. 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.


(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	352	0.395
NREM SWA decline in baseline (1/2) +	0.0009	352	0.400
Weight-adjusted age	0.0297	352	0.400
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	350	0.53
NREM SWA (4/2) +	0.000037	346	0.575
Increase in wake alpha (8–12 Hz)	0.0015	346	0.575
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	340	0.669
(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	365	0.390
NREM SWA decline in baseline (1/2) +	0.000095	362	0.435
Length of time since last sleep	0.029	362	0.435
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	307	0.446
NREM SWA decline in baseline (1/2) +	0.012	312	0.360
Weight-adjusted age	0.038	312	0.360
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	316	0.412
NREM SWA (4/2) +	0.0039	313	0.466
Increase in wake alpha (8–12 Hz)	0.0041	313	0.466
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	311	0.567
(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	326	0.265
NREM SWA decline in baseline (1/2) +	0.00084	316	0.444
Length of time since last sleep	0.00260	316	0.444
NREM SWA (1/2) × Length of time since last sleep	0.026	312	0.527