ABSTRACT
Neuroscience.—The term function in neuroscience refers to a set of active, dynamic properties that competes to achieve the same goal in a living being. Since its beginnings, cognitive neuroscience has been attempting to establish a more or less direct correspondence between functions and brain structures (→LOCALIZATION OF FUNCTION, NEUROPSYCHOLOGY). The views on this issue have oscillated between a localizationist tendency and an antilocalizationist tendency. At the present time, studies using functional neuroimaging techniques (→FUNCTIONAL NEUROIMAGING) are often regarded as neophrenological (in reference to phrenology, the study of the “bumps of the skull” conducted around 1800 by Franz Gall), insofar as they relate brain activation patterns to a sensory, motor, or cognitive function. However, neuroimaging research sheds a new light on structure-function relationships. The subtractive approach (subtraction of images corresponding to different experimental conditions) has shown that elementary operations are localized in discrete brain regions. As a corollary, cognitive tasks are performed by broadly distributed neuron networks (→NEURAL NETWORK). Rather than a simple serial model, some kind of nonlinear organization must be postulated, one where the activity of a brain region is a function of its own activity as well as that of other areas (→ACTIVATION/INHIBITION). Indeed, a given region has many inputs, some of which originate in lower regions. And input regions also project into output regions.
