He is experiencing what sleep specialists call the first-night effect. "They are saying that, like in dolphins, part of the brain is awake when you are sleeping," Mayeli said. "It’s not exactly like dolphins, but still, studies show part of the brain is sleeping less." People who have trouble sleeping at home might also fare better because they do not associate the new environment with a history of restless nights. While anyone can experience the first-night effect, Strauss said those who are more anxious at baseline are especially vulnerable.