I can feel the rising and falling of sensations in vipassana, but what to make of thoughts?

There are two things I want to understand here. Firstly, though I'm not overly disturbed by thoughts during vipassana sitting, I just don't know how do I treat them. What I presently do is just try to ignore them and continue observing the rising and falling. But if the thoughts are too strong and persist, I tend to observe them impartially until they leave of their own accord (but during this time my observance of anicca has stopped). Am I doing this thing rightly or not? Secondly, I want to understand the *reality* of thoughts. I know that ultimately none of these have permanent reality, but compared to conditioned reality of sensations what is the conditioned reality of thoughts? Basically, I want to know whether they have any objective reality, or they are subjective (just things in my head)? I recently read in a book that reality keeps vibrating each and every instant, and we need to look into the arising/vanishing of these vibrations, as that is what anicca is all about. My question is do these vibrations apply to thoughts as well or just sensations?