Evaluation of attentional demands during motor learning: validity of a dual-task probe paradigm

The aim of this study was to examine the validity of a 2-choice audio-vocal reaction time (RT) probe task for measuring the changes in attentional demand during practice and learning of a discrete motor task. Twenty participants practiced the motor task across 3 days and were probed with the RT task during either the preparation or execution phase of the primary task. As practice progressed, participants improved in the primary task performance and shortened the RTs to the probe task. This indicated that less attention was required to plan and execute the movement and suggested that the RT probe task was a sensitive and valid tool to measure changes in attentional demands across practice. The authors implemented several additional experimental controls to address possible confounders including unintentional learning of the probe task, primary-secondary task trade-off effects, and compliance with task priority instructions. These experimental controls further ensured the validity of the probe paradigm and interpretability of the dual-task cost findings. Our experimental methods provided confirmatory evidence for the validity of the 2-choice RT task as a means to assess attentional demands during motor learning.