First off realize that these days it's hard to find a career that does not involve computers in some fashion, and if you have an aptitude and interest in computer software or hardware you're likely going to find ways to utilize it regardless of what you study.
In my current job, which is full of highly skilled computer folks, the educational backgrounds of my co-workers span the full spectrum. Two are linguists, one studied music, a bunch are various types of engineers. I'm an aerospace engineer originally. So this is to say, your choices today aren't going to pigeonhole you into a specific career. Indeed, you may well not know what career you're going to end up in, until you're out of school and through one or two jobs.
Second, who says you're going to have only one career? Pick one of the things you're most passionate about right now, and delve into it. 5-10 years of working experience later, maybe you decide that you don't actually like abstract research and want to get to something more hands on (or vice versa).
But one thing you might want to consider right now is, how much education do you want to get? For software engineering a simple 4-year bachelor degree is likely going to be quite sufficient, but for neurology and especially physics some post-graduate education might be necessary. Will the difference in salary, type of work, or etc. be worth the time and money for getting the additional education?
Finally, I should think that the particular combination of neurology, physics, computer software, and computer engineering do indeed meld into a specific career field: Robotics. This is a very active field these days, both academically and commercially. Check out if your university has any robotics hobby groups that'd let you dip your toes in to see what the field's like.