Primitive Reflexes
Understanding reflex integration and its role in neurodevelopment
What are Primitive Reflexes?
Primitive reflexes are automatic survival responses controlled by the brainstem. They are present in newborns and help with feeding, movement, and protection during the earliest stages of life.
As the nervous system matures, these reflexes integrate (fade) and allow voluntary movement, postural control, and higher brain function to develop. Therapists track reflex integration because persistent reflexes can interfere with motor skills, attention, and sensory regulation.
The Development Sequence
Primitive reflexes must integrate so that postural reflexes and voluntary movement can emerge. This is the foundational principle of neurodevelopment.
Reflex Integration Timeline — Quick Reference
| Reflex | Purpose | Appears | Integrates |
|---|---|---|---|
Moro | Fight or Flight reaction, sympathetic nervous system response | Birth | 2–4 months |
Rooting | Autonomic response to locate food and breast | Birth | 3–4 months |
Palmar | Autonomic flexion of the fingers to grab when the palm is stimulated | Birth | 3–6 months |
ATNR | Assists with movement through the birth canal and early hand-eye coordination via cross-pattern movements | Birth | 6 months |
Spinal | Important during the birthing process and helps facilitate movement of the hips during descending the birthing canal | Birth | 3–9 months |
TLR | Foundational for postural stability for large muscle groups | In Utero | 3.5 years |
Landau | Necessary for postural development | 4–5 months | 1 year |
STNR | Foundational for crawling | 6–9 months | 9–11 months |
Reflex Retention Matrix
Each reflex is linked to specific sensory systems. When a reflex is retained, those systems may remain dysregulated.
| Reflex | Sensory Systems | Functional Role | If Retained |
|---|---|---|---|
Moro Reflex | VestibularAuditory | Startle response, survival alert | Anxiety, exaggerated startle response, Overreaction to sound, light, or touch |
Palmar Grasp Reflex | TactileProprioceptive | Early grasping response | Poor manual dexterity, deficits with pencil grip |
ATNR | VisualProprioceptive | Hand-eye coordination and early reaching | Difficulty crossing midline, Poor handwriting, awkward pencil grip |
Spinal Galant Reflex | TactileProprioceptive | Trunk movement and early locomotion | Postural issues like scoliosis, misaligned or rotated pelvis |
TLR | VestibularProprioceptive | Postural tone and body orientation | Clumsiness or poor coordination, Slumped or rigid posture |
STNR | VestibularProprioceptive | Helps transition from lying to crawling | Slouching or leaning on desk, Difficulty coordinating upper and lower body |
Visual Integration Timeline
Each bar shows when a reflex is active. Longer bars mean a wider integration window.
Why Reflex Integration Matters
If primitive reflexes remain active beyond their expected timeline, they may interfere with development.
Anxiety, sensory sensitivity
Difficulty crossing midline, writing issues
Poor sitting posture
Balance problems
Fidgeting, attention difficulty
Key Principle
Primitive reflexes must integrate so that postural reflexes and voluntary movement can emerge. When reflexes persist beyond their expected window, they can interfere with motor skills, attention, sensory regulation, and cognitive development. Understanding this timeline is essential for identifying developmental delays early and guiding effective therapeutic interventions.