Thought experiment: If a mad scientist gave a newborn infant a third eye that was offset along a fourth spatial dimension from the baby’s other two eyes, the baby’s brain would naturally acquire the ability to visualize in four dimensions. Wiring up three eyes probably requires three visual cortices, which will have knock-on effects on the overall geometry of the brain. I doubt that it requires the brain itself to be a 4D structure though.
Thought experiment: If a mad scientist gave a newborn infant a third eye that was offset along a fourth spatial dimension from the baby’s other two eyes, the baby’s brain would naturally acquire the ability to visualize in four dimensions. Wiring up three eyes probably requires three visual cortices, which will have knock-on effects on the overall geometry of the brain. I doubt that it requires the brain itself to be a 4D structure though.