'Everybody wants to believe they're clairvoyant and psychic': Neuroscientist explains the human brain when you're dreaming

Neuroscientist and TED speaker Sarah Baldeo explains how dreaming occurs in the human brain on CTV Morning Live Edmonton.

 

This transcript has been edited for length and clarity.

 

Kent Morrison: Well, it's something mostly everyone does every night, but rarely do we remember what happened, or understand what's going on inside our minds. It is dreaming. Sarah, what exactly goes on in our brain when we're dreaming?

Sarah Baldeo: The interesting thing is, a lot of people think they fall asleep and they start dreaming right away. This is not what happens. Dreams only occur in one cycle of sleep, and that is the rapid eye movement cycle, or symptoms of the REM cycle. You've got to go through three stages of sleep before you even get to REM sleep, and then your brain activity starts to switch. There's five key areas of your brain that are active during this period. The first is your brain stem, which actually paralyzes your muscles, which is important when you're sleeping because you don't want to be sleepwalking. The second is your amygdala, which is why dreams feel so emotional. The third is basically activating your memories, your short-term and long-term memories, that's the part of your brain called the hippocampus. The fourth is why we have these lucid dreams that seem so real, it activates your vision centre or your occipital lobe, which is bizarre because it's the back of your brain. Then finally, your prefrontal cortex, which is right at the front of your brain, becomes significantly less active when you're dreaming, and that's why sometimes dreams don't make sense.

Kent: Very interesting, that everything is so active. Why do we dream it all?

Sarah: The purpose of dreaming is for you to make sense of your waking life and to process your emotions. From a physiological perspective, what your brain is doing is it's purging these chemicals called neurotoxins that accumulate throughout the day. As I said, you can't dream unless you get to the REM cycle, which is why it's not just the quantity of sleep that's important, but the quality of sleep. So you can start to purge those neurotoxins as you're dreaming and that's why dreaming is so important.

Kent: Do our dreams mean anything?

Sarah: I get this question a lot. Everybody wants to believe that they're clairvoyant and they're psychic. From a scientific perspective, dreams only mean something in terms of looking for patterns in your waking life. That's what your brain is doing, it's processing data, it's looking for patterns. If you have a dream and then it comes to fruition in real life, try to look at the statistics of how many times you have a dream, and nothing happened (or) something happened and you didn't have a dream. You're just experiencing something called confirmation bias, which makes you believe that your dreams are predicting the future. They just mean that you're looking for patterns.

Kent: OK, that's interesting to know. Now, there's new technology that can record dreams for playback. Is this a good thing or a bad thing?

Sarah: I think it's a fascinating thing. In Kyoto, Japan, researchers have found a way to use artificial intelligence algorithms and functional magnetic resonance imaging machines. Basically, they're taking pictures of your brain, they're looking for patterns in the neural activity, and then it plays back for you, kind of like a movie. I think potentially, this is just too nascent in technology to say, “how does it impact us?” (and) “What happens when we're watching our dreams?” It also doesn't account for the fact that there's different sleep patterns and anomalies in the sleep patterns. Entertainment value? It's great. Scientific value? It still has a long way to go before we can believe that it's accurate.