You might have noticed that you don’t always remember your dreams. On some nights, you can have incredibly vivid dreams that you easily remember when you wake up. On other nights, you get out of your bed without having even the tiniest fragment of a dream in your mind. Why does it happen?
Why don’t we remember our dreams? It happens due to our brain’s mechanism that controls remembering and forgetting and the way it works during sleep. It turns out that our brain deals with dream recall in a similar way it deals with memory recall. This is supported by a recent study by Luigi De Gennaro, professor at the University of Rome, and his team, who used an electroencephalogram to monitor the brain activity of students as they slept.
The experiment involved 65 students: 30 who usually wake up during REM sleep (the stage of sleep when the eyes are in a rapid motion), and 35 who usually wake up during the second stage of sleep. Approximately, two-thirds of both groups remembered most of their dreams.
Those who woke up during REM sleep and remembered their dreams were more likely to have brain oscillations of the type called Theta. This type of brainwaves occurs in the regions of the prefrontal cortex and we rely on it when we are thinking about something. We also use theta brainwaves when we are trying to recall a memory when we are awake.
Those who did not wake up during REM sleep but during the second stage of sleep and could remember their dreams had brain oscillations of Alpha type in the prefrontal lobe. These oscillations occur when we see or feel something that stimulates us emotionally when we are awake.
So, in conclusion, De Gennaro emphasizes that when we sleep, the brain activates the same parts that we use in the awake state. The scientists concluded that when the parts of the brain responsible for emotions were activated, then the students managed to remember their dreams in more detail.
This could explain why we remember some dreams so well as if they were real and completely ignore some others. You are also more likely to remember an intense dream or a creepy nightmare because this kind of experience would trigger the brain regions responsible for emotion processing. Why don’t we remember our dreams? In the end, it all comes down to our brain activity.