In scientific studies it has been discovered that the brain stays as active in the sleep state, as it is in awake state. But in the sleep mode neurons are acting in a more synchronized way. The REM (Rapid Eye Movement) sleep is the final stage of our sleep cycle, so that explains why early morning around 3 to 4 AM is a good time to have these experiences. Further the pre-frontal cortex, that deals with logic and self-control, is not very active during the dream state. During REM sleep, our muscles become temporarily paralyzed, to prevent the body from acting on the dream stimulus.
In meditation our primary goal is to reduce or eliminate the normal chatter in our brains so that it can be turned into a sophisticated instrument of perception. Further we are trying to lose body consciousness, in order to maintain deep focus. The scientific description of the sleep state seems to satisfy all our needs except that we are trying to maintain complete consciousness, which means that pre-frontal cortex needs to be active, so that we can control our dream state. So it should be probably straightforward to verify the fact that a dreamer is leveraging his dream state to do conscious work.
When we move to the contents of the dream, there is no single accepted theory of why we dream and what is the value of the dream. One theory says that the dream reflects our emotional state, for instance after a traumatic event, we may get intense dreams that reflect the emotional state in that event. Another theory postulates that dreams help us store memories. There is no clear and proven theory of why the dreams occur although the parts of the brain involved in dreaming have been fairly identified.
I would encourage us to think much broader than these rather limited and conservative theories. I have specifically experimented with this state in many ways and believe that the state contains much more possibilities. For instance, in one of these sessions, I focused on a technology company which was hiring at senior levels, trying to get some information about the existing leadership and check if I had a chance to get in. I was shown two individuals who I knew could not have been part of the executive team, since I knew most of the executive team. I did a quick search on linkedin and found that those two persons had very recently joined the company. The dream not only described the names of those two people to a good accuracy level, it also provided glimpse of their personality and my familiarity with them, one of them I had worked with before and second was unfamiliar. Scores of such successful experiments were a huge motivation for me to continue moving forward on this rater unconventional journey.