I'm working on a large, content-heavy website with multiple levels of navigation and was having a discussion with the designer about selected states in navigation. She said that since we have breadcrumbs at the top of the page, it's unnecessary to show a selected state on the main navigation item, since the breadcrumbs can help orient the user to which main nav section they're in. I agree with her, but wanted to see if there was any recent research out there around this. I feel like this was a best practice awhile ago that has fallen out of favor in more modern designs.
So, what are your thoughts: is providing a visual change of selected state to the user still necessary?