Note: This is one of a series of articles in the Mind and Brain section of The Box Move issue 1, which deals with the newer areas into which classic psychological mysteries have gone. Here, Mahd Tauseef delves into one of the most elusive aspects of psychological research: dreaming. For more on Mind and Brain, check out issue 1 here, or head to our affiliate Brain Talk run by the Editor of the Mind and Brain section for issue 1. Contact us if you want to contribute to this section for Issue 2!
Ever since the beginning of mankind, the phenomenon of dreams has captivated our race. Our curiosity of the unknown has pulled us towards this subject and our irrepressible need to formulate explanations has lead to a myriad of theories being laid across the table. What are dreams? What is their significance? The ancients linked dreams to divinity; dreams were the messages from beyond. Later on philosophers and psychologists struggled to find a ‘scientific’ answer and it was Sigmund Freud who came up with the first major dream theory; dreams were the portal to the unconscious. However, with time as psychoanalysis lost steam, more contemporary theories surfaced and soon two vastly different ideas emerged as the leading contenders for the true explanation. The first of these is Hobson’s and McCarley’s Activation-Synthesis hypothesis stating that dreams are the result of random neural activity and the second is the evolutionary theory of dreams which suggests that dreams help us to perform better in our lives. In this article we investigate these two ideologies and try to determine which of these theories trumps the other.
Before we start on this analysis it is note-worthy to first realize why an explanation of dreaming has eluded mankind for so long. The dream state is a vastly subjective and personal experience that varies considerably between individuals. While some of us may have vivid dreaming experiences with detailed visual imagery and clarity, there are many who fail to remember but the very superficial themes of their dreams. With dream dynamics being so fluid it was inevitable that a multitude of explanations emerged as each researcher’s view on dreaming may be influenced by their own experiences of dreaming. Moreover, it is extremely difficult to perform experimental studies on dreaming for a number of factors. For one, there is no way to induce a dream to occur and the dream content can’t be varied on will which means there is no independent variable to manipulate. Secondly, these experimental studies rely a lot on introspection and thus lack objectivity. The researcher can’t view the dream as it unfolds and the dreamer can’t narrate it either. Dream accounts must therefore come once the subject is awake and since many people tend to forget their dreams, the accounts often consist of pieces that were remembered, while a significant chunk of data is lost. Perhaps, with developments in current fMRI technology dream imaging may improve enough to solve this problem and so yield more information on the dream state. Until then scientists have little to work on which is why a concrete dream theory has not emerged.
This theory has been popular for quite some time because many people can easily relate it to their own personal dreaming experiences. It attributes the bizarreness of dreams to the brain’s efforts to link up information that is in essence, quite random. This also fits well with the known neuro-scientific phenomenon of confabulation – the process by which the brain unconsciously fills up gaps in memory to make coherent sense out of bits of information.
However, this theory raises a lot of questions and has been criticized as vehemently as it has been supported. For one, it begs the question as to why dream research should be carried out in the first place if it is such a useless and random process. Moreover, Domhoff through his extensive statistical research has shown that dream content isn’t totally random. In fact, many individuals regard their dream states to be realistic and to be following a roughly continuous storyline. Individuals also often dream of recurring themes which does not tie in well with the randomness of dreams as suggested by Hobson. Solms, through his recent research also discovered that patients who had lesions on their pons (see diagram below) could dream just as well as normal people. Solms discovered that forebrain, rather than the brain stem was the crucial ingredient required for dreaming. All this suggests that dreaming is not totally random and Hobson’s hypothesis cannot on its own present a satisfying solution. On contrary, the fact that dreams often revolve around recurring themes suggests that dreams are anything but random.
For this theory to hold two things must first be true; first, that a high percentage of dreams must revolve around a threatening situation and second, that whatever we experience in the dream state must confer an actual advantage when facing a similar situation in the real world. It turns out that both of these have in fact been supported by different research. Statistical analysis of dream reports by Hall and Van de Castle has shown that around 80% of dreams contain negative elements. They have further shown that these 80% of dreams often contain threatening scenarios such as hostile strangers or being chased by animals. Such high correlation shows that dreams are truly not random. Secondly, research on mice has shown that REM sleep does help in real life scenarios. In such experiments, mice were first taught a maze and then allowed to sleep. One group of mice was allowed to sleep uninterrupted and it was observed that during REM sleep, the same neural pathways were being activated more frequently that were active while they were running through the maze. The other group of mice was allowed to sleep an equal amount but was woken up every time they were going into REM sleep. When the two groups were run through the maze later, the mice who underwent REM sleep remembered the maze better.
Similar research on humans involving reaction times has yielded similar results. Much support has come for this theory from experiments involving lucid dreaming – a dream state in which the person is aware that he is dreaming and that his real self is asleep in bed. Lucid dreaming gives the dreamer a greater power to manipulate his or her dreams. This has allowed researchers to somewhat control the dream state by asking the subjects to do a particular task while dreaming. Measuring of brain activity of lucid dreamers has shown an increase in left hemisphere activity when they count in a dream and an increase in the right hemisphere when they sing which is what would be the case if they were awake. Athletes have also been known to practice their tennis serve or golf stroke through lucid dreaming. All of this suggests that things learnt in dream-state are carried over to the real world. So, in a nutshell, what Revonsuo theorizes is that our ancestors who were better dreamers were better able to prepare for threatening scenarios, for example, eluding a tiger, and so they were naturally selected.
So in conclusion, dreaming is still a mystical phenomenon. Both the theories that have been laid above appeal to our intuitive self but do not give a complete picture of the mechanism behind dreaming. While Hobson has effectively explained the bizarreness of dreams, Revonsuo has provided to us an explanation for the regularity of dream themes. Perhaps the true explanation is an amalgam of the two. For instance, it is possible that the stimuli that originate in the pons is not just random noise but gives us an evolutionary advantage. This ‘noise’ may enable our dream states to achieve more variety, or in other words to simulate more varied threat scenarios, instead of just repeating the same dream over. However, that still leaves the paradox unanswered; if dreaming is of evolutionary significance, then why don’t we all remember our dreams? Could it be that their remembrance is unnecessary and just the rehearsal in the dream does the trick? And what about the dreams that are positive? Are they there just by accident? There are many questions that still need answering before we can truly unravel the realm of dreams. Perhaps, with improvements in brain imaging researchers will have more quantity of objective data to work with. Until then we can only speculate.
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