Most people I know have experienced this phenomenon: a startling dream wakes you up from a deep slumber and then within seconds you forget the dream that caused you to wake up in the first place. But this scenario doesn’t play out for everybody. Some people CAN remember their dreams while other CANNOT. To figure out why this is true, researchers devised an experiment that used electroencephalography (the measurement of electrical activity in different parts of the brain). The experiment involved 36 adult subjects who were sleeping while their names were being called out to them. Out of those 36 people, eighteen remembered their dreams while eighteen did not. The ones who remembered their dreams are known as high recallers , and those who did not are referred to as low recallers.

Why does this happen? Why can certain people recall their dreams while others cannot?

Current research points to brain variations. More specifically a decrease in alpha waves; Alpha waves are neural oscillations in the frequency range of 8–12 Hz. In addition high recallers use different parts of the brain while dreaming. Alpha waves work in opposite ways between high recallers and low recallers. Researchers also determined that high recallers woke up while sleeping more often than low recallers did.

One popular theory for why we forget dreams is related to “neurochemical conditions in the brain that occur during REM sleep”. REM sleep is a stage of sleep that involves rapid eye movements. One cause of these “neurochemical conditions” that result in the forgetfulness of our dreams is the absence of norepinephrine (a hormone) from the cerebral cortex (the part of the brain that processes sensory information).

There is also another school of thought of why certain people forget dreams although it is not supported by many people. The explanation: dreams are nonessentials memories and humans have a hard time remembering nonessential things.

The answer to this question is quite controversial and scientists have yet to come up for a concrete explanation of this phenomenon.- Post Written by Yash Banga

Sources:
https://www.livescience.com/38856-why-people-recall-dreams.html

https://mentalfloss.com/article/558092/why-some-people-cant-remember-dreams

https://www.scientificamerican.com/article/why-do-memories-of-vivid-dreams/