Experiment 1: 19 participants (15 female; age range 18-40) took part in the study. Inclusion criteria were set to individuals aged 18-40, with normal binaural hearing, no visual impairment and no history of cardiovascular, neurological or psychiatric disease. To increase the probability that participants would fall asleep, only easy sleepers, as assessed by the Epworth Sleepiness Scale (ESS; Johns, 1991), were selected for this study. Recruited participants were considered healthy with relatively high ESS scores but not corresponding to a condition of pathological sleep such as hypersomnia. Participants were recruited via the Cambridge Psychology SONA system. They gave written informed consent to participate in the study and received a remuneration of £10 per hour (i.e., approximately £30 per participant). The Cambridge Psychology Ethics Committee approved the study (CPREC 2014.25). Experiment 2: 10 participants (11 female; age range 18-40) took part in the study. Inclusion criteria, recruitment processes and remuneration were similar to Experiment 1. All participants gave written informed consent to participate in the experiment. The Cambridge Psychology Ethics Committee approved the study (CPREC 2014.25). Experiment 3: 40 participants (6 female; age range 19-39) took part in the study. Inclusion criteria were set to individuals aged 18-40 who exercise at least 8 hours of cycling or triathlon per week, with normal binaural hearing, no visual impairment and no history of cardiovascular, neurological or psychiatric disease. Participants were recruited from the University of Granada, Spain. Subjects gave written consent to participate in the study and received a remuneration of 10€ per hour (i.e., 30€ per participant). Note that well-trained cyclists were selected because they are used to maintaining the pedalling cadence at high intensity during long periods of time. Furthermore, they are able to keep a fixed posture over time, which notably reduce movement artefacts. The University of Granada Ethics Committee approved the study (287/CEIH/2017).