The different degrees of sleep and wakefulness through which newborns cycle, ranging from deep sleep to great agitation, are called states of arousal. These states are regular sleep, irregular sleep, drowsiness, quiet alertness and crying. About eight to nine hours each of an infant's day is dedicated to regular and irregular sleep. So, most of the time of the infant is spent in these states. These are the states where the brain of an infant is developing the important connections for growth and survival. Crying is the means for infants to communicate their needs. Different type of cries would represent different needs of the infant.
