TABLE 2.

Sleep architecture and sleep characteristics of the current sample (N = 36).

	Group
	HFR	LFR
Variable	(n = 19)	(n = 17)	t/U	p	ESE
Sleep Onset Latency	32.84 (20.65)	22.10 (14.85)	1.78	0.084	0.58
Sleep Efficiency	85.21 (11.45)	90.07 (5.45)	–1.60	0.120	0.52
WASO%	14.45 (10.95)	7.04 (3.74)	75.00	0.003∗∗	0.46a
NREM 1%	11.06 (4.87)	12.87 (7.51)	–0.87	0.393	0.28
NREM 2%	57.50 (15.42)	58.76 (7.73)	–0.306	0.762	0.10
NREM 3%	15.05 (7.57)	13.50 (4.95)	0.737	0.466	0.23
REM sleep%	13.31 (6.81)	14.99 (5.06)	–0.831	0.412	0.27
REM Onset Latency	143.50 (69.94)	174.64 (33.68)	–0.167	0.104	0.54
Total Awakenings	25.26 (10.79)	18.59 (6.41)	2.222	0.017∗	0.72
Stage 2 Awakenings	17.47 (9.95)	10.29 (4.82)	2.704	0.011∗	0.88
Stage 3 Awakenings	2.47 (0.91)	2.65 (1.77)	159.00	0.933	0.01
REM Awakenings	5.21 (3.43)	5.77 (4.12)	–0.441	0.662	0.15
Total REM Density	44.80 (27.40)	36.58 (15.47)	132.00	0.175	0.18

For all variables means are presented with standard deviations in parentheses. HFR, High Frequency Recall individuals, LFR, Low Frequency Recall individuals; WASO%, Wake After Sleep Onset percentage; t Statistic computed for all variables, except for WASO%, Stage 3 Awakenings, and Total REM Density where Mann–Whitney U was computed as part of non-parametric analyses. ESE, Effect size estimate; ^aCohen’s d computed for all variables, with the exception of WASO%, Stage 3 Awakenings, and Total REM Density where r was computed; two-tailed analyses implemented for all variables, except for WASO%, Total Awakenings, and Total REM Density where a priori predictions were made. ^∗p < 0.05; ^∗∗p < 0.001.