We often wake up with a fleeting sensation: we just had a dream, but the details quickly dissolve. Why does this happen? According to neuroscience, forget your dreams it is a natural process linked to the functioning of the brain during sleep. The key to the mystery lies inactivity of some brain areas and in the mechanisms of memorywhich go into “sleep mode” during sleep.
The neuroscience of dreams
THE’hippocampus it is the central station of our memories in the brain, the one responsible for sorting dreams and allowing us to remember them. Right during the REM phase (Rapid Eye Movement“rapid eye movements”) the hippocampus has areduced activation. His “part time” job means that many of the things we dream do not go through the memorization process that we usually have fully functioning when we are awake. During the day, in fact, the hippocampus tirelessly archives new information, transferring it to long-term memory, which is widespread in our cortex, in particular that of the frontal lobe. At the same time, many too neurotransmitters with an essential role in the consolidation of memories undergo significant decreases during REM sleep. This is the case of serotonin and of norepinephrinethe reduction of which compromises the ability to store dream information. Lastly, also the prefrontal cortex drastically reduces its activity during this phase. The prefrontal cortex is responsible for rational thinking, but also for formation of memories and their effectiveness conservation. On the contrary, the limbic systemor the deepest and oldest area of the brain that processes emotionsshe is very active! That’s why I often dreams I’m like that emotionally chargedbut also less structured, bizarre and absurd. Often lacking logical and temporal coherence, it becomes further difficult for us to remember the development of the stories
What happens in the brain when we wake up
The transition from sleep to wakefulness is a crucial moment that will decide how much of our nightly dreams we will be able to remember when we open our eyes. During awakening, the brain it goes by quickly from low to high activity. Studies show that those who do wakes up during or near REM sleep greatly increases the chances of remember the last dream had, compared to those who wake up in other phases of sleep. However, precisely due to the suddenness of the transition from low to high brain activity, memories fade quickly, and without being called back verbally or transcribed on a sheet of paper, they risk disappearing forever very quickly.
Why some remember dreams more and others less: neurological reasons
The ability to remember dreams it is not the same for all of us. Some people have a greater ability to remember, precisely because i activation levels of the hippocampus and frontal cortex, as well as neurotransmitter levels, during REM sleep are slightly different from individual to individual. Consequently it is easy to understand that the genetic predispositionsbut also the habits related to sleep, the regularity of circadian rhythms and how disturbed our sleep is. External factors such as stressthe exhaustion and the hiring of substances like drugs or alcohol, they influence REM phase activity very often by suppressing or severely limiting it, consequently reducing the probability that our brain generates dreams.
