Lucid dreaming is an unusual phenomenon in which some people are able to "wake up" while still in a dream. Though the dreamer is technically asleep, they are aware of their situation and are able to control the content of their dreams. In this state, people are also able to signal to researchers that they have entered a lucid dream through a series of prearranged eye movements; no other movement is possible during REM sleep.
Being in command of dreams opens up opportunities to manipulate them for learning and training that have an impact once the dreamer wakes up. Peter Morgan at Yale University and colleagues have shown that lucid dreamers perform better in a gambling task designed to test the functioning of the brain's ventromedial prefrontal cortex, which is thought to be involved in emotional decision-making and social interactions (Consciousness and Cognition, DOI: 10.1016/j.concog.2010.08.001). By training this region through lucid dreams, Morgan hopes to be able to improve a person's social control and decision-making abilities.