Appendix - I INFORMATION SHEET

Ability to perceive fast-paced events (a rangeof short intervals) is one of the important cognitive skills inhumans. The underlying mechanism of this ability stillremains elusive. We designed a study to investigate thesubjective perception of short-intervals (10, 20, 60 and120 s) in a cohort of healthy young male and female uni-versity students. The subjects estimated the time intervals,prospectively using time production (TP) and verbal esti-mation (VE) methods. Of the four tested intervals, subjectsproduced 60 s close to accuracy than other intervals. Theintervals were overproduced and underestimated with TPand VE, respectively. Males estimated 60 s more accu-rately than females. In all subjects, verbal estimates of 60and 120 s were positively correlated with sleep duration.The duration of exposure to direct sunlight was signifi-cantly correlated with the verbal estimation of 60 and 120 sintervals in females. It is concluded that humans trackpassage of short intervals fairly accurately and 60 s mightbe the interval that is judged more accurately in males. Thisbehavior could be ascribed to the interval timer that mighthave evolved with frequently used verbal expression, i.e.,‘‘wait a minute please!’’ In addition, the factors, such asgender, sleep duration and length of sunlight exposuremight considerably modulate human abilities to sense time.