Primitive Reflexes and Postural Reactions

1. Primitive Reflexes and Postural Reactions Mary Ann Roberton Stephen Langendorfer Bowling Green State University

2. Inter-task Developmental Sequences • Developmental sequences are the chronological ordering of events according to the order of their appearance in most people’s repertoire. • Inter-task developmental sequences are the chronological listing of different tasks or skills.

3. In infancy there are several interesting developmental sequences • Two of them are • The general sequence from primitive reflexes to postural reactions to voluntary movement • The sequence from specific primitive reflexes to specific voluntary movements

4. The firstInter-task • Developmental Sequenceof Infancy • Parallels and Assists the • Development ofVoluntary • Movement Primitive Reflexes Postural Reactions Voluntary Movement

6. Rate Limiters • Postural reactions act as a “rate limiter” on the development of voluntary movements • Many voluntary movements cannot completely develop until the postural reactions develop • The postural reactions limit the rate at which voluntary movements can appear.

7. Primitive Reflexes Disorganized Movement Voluntary Movement Sometimes primitive reflexes seem to foreshadow certain voluntary movements. This creates the second kind of developmental sequence in infancy Dr. Myrtle McGraw studied such sequences. She summarized them as:

8. Swimming and Walking are good examples.

9. In swimming, the sequence goes from • Reflex swimming • Disorganized movements • Voluntary swimming

10. In walking, the sequence goes • Reflex stepping • Disorganized movement • Voluntary walking

11. A Developmental Mystery • One of the big mysteries of motor development is • Why are babies born with the primitive reflexes? • AND • Where do the primitive reflexes go when they disappear?