The Effects of Concurrent Performance of Cognitive Tasks and Speech Tasks on Speech Fluency of Individuals who Stutter

Lee, Hye-Ran; Hwang, Mina

ORIGINAL ARTICLE

Commun Sci Disord. 2001;6(2): 428-446.

Hye-Ran Lee^` , and Mina Hwang^`

이혜란(Hye-Ran Lee)| 황민아(Mina Hwang)

ABSTRACT

The purpose of the present study was to test whether stutterer s speech disfluencies changed when they concurrently performed 3 kinds of cognitive tasks with different levels of demands- - a detection task, and two discrimination tasks with different number of choices. The effect of the increasing demand on stutterers disfluencies were measured in 2 different speech tasks- - counting which was thought to require minimum resources and story retelling which was thought to resemble our daily life discourse requiring higher demands. Nine adult stutterers and 10 non- stuttering adult s participated in the study. Inconsistent with demand and capacity model of stuttering, stutterer s disfluencies did not increase significantly when the demand increased with concurrent performance cognitive tasks. This result was found regardless of the difficulties of cognitive tasks and the types of speech tasks. Interestingly, concurrent performance of cognitive tasks did significantly increase non- stutterers disfluencies during story- retelling. Because no significant group differences were noted either in RT or in the accuracy of the cognitive tasks, it is not likely that the stutterers kept their speech performance at the cost of cognitive task performance. The examination of stutterer s individual data in story- retelling showed a wide variability among the participant s. Such result s indicated that although non- stutterer s speech fluency is generally affected by the demand of cognitive tasks, there may be substantial individual differences in the stutterer s susceptibility to the increased cognitive demand.