Sleep deprivation: Does it linger more than a day? Researchers designed a study using 21 subjects between the ages of 18 and 25. All 21 participants took a computer-based visual discrimination test as part of the study. Then the subjects were randomly assigned into two groups. The subjects in one group were deprived of sleep for an entire night in a laboratory setting. The 10 subjects in the other group were allowed unrestricted sleep for the night. Both groups were allowed as much sleep as they wanted for the following nights. On Day 2, all the subjects took the same visual discrimination test on the computer. Researchers recorded the improvement in time (measured in milliseconds) from Day 1 to Day 2 on the test for each subject. The table shows summary statistics for the two groups:
Group Mean
Unrestricted sleep 19.82
Sleep-deprived 3.90
We used software to randomly reassign the 21 subjects to the two groups 100 times, assuming that the treatment received doesn't affect each individual's time improvement on the test. A dotplot of the simulated difference (Unrestricted Sleep - Sleep-deprived) in mean time improvement is shown.
Explain why the researchers chose to have a sleep-deprivation group and an unrestricted sleep group in this study. Describe the type of estimate and simulation used. Use the results to interpret the p-value. What conclusion would you make?