Primitive Reflex Development: Response Strength vs. Age (2D)

This 2D companion adds the dimension the 3D reflex lab only describes in its info panel: a real age slider. Choose a primitive reflex — Moro, rooting, palmar grasp, tonic neck, or Babinski — and a schematic 2D infant figure runs through its real stimulus-to-response cycle: a startle fling, a head-turn-and-root, a finger curl around a grasped object, the asymmetric "fencing" posture, or a big-toe extension with toe fan. The response amplitude is not fixed — it is driven by a logistic decay curve strength(a) = 1 / (1 + exp((a − a50) / k)) parameterized per reflex with its own published typical integration age (a50), so dragging the age slider from birth toward 24 months visibly and numerically weakens the response until it reads "Integrated," exactly the transition a pediatric exam is designed to catch. A stimulus-intensity slider and a live strength/status readout make the fade quantifiable rather than just visible.