Skill acquisition processes in a visual occlusion motor task


Prediction motion tasks (PMT) require the estimation of an object’s temporal and spatial position after its trajectory has been visually occluded (Tresilian, 1995). The purpose of this experiment was to investigate motor learning in PMT. Ten participants (mean age: 21.8 years) responded to a visual display (E-Prime, PST, Pittsburg, PA) using a mouse. The display depicted a ball moving towards a target region with the path being occluded at the mid-point. The goal was for the participant to move the cursor so that the occluded ball and the cursor coincided within the target region. Participants completed five blocks of 30 randomized trials, which included three speeds (fast/medium/slow) with visual feedback after each trial. The difference between the ball and cursor’s location was recorded to calculate the dependent measures (CE/VE). Ten minutes and 60 minutes after completion participants performed 30 randomized trials of the three speeds without feedback. The acquisition data were analyzed using a 3-Speed by 5-Block repeated measures ANOVA. Results for CE showed main effects for Speed and post-hoc test (Tukey HSD, p<0.05) showed slow different than fast/medium. Analysis for Block demonstrated 1 as having greater error than 2-5. Results for VE showed a main effect for Block (1 more variable than 2-5). The 10-minute (Retention 10) and 60-minute (Retention 60) retention data were analyzed along with Acquisition Blocks 1 and 5 using a 3-Speed by 4-Time repeated measures ANOVA. Results for CE revealed main effects for Speed and Time. Post-hoc analyses showed the slow condition with more error than fast/medium and Acquisition 1 different than Retention 10, which was not different than Retention 60. Overall, there was a distinct improvement as a function of time (decreasing CE). These results will be discussed in relation to skill acquisition processes (eg. contextual interference) and its specific implications for PMT.

Acknowledgments: We would like to acknowledge the support of the Sport Science Association of Alberta.