What causes dreamers to accept dreams as reality? I have long had interest in dreaming, and one of the defining features of ordinary dreams is that the dreamer either accepts the dream as "real life", or does not question the surroundings.

Compare these ordinary dreams with "lucid dreams", or conscious dreaming, where the person is aware of the fact that he/she is dreaming. Within an ordinary dream, a person "goes with the flow", while within a lucid dream, the person can think clearly and act voluntarily without waking up.

Have these been any studies that used fMRI or other techniques to try to determine what is it within the human brain that causes the distinction between conscious and ordinary dreaming?
If you are searching specific part of the brain, I think that frontal regions of cortex will be an answer(In particular, the dorsolateral prefrontal cortex which was associated with self-focused metacognitive evaluation). But, as it common in real life, becoming aware of dreaming state required coordinated work of different parts of brain.
You can read this very good article and wiki of course.


  Lucid dreaming is characterized by a regaining of higher cognitive capabilities, eventually leading to the awareness of the dreaming state. Recent quantitative EEG data have shown that this wake-like intellectual clarity is paralleled by neural activations in frontal and frontolateral regions. Likewise, PET data show cognitive control in dreams to be associated with activation of frontal cortex components. via