There are lots of people who can’t remember their dreams, and it’s kind of strange that we can’t recall something that we do almost every single night. We are asleep about a third of our lives and dream at least 25% of that time.
Most of our dreaming occurs during a stage of sleep called Rapid Eye Movement or REM. In this stage, as the name suggests, our eyes move around, but the rest of our body becomes paralyzed. That may seem terrifying, but it stops you from acting out your dreams which could have some severe consequences like you falling off your bed or flying into the Sun.
But dreaming isn’t limited to just REM. Dreams have been reported even when the sleeper had an only non-REM sleep, and even if a person gets an average amount of REM sleep lesions in their temporoparietal junction and medial prefrontal cortex are associated with a loss of dream recollection. But luckily most of us don’t have that problem.
So then why do we forget most of our dreams? Well, as we talked about in our video about why we forget things, humans are really good at filtering out information that doesn’t matter. If something doesn’t grab our attention or isn’t essential to know, you don’t remember it.
Think about the stream of consciousness you have when you’re making breakfast in the morning; chances are you can’t recite it back. And some scientists think the same is true of dreams, but perhaps there is a neurological difference between those who recall most of their dreams and those who do not. To test this, researchers study the brainwaves of both types of sleepers. They primarily studied alpha waves, between 8 to 12 Hertz which are also present when you are awake. Interestingly oscillations of these alpha waves are associated with inhibition, meaning that a decrease in amplitude would correspond to a release in inhibition and therefore increased excitability.
So let’s relate that back to our dreams while the volunteers were awake. Tones were played in their ears along with occasional and random first names. Those who recall their dreams four or more times a week had a more sustained decrease in their alpha waves compared to those who only recall their dreams once or twice a month.
In other words, the high recalling group had a deeper processing of the first names while they were awake. However, this difference was not there during REM sleep. Instead, the alpha waves increased possibly causing the volunteer to wake up. In fact, the main difference between groups was that those who recalled their dreams often woke up more throughout the night. This led scientists to believe that the time awake allows the dreams information to be encoded into long-term memory allowing the sleeper to remember at the next morning; more time awake, more time to store the information. Makes sense right?
But before we can say anything conclusive, we need more research, and we are just at the tip of the iceberg when it comes to our knowledge about dreams.