The Influence of Speech on a Precision Fitting Task
Purpose: Dual tasking is a common practice in everyday life for young adults. However, the impacts of dual tasking on performance and prioritization in ecologically-valid paradigms are less well-studied. The purpose of the present study was to examine the changes in trunk kinematics, arm kinematics, speech, and syntactic complexity in a dual task requiring standing manual precision fitting and speech. Methods: 15 young adult female participants participated in one experimental session in a one-factor repeated measures analysis of variance (ANOVA) design, with the repeated factor of condition. They were asked to complete eight conditions of the dual task and a control condition of standing and speech (no precision fitting). For the manual precision fitting task, participants were asked to pick up a block, reach it into a board with an opening, and then hold it in the opening for 40 seconds without hitting the sides. Difficulty was varied by reach distance (near or far), opening size of the fitting board (large or small), and with the addition of speech (with speech or without speech). Kinematic measures included: peak arm velocity, acceleration, straightness of wrist motion, wrist – trunk coordination, and wrist – center of mass coordination. Speech and language measures included the total number of pauses per second, average duration of pauses for each trial, utterance length, sound pressure level, speech rate, and syntactic complexity. Results: Overall, participants were able to successfully complete a dual task of precision fitting and speech without task failure. Participants generally prioritized precise completion of speech samples over accurate completion of the task. Number of pauses per second were lower for the standing and speech (no reaching) condition compared to any dual task conditions. Sound pressure level was higher for the standing and speech (no reaching) condition compared to the near distance small opening with speech condition. With the addition of speech to the task, maximum trunk velocity while reaching increased, as well as average wrist velocity and standard deviation of the wrist while holding the block in the opening. However, the addition of speech did not impact arm kinematics while reaching. With the large opening, acceleration/deceleration time and average wrist velocity increased. Conclusions: In a dual task of precision fitting and speech of this type, participants maintained adequate performance on both tasks. They modified kinematic arm and trunk movements to complete the fitting task with little effect on speech, suggesting that young adults can effectively modify their kinematic movements to prioritize speech without compromising performance on the fitting task. Increased pausing was noted in the dual tasks, suggesting that young adults produce shorter utterances when engaged in a dual task. It is possible that this is a result of task switching in which young adults must attend to reaching and speech alternatively as opposed to standing and talking without a dual task. Further research is required to understand the factors which impact prioritization of this dual task and others, particularly those which have different consequences associated with task failure.
Haddad, Purdue University.
Speech therapy|Health sciences|Kinesiology
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