Sublexical speech perception and attention networks in bilingual adults who stutter: A behavioral and electrophysiological study

Purpose

Several studies show that adults who stutter have deficient auditory perception and attentional control. Moreover, these studies tend to focus on monolinguals, whereas both stuttering and bilingualism seem to have implications for these processes. This study aimed (1) to compare sublexical speech perception and nonlinguistic, nonauditory attention networks between bilingual adults who stutter (BAWS) and who do not stutter (BANS) and (2) to explore to which extent second language (L2) proficiency influences these processes.

Method

Thirteen BAWS and thirteen BANS were enrolled in an electrophysiological protocol using an inattentive (MMN) and an attentive auditory oddball paradigm (P300) containing a phonemic contrast (place of articulation). The Attention Network Test (ANT) was administered as a behavioral measure of attentional control.

Results

(1) The amplitude and onset latency of the MMN and P300 effect did not differ between BAWS and BANS, but BAWS did not show a typical differentiation between standard and deviant syllables as measured by the P2. Behaviorally, BAWS displayed a less efficient alerting network and executive attention network. (2) L2 proficiency had no significant effect on sublexical speech perception, but was negatively associated with executive attention in BAWS.

Conclusions

These results suggest that BAWS display difficulties in maintaining an alert state and inhibiting irrelevant and selecting relevant information, rather than selecting information from sensory input. In sensory processing, BAWS showed an atypical pattern compared to BANS, but no disparities in phoneme discrimination or categorization, regardless of an inattentive or attentive listening mode. Lastly, L2 proficiency influenced nonlinguistic, nonauditory attention in BAWS, emphasizing the need for more comprehensive research on bilingual profiles in people who stutter.