People who are in a deep slumber may not be able to say whether they're dreaming, but their brain waves might. In a new study, scientists say they can predict whether people are dreaming by looking at the brain activity in a region at the back of the brain, which they dub the posterior cortical "hot zone."  "Monitoring this posterior 'hot zone' in real time predicted whether an individual reported dreaming or the absence of dream experiences … suggesting that it may constitute a core correlate of conscious experiences in sleep," the researchers wrote in the study, published online April 10 in the journal Nature Neuroscience. Read more