Author(s): ZHOU, Q., FRICKE, L., RAGERT, P., Institution: FACULTY OF SPORT SCIENCE, Country: GERMANY, Abstract-ID: 878

INTRODUCTION:
Implicit motor sequence learning (IMSL) is deeply embedded in daily life, with sport representing a prominent real-world domain. Interestingly, IMSL has so far only been investigated using simplified laboratory paradigms with minimal motor demands which limits ecological validity. It remains unclear how IMSL emerges in ecologically valid, whole-body scenarios. This study therefore examined IMSL in a target-directed football kicking task under varying task difficulty.
METHODS:
Participants with prior football experience completed a target-directed football kicking task. Here, visual targets were projected onto a wall, and participants had to respond to each target by kicking a ball toward the target as fast and as accurately as possible from a shooting distance of 5 m. The task comprised 10 learning sequences (12 targets per sequence), preceded and followed by one random sequence each. In our study, three task conditions were implemented: a difficult task condition (DT, n = 20) with targets distributed across three vertical levels, an easy task condition (ET, n = 12) with targets restricted to a single level, and a random sequence condition (RS, n = 10) using three vertical levels but without a fixed sequence. As outcome measures, response time and radial errors were recorded for each participant. Additionally, a performance index was calculated by combining z-transformed response times and radial errors to account for potential speed–accuracy trade-offs. Sequence-specific learning effects were assessed by comparing outcome measures between the last learning- and random- sequences in each condition.
RESULTS:
For DT we observed a significant sequence specific learning effect for response times (t(19) = 4.76, p < .001, d = 1.06) and performance index (t(19) = 4.00, p < .001, d = 0.9) while no such effects could be observed for ET and RS. In general, radial errors did not change for the respective conditions indicating that sequence-specific learning only affects speed but not accuracy in the target-directed football kicking task. For ET, however, there was a significant change in radial errors (t(11) = 3.88, p = .003, d = 1.12) and performance index (t(11) = 2.59, p = .025, d = 0.75) between the first and last random sequences, reflecting sequence-unspecific performance improvements.
CONCLUSION:
In the present study we provide first evidence that IMSL can be detected in a target-directed football-kicking task but seems to be modulated by task difficulty. Apart from sequence-specific improvements in response time and performance index in DT, sequence-unspecific improvements in radial error and performance index could also be observed for ET. These findings indicate motor task demand seems to affect motor learning outcomes and point towards more difficult task settings when specific sequential movements have to be optimized. Overall, the results underscore the importance of ecologically valid, whole-body paradigms for investigating motor sequence learning in sport-specific contexts