That’s interesting! My mind always just assumes the reason is some “core” biological reason. I think contralateral wiring helps the brain manage signal sequencing while preserving evolutionary symmetry.
The spinal cord handles rapid reflexes (pulling away from a hot stove), leaving the brain for slower non-immediate tasks. By crossing nerves before they reach the brain a standardized delay is introduced, giving the brain a predictable offset to filter against. The optic chiasm follows the same logic.
And I think this is necessary to keep same-side brain-body pairs from over-optimizing (direct nerve connection from the right hand to the right brain hemisphere) their paths at the expense of balance, preserving biological symmetry.
The spinal cord handles rapid reflexes (pulling away from a hot stove), leaving the brain for slower non-immediate tasks. By crossing nerves before they reach the brain a standardized delay is introduced, giving the brain a predictable offset to filter against. The optic chiasm follows the same logic.
And I think this is necessary to keep same-side brain-body pairs from over-optimizing (direct nerve connection from the right hand to the right brain hemisphere) their paths at the expense of balance, preserving biological symmetry.