Table 4.
Parameter estimates with confidence intervals for the 4-parameter logistic models of behavioral, self-report, and physiological correlates of alertness and executive functioning and goodness of fit based on data of the afternoon sessions.
| Variable | a | b | c | d | R 2 | |
|---|---|---|---|---|---|---|
| Behavioral indicators | PVT | −0.58 (−0.74, −0.41) | 1.82 (−55.91, 59.53) | 233 (−8.44 × 106, 8.44 × 106) | −0.40 (−0.49, −0.31) | 0.07 |
| Go-NoGo task, speed | −0.88 (−1.27, −0.48) | 2.17 (−109, 113) | 375 (−8.00 × 105, 8.00 × 105) | −0.53 (−0.86, −0.19) | 0.04 | |
| Go-NoGo task, accuracy | −0.25 (−7574, 7573) | 0.66 (−4.18 × 104, 4.18 × 104) | 0.12 (−3298, 3298) | 0.23 (−5748, 5749) | <0.01 | |
| 2-Back task, speed | −0.59 (−1984, 1983) | 0.70 (−4596, 4597) | 0.22 (−661, 661) | 0.45 (−1219, 1220) | 0.03 | |
| 2-Back task, accuracy | −0.83 (−533, 531) | 0.18 (−274, 275) | 0.58 (−152, 153) | 0.18 (−32.11, 32.48) | 0.07 | |
| Subjective indicators | Sleepiness | 7.51 (−252, 267) | 0.97 (−16.30, 18.23) | 3.07 (−28.59, 34.73) | −0.10 (−4.35, 4.15) | 0.10 |
| Vitality | −0.60 (−0.85, −0.35) | 2.40 (−86.38, 91.18) | 316 (−1.64 × 106, 1.64 × 106) | 0.02 (−0.27, 0.32) | 0.18 | |
| Physiological indicators | HR | −1.27 (−2.67, 0.13) | 2.74 (−618, 623) | 619 (−7.52 × 106, 7.52 × 106) | −4.27 (−6.79, −1.75) | 0.09 |
| SCL | 7.04 (4.33, 9.74) | 1.49 (−25.43, 28.41) | 136 (−2.72 × 105, 2.72 × 105) | 0.85 (0.17, 1.54) | 0.28 |
PVT = Psychomotor Vigilance Task; HR = heart rate; SCL = skin conductance level. All values correspond to difference scores compared with baseline. Parameters b and c are printed in bold if significantly different from 0; parameters a and d are printed in bold if their 95% confidence intervals do not overlap.