What function do dreams serve in evolutionary terms? a warning a reminder a stubborn refusal to forget a way of keeping past fear close? terrible, terrible dreams. http://www.epjournal.net/filestore/ep035978.pdf " Threat Rehearsal When awoken abruptly from a terrifying nightmare, it is easy to understand the strength dream imagery has in generating both physiological and cognitive responses. In the case of a nightmare, heart rate is accelerated, sweating occurs, and a general feeling of fear and anxiety can extend for some time after the dream has finished (Mellman et al., 1985). Even though dreams are a form of mental representation, in the sense that perception is not tied to stimuli in the environment, they are generally experienced as real and the content is perceptually indistinguishable from waking perception (Freud, 1900). If merely imagining an event has the power to better prepare us for an actual event by physically acti...