A Preliminary Evaluation of the Physiological Mechanisms of Action for Sleep Restriction Therapy

Table 6

Correlation coefficients between subjective sleepiness, alertness, and sleep variables for each participant during treatment.

Participants/alertness and sleepiness	Sleep variables
	SOL	WASO	TWT	TST	SE
Participant 1
Alertness	−0.30*	0.13	−0.07	0.19	0.12
Sleepiness	0.51***	0.01	0.35**	−0.37**	−0.42
Sleepy at night	−0.39**	−0.29*	−0.39**	−0.02	0.32
Participant 2
Alertness	−0.41**	−0.28*	−0.32*	0.53***	0.35**
Sleepiness	−0.01	0.26	0.28*	−0.17	−0.28*
Sleepy at night	−0.29*	−0.07	−0.07	−0.07	0.01
Participant 3
Alertness	−0.02	−0.28	−0.22	0.25	0.21
Sleepiness	−0.02	0.32*	−0.02	−0.16	0.01
Sleepy at night	−0.16	0.31*	0.05	−0.08	−0.04
Participant 4
Alertness	0.01	−0.27	0.08	0.29	0.03
Sleepiness	0.13	0.55***	0.17	−0.52***	−0.28
Sleepy at night	−0.30	−0.16	−0.05	0.18	0.09
Participant 5
Alertness	−0.13	−0.44**	−0.28	0.29	0.31*
Sleepiness	−0.07	0.39**	0.17	−0.17	−0.19
Sleepy at night	−0.25	−0.27	−0.38**	0.24	0.36*

SOL: sleep-onset latency; WASO: wake after sleep-onset; TWT: total wake time including SOL, WASO, and early morning awakening; TST: total sleep time.
* 𝑃<0.05; **𝑃<0.01; ***𝑃<0.001.