While we might not all have the intellect of Einstein, our brains work tirelessly to compute everyday experiences into memories we treasure. Here, we find out how…
Today, many of us will have clicked the ‘save’ button – not on our computers or word documents, but in our minds. Memories are one of the most marvellous functions of the human brain and without them, we wouldn’t be able to nurture close connections or discover new loves or languages. However, our brains are not flawless. If you’ve ever tried to retell an event with your partner at a dinner party, you’ll probably know that one tale might conjure two different versions. To find out why we sometimes misremember experiences, we turned to neuroscientist Dr Sabina Brennan, author of Beating Brain Fog: Your 30-day Plan To Think Faster, Sharper and Better and host of the podcast, Super Brain (sabinabrennan.ie).
Making memories
“Essentially, human memory is fallible; it’s not the objective record keeper that we credit it with being,” says Dr Brennan. “The memorymaking process has three phases and we call them Encoding, Consolidation, and Retrieval. Throughout the day we take in details that go into a temporary repository called the hippocampus (four little seahorse-shaped parts of your brain). However, there is only so much information that our brains can take. When you go to sleep at night, that info is cleared out and that space freed up so you can take in more the next day. In the early part of the sleep cycle, there is electrical activity between the hippocampus and the frontal lobes in your brain – the frontal lobes are the part of the brain that look after the higher order functions; decision making, planning, organising, inhibiting your behaviour – all those kinds of actions we use every day. All the information that you have taken in during the day needs to be filtered and a decision made, whether it needs to be kept and consolidated, or discarded.”
REM influences ‘when’
Our dreams are often a fusion of childhood memories and day-to-day happenings. It might cause a little confusion when you wake up, but rest-assured, it’s simply your brain amalgamating old information with fresh knowledge. “Later in the sleep cycle, often around early morning when you have more rapid eye movement (REM) sleep, that recent information becomes integrated with your previous experiences and knowledge,” explains Sabina. “That’s why you have those strange dreams that have a little of something from today and then something from your childhood. REM sleep is critical to memory and to brain functioning; if you miss any part of that process, your memory will suffer. Quality sleep leads to more insightful ideas and solutions, because your brain can figure out problems without you consciously having to recall an experience.”
Bear in mind
Misremembering a shared event with a friend or partner comes down to the individual coding that our brains do when learning to keep a memory. “When your brain is coding memory, it’s influenced by multiple factors,” says Dr Brennan. “Firstly, what you each pay attention to – even if you’re looking in the same direction, one of you might be looking at a different thing. And then, there are the expectations of what an experience might be; whether you’re in a foul mood, annoyed or stressed, all of that will influence the information you’ll take in. Next, there is the consolidation phase. One friend might filter out something that’s unimportant that another person sees as important. However, if you had little sleep that night, consolidation may not have occurred properly. What’s kept is integrated with existing knowledge, and when you come to retrieve it, those factors will play a role. Say you’ve had an argument with your partner before you try to recollect something, you’ll be more inclined to disagree with what they remembered or you might be attuned to picking out pieces of information that contradict what they said. The chances are your memory will become fractured over time. If your memory is fragmented, your brain will fill in the gaps and sometimes that will contain incorrect details. It doesn’t mean you’re lying, it’s just your brain is working to bring forward a coherent recollection.” Our brains are fallible. Misremembering something can purely be a disparity in how the experience was received.
3 steps to… Improving your memory
If you want to make a memory…
“I often say to people, if they want to recount their memories, to activate as many senses as possible, as various areas of the brain will retain that experience,” says Dr Brennan. “When we go to school as infants and young children, we explore the world with all of our senses, but as we grow up, there’s a narrow focus on just taking information in hourly, mostly by listening. That limits your ability to retain that learning or memory.”
If you want to keep it…
“Prioritising sleep is absolutely critical,” says Dr Brennan. “Impaired sleep means it will impair your consolidation. Another factor that affects memory retention is stress. It’s essential for challenging yourself and learning new things – however, if you have chronic, poorly managed stress, that will ultimately interfere with learning and memory. It’s particularly damaging for the hippocampus and your frontal lobe. And, of course, stress and sleep are inextricably linked. If you’re stressed, it’s likely to affect your sleep and interfere with your memory. Exercise is also brilliant for your brain – your brain only weighs two percent of your body and 25 percent of your oxygen will circulate in it at any time. If your cardiovascular system is not working well, then your brain is going to be deprived of oxygen and that will affect its performance. Mental exercises are just as important as physical; not just academic learning but having new experiences, such as tasting new food.”
If you want to recollect it…
“To people who want to activate their memories, think about triggers,” says Dr Brennan. “You’ll know if you’ve got a rich memory for certain things, such as a smell or taste. I can walk down a street and there’s a house I walk past that always smells amazing, that reminds me of something specific. What’s happening in that moment is the sensory part of our brain is working to bring forth that experience.”
