TABLE 3.
Correlation coefficients (Spearman’s rank) for sleepiness and driving performance measures after sleep deprivation are reported: (A) maintenance of wakefulness test (MWT), (B) driving simulator (DSim), and (C) between the MWT and the DSim.
| (A) MWT | |||||||||||||
| MSE-L (min) |
AASM-L (min) |
Difference between MSE-L and AASM-L (min) |
Median MSE duration (s) |
MSE rate (#/min) |
Cumulative MSE duration (%) |
||||||||
| MSE-L (min) | |||||||||||||
| AASM-L (min) | 0.60** | ||||||||||||
| Difference between MSE-L and AASM-L (min) | 0.45 | 0.97** | |||||||||||
| Median MSE duration (s) | 0.11 | −0.45 | −0.57* | ||||||||||
| MSE rate (#/min) | −0.53* | −0.52* | −0.41 | 0.11 | |||||||||
| Cumulative MSE duration (%) | −0.27 | −0.50* | −0.48* | 0.55* | 0.77** | ||||||||
| (B) DSim | |||||||||||||
|
MSE-L (min) |
AASM-L (min) |
Difference between MSE-L and AASM-L (min) |
Median MSE duration (s) |
MSE rate (#/min) |
Cumulative MSE duration (%) |
OFF-L (min) |
Median OFF duration (s) |
OFF rate (#/min) |
Cumulative OFF duration (%) |
SDLP | |||
| MSE-L (min) | |||||||||||||
| AASM-L (min) | 0.09 | ||||||||||||
| Difference between MSE-L and AASM-L (min) | −0.52* | 0.73** | |||||||||||
| Median MSE duration (s) | −0.08 | −0.47 | −0.27 | ||||||||||
| MSE rate (#/min) | −0.62** | −0.42 | 0.02 | 0.72** | |||||||||
| Cumulative MSE duration (%) | −0.57* | −0.39 | −0.00 | 0.76** | 0.99** | ||||||||
| OFF-L (min) | 0.03 | 0.58** | 0.45 | −0.38 | −0.35 | −0.32 | |||||||
| Median OFF duration (s) | −0.03 | −0.59* | −0.44 | 0.49* | 0.44 | 0.42 | −0.67** | ||||||
| OFF rate (#/min) | −0.15 | −0.66** | −0.39 | 0.47* | 0.46 | 0.43 | −0.83** | 0.81** | |||||
| Cumulative OFF duration (%) | −0.14 | −0.73** | −0.46 | 0.53* | 0.51* | 0.49* | −0.81** | 0.91** | 0.97** | ||||
| SDLP | −0.11 | −0.72** | −0.53* | 0.43 | 0.45 | 0.42 | −0.84** | 0.83** | 0.83** | 0.90** | |||
| (C) DSim and MWT | |||||||||||||
| MWT |
MSE-L (min) |
AASM-L (min) |
Difference between MSE-L and AASM-L (min) |
Median MSE duration (s) |
MSE rate (#/min) |
Cumulative MSE duration (%) |
|||||||
| DSim | |||||||||||||
| MSE-L (min) | 0.16 | 0.07 | 0.09 | −0.06 | −0.54* | −0.44 | |||||||
| AASM-L (min) | 0.19 | 0.25 | 0.17 | 0.14 | −0.21 | −0.04 | |||||||
| Difference between MSE-L and AASM-L (min) | 0.05 | 0.04 | −0.03 | 0.19 | 0.28 | 0.28 | |||||||
| Median MSE duration (s) | −0.36 | −0.46 | −0.45 | 0.33 | 0.36 | 0.29 | |||||||
| MSE rate (#/min) | −0.44 | −0.28 | −0.23 | 0.14 | 0.63** | 0.52* | |||||||
| Cumulative MSE duration (%) | −0.44 | −0.30 | −0.26 | 0.22 | 0.62** | 0.58* | |||||||
| OFF-L (min) | 0.38 | 0.41 | 0.36 | −0.12 | −0.10 | −0.05 | |||||||
| Median OFF duration (s) | −0.35 | −0.26 | −0.17 | 0.10 | 0.35 | 0.21 | |||||||
| OFF rate (#/min) | −0.38 | −0.43 | −0.38 | 0.28 | 0.32 | 0.30 | |||||||
| Cumulative OFF duration (%) | −0.38 | −0.39 | −0.32 | 0.19 | 0.36 | 0.27 | |||||||
| SDLP | −0.44 | −0.36 | −0.26 | −0.03 | 0.31 | 0.12 | |||||||
Significant correlations are indicated in bold (*p < 0.05, **p < 0.01). Our correlational analyses were of exploratory character and thus no corrections to p-values were performed. The latency to the first microsleep episode (MSE-L), latency to AASM-defined sleep (AASM-L), latency to the first off-road event (OFF-L), rate and duration of MSEs and off-road events (OFF), and standard deviation of lateral position (SDLP) were analysed until AASM-defined sleep onset.