Explain sensory reweighting on foam surface with eyes closed vs eyes open.

• A. On foam with eyes closed proprioception unreliable; increasing vestibular reliance; with eyes open vision can compensate
• B. On foam with eyes closed vestibular cues degrade and vision cannot compensate
• C. On foam with eyes open vestibular cues disappear
• D. On foam, vision alone handles all balance; proprioception irrelevant

Answer: (A)

When you stand on foam, the ground beneath your feet gives poor, unreliable proprioceptive feedback about where your body is in space. The brain then shifts weight toward the sensory inputs that remain more stable: vestibular information about head and body motion, and, if the eyes are open, visual information about orientation in the environment. With eyes closed, vision isn’t available, so balance relies more on vestibular cues to detect sway and changes in position, which can still help but may not be as precise as when vision is present. When eyes are open, vision provides a clear reference frame and can compensate for the degraded proprioception, improving postural stability. The other statements don’t fit because vestibular signals don’t inherently degrade on foam, and vision can and does help when available.