Table 1 Sample characteristics (mean ± SD).

From: Preserved wake-dependent cortical excitability dynamics predict cognitive fitness beyond age-related brain alterations

 

n = 60

Sex

42w/18 m

Age

59.6 ± 5.5

Education

15.4 ± 3.2

Right-handed

59

Ethnicity

Caucasian

Dementia rating scale

142.1 ± 2.3

Raven’s progressive matrices

50.5 ± 4.9

Mill Hill vocabulary scale

26.9 ± 3.9

Body mass index (kg/m²)

24.6 ± 2.9

Anxiety

2.6 ± 2.5

Mood

4.4 ± 4.7

Caffeine (cups/day)

3.6 ± 1.9

Alcohol (doses/week)

3.9 ± 4.0

Treated for hypertension (stable > 6 months)

7

Treated for hypothyroidism (stable > 6 months)

12

Systolic blood pressure (mmHg)

118.74 ± 11.62

Sleep quality

5.1 ± 3.0

Daytime sleepiness

6.2 ± 3.9

Chronotype

53.8 ± 8.3

Clock time of dim-light melatonin onset (hh:min, PM)

08:20 ± 00:59

In-lab baseline sleep duration (min, EEG)

388.0 ± 44.3

In-lab baseline sleep efficiency, including N1 stage (%, EEG)

82.6 ± 9.6

Baseline sleep time (hh:min, PM)

10:47 ± 00:36

Baseline wake time (hh:min, AM)

06:46 ± 00:43

Gray matter volume (% of total volume)

41.04 ± 3.73

[18F]Flutemetamol (SUVR)

1.16 ± 0.08

[18F]THK-5351 (SUVR)

1.32 ± 0.10

  1. Anxiety was measured by the 21-item Beck Anxiety Inventory53; mood by the 21-item Beck Depression Inventory II54; caffeine and alcohol consumption by self-reported questionnaires; sleep quality by the Pittsburgh Sleep Quality Index55; daytime sleepiness by the Epworth Sleepiness Scale56; chronotype by the Horne‐Östberg questionnaire (no participants were extreme chronotypes, i.e. scores <30 or >7057). Systolic blood pressure was measured in-bed after laying down for >15 min and 1 to 2 h prior to bedtime