<p>Most people don’t double major. I know one girl who does, who has more energy than 3 average people. 
Besides double majoring, you could minor in something else, or use your electives to explore other stuff. </p>
<p>Neuroscience is a pretty hard major–up there with physics, math, chemistry, cognitive science, that sort of thing. You will need to know a lot of raw information, and even more concepts. Some concepts are pretty tricky–not intuitive.</p>
<p>As far as applicants, I have no idea how many people apply. I will tell you that just about any time anyone asks me what my major is and I say “Cognitive Science/Neuroscience” I get a really funny look of bewilderment. So I don’t think there are too many–but it is rumored to be hard to get into nonetheless. One tip: if you don’t have every singlelast prerequisite, Dr. Hill (who is a really great guy) will let you take them at the same time as the Major. (You know, if you have the wrong Calculus, or no Chemistry or something like that.)</p>