Table 2.

Summary of the subjective sleep assessment data for the Antarctic group and the control group

Good Sleeper Control GroupAntarctic Group
MeanSDMeanSD
Sleep quality7.61.14.81.6
KSS evening5.41.74.01.1
KSS morning4.41.75.31.3
  • KSS, Karolinska Sleepiness Scale. Sleep quality was a score that participants had to rate from 1 to 10. Both groups were compared through an independent samples t-test for sleep quality (t = 5.5; P < 0.001) and with a mixed ANOVA with group as a between-subject factor and moment as a within-subject factor for the Karolinska scores. Neither group nor moment showed significant effects, but the interaction between group and moment was highly significant [F(1,32) = 14.2; P = 0.001].