Discourse management during speech perception: A functional magnetic resonance imaging (fMRI) study

Discourse structures enable us to generate expectations based upon linguistic material that has already been introduced. We investigated how the required cognitive operations such as reference processing, identification of critical items, and eventual handling of violations correlate with neuronal activity within the language network of the brain. To this end, we conducted a functional magnetic resonance imaging (fMRI) study in which we manipulated spoken discourse coherence by using presuppositions (PSPs) that either correspond or fail to correspond to items in preceding context sentences. Definite and indefinite determiners were used as PSP triggers, referring to (non-) uniqueness or (non-) existence of an item. Discourse adequacy was tested by means of a behavioral rating during fMRI. Discourse violations yielded bilateral hemodynamic activation within the inferior frontal gyrus (IFG), the inferior parietal lobe including the angular gyrus (IPL/AG), the pre-supplementary motor area (pre-SMA), and the basal ganglia (BG). These findings illuminate cognitive aspects of PSP processing: (1) a reference process requiring working memory (IFG), (2) retrieval and integration of semantic/pragmatic information (IPL/AG), (3) cognitive control of inconsistency management (pre-SMA/BG) in terms of "successful" comprehension despite PSP violations at the surface. These results provide the first fMRI evidence needed to develop a functional neuroanatomical model for context-dependent sentence comprehension based on the example of PSP processing.