乳児期の初期反射

Early reflexes in infancy are automatic, involuntary responses to stimuli.

Some reflexes are present at birth or appear soon after. These are called primitive reflexes, and they support early survival.

For example, sucking and rooting reflexes help newborns find the nipple and feed effectively.

Another primitive reflex is the palmar grasp. In this reflex, an infant tightly grasps an object placed in the palm.

As the brain develops, most primitive reflexes fade during the first few months of life.

For instance, the Moro reflex, in which a startled infant throws its head back, extends its arms and legs, cries, and then pulls its arms back, fades between 4 and 6 months.

Gradually, as the brain matures, postural reflexes begin to appear.

For example, between 6 and 9 months, the parachute reflex appears, in which an infant tilted forward extends its arms to break the fall.

However, some protective reflexes, such as blinking and coughing, remain throughout life.

As a child grows, changes in these reflexes show that their nervous system is developing normally.