Actions in response to specific stimuli that are present in newborn infants.

Neonatal reflexes are the reflexes that are present at birth. They are believed to be inborn and have predictable action patterns. Reflexes, more accurately described as unconditioned reflexes, are not learned or developed through experience. Normally developing neonates (infants up to about four weeks of age) are expected to respond to specific stimuli with a specific, predictable behavior or action. Any variation in, or absence of, response may be a sign of abnormality in development. Further testing of the infant is usually recommended when any response to a stimulus differs from the expected norm. Some neonatal reflexes disappear with maturation; other persist into adulthood.

Although reflex actions are complex, most reflexes can be simplified into four basic steps. In the first step, the stimulus is received by nerve endings involving one of the senses...