Table 1.
Demographic and polysomnography variables across To-Do List and Completed List conditions. Standard deviations are in parentheses. Mean arterial pressure data are missing for one participant and the self-reported sleep data of night before the experiment were missing from three participants.
| Completed List (N=29) | To-Do List (N=28) | Condition Main Effect | |
|---|---|---|---|
| Chronological Age | 20.45 (2.35) | 20.00 (1.28) | t(43.47L) = −0.90, p = 0.37, d = 0.24 |
| Gender (% Female) | 75.86% | 57.14% | χ2(1) = 2.25, p = .13, ϕ = 0.20 |
| List Specificity (#of items written) | 14.10 (5.74) | 15.96 (9.14) | t(45.16L) = −0.92, p = 0.36, d = 0.24 |
| Pre-Writing Mean Arterial Pressure | 81.76 (7.78) | 83.95 (9.72) | t(54) = −0.93, p = .36, d = .25 |
| Post-Writing Mean Arterial Pressure | 81.62 (8.17) | 82.06 (7.96) | t(54) = −0.21, p = .84, d = .06 |
| Perceived Stress Scale Score | 16.93 (5.54) | 14.82 (6.10) | t(55) = 1.37, p = .18, d = .37 |
| Need for Cognition Scale Score | 64.55 (10.83) | 68.71 (7.81) | t(50.96L) = −1.67, p = .10, d = .44 |
| PRMQ – Prospective | 2.59 (0.44) | 2.56 (0.41) | t(55) = 0.25, p = .80, d = .07 |
| PRMQ – Retrospective | 2.38 (0.40) | 2.26 (0.44) | t(55) = 1.06, p = .30, d = .29 |
| Total Sleep Time (self-report)a | 414.14 (78.65) | 412.25 (89.51) | t(52) = 0.08, p = 0.93, d = .02 |
| Sleep Onset Time (self-report)a | 16.68 (14.32) | 14.58 (15.15) | t(52) = 0.52, p = 0.60, d = .14 |
| Wake After Sleep Onset (self-report)a | 3.50 (6.57) | 5.87 (13.48) | t(52) = 0.73, p = 0.47, d = .20 |
| Bedtime (self-report)a | 12:41am (1:25) | 12:28am (1:24) | t(52) = 0.55, p = 0.58, d = .16 |
| Wake Time (self-report)a | 7:55am (1:10) | 7:41am (1:19) | t(52) = −0.83, p = 0.41, d = .23 |
| Polysomnography | |||
| Lights Out | 10:24pm (0:21) | 10:28pm (0:21) | t(55) = 0.631, p = .53, d = .17 |
| Sleep Onset Latency (minutes) | 25.09 (15.94) | 15.82 (14.07) | t(55) = 2.32, p = 0.02, d = 0.63 |
| Total Sleep Time (minutes) | 492.40 (45.26) | 498.53 (62.44) | t(55) = −0.43, p = 0.67, d = 0.12 |
| Number of Awakenings | 26.38 (11.54) | 20.93 (10.31) | t(55) = 1.88, p = 0.07, d = 0.51 |
| Wake After Sleep Onset (minutes) | 38.43 (26.82) | 34.08 (41.38) | t(55) = 0.47, p = 0.64, d = 0.13 |
| Sleep Efficiency (percentage) | 88.53 (6.10) | 90.74 (8.87) | t(55) = −1.10, p = 0.28, d = 0.30 |
| N1 (proportion) | .06 (.04) | .05 (.04) | t(55) = 1.21, p = 0.23, d = 0.33 |
| N2 (proportion) | .58 (.07) | .59 (.06) | t(55) = −0.41, p = 0.69, d = 0.11 |
| N3 (proportion) | .16 (.05) | .15 (.04) | t(55) = 0.19, p = 0.85, d = 0.05 |
| REM (proportion) | .20 (.05) | .21 (.05) | t(55) = −0.73, p = 0.47, d = 0.20 |
Abbreviations: PRMQ = Prospective and Retrospective Memory Questionnaire
L
Indicates that Levene’s test was significant and the degrees of freedom and p values have been corrected accordingly.
a
The self-reported sleep measures were taken for the night before the experiment.