How Senses Affect Linguistic Communication pt 1

I used my adoration of philosophy to fuel my research into linguistics of the deaf and blind. As we generally think in words, I often wonder how blind people think, or if those who are deaf think their thoughts in hand signals. I wonder too, what people who are blind from birth see when they dream.
It's strange - when we think in words, we do not tend to visualise the word. If deaf people think in sign language, must they visualise it to think it? Does it become second nature to think that way, and they do not neccessarily need to visualise their thoughts? If blind people dream, do they dream in words, and sounds and music? If so, do they dream in touch, taste and smell too?

I plan on doing a lot more research into the linguistics of sign, specifically, but also the communication of those who can't see.
For both the blind and the deaf, how does their inabilities affect their process of language? And how to their other senses compensate for their inabilities, and their need for communication?