Comparing Semantic and Phonemic Fluency Performance in Adults Who Do and Do Not Stutter

This study investigated lexical access and executive control in adults who do (AWS) and do not stutter (AWNS) via phonemic and semantic fluency tasks. Analysis of the participants' accurate responses, as well as clustering (i.e., organization of responses into subgroups) and switching (i.e., shifting between subgroups), provided insight into which processes (e.g., word storage, strategic search) are particularly challenging for AWS and contribute to their diminished lexical access abilities.

Thirty-two AWS and 32 well-matched AWNS generated as many words as possible in 60 s, which began with a specific letter of the alphabet (i.e., F, A, and S) or belonged to a specific semantic category (e.g., animals, supermarket).

Mixed-effects model analyses revealed that AWS produced significantly fewer accurate responses than AWNS did in phonemic fluency but not in semantic. No differences in clustering were found between the two groups. Lastly, AWS had significantly fewer switches than AWNS did.

Poorer performance in phonemic fluency and fewer switches suggest weaker lexical access for phonological information and executive control abilities in AWS compared to AWNS. The lack of between-group differences in semantic fluency and clustering suggests that word storage and organization of long-term memory seem intact in AWS.