Adults Who Stutter Show Diminished Word Fluency, Regardless of Mode

Purpose: Language abilities have long been thought to be weaker in adults who stutter (AWS) compared to adults who do not stutter (AWNS). However, it is unknown whether modality affects language performance by AWS in time pressure situations. This study aimed to examine lexical access and retrieval abilities of AWS in oral and typed modes. Method: Fifteen AWS and 15 well-matched AWNS completed computer-administered letter fluency tasks. Adults were asked to orally produce words that began with one of two letter targets and type words that began with one of two alternate letters. Conditions were counterbalanced across participants. Results: Generalized linear mixed-effects models were evaluated to determine the effects of group (AWS/AWNS), mode (oral/typed), and expressive vocabulary on letter fluency performance. Group predicted letter fluency such that AWS generated fewer items on both the oral and typed letter fluency tasks. Mode did not impact letter fluency results. Expressive Vocabulary Test scores predicted letter fluency similarly in both AWS and AWNS. Conclusions: AWS were not penalized by oral task demands. AWS generated fewer items on the letter fluency tasks regardless of response mode, suggesting that they have weaker lexical access abilities. Furthermore, better expressive vocabulary skills were associated with better letter fluency performance in both groups.