Résumé
Most daily activities require humans to perform motor sequences. With practice we use predictive processing to anticipate and perform these routines quickly and accurately. However, little is known about the role of the oculomotor system for the acquisition of explicit motor sequences. Given the coupling between eye and hand movements, a detailed understanding of how gaze and limb movements are coordinated throughout sequence learning will provide insight into how humans acquire motor sequences. Ten participants (19-36 years-old) learned an explicit 12-item motor sequence by performing manual aiming movements to series of visual targets on a touchscreen monitor. Participants sat at a table in front of the touchscreen with their forehead resting in a flexible arm mount of the gaze tracker (EyeLink1000Plus, SR Research). They practiced a 12-item sequence, repeated 10 times per block. Participants completed a series of acquisition, transfer and random sequence blocks across two consecutive days. Sequence acquisition was quantified through sequence completion time, saccade onset time, as well as number of correct/incorrect primary saccades following stimulus onset, in early and late stages of practice. We found sequence completion time and saccade onset time reduced significantly from early to late practice. Notably, the number of incorrect primary saccades increased from early to late stages of practice. Together the results reveal increased temporal efficiency through participants’ use of predictive processing. The increased number of incorrect saccades suggest participants prioritized movement speed before accuracy of sequence order. Future research should assess if extended practice mitigates this effect.
