1. As you're falling asleep, your heart rate slows down. However, it increases again upon reaching: Choice the best answer: Circadian Sleep Stage 3 Sleep REM Sleep The Meditative State Stage 2 Sleep...

3. Garrett is studying pain perception. He wants to see the influence of age on pain perception. He recruits 300 5-year-olds and brings them to the lab. Once there, they receive a mild electric shock and they indicate how much pain they experienced (on a scale of 1 to 10). He then brings them back  5 years later and runs the same test.

He's conducting ______________ research and must worry about the effects of ______________.