Dream and motivation: a psychobiological approach

Several lines of evidence point to the dream as a mediator of incentive phenomena. We review herein evidence from ontogenetic studies of the pleasure reaction, phylogenetic studies of the evolution of intelligence, studies of brain stimulation and recording, and clinical observations. These all suggest that it is possible to identify an evolutionary specialization of pleasure that (a) has served to mediate cognitive phenomena and (b) that the pontine noradrenergic locus coeruleus nucleus and its projections may play a role in this mediation.