Modeling error correction in a self-paced periodic tapping task

This talk is concerned with the implementation of period error correction in the adaptive control of thought - rational (ACT-R) architecture as part of a novel periodic tapping motor extension. Past sensorimotor synchronization models have often implemented error correction via joint phase and period correction mechanisms in the context of synchronization-continuation paradigms (Repp, 2005). Unlike past work, our goal was to model error correction in a self-paced tapping task with discrete feedback. To do so, we designed a new experiment named ChemLab in which players filled rows of 8 beakers by pressing the space bar periodically. In this task, feedback was provided both visually and auditorily. Specifically, taps that were too fast triggered a high-pitched sound and turned on a red light on the screen. Conversely, taps that were too slow triggered a low-pitched sound and turned on a blue light on the screen. We assessed periodic tapping in 4 non-overlapping temporal intervals between 200 and 1,200 ms. For each row of beakers, the temporal interval was set to switch once between the 3rd and the 5th beaker, such that participants either needed to speed up or slow down. In this talk, we show how period correction can be modeled in ACT-R with productions implementing feedback perceptual processing, and a basic motor error correction mechanism. We conclude by showing that modeling error correction in periodic tapping tasks with discrete feedback requires one to capture task-specific elements of feedback in addition to more general motor mechanisms.