Oftentimes when we sleep, we find ourselves in a dream state. Scientists still aren’t completely sure why we dream or what dreams mean, but there are many theories revolving dreams which are currently being explored.

One of the theories is the “activation-synthesis hypothesis,” which states that dreams actually have no meaning to them, but are instead a medley of pulled thoughts and memories fed to our brain during sleep through electrical brain impulses. However, evidence shows that dreams actually do have purpose, which is where many theories of dreams stem from, namely the “threat simulation theory”. This theory suggests that dreams are a defense mechanism which roots back to the start of civilization, giving those who had them an advantage because they were experiencing the stimulus of real world problems in their dreams, exposing them to it and allowing them to be equipped for these situations.

Another theory revolving around why we dream is that dreams are a biological response to life experiences. This may explain why certain people dream about their fears or specific situations which correlate to different aspects of their lives.

Either way, dreams work by allowing the cortical parts of the brain to be active without the body responding actively to stimulus as it would when one is awake. The reason dreams seem so vivid and real, is because although these sensory receptors are inactive while we are asleep, the parts of the brain which accept and respond to stimulus are active.

One of the parts of the brain which isn’t active during dreams, though, is the prefrontal cortex, which is the part of the brain that is associated with higher order thinking. This explains why dreams sometimes do not follow the normal rules of reality, such as gravity, because the part of the brain which makes things logical is not working.

Furthermore, it is proven that everyone dreams about three to six times per night; however, not everyone remembers what they’ve dreamed or even that they’ve dreamed. As for why dreams are remembered on some nights but not the others, the reason may be due to which sleep cycle you’ve woken up on that day. Out of the two cycles, REM (which occurs during deep sleep) and Non-REM (which occurs during early hours of sleep), those who wake up during the former cycle are more likely to remember the context of their dreams.

Although we do not know much about dreams, what we do know of them is fascinating, and as we advance into a future of technological advancement, hopefully there will be a potential for more studies done in the field to further the scope of knowledge there is on this subject matter.