Timing of covert articulation: an fMRI study.

Timing is an important constituent of speech and language. Different brain regions have been associated with time management functions such as time estimation and motor timing. This study aims to identify the less well known neural networks associated with timing of internally paced covert articulation. Functional MRI was performed on subjects who either spontaneously, or in response to a visual cue, covertly generated words every 2 s. Results show the involvement of anterior cingulate gyrus, right dorsolateral and inferior frontal and right inferior parietal cortices in a putatively modality independent circuit associated with timing of covert speech. Modality specific activation in the right temporal cortex may have reflected the involvement of this region in auditory-verbal processing.