Eye movements of stutterers.

As a consequence of recent inquiries into the brainstem activity of stutterers, saccades and pursuit were evaluated in stutterers and their matched normals while silent and talking. No ocular motor instabilities or aberrations caused by speech were found. Saccadic latencies and gains for the stutterers were normal, but peak velocities were higher and durations were shorter. This finding is consistent with hypotheses of speech dysfluency proposed by others. The gains of these fast saccades were kept normal by an adaptive decrease in the duration of the neural pulse producing the saccade. It is proposed that these fast saccades are a result of increased excitatory input to the burst cells in the brainstem.