Of course they vary from subject to subject, but in most cases there:
a) Wouldn't be enough time to devote to a single topic like that
b) Will already be, to some extent, a pre-determined structure to the interview, and unless they're aware of the reading you've done/particular interest you have, then they won't have factored this into their plans
Did you mention it in your personal statement at all? That's generally the place to put any wider reading, and then the tutors have the option to ask you for expansion if it's desired.