Spending approximately one third of our life sleeping, many of us would have experienced all sorts of dreams in our life time: boring ones, weird one, scary ones, exciting ones, etc. In fact, dreams are so common that we often just ignore and forget about them after waking up. Yet, why exactly do we dream? Are there any significance of dreaming?
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Dreams are produced during the rapid eye movements (REM) phase of sleep. At this phase, the brain activities of the sleepers peak and their eyes would move rapidly and randomly. A normal person would generally experiences 4-5 REM phases during each night, which sums up to a dreaming time of about 90-120 minutes of the time asleep. There are several theories of how REM contributes to dreams. One of them is that the directions of the eye movements mimic the eye reactions of the dreamers in their dreams. Another theory hypothesized that the rapid eye movement stimulates the neural junctions in our brains that are inactive while we are awake. Whether or not REM functionally contributes to dreams do not have enough evidence yet. However, it is confirmed that dreams occur during REM.
Current research has found that dreaming may benefit us both neurologically and psychologically. For the neurological aspect, the Continual-Activation theory is hypothesized by Jie Zhang, stating that dreams trigger the transition of short term memory to long term memory. It is also hypothesized by Crick and Mitchison that during dreaming, the brain would sift through ideas and information, and dispose unwanted ones; this is called reverse learning. Both of these theories do not have enough evidence to support them yet, and are therefore controversial. However, there are many experiments that show the positive relationship between learning (memorization) and REM activity (dreaming). Some of these experiments are mentioned in the following clip, which is an interesting introduction of the science behind dreaming:
For the psychological aspect, Coutts hypothesized that during the different scenes in the dreams, the emotional reactions of the dreamer would be sieved. The emotions that are adaptive to the scenarios would be retained while those that are maladaptive would be eliminated. In short, dreamers learn how to emotionally deal with social situations by going through them in the dreams.
Image by: Aupneet Boparai
To summarize, dreams occur during the REM phase of sleeping. There are numerous theories indicating how dreams benefit us neurologically and psychologically. Yet, dreams are very abstract; they are not objects that can be quantified or qualified. Therefore, it is very hard to find evidence to back up these theories. Nevertheless, scientists would continue to study dreams, and hopefully, can decode the science behind this mysterious phenomenon in the near future.
