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. Author manuscript; available in PMC: 2013 Jun 14.
Published in final edited form as: Brain Sci. 2013 Mar 19;3(1):318–343. doi: 10.3390/brainsci3010318

Table 2.

Multiple predictor linear regression for the SWA rebound after sleep deprivation (A,D), the SWA changes from immediately before to after sleep deprivation (B,E), and the SWA changes during spontaneous periods of wake (C,F). A–C, frontal cortex; D–F, parietal cortex. The appropriateness of models to explain the variability in SWA changes was assessed using the Akaike’s information criteria (AIC). For models including multiple predictors, p-values indicate the probability that the corresponding parameter has predictive value when all other parameters are included. AIC and R2 are given for each model; R2 indicates the portion of variance explained by the model and will increase when additional variables are added to a model. AIC is a measure of the relative goodness of fit for a model. More adequately fitting models have lower AIC, but adding poor predictors will increase AIC (indicating a less appropriate model) even if the R2 increases.

Inline graphic
(A) Frontal: Predictors for SWA rebound (5/1); % change SWA (5/1) = B0 + (predictors) p AIC R2
Weight-adjusted age (using Gompertz fit) 0.00507 362 0.189
Recovery days from surgery 0.43 370 0.0164
REM/NREM amount (12 h of recovery) 0.0071 363 0.175
n of sleep attempts during sleep deprivation 0.053 367 0.0953
Sleep during sleep deprivation (min/4 h) 0.0582 367 0.0913
Brief arousals (n/min of sleep, first 4 h of recovery) 0.31 369 0.0273
Increase in wake SWA (1–4 Hz) during sleep deprivation 0.76 370 0.0249
Slow wave energy (SWE = SWA × time) during deprivation (wake and NREM) 0.84 371 0.0011
Time spent awake since last sleep 0.91 371 0.00033
NREM SWA decline in baseline (1/2) 0.000154 355 0.317
NREM SWA decline in baseline (1/2) + <0.0001 352 0.395
Increase in wake alpha (8–12 Hz) 0.0352
NREM SWA decline in baseline (1/2) + 0.0009 352 0.400
Weight-adjusted age 0.0297
NREM SWA decline in baseline (1/2) + 0.00043 352 0.431
Increase in wake alpha (8–12 Hz) + 0.17293
Weight-adjusted age 0.14348
(B) Frontal: Predictors for SWA change from before to after sleep deprivation (5/4); % change SWA (5/4) = B0 + (parameters) p AIC R2
Weight-adjusted age (using Gompertz fit) 0.00025 364 0.30
Recovery days from surgery 0.64 378 0.00595
REM/NREM amount (12 h of recovery) 0.0036 369 0.20
Length of time since last sleep 0.00462 369 0.19
Increase in wake alpha (8–12 Hz) 0.00013 362 0.324
NREM SWA increase in baseline (4/2) <0.0001 355 0.44
NREM SWA (4/2) + 0.00017 350 0.53
Weight-adjusted age 0.01467
NREM SWA (4/2) + 0.000037 346 0.575
Increase in wake alpha (8–12 Hz) 0.0015
NREM SWA (4/2) + 0.00044 344 0.615
Increase in wake alpha (8–12 Hz) + 0.00618
Weight-adjusted age 0.06158
NR SWA (4/2) × Increase wake alpha (8–12 Hz) + 0.022 340 0.669
Weight-adjusted age 0.071
(C) Frontal: Models Predicting SWA % change (3/2); % change SWA (3/2) = B0 + (parameters) p AIC R2
Weight-adjusted age (using Gompertz fit) 0.913 383 0.0003
Recovery days from surgery 0.39 382 0.0197
Length of time since last sleep 0.016 376 0.14
Increase in wake alpha (8–12 Hz) 0.018 377 0.139
NREM SWA decline in baseline (1/2) 0.000047 365 0.357
NREM SWA decline in baseline (1/2) + 0.00039 365 0.390
Increase in wake alpha 0.1654
NREM SWA decline in baseline (1/2) + 0.000095 362 0.435
Length of time since last sleep 0.029
NREM SWA (1/2) × Length of time since last sleep 0.029 358 0.506
(D) Parietal: Predictors for SWA rebound (5/1); % change SWA (5/1) = B0 + (predictors) p AIC R2
Weight-adjusted age (using Gompertz fit) 0.0045 317 0.219
Recovery days from surgery 0.46 325 0.0165
REM/NREM amount (12 h of recovery) 0.0024 315 0.246
N of sleep attempts during sleep deprivation 0.0100 318 0.185
Sleep during sleep deprivation (min/4 h) 0.011 318 0.180
Brief arousals (N/min of sleep, first 4 h of recovery) 0.62 325 0.0076
Increase in wake SWA (1–4 Hz) during sleep deprivation 0.581 325 0.0093
Slow wave energy (SWE = SWA × time) during deprivation (wake and NREM) 0.801 325 0.0020
Time spent awake since last sleep 0.967 325 0.0000
NREM SWA decline in baseline (1/2) 0.0015 314 0.266
NREM SWA decline in baseline (1/2) + 0.00048 307 0.446
N of sleep attempts during sleep deprivation 0.00292
NREM SWA decline in baseline (1/2) + 0.012 312 0.360
Weight-adjusted age 0.038
NREM SWA decline in baseline (1/2) + 0.0033 307 0.470
N of sleep attempts during sleep deprivation + 0.0164
Weight-adjusted age 0.2466
(E) Parietal: Predictors for SWA change from before to after sleep deprivation (5/4); % change SWA (5/4) = B0 + (parameters) p AIC R2
Weight-adjusted age (using Gompertz fit) 0.0004 319 0.322
Recovery days from surgery 0.51 332 0.0135
REM/NREM amount (12 h of recovery) 0.0004 319 0.320
Length of time since last sleep 0.0046 324 0.219
Increase in wake alpha (8–12 Hz) 0.00059 320 0.304
NREM SWA increase in baseline (4/2) 0.00056 320 0.306
NREM SWA (4/2) + 0.034 316 0.412
Weight-adjusted age 0.023
NREM SWA (4/2) + 0.0039 313 0.466
Increase in wake alpha (8–12 Hz) 0.0041
NREM SWA (4/2) + 0.063 311 0.526
Increase in wake alpha (8–12 Hz) + 0.010
Weight-adjusted age 0.057
NR SWA (4/2) × Increase wake alpha (8–12 Hz) + 0.100 311 0.567
Weight-adjusted age 0.034
(F) Parietal: Models Predicting SWA % change (3/2); % change SWA (3/2) = B0 + (parameters) p AIC R2
Weight-adjusted age (using Gompertz fit) 0.953 334 0.000
Recovery days from surgery 0.47 334 0.016
Length of time since last sleep 0.0060 326 0.207
Increase in wake alpha (8–12 Hz) 0.133 332 0.067
NREM SWA decline in baseline (1/2) 0.0018 324 0.258
NREM SWA decline in baseline (1/2) + 0.0061 326 0.265
Increase in wake alpha 0.5839
NREM SWA decline in baseline (1/2) + 0.00084 316 0.444
Length of time since last sleep 0.00260
NREM SWA (1/2) × Length of time since last sleep 0.026 312 0.527