Research Design: Sleep Deprivation Study

In a recent study, researchers explored the effects of sleep deprivation on cognitive performance among college students. They randomly assigned 60 participants to two groups: the experimental group, which was sleep-deprived for 24 hours, and the control group, which had a normal sleep cycle. After the deprivation period, both groups were given the same cognitive performance test to measure reaction times and accuracy.

Based on the information provided, answer the following:

1. Define and distinguish between 'independent variable' and 'dependent variable' in the context of this experiment.
2. Explain what type of statistical test would be appropriate to analyze the data collected from the cognitive performance tests and justify your choice.
3. Discuss one potential confounding variable in this study and how it could affect the results.