ABSTRACT
Neuropsychological research provides speech therapists with precious information about the relationships between gesture and speech. Cognitive psychology contributes to the endeavour by proposing explicit models of mental organization while neurosciences describe the "working brain" that physically instantiates the mind. The neuropsychological approaches to gestural communication rely on three kinds of observations: the study of lateral differences in manual activities, the analysis of the consequences of brain damage acquired after a typical development and the results of experiments using functional neuroimaging techniques to record regional brain activation during cognitive processing. In patients with anomic aphasia and phonological impairments, gestures were mainly "ideational" gestures, whereas in patients with conceptual impairments, the proportion of gestures called indefinite was larger than in other patients or in healthy control subjects. The first release of publications of studies using neuroimagery to investigate the cerebral bases of language processing dates from 1988 for positron-emission tomography (PET) and 1993 for functional magnetic resonance imagery (f-MRI).
