Circadian Levels of Serum Melatonin and Cortisol in relation to Changes in Mood, Sleep, and Neurocognitive Performance, Spanning a Year of Residence in Antarctica
Table 8
Results of neurocognitive assessment during the polar summer and winter.
Number of participants ()
Summer
Winter
S. no
Domain/Cognitive Test
Mean ± SD
Mean ± SD
Effect size (d)†
1
Attention
1.1 Card sort test (CST)
CST correct
48.98 ± 7.94
50.22 ± 7.52
0.038
−0.160
CST errors
11.52 ± 4.27
11.10 ± 3.96
0.340
0.101
CST reaction time (ms)
1109.43 ± 196.66
1108.56 ± 208.83
0.959
0.004
1.2 Digit span
5.98 ± 0.69
6.08 ± 0.73
0.258
−0.140
1.3 Continuous performance test (CPT)
CPT target accuracy rate
0.97 ± 0.02
0.98 ± 0.02
0.514
−0.500
CPT foil accuracy rate
0.76 ± 0.12
0.74 ± 0.13
0.379
0.159
CPT correct RT (ms)
438.78 ± 37.78
433.28 ± 43.16
0.705
0.135
CPT error RT (ms)
350.11 ± 103.38
336 ± 91
0.329
0.144
2
Executive function
Stroop test
Stroop congruent RT (ms)
97.39 ± 32.95
94.59 ± 31.63
0.404
0.086
Stroop incongruent RT (ms)
105.87 ± 34.78
105.316 ± 33.28
0.876
0.016
3
Visual motor ability
FTT right (taps/10 seconds)
47.84 ± 7.12
48.14 ± 7.65
0.725
−0.040
FTT left (taps/10 seconds)
39.19 ± 6.72
39.34 ± 7.22
0.854
−0.020
4
Visual memory
6.3 ± 2.2
6.4 ± 1.96
0.343
−0.021
5
Arithmetic
Mean total equations solved (accuracy %)
47.1 ± 15.24 (91.45%)
55.35 ± 14.66 (77.95%)
0.014
−0.551
Equations per minute
13 ± 3.98
16.35 ± 3.75
0.000
−0.788
6
Speed of processing
6.1 Mean simple RT (s)
0.4205 ± 0.102
0.4355 ± 0.100
0.387
−0.148
Long SRT (s)
0.5218 ± 0.195
0.5194 ± 0.167
0.969
0.013
Short SRT (s)
0.2980 ± 0.075
0.2894 ± 0.056
0.649
0.135
6.2 Mean choice RT (ms)
2037.95 ± 542.36
1508.2 ± 320.02
0.000
1.189
Correct trials
19.5 ± 5.55
32.9 ± 7.35
0.170
−1.625
Accuracy rate of CRT (%)
89.1 ± 8.85%
92.68 ± 22.73%
0.214
−0.207
RT: reaction time; SRT: simple reaction time; CRT: choice reaction time; FTT: finger tapping test; SD: standard deviation. ∧Paired sample t test for difference of means significant at . †Effect size using Cohen’s d test.
