding problem is temporal binding. According to this principle, a set of neurons expresses grouping into a composite symbol by correlating their signals with one another in time.