Do you have any idea how difficult it is to figure out precisely what changed in the brain of a stroke patient and connect that to changed behavior?

People have been doing it successfully since Broca and Wernicke in the mid 1800s. It's the way everyone does it in neurology, and it's produced a vastly greater amount of knowledge (in its specific area) than the way you're suggesting.

Likewise, helium was discovered in the sun before it was found on Earth. It's a standard method - study extremely weird conditions, seeing how they differ from normality, asking what could have created those differences, and discovering the general principles involved.

Eliezer condemns those who ignore zebras to dream of dragons. But it's not especially virtuous to refuse to look at zebras and stare only at the ground, since the ground is even more mundane than zebras are.