Have you ever heard of Portfolio days? They happen around the country at different art schools and art museums. You should gather a portfolio together and show it to the potential art schools you're interested in. Hearing what they have to say about your art and what they would offer you in their programs may be a good way for you to decide if it's right for you or not. (:
Also, keep in mind income. Art isn't going to promise you a wealthy life and art is something you could always pick up at any time. Some people don't even need to go to art school to make a career of it. Really weigh your options!
I weighed option of deciding to go to art school vs a normal college a few years ago and decided to go to art school. I'm in such a comfortable environment and know it was absolutely the right choice for me. You could always take a summer class at an art school to see if you like the feel of it. I've found that art school is very different than your normal college, but to me, that's comforting.
As others have said, neurobiology seems like a better job. It seems like a difficult field so if you're even naturally gifted for it all the more reason to rely on it rather than art for income. Art is fickle in that sense, and it can be practiced and doesn't require classes to learn. You could also offer commissions if you'd like to sell your art online. Being forced to do certain art can also ruin the fun of it, when it comes to studying it.
Go with science. It's easier to get a job and get an income - you can ALWAYS pursue art later. You can't always go back and get a science degree later. (Or rather, you always *can* but it's about 50x harder than doing the same with art school). Life is weird like that! Good luck
If you go for neurobiology first, you can then take an art degree and either teach both, or do/teach medical or scientific illustration. Science illustration can be 2D or 3D or animated so lots of choices If you are, I think there's a very good group to join for scientific illustrators but I'll need to find that group again. Just my two cents...
There is no saying that you cannot do both. You're still in school - that means that, hopefully, you'll have at least forty more years left of your career, which if you work hard is plenty of time. I would say Neuro since it is a lot more difficult to get into that path than it is to join art classes - not saying it is easy to become a professor of art, but if I took a quick guess I would say it is a lot more difficult to become a professor in neurobiology.
And hey, if you DO become a professor of neurobiology and then take the art classes, you will have better understanding than most neuros about the way art affect the brain. I'd say that is stuff that needs a lot more mapping out.
Whatever you choose, though, make sure to go for it.
Art school can't really do crap for you. If you're going to be an artist you have to have a good market/demand for the work you do. For example my friend is a wonderful artist so she's using that to get into advertising as a career because she is artistic and creative. That way she has found a good demand for her skills. Go for Neuobiology and try to minor in art.