Fidelity of Information Processing on a Psychomotor Vigilance Task Predicts Changes in Self-Reported Sleepiness Ratings

Figures & data

Table 1 Demographics and Characteristics of Total Sample (N = 66)

Characteristics	Measure of Central Tendency
Demographic variables
Age, years	23[21,25]
Gender, female	31(47%)
Race, white	58(88%)
Education, some college	65(98%)
Psychological variables
Patient Health Questionnaire-9	3[1,5]
State-Trait Anxiety Inventory state score	32[25,37]
Insomnia Severity Index	7[3,13]
Composite Scale of Morningness chronotype score	37.5(0.8)
Sleep diary variables
Average total sleep time	428[391,458]
Average sleep efficiency	92[87,95]
Average sleep onset latency	15[11,23]
Average wake after sleep onset	7[3,11]
Actigraphy variables
Average total sleep time	464.8(49.3)
Average sleep efficiency	96[92,97]
Average sleep onset latency	11[8,19]
Average wake after sleep onset	4[2,13]
Polysomnography variables
Total sleep time	365.5(9.4)
Sleep onset latency	44[21,100]
Wake after sleep onset	19[10,34]
Sleep efficiency	83[72,90]
Periodic limb movements with arousal	1[0.6,2]
Apnea-Hypopnea index	1[0.6,2]
PVT metrics
Mean reaction time	270.5(26.6)
Mean reciprocal reaction time	3.9(0.04)
Standard deviation of reaction time	49[38,59]
Number of lapses	0[0,1]
Log transformed signal-to-noise ratio	16(0.2)
Pre-PVT sleepiness score	4[2,7]
Post-PVT sleepiness score	4[3,6]

Notes: M (SD), Mdn[IQR], n (%).

Abbreviation: PVT, psychomotor vigilance task.

Table 2 Ordinal Regression Model Predicting Post-PVT Sleepiness Scores

	B	SE (B)	Wald	Odds Ratio	95% Confidence Interval
Pre-PVT sleepiness score	1.43	0.21	48.82***	4.203	1.03	1.84
Insomnia Severity Index total score	0.00	0.41	0.00	1.000	−0.80	0.80
Mean reciprocal reaction time	−0.78	0.67	1.35	0.459	−2.09	0.53
Log-transformed signal to noise ratio	−0.45	0.15	8.85**	0.639	−0.74	−0.15

Notes: **p<0.01 ***p<0.001.

Abbreviation: PVT, psychomotor vigilance task.

Table 3 Correlations of Pre-PVT Sleepiness Score, Post-PVT Sleepiness Score, Changes in Sleepiness Score from Pre-to-Post PVT, Log-Transformed Signal-to-Noise Ratio with Person-Level Factors and PVT Performance Metrics

Characteristics		Pre-PVT Sleepiness Score	Post-PVT Sleepiness Score	Pre-Post PVT Change in Sleepiness	Log-Transformed Signal-to-Noise Ratio
Demographic variables
Age	rs	0.096	0.015	−0.106	0.290*
	N	66	66	66	66
Sex	rs	−0.170	−0.272*	−0.203	0.066
	N	66	66	66	66
Education	rs	0.077	−0.002	−0.073	0.106
	N	66	66	66	66
Psychological variables
Patient Health Questionnaire-9 total score	rs	0.343**	0.382**	−0.017	−0.134
	N	65	65	65	65
State-Trait Anxiety Inventory state score	rs	0.463**	0.467**	−0.090	−0.287*
	N	62	62	62	62
Insomnia Severity Index score	rs	0.450**	0.433**	−0.081	−0.191
	N	66	66	66	66
Composite Scale of Morningness chronotype score	rs	0.062	0.056	0.085	−0.101
	N	66	66	66	66
Sleep diary variables
Average total sleep time	rs	−0.068	−0.071	0.063	−0.006
	N	66	66	66	66
Average sleep efficiency	rs	−0.130	−0.128	0.039	−0.062
	N	66	66	66	66
Average sleep onset latency	rs	0.242*	0.231	−0.109	−0.042
	N	66	66	66	66
Average wake after sleep onset	rs	−0.026	−0.070	−0.108	0.146
	N	66	66	66	66
Polysomnography variables
Total sleep time	rs	−0.280*	−0.169	0.203	0.040
	N	62	62	62	62
Sleep efficiency	rs	−0.272*	−0.261*	0.027	0.091
	N	62	62	62	62
Sleep onset latency	rs	0.151	0.210	0.058	−0.152
	N	62	62	62	62
Wake after sleep onset	rs	−0.004	−0.031	−0.029	0.073
	N	62	62	62	62
PVT metrics
Mean reaction time	rs	0.131	0.310*	0.237	−0.364**
	N	66	66	66	66
Standard deviation of reaction time	rs	0.217	0.407**	0.376**	−0.906**
	N	66	66	66	66
Number of lapses	rs	0.322**	0.435**	0.226	−0.546**
	N	66	66	66	66
Mean reciprocal reaction time	rs	−0.115	−0.275*	−0.201	0.266*
	N	66	66	66	66
Log-transformed signal-to-noise ratio	rs	−0.177	−0.350**	−0.370**	–
	N	66	66	66	–

Notes: *p<0.05 **p<0.01.

Abbreviations: r_s, Spearman correlation coefficient; PVT, psychomotor vigilance task.

Figure 1 This figure depicts the scatter plot between the LSNR and pre-to-post changes in sleepiness. The correlation between LSNR and pre-to-post changes in sleepiness was significant (r_s = −0.370, p < 0.01). Participants who had lower fidelity of information processing during the PVT reported greater sleepiness after completing the PVT than they had immediately before doing the PVT, whereas participants who had higher fidelity of information processing reported less sleepiness after the PVT, in individuals with and without insomnia symptoms. Removing the participant who appeared to have an extreme change in sleepiness ratings in the negative direction did not alter the pattern of results or significance level.