Table 2.

Descriptive characteristics of sleep parameters in the Nap group.

Variable	Mean (SD)
Sleep duration (min)	41.16 (12.35)
Sleep efficiency (%)	70.28 (16.27)
Wake duration (min)	16.53 (7.77)
S1 duration (min)	6.02 (3.62)
S2 duration (min)	17.93 (6.59)
SWS duration (min)	16.89 (12.82)
Fr. fast spindle density	6.37 (0.96)
Cent. fast spindle density	7.45 (0.83)
Post. fast spindle density	7.35 (0.93)
Fr. fast spindle amp.	4.56 (1.32)
Cent. fast spindle amp.	6.01 (1.56)
Post. fast spindle amp.	5.38 (1.38)
Fr. slow spindle density	7.31 (1.12)
Cent. slow spindle density	7.33 (1.19)
Post. slow spindle density	7.4 (1.16)
Fr. slow spindle amp.	3.91 (1.85)
Cent. slow spindle amp.	3.28 (1.49)
Post. slow spindle amp.	2.54 (0.96)

S1, Stage 1; S2, Stage 2; SWS, Slow Wave Sleep, Fr, Frontal; Cent, Central; Post, Posterior.