Yes, we still dream. As far as nightmares go, they're almost not existent anymore. When I was a kid, I'd have a nightmare every two weeks. Being an American, it was often about Indians surrounding our house and shooting away and things like that, but with this practice dreams do change. Sometimes there's the ability to know what you're doing inside the dream and actually wake yourself up if it is what would become a nightmare-type dream.
Personally, I had one dream where I was supposed to die twice, and in the first part I simply recognized I was dying and started doing some Compassion/Lovingkindness meditation. I was in a truck that was crashing. It went down into a body of water and I wasn't dead yet. The truck then went deeper into the water and I realized I was going to drown. I wasn't just going to die from a truck crashing, but I was going to drown. So I went back to doing my Compassion/Lovingkindness meditation. I woke up without any fear. It was a lovely dream to have.
I'm not saying that in a sense of building myself up; it's just that that's what does happen for people who have developed more of a Compassionate/Lovingkind attitude in their daily life. It's going to carry over into their dreams. It's just a matter of Law of Cause and Effect. So, in particular, if you happen to have a lot of nightmares, then, yes, you would like to develop more Compassion/Lovingkindness in your attitude during the day. You also have to stop unwise thoughts coming into your mind such as violent movies, of course, and other things like that.
In this type of practice, we're not trying to blank our minds. We're trying to purify our minds. There's a difference there. If you want to blank your mind, there are a lot of ways to do it in ordinary life. You can be listening to a song and just get lost in the song. When playing music, a lot of people are one with the music. This can even happen playing sport. With art, people who are painters can get lost in their art, absorbed in what they're doing. People who read a book can get absorbed and everything disappears from their mind. Meditation concentration practice is to get everything out of the mind, but as soon as you're done meditating that way, everything is back into your mind. In the type of practice we're doing, which is properly called Vipassana in Pali, we're purifying the mind. We're not emptying it. We're not getting rid of thought; we're just purifying thought. Instead of angry thoughts, we have loving thoughts, instead of restless thoughts, we have calm thoughts, and so on.