Non-linguistic auditory processing in stuttering: Evidence from behavior and event-related brain potentials

Abstract

Auditory processing deficits have been hypothesized to play a role in the disorder of stuttering (Bloodstien, 1995). The current study focused on non-linguistic auditory processing without verbal responses to rule out effects of language processing differences and articulatory planning for speaking. A pure-tone, oddball paradigm was utilized to compare behavioral responses of accuracy and reaction time, and event-related potentials elicited by brief standard and target tones. Results revealed that, as a group, AWS tended to perform less accurately and were slower to respond to target stimuli. However, inspection of individual data indicated that most AWS performed well within the range of the NFS, and only 3/11 AWS were clearly outside the range. No overall group differences were found for early perceptual processes (N100 and P200), however, the AWS with small amplitude N100 responses were those who performed less accurately and those with reduced P200 amplitudes performed more slowly. Thus, a small subset AWS demonstrated early perceptual processes indicative of reduced cortical representation of auditory input that may have resulted in reduced behavioral performance. P300 mean amplitude, which tended to be reduced overall for the AWS compared to the NFS, did not correlate with behavior for the AWS. However, P300 mean amplitude was significantly correlated with accuracy for the NFS indicating that stronger working memory updating processes enhanced performance for NFS. Taken together, these findings emphasize the importance of examining individual differences among AWS and point to the possibility of non-linguistic auditory processing deficits in only a subset of AWS.

Pesquisa do efeito de supressão e do processamento auditivo em indivíduos que gaguejam

“…These alterations are characterized as a differential in the comparison between individuals who stutter and non-stutters, and the chance of adult individuals who stutter present this disorder is approximately 60.7 times that of non-stutters. This result was expected, considering that national and international studies have reported auditory processing difficulties in children and adults who stutter (3,(13)(14)(15)(16) . Such changes in auditory processing result in decreased ability to produce auditory perception patterns in individuals who stutter.…”

“…Disabilities of auditory nature are manifested in a variety of ways. Some studies have shown evidence of decreased activity in the left auditory cortex prior to speech-language therapy and normal or improved activity levels immediately after therapy (3) . Other studies have indicated neuroanatomical differences between individuals who stutter and non-stutterers (18,19) .…”

“…Stuttering is a complex disorder that can be easily recognized as an impairment of motor nature due to its characteristic disruptions. However, aiming at a better understanding of the framework of this disorder, the numerous models currently seeking to explain stuttering consider atypical neurophysiology, genetic and environmental factors, learning abilities, auditory processing, and speech and language production skills (1,3) . Some studies have investigated the sensory abilities of individuals who stutter focusing on aspects related to sight, touch, movement, and hearing, indicating how these mechanisms contribute and act in conjunction with the motor mechanism to achieve adequate speech production (2) .…”

“…Studies have investigated auditory complaints, the action of middle ear muscles, and the functioning of the central auditory system, also using imaging tests (4,5) , aiming to associate hearing development with dysfluent speech (6) . Some studies have demonstrated the relationship between auditory information processing and stuttering (3,6) . However, no studies have been conducted on the suppression effect of otoacoustic emissions on stuttering individuals.…”

Efeito da retroalimentação auditiva atrasada na gagueira com e sem alteração do processamento auditivo central

“…Delayed auditory feedback in individuals who stutter decreases or inhibits stuttering (11) , and this effect is not related to the reduction of speech rate, but mainly to altered auditory input (12,13) . This fact suggests that auditory input processing could be different in individuals who stutter when compared to fluent individuals (14,15) .…”