Inner speech in anarthria: neuropsychological evidence of differential effects of cerebral lesions on subvocal articulation.

The role of articulation in verbal short-term memory was investigated in two anarthric patients, C.M. and F.C., both showing normal comprehension for written and spoken language, above average intelligence and visuo-spatial abilities. Based on experimental results, we propose that subvocal articulation might be impaired in anarthric patients in different ways, according to the site of lesion: in 'locked-in' patients only the articulatory rehearsal processes necessary to enhance memory performances is involved, while in cortical anarthric patients the lesion affects the articulatory recoding processes involved in transferring visually presented material into an articulatory form for better retention.