Figure 3.

Prolongation induced left hemisphere facilitation in adults who stutter. Box plots illustrate tongue motor cortex excitability during the prolongation of the labio-dental fricative related to resting state. Normalized MEPs are depicted separately for the contralateral and for the ipsilateral tongue projections (± SEM). ANOVA yielded a significant interaction of Group × Hemisphere for the contralateral projections. Post hoc t-tests resulted in a right-lateralized facilitation in fluent speakers and a left-lateralized facilitation in adults who stutter (filled box). A group differences was significant in the left hemisphere contralateral projection. Filled box indicates significant change (P < 0.05). Asterisk indicates level of difference between groups: *P < 0.05.