Cerebral lateralization of visual stimulus recognition in stutterers and fluent speakers

Abstract Cerebral lateralization of stutterers and nonstutterers was assessed in terms of choice reaction times to stimuli presented to either the left or right visual hemifield on letter recognition and figure recognition tasks. Reaction times on both tasks were determined before and after a behavioral speech therapy program. Stutterers demonstrated a significant reduction in mean reaction times in the letter recognition task over the course of the therapy program. This change differed significantly from that obtained from stutterers in the figure recognition task. The stutterers' responses were in contrast to the responses of the nonstutterers, who showed no reduction in mean reaction times for the letter or figure recognition tasks. The results were discussed in terms of alterations in aspects of central nervous system processing as a result of participation in the behavioral speech therapy.