Real-time processing in picture naming in adults who stutter: ERP evidence

• Psycholinguistic research with adults who stutter may benefit from increased precision afforded by brain event-related potentials (ERPs).
• ERPs were elicited and compared in adults who stutter (AWS) versus typically fluent adults (TFA) in a masked picture priming task.
• Results suggest that language/cognitive processing differs in AWS versus TFA and may therefore warrant attention in interventions for adulthood stuttering.

ObjectiveThe aim was to compare real-time language/cognitive processing in picture naming in adults who stutter (AWS) versus typically-fluent adults (TFA).MethodsParticipants named pictures preceded by masked prime words. Primes and target picture labels were identical or mismatched. Priming effects on naming and picture-elicited ERP activity were analyzed. Vocabulary knowledge correlations with these measures were assessed.ResultsPriming improved naming RTs and accuracy in both groups. RTs were longer for AWS, and correlated positively with receptive vocabulary in TFA. Electrophysiologically, posterior-P1 amplitude negatively correlated with expressive vocabulary in TFA versus receptive vocabulary in AWS. Frontal/temporal-P1 amplitude correlated positively with expressive vocabulary in AWS. Identity priming enhanced frontal/posterior-N2 amplitude in both groups, and attenuated P280 amplitude in AWS. N400 priming was topographically-restricted in AWS.ConclusionsResults suggest that conceptual knowledge was perceptually-grounded in expressive vocabulary in TFA versus receptive vocabulary in AWS. Poorer expressive vocabulary in AWS was potentially associated with greater suppression of irrelevant conceptual information. Priming enhanced N2-indexed cognitive control and visual attention in both groups. P280-indexed focal attention attenuated with priming in AWS only. Topographically-restricted N400 priming suggests that lemma/word form connections were weaker in AWS.SignificanceReal-time language/cognitive processing in picture naming operates differently in AWS.