Recent studies have indicated a further need to investigate the role of motivation in workingmemory (WM) training and that time perception affects motivation. We addressed whethersubjectively perceived time on task in reference to objective time on task could serve as animplicit measure of motivation, while controlling for individual differences in timeperception. Here, the relationship between different measures of time perception, WM, andmotivation was explored in healthy children. Fifty children in three natural groups (ages: 6-7,8-9, 10-11) at a Swedish school participated. WM scores changed with age as expected.However, the absence of correlations between WM performance and intrinsic motivationwere inconsistent with previous findings, presumably due to the low statistical sensitivity.Nevertheless, time perception accuracy (r=0.318, p=0.043) and state motivation (r=0.434,p=0.005) correlated with performance on task interference, but not WM. With somereservations due to low sensitivity, time perception accuracy appears to be linked tocoordinative capacity required for shifting attention, but to a lesser degree sequential working memory capacity.