Their finding is part of wider realization in the neuroscience community, that our brain does not simply react to what comes in through our senses. Instead, we have a predictive brain, that permanently predicts what comes next. The expected sensory input is then suppressed. We see the world from the inside out, rather than from the outside in.
Based on all this, we suggest that the function of dreams resides in their waking use – how they enable self-disclosure, for the benefit of the group, even if it can sometimes be uncomfortable for the individual. The remembering and telling of dreams is thus essential to their evolved function.