Table 2.

PSG sleep parameters, nocturnal cognitive arousal and somatic arousal on the adaptation nights and baseline night for full sample and by insomnia status.

	Full sample n=52	No Insomnia n=34/52; 65.4%	Insomnia Disorder n=18/52; 34.6%
Adaptation night
Nocturnal cognitive arousal	14.44±5.76	12.56±3.79	18.00±7.15	t(50)=3.60**, d=.95
Nocturnal somatic arousal	12.75±11.50	11.94±2.95	14.28±4.27	t(5)=2.32*, d=.64
Sleep latency	22.70±18.13 mins	21.68±17.48 mins	24.64±19.66 mins	t(50)=.56, p=.58
Latency to persistent sleep	32.89±24.97 mins	33.25±26.12 mins	32.19±23.37 mins	t(50)=−.14, p=.89
Wake after sleep onset	61.09±54.94 mins	56.75±58.47 mins	69.28±48.07 mins	t(50)=.78,p=.44
Sleep efficiency	82.40±13.36	83.59±14.04	80.15±12.03	t(50)=−.88, p=.38
Total sleep time	6.59±1.07 hrs	6.71±1.12 hrs	6.41±0.96 hrs	t(50)=−.85, p=.40
Baseline night
Nocturnal cognitive arousal	13.37±54.40	11.85±3.53	16.22±4.55	t(50)=3.84***, d=1.07
Nocturnal somatic arousal	12.75±11.50	10.74±2.76	13.67±3.45	t(50)=3.34**, d=.94
Sleep latency	27.12±28.91 mins	22.22±27.15 mins	36.36±30.63 mins	t(50)=1.71, p=.09
Latency to persistent sleep	34.98±31.19 mins	31.03±31.31 mins	42.44±30.41 mins	t(50)=1.26, p=.21
Wake after sleep onset	44.53±53.46 mins	34.71±45.86 mins	63.06±62.73 mins	t(50)=1.86, p=.07
Sleep efficiency	84.21±14.58	86.92±13.76	79.11±15.09	t(50)=−1.88, p=.07
Total sleep time	6.73±1.16 hrs	6.96±1.10 hrs	6.30±1.18 hrs	t(50)=−2.00, p=.05

Note: No Insomnia = did not endorse DSM-IV insomnia disorder. Insomnia disorder = endorsed DSM-IV insomnia disorder. Nocturnal cognitive arousal measured by the Pre-Sleep Arousal Scale, Cognitive factor. Nocturnal somatic arousal measured by the Pre-Sleep Arousal Scale, Somatic factor. Sleep latency, latency to persistent sleep, wake after sleep onset, sleep efficiency, and total sleep time assessed via overnight polysomnography. t = t-statistic for comparison of means between participants with vs without insomnia. p = significance value.

^*p<.05

^**p<.01

^***p<.001.

d = Cohen’s d effect size.