THE PAST AND PRESENT STATUS OF »MOTOR SPEECH AREA«: FROM CLASSICAL MODULAR »CENTER« TO NODAL AND SUPRAMODAL COMPONENT OF MULTIPLE NEURONAL NETWORKS

Abstract

Summary. In the classical, aphasiological (Wernicke-Lichtheim) model for neural basis of language, speech production was assigned to the »motor speech area« located in opercular and triangular part of the left inferior frontal gyrus (fronto-opercular cortex, Broca’s area) and conceptualized as a classical »modular centre« within a simple, language-specific neural network. However, recent neuroimaging studies on healthy volunteers have demonstrated a far more complex connection between brain and language: the left fronto-opercular cortex is just one of many nodal points in multiple and partially overlapping neural networks subserving language. In addition, the fronto-opercular cortex is not a simple motor centre, but part of supramodal (executive) frontal system with a number of language and non-language functions. We review these novel roles of the left fronto-opercular cortex, with focus on its functions which extend far beyond the scope of classical Wernicke-Lichtheim model.