What characterizes active sleep in a neonate?

Active sleep in neonates is characterized by frequent movements, which can include twitching and jerking of limbs and facial muscles. This phase of sleep is associated with the presence of rapid eye movement (REM) sleep, even in infants, and is crucial for their development. During active sleep, brain activity is higher, resembling wakefulness, and the infant may exhibit irregular movements as their body goes through various reflexive actions, rather than being inactive or still.

The other characteristics such as regular breathing patterns, low muscle tone, and the absence of eye movement do not apply to active sleep. Instead, during this stage, neonates may display irregular breathing and higher muscle tone compared to quiet sleep. The presence of eye movements, especially in the REM phase, is an intriguing aspect of neonates' active sleep that further distinguishes it from other sleep states.