Procedure and tasks
napping
A familiarization session (with the experimenters, used material/devices, and tests) was carried out with all the participants, one week before the experiment. After that, the experiment was run in groups of five participants during sessions of approximately 60 min, while respecting the school’s daily schedules. In each group, students individually attended two sessions (with only one session per day) in a quasi-random order: one in the morning (between 08:00 and 09:00 h) and one in the late afternoon (between 16:00 and 17:00 h), under one of the three experimental conditions (static pictures, or enriched static-pictures, or video). Note that (a) the playing system presented in the morning was different (but with similar level of complexity) to the playing system presented in the late afternoon, (b) the order of the three experimental conditions was counterbalanced within subjects, and (c) any masking effects for the consumption of coffee, energy drinks, napping, or even strenuous mental/physical activity before testing were verified.Fifteen minutes before starting each session, the participants came to the university laboratory (with stable mean ambient temperature and relative humidity; 21.1 ± 1.1 °C and 44.3 ± 7.6%, respectively). The principal investigator gives a brief description about the study protocol, objectives, and benefits. Afterward, the students moved, one by one, to an experimental box, equipped by an Acer aspire E15 Laptop (Taipei, Taiwan) placed at an empty desk with chair. At this moment, oral temperature was measured with a calibrated digital clinical thermometer (Omron