Neurons versus Networks: The Interplay between Individual Neurons and Neural Networks in Cognitive Functions

The main paradigm of cognitive neuroscience is the connectionist concept postulating that the higher nervous activity is performed through interactions of neurons forming complex networks, whereas the function of individual neurons is restricted to generating electrical potentials and transmitting signals to other cells. In this article, I describe the observations from three fields-neurolinguistics, physiology of memory, and sensory perception-that can hardly be explained within the constraints of a purely connectionist concept. Rather, these examples suggest that cognitive functions are determined by specific properties of individual neurons and, therefore, are likely to be accomplished primarily at the intracellular level. This view is supported by the recent discovery that the brain's ability to create abstract concepts of particular individuals, animals, or places is performed by neurons ("concept cells") sparsely distributed in the medial temporal lobe.