What are Reflexes?
Your baby’s early movements are controlled by reflexes. Reflexes are automatic reactions to sensory stimulation. Several reflexes are present at birth and gradually disappear over the next six months as voluntary control develops. Reflexes have survival value and are protective.
For example, parents may create a calmer and perhaps safer environment to avoid a baby’s startle reflex. Reflexes also help babies develop motor skills, such as rolling over and reaching toward a toy. Some common reflex patterns are listed and then explained below:
• rooting reflex
• sucking reflex
• startle reflex
• grasping reflex
• asymmetrical tonic neck reflex (ATNR)
When a nursing mother touches baby’s lips, the baby will attempt to find a nipple. At the same time, mother will relax upon feeling the lips turn toward her nipple and this helps the milk to flow. Seekingout a source of nutrition is a survival reflex. This reflex is gone by around four months of age. However, it has been an important influence on the baby’s motor development as she turns her head and trunk toward a toy and eventually rolls over.
Babies will instinctively press the nipple between their tongue and palette and coordinate tongue movement, breathing, and swallowing. Nature gave your baby wonderful reflexes to find nourishment. Some babies benefit from a pacifier or adult finger in the mouth to satisfy these sucking needs when not being fed. Babies voluntarily suck at around two months of age.
You may have noticed your baby’s startle reflex when she hears a loud, sharp sound or experiences sudden movement. She will fling her arms back and then quickly bring them into the chest and cry. It is unsettling for parents to see their baby startle, and they quickly learn how to avoid sudden sounds and movements. Your baby’s reflexes teach you how to make her feel safe and comfortable. This reflex lasts about five to six months. The startle reflex prepares your older baby to be aware of the many stimuli in the environment so that she withdraws from things that are dangerous, such as hot rocks, and reaches toward pleasurable stimuli, such as bubbles.
Touch your baby’s palm and the stimulation will make her automatically grasp your thumbs. This grasp might be tight enough for you to lift her off the bed and protect her from a fall! It is another example of a protective reflex. The grasping reflex also prepares your baby’s hand muscles and joints to grasp toys in the near future. Your baby will grasp reflexively only for a couple of months as voluntary grasping, where she controls her own grasp, gradually emerges.
Asymmetrical tonic neck reflex (ATNR)
During your baby’s first two months, you may have noticed that her arms and legs respond to the movement of her head. This reflex will make her extend her arm and leg on the same side her turned head faces, and it encourages visual inspection of the extended arm. At the same time the other arm and leg bend. This bending is called flexion. The ATNR reflex lasts about six to seven months.
As the influence of this reflex diminishes, your infant gradually gains the control to bring the hands to the middle of her body. The reflex prepares her to use eyes and hands together for manipulation and to eventually sit with good stability while reaching for toys. Fortunately, as reflexes gradually disappear, your baby’s voluntary control improves. Eventually she will choose to suck on a nipple because she has learned that it stops the hunger sensation. She will also grasp an object because it feels good, and this behavior makes others smile. In this case, sensory and social stimulation reinforce your baby’s movements
Large Motor Skills and Reflex Integration
The development of the large muscles used for head control, rolling and reaching will be influenced by the presence and then gradual disappearance of reflexive movements, the sensory stimulation you provide, and muscle tone. Your baby will eagerly move her head, arms and entire body toward toys and faces. The term reflex integration refers to the disappearance of primitive reflexes as the baby gains voluntary motor control.
The following videos demonstrate these reflexes:
Asymmetrical Tonic Neck Reflex
When Infant/Primitive Reflexes are retained....
The following resources explain how reflex testing is used to diagnose possible brain injury and abnormal motor patterns and the role of therapy in promoting reflex integration.