What occurs during the Moro reflex in infants?

The Moro reflex, also known as the startle reflex, is a crucial primitive reflex that typically occurs in infants when they feel a sudden loss of support or experience a loud noise. During this reflex, the infant instinctively throws their arms out to the sides and then may draw them back in, while their legs extend. This reaction is thought to be a protective mechanism, signaling the infant's response to what is perceived as a threat or danger.

This reflex is important in the early stages of life and generally fades as the infant's nervous system matures, usually disappearing by the time the baby is around 6 months old. The other options describing laughter, head turning, or crawling do not accurately represent the Moro reflex and pertain to different developmental milestones or reflexes in infants.