Dreaming – does it necessarily have a purpose?

  In his recent work Antonio Damasio has argued that the brain has evolved primarily as an organ for representing the body in its social and physical environment, and projecting that representation forward into the future.  The representation of the body Damasio writes about is story-telling, dynamic not static. Other researchers argue that a primary function of consciousness is to consider the potential outcomes of alternative actions as a basis for making decisions.  These ideas together suggest that the stories we invent in our dreams – both daydreams and sleeping dreams – are an extension of the process through which we represent and project forward our body’s physical and social presence.  

In “When Animals Dream” Peña-Guzmán argues that animals actually experience their dreams, and takes it as evidence that animals have some form of conscious experience, though the quality of that experience is likely to be quite different from that of human consciousness.  

I think it is reasonable to extend Damasio’s account of mental representation to dream behavior in both humans and other animals.  Perhaps, as Peña-Guzmán and others argue, dreams provide a way of consolidating mental representation, rehearsing behavioral responses, or both.  But it is also possible that the dream behavior is simply a continuation of forward-projection, disconnected from actual sensory input, so drawing its substance from random fragments of memory, sometimes but not always including memories of recent (e.g. yesterday’s) experience.  If that is the case, dreams may be simply an epiphenomenon, lacking any function at all - sometimes disturbing, sometimes entertaining.