Question

Should I do my honours in neuroscience, physiology or pharmacology?

Answer 1

What's ur interest?

Answer 2

That's the thing, I think I'd like to do something on autism for the project but other than that it's all good

Answer 3

Then, do in physicology

Answer 4

I second what Aadarsh said (in his first comment). Follow your heart. We can't make this decision for you.

But I'm not sure if physiology is necessarily the best choice. It might be, but ONLY if that's what you're interested in. You can approach autism from many different angles, and the right one will be the angle from which you can work to your full potential.