Abstract

We discuss the role of synchrony of activationin higher-level cognitive processes. Inparticular, we analyze the question of whethersynchrony of activation provides a mechanismfor compositional representation in neuralsystems. We will argue that synchrony ofactivation does not provide a mechanism forcompositional representation in neural systems.At face value, one can identify a level ofcompositional representation in the models thatintroduce synchrony of activation for thispurpose. But behavior in these models isalways produced by means conjunctiverepresentations in the form of coincidencedetectors. Therefore, models that rely onsynchrony of activation lack the systematicityand productivity of true compositional systems.As a result, they cannot distinguish betweentype and token representations, which resultsin misrepresentations of spatial relations andpropositions. Furthermore, higher-levelcognitive processes will likely integrateinformation from widely distributed areas inthe brain, which puts severe restrictions onthe underlying neural dynamics if synchrony ofactivation is to play a role in theseprocesses. We will briefly discuss theserestrictions in the case of feature binding invisual cognition