You used to be able to do it by viewing the app's description and scrolling to the bottom under WHAT'S NEW. Now, you can't even do that.
I'm not sure if I feel comfortable turning on auto-updates without knowing what each update adds or fixes, especially when, for example, NVIDIA has shipped bad versions of its NVIDIA Games apps before. In fact I'd like to disable that giant text entirely.
click the text/app description above install button