Reflex Integration

Primitive reflexes are automatic stereotypic movements directed from the brainstem and require no cortical involvement (thought). They are needed for survival and development in the womb and in the early months of life. However, as higher, more sophisticated centers of the brain mature, these primitive reflexes become a nuisance and must be abated in order for  proper neurological organization of the brain to develop.

If the Primitive Reflexes are retained past the first year of life (at the very latest) they can interfere with social, academic, and motor learning. Each reflex is associated with one or more of the sensory systems. Therefore, if retained, a child may experience dysfunction within one or several of the sensory processing systems. 

https://pktherapyot.com/2020/05/09/primitive-reflexes-and-daily-activities/