Concurrent cognitive load and lexical-semantic similarity judgments for action verbs and object nouns in Persian-speaking adults who stutter.

PURPOSE: This study examined whether lexical-semantic processing of action verbs versus object nouns is differentially affected by concurrent cognitive load in Persian-speaking adults who stutter (AWS), compared with adults who do not stutter (AWNS), using a dual-task paradigm.

METHODS

Twenty-nine AWS and 29 matched AWNS performed a Semantic Similarity Judgment Task (SSJT) while simultaneously completing a tone-decision task. Tones were presented at short or long stimulus onset asynchronies (SOAs) relative to SSJT onset. SSJT stimuli included action verbs and non-action nouns. Reaction times (RTs) and accuracy were recorded.

RESULTS

AWS exhibited slower overall RTs than AWNS (p = .04). A significant Group × Task interaction (p = .03) and Group × Task × SOA interaction (p = .04) revealed greater dual-task costs for AWS on the tone task, particularly under high cognitive load. Moreover, a significant group difference in SSJT RTs was observed (p = .03), especially for action verbs at short SOA (p = .04).

CONCLUSION

These findings indicate that AWS are more susceptible to interference from concurrent cognitive demands and may require greater attentional resources for processing action verbs. This highlights the role of cognitive-linguistic interactions in stuttering and the potential influence of cognitive load on speech fluency.