Neural Associations

Abstract

If the operating principle of nervous systems is making trial-and-error associations among neurons by accumulated learning over evolutionary and individual time, a next step is to define “associations” more exactly and to review the ways they are created. Neurobiologists have generally focused on the cellular mechanisms that alter synaptic structure, physiology, and biochemistry as a result of individual experience (“neural plasticity”), while psychologists have approached neural associations from the perspective of behavior. Neuroscientists of all stripes agree, however, that associations are based on the connections among neurons and neuronal populations. This chapter examines more specifically how neural connectivity evolves, how it arises during development, and how it is modified over animal lifetimes.