Right rolandic activation during speech perception in stutterers: a MEG study

The focus of our magnetoencephalographic (MEG) study was to obtain further insight into the neuronal organization of language processing in stutterers. We recorded neuronal activity of 10 male developmental stutterers and 10 male controls, while they listened to pure tones, to words in order to repeat them, and to sentences in order to either repeat or transform them into passive form. Stimulation with pure tones resulted in similar activation patterns in the two groups, but differences emerged in the more complex auditory language tasks. In the stutterers, the left inferior frontal cortex was activated for a short while from 95 to 145 ms after sentence onset, which was not evident in the controls nor in either group during the word task. In both subject groups, the left rolandic area was activated when listening to the speech stimuli, but in the stutterers, there was an additional activation of the right rolandic area from 315 ms onwards, which was more pronounced in the sentence than word task. Activation of areas typically associated with language production was thus observed also during speech perception both in controls and in stutterers. Previous research on speech production in stutterers has found abnormalities in both the amount and timing of activation in these areas. The present data suggest that activation in the left inferior frontal and right rolandic areas in stutterers differs from that in controls also during speech perception.