Interactions among Speech, Language, Cognitive, and Visual-Motor Activities

C Dromey, E Bates


Labial kinematic activity was examined across several repetitive speaking conditions (speech alone, and speaking concurrently with a linguistic, cognitive, or visual-motor challenge task) in 20 young adults. Performance in these non-speech activities was also compared between isolated tasks and concurrent speech conditions.  Linguistic challenges resulted in increased spatiotemporal variability of lip displacement across repetitions.  Motor challenges led to more rapid speech with smaller lip displacement.  These qualitatively different changes suggest that different aspects of attention are required for linguistic versus manual visual-motor activity.  Vocal intensity increased for all concurrent task conditions compared with speech alone, suggesting increased effort compared to the control condition.  Scores for linguistic performance decreased when utterance repetition occurred concurrently with the syntactic challenge.  This indicates that speech motor activity can influence language performance as well as be influenced by it.  Although these data come from healthy speakers, they suggest that intervention efforts with disordered speakers should not overlook the potential interactions between the demands of language formulation, cognitive activity, and speech motor performance.