This study investigated the impact of task difficulty level and time-pressure on the morning-evening changes in
psychomotor performance and perceived difficulty to it among 9–10 years-old boys. Twelve healthy right-handed boys (age =9.8 ± 0.5 years, height = 144 ± 6.2 cm and body mass = 32.7 ± 3.4 kg) volunteered to take part in the study. They were asked to throw darts to a target from a short (2m, SD) and long (2.37m, LD) distances, either in free (no time limitation, NC) or time-pressure (TPC) conditions, on nonconsecutive days and in a counter-balanced randomized order.
Mean scores, missed darts and variability of scores were recorded and analyzed using a three-way ANOVA with repeated measures. Intra-aural temperature and perceived difficulty were recorded too. The results showed higher performance in the afternoon than the in the morning, with higher mean scores around the time of maximum oral temperature (p<0.001). The number of missed darts and variability of scores were lower at 17:00 h in comparison with 07:00 h (p<0.05). Perceived difficulty decreased significantly with time-of-day, with greater values at 07:00 h than at 17:00 h (p<0.05).
Psychomotor performance was better in the afternoon than the morning. It seems that, in the early morning, children are less sensitive to the increased level of difficulty when under time-pressure than when throwing a greater distance from the target.