Correlation coefficients between demographic variables, subjective ratings, and sleep duration.

Note. Sleep time 1 and 2 indicate the time that children went to bed on the nights before and after training, respectively. Wake-up time 1 and 2 represent the time that they woke up on the training and retest mornings, respectively. Sleep durations were calculated from the sleep times and wake-up times. Awake duration 1 and 2 represent the time intervals from wake-up to when children performed the training and the retest tasks. *p<0.05, **p<0.01. Correlation coefficients between demographic variables, subjective ratings, and sleep duration.