From ancient civilizations, where Greeks and Romans believed that dreams had prophetic powers, to the famous Sigmund Freud and his student Carl Jung with theories that are still applicable in modern society, the reason why people dream and what dreams mean has been a long-time question for humankind.
Since then, the advancement of technology has aided the development for other theories. One that is dominant is the neurobiological approach, where the theory of “activation-synthesis hypothesis” came to place. This theory believes that dreams do not have a definition, in other words, that dreams are meaningless. Instead, dreams are simply electrical impulses of the brain, which pulls thoughts and images from memories in a random manner. In this theory, as humans wake up, they try to make sense of the dream. However, another popular approach of evolutionary psychologists believe that dreams have a purpose, one of the prominent theories being the “threat simulation theory”, which suggests that dreams is a form of ancient biological defence mechanism, and it provides an evolutionary advantage due to its repeated simulation of potential threatening events. In theory, this would enhance the neuro-cognitive mechanisms required for efficient threat, such as avoiding the threat, and how the threat is perceived by the mind.
There have been previous studies which have shown that the memory of dreams are generally enhanced if woken directly after REM sleep, though a recent study has shown that those who have low frequency theta waves in their frontal lobes also remember their dreams quite likely too. This was particularly interesting because researchers have also found that an increased frontal theta activity looks identical to the success of encoding and retrieval of autobiographical memories seen when one is awake. In other words, neurophysiological syndromes humans employ whilst dreaming is identical compared to whilst awake.
Another recent study used the MRI imaging technique in order to investigate the relation between dreaming and the role of deep-brain structures. The study showed that vivid and bizarre dreams (what people typically tend to remember) engaged activities in the amygdala and hippocampus; both parts are linked to emotions and the storage and processing of memory. This connection between dreams and emotions has been revealed further by another study in which scientists discovered that a reduction in REM sleep, or dreaming less, influences the ability to understand complex emotions in daily life. Furthermore, scientists have identified where dreaming is likely to occur in the brain. However, someone who suffers from a syndrome named “Charcot-Wilbrand Syndrome” (the loss of ability to dream) suffers from no other effects.
By piecing these information together, a conclusion can be drawn in which dream aids with encoding and constructing memories and emotions. Though dreams can show both the reality as well as something that is not real, the emotions within them are definitely true. Essentially, dreams try to strip emotions away from an experience, by creating a memory of it instead, which allows the emotion to no longer be active. As bizarre as that may sound, it is vital in stripping away negative emotions, which is a reason why people who sleep earlier tend to be happier than those who sleep less, as those who sleep earlier tend to dream more. This also explains why the deprivation of the REM sleep can lead to severe mental disorders. All in all, dreaming helps in bridging the gap and connects experiences to memories and emotions.
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Written by: Erin Zhang
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References:
Linden, S. V. D. (2011, July 26). “The Science Behind Dreaming”. Scientific American.
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