Table 2 Late development (>2.4 years).

Summary of the key empirical results and theoretical tests of our model for the various ratios of sleep times in the first column during the period of late development (>2.4 years old). The second column contains the values and 95% confidence intervals of the scaling exponents as determined from direct empirical data, whereas the third through fifth columns contain the ranges of predicted values for the scaling exponents based on theories that sleep function is primarily for neural reorganization in either REM (third column) or NREM (fourth column) sleep or that it is primarily for neural repair (fifth column). The 95% confidence intervals for the predictions are derived from the confidence intervals determined for the scaling exponent α = − 1.70 ± 1.66 in later development (fig. S2). NA denotes that the corresponding theory makes no prediction for that specific variable. Predictions that match data are in bold. For these data, the predictions of the theory that sleep function during early development is primarily or neural repair and clearance are all supported, whereas the predictions of the theory that, during early development, sleep function is primarily for neural reorganization in REM sleep or NREM sleep are all rejected.

RatioMeasured
exponent
REM reorganization
prediction
NREM reorganization
prediction
Repair
prediction
tS/tA−3.50 ± 0.23NANA−2.70 ± 1.66
tR/tS−0.01 ± 0.528.90 ± 3.55NA0
tR/tA−5.10 ± 0.205.40 ± 3.32NANA
tNR/tA−3.16 ± 0.26NA5.40 ± 3.32NA