Not impossible but much, much, much more plausible with embryos. Modifying billions of neurons is a very, very tall order, and would likely be much less effec

Not impossible but much, much, much more plausible with embryos. Modifying billions of neurons is a very, very tall order, and would likely be much less effective after the brain is grown. Embryo selection and modification are almost doable now, we just don't know which alleles to select for or edit in. A gift you can give your children but one you are unlikely to be able to get for yourself.