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 7
Correlation of diurnal serum melatonin levels with clinical parameters, psychological test results, and neurocognitive performance during the polar summer and winter photoperiods.
S. No
Parameter/Test
Summer
Winter
Pearson’s correlation coefficient r
8 am
3 pm
8 pm
2 am
8 am
3 pm
8 pm
2 am
1
Age
−0.244
−0.150
−0.333
0.159
−0.057
−0.127
0.072
−0.454
2
Weight
−0.128
−0.113
−0.225
0.137
0.124
−0.287
−0.118
0.170
3
BMI
0.217
0.014
−0.213
−0.214
0.343
0.129
−0.412
0.125
4
DASS 42
0.099
0.268
−0.207
0.047
−0.122
0.603*
−0.130
0.375
5
ESS
−0.328
0.024
0.246
0.179
0.044
−0.104
0.102
0.068
6
MEQ
0.123
0.332
0.312
0.221
−0.212
−0.123
0.213
0.251
7
MMSE
−0.353
−0.012
−0.080
−0.672*
−0.009
−0.392*
0.114
−0.244
8
Attention
Card sort test (correct response)
−0.220
0.134
0.401
−0.002
0.347*
0.219
0.014
−0.013
Digit span
−0.280
0.107
0.127
0.901*
0.306*
−0.271
0.120
0.813
Continuous performance test (target accuracy rate)
−0.219
0.061
0.312
0.208
0.143
0.247
0.134
0.287
9
Executive function Stroop test (mean reaction time)
0.309
0.149
−0.213
0.134
0.103
−0.124
0.217
0.219
10
Visual motor ability FTT
0.012
0.312
0.204
0.132
0.139
0.412
−0.132
−0.012
11
Visual memory
0.029
−0.134
0.013
0.210
0.403
0.410
0.176
0.289
12
Arithmetic (equations per minute)
−0.247
−0.143
0.124
−0.065
0.451*
−0.002
−0.166
0.316
13
Speed of processing mean simple RT
0.360
0.312
0.132
0.466*
−0.113
−0.314
0.304
0.289
Mean choice RT
0.115
0.198
−0.312
0.113
−0.213
0.274
0.149
0.163
BMI: body mass index; FTT: finger tapping test; RT: reaction time. *Significant at .
