Nicolas Bourguignon

Ghent university, Belgique

Prefrontal executive control and language production: a neural-computational approach

Fluent language production is widely assumed to involve cognitive control (CC), a central frontal lobe function required for the goal-directed selection of actions and thought amongst competing alternatives. The exact role of CC in the various aspects of spoken language, however, remains poorly understood. In particular, few accounts, if any, have explicitly examined whether the neural-computational mechanisms involved in resolving competition during spoken language are analogous to those underlying nonverbal behaviour. To elucidate this issue, I propose a model of CC in language production in terms of a gradient of selection and retrieval mechanisms organised along the rostro-caudal axis of the human prefrontal cortex and tasked with resolving competition at phonological and semantic levels of representation. In line with information-theoretic, hierarchical approaches to general behaviour, I argue that these selection/retrieval mechanisms can be operationalised by Shannon?s index of uncertainty, predicting distinct patterns of brain activation and behavioural correlates at the word and sentence level. I will present neurophysiological evidence supporting these predictions at the word level and discuss possible avenues of investigation at the level of sentence and discourse