What type of sleep seen in infants is very similar to adult NREM sleep?

The correct answer is quiet sleep, which in infants is indeed very similar to the non-rapid eye movement (NREM) sleep observed in adults. During this stage, infants exhibit a significant decrease in metabolic activity and muscle tone, similar to the characteristics seen in adult NREM sleep. The brain activity during quiet sleep shows slower waves, indicating deep relaxation and a state of restful inactivity, resembling the stages of NREM sleep in adults.

In contrast to quiet sleep, active sleep in infants shares more similarities with REM (rapid eye movement) sleep in adults, where brain activity becomes more active, and bodily movements occur. Wakefulness is characterized by full alertness and interaction with the environment. The term intermediate is less common and does not have a defined role in sleep categorization for infants in the same way that the other types do. Understanding these differences emphasizes the unique development of sleep patterns as they relate to age.