Table 2. Results of the literature review.
“Experiment type”: location of the experiment and type of objective sleep validation (PSG = polysomnography, EEG = electroencephalography; EOG = electrooculography; Act = Actigraphy); in case of multiple studies within a paper, S1 indicates the first and S2 the second study. “Sleep type”: nocturnal or diurnal sleep. “Nr. Participants”: total experimental sample size. “Age (SD)”: age range or average for the whole participant group and corresponding standard deviations (SD) when available. “Successful criterion”: criterion used to define a successful self-awakener, usually a time window around the expected awakening time (absolute value in minutes). “Nr. SA”: number of self-awakeners explicitly reported in the study or whether the study investigated successful self-awakening events. “% SA/total”: percentage of self-awakeners on the study sample size either reported in the manuscript or calculated based on the available data. “SA age (SD)”: age of self-awakeners and its standard deviation. Additional notes, symbols, and abbreviations: *15 participants were recruited but only 12 underwent EEG. ** depending on the questionnaire question and concerning the ability to wake-up with or without an alarm; *** five participants follow within the second criterion and are considered “moderately successful”; § = studies designed to select only self-awakeners; # = 9 self-awakeners were identified but data of one were lost, leaving 8 participants; ## = PSG failed for one participant, leaving 8 participants (6 F; mean age = 21.8 ±.6 years).
| Article | Experiment type | Sleep type | Nr. Participants (males / females) | Age (SD) | Successful criterion |minutes| | Nr. SA (males/females) | % SA/total | SA age (SD) | |
|---|---|---|---|---|---|---|---|---|---|
| 1 | Tart, 1970 [27] | S1: home exp | nocturnal | 10 | |10| | events | |||
| S2: sleep lab (PSG) | nocturnal | 3 (2 /1) | 18 (—) | |10| | events | ||||
| 2 | Zung & Wilson, 1971 [28] | sleep lab | nocturnal | 22 (4 / 18) | 20–45 | |10| | events | ||
| 3 | Lavie et al., 1979 [29] | S1: sleep lab (PSG) | nocturnal | 7 (6 / 1) | 21–30 | |10| |20| |30| |40| |
events | ||
| S2: sleep lab (PSG) | nocturnal | 2 | |20| | events | |||||
| 4 | Bell, 1980 [30] | home exp | nocturnal | 38 (20 /18) | events | ||||
| 5 | Zepelin, 1986 [31] | S1: sleep lab (EEG, EOG) | nocturnal | 15 * (7 / 8) | 15–32 | |15| | 11 | 73 | |
| S2: sleep lab (EEG, EOG) | nocturnal | 2 | events | ||||||
| 6 | Hawkins, 1989 [32] | home exp | nocturnal | 84 (31 / 53) | 22.7 (6.7) | |30| | 22 | 26 | |
| 7 | Hawkins & Shaw, 1990 [33] | home exp | nocturnal | 146 (38 / 108) | 22.9 (6.2) | |30| | 15 | 10 | |
| 8 | Moorcroft et al., 1997 [34] | S1: telephone survey | nocturnal | 269 (129 /140) | 21–84 | 23, 29, 24 ** | |||
| S2: home exp (Act) | nocturnal | 15 (6 / 9) | 19–62 | |10| |15| |
5 5 *** |
33 | |||
| 9 | Kaida, Nakano, et al., 2003 § [35] | sleep lab (PSG) | diurnal | 11 (4 / 7) | 21.7 (1.25) | |5| | 9 (3 / 6) | 21.6 (1.24) | |
| 10 | Kaida, Nittono, et al., 2003 [36] | sleep lab (PSG) | diurnal | 14 (6 / 8) | 21.3 (1.3) | |5| | 10 (4 / 6) | 71 | |
| 11 | Kaida et al., 2005 § [37] | home exp (sleep diary, PSG) | diurnal | 10 | |5| | 9 (7 / 2) | 74.1 (5.01) | ||
| 12 | Kaida et al., 2006 § [38] | home exp (sleep diary, PSG) | diurnal | |5| | 9 (7 / 2) | 74.1 (5.0) | |||
| 13 | Ikeda & Hayashi, 2008 § [39] | sleep lab (PSG) | nocturnal | 10 (3 / 7) | 21.7 (.06) | |30| | 8 # (2 / 6) | 21.8 (0.7) | |
| 14 | Matsuura & Hayashi, 2009 [40] | sleep lab (PSG) | nocturnal | 17 (10 / 7) | 19.7 (1.55) | |30| | 11 (5 / 6) | 65 | 19.0 (1.73) |
| 15 | Ikeda & Hayashi, 2010 [41] | sleep lab (PSG) | nocturnal | 10 (3 / 7) | 21.8 (.6) | |30| | 9 ## (2 / 7) | 90 | 21.8 (0.6) |
| 16 | Aritake et al., 2012 [10] | sleep lab (PSG) | nocturnal | 15 (15 / 0) | 22.1 (.7) | |30| | 7 (7 / 0) | 47 | |
| 17 | Ikeda et al., 2014 [42] | sleep lab (PSG) | nocturnal | 15 (15 / 0) | 40.5 (6.9) | |30| | events |