How does memory work?
My earliest memory involves a lunch box. I was five years old and found one that matched my red plaid skirt. In the early 1960s girls dressed up for school, had their hair pulled up into pigtails or ponytails with matching ribbons, and wore lacy ankle socks poking out of their black and white saddle shoes.
What is memory? How are our memories formed? Where do they exist and hang out? How do we access them? And why do memories change over time?
what is memory?
Memory is the process of capturing, storing, and retrieving our experiences and knowledge, and is critical for our quality of life.
There are several different models of memory. One is based on the stages our memories go through — sensory, short-term memory, and long-term memory.
Sensory memory sucks up lots of sensory details quickly (in a couple of seconds). How red was that plaid lunch box? How tinny did it sound when the clasp opened? How cool was the metal to the touch if kept in the refrigerator overnight?
Short-term memory or working memory fills up by paying attention to details and allows us to hold information in our heads for 20-30 seconds. Like when a friend recites navigation instructions while you are driving.
Long-term memory depends on several factors that influence how robust those memories remain. First, how vivid the experience played out in your mind. Then, the number of times you access and replay the memory.
My lunch box memory involved asking Mom for help. She didn’t say no, she wanted to understand why I wanted a lunch box if I ate lunch at home. Was I hungry and wanted a snack at school?
Transition theory suggests that during significant transitions in our lives (late adolescence and early adulthood, moving, sickness, etc.) there is a reminiscence bump because of the novelty of the experience. In contrast, the brain fog many people have reported during COVID lockdown may be due to an environment of sameness. People aren’t able to distinguish between day-to-day activities because less stands out as novel.
walking through a doorway causes many to forget (event boundary)
closing your eyes helps you remember more details (fewer distractions)
mindfulness improves memory (try meditation)
left-handed people remember more information (larger corpus callosums)
positive memories persist more than negative ones (lessons learned to help us adapt)
taking photos makes our memories of the time worse (we’re less engaged)
where do memories exist?
Our brains simmer with activity. Different neurons (nerve cells) carry different thoughts or perceptions and they float in and out of what we focus on.
Memory is a reactivation of a specific combination of neurons in our hippocampus (an important memory structure in the brain). Connections and associations become stronger or weaker depending on how often they are activated. But what allows a specific combination of neurons to be triggered?
Something called synaptic plasticity - think of it as your central dispatch system - your inner organizers at a networking event. They’re busy introducing people to each other and creating new connections. And like with relationships, active connections tend to be stronger, and less active ones become weaker.
Our memory reactivation happens in ensembles for different memories. At five, the word house might trigger a drawing. As an adult house might trigger your own home. Same input, but your experience and memories have changed the neuron connections.
Luckily as adults, we are able to create new neurons in our brains through physical exercise to help out during our internal networking events.
During sleep, the hippocampus and neocortex take part in a carefully choreographed dialogue. The hippocampus replays recent events and lets the neocortex know what needs to be stored.
Pixar’s Inside Out
The film follows the inner workings inside the mind of a young girl as five personified emotions dispatch her thoughts and actions as she struggles through her family's relocation. Her emotions create memories in the form of balls. Some are core memories, and some are stored in long-term memory.
The director came up with the idea when he noticed changes in his daughter's personality as she grew older. During production, the filmmakers consulted psychologists and neuroscientists. What a delightful exploration of the interaction between our inner workings and outer displays of emotions.
why do memories change?
Memories are often likened to a computer. First, information enters short-term memory (temporary). Then moves into long-term memory (relatively permanent unless your computer crashes).
Researchers have found that memories update every single time you access them. Our brains store original memories. But every time we take them out for a spin, our brains create a non-identical replica. Subtle details may change.
When I recently recalled my lunch box memory, I opened the box and remembered a wire spring that held a matching red plaid thermos. I vaguely recall steamy Campbell’s mushroom soup when I was older. My brain created an expanded version of my memory.
Joshua Foer’s Ted Talk: Feats of Memory Anyone Can Do
how can we improve our memories?
Over the centuries we’ve developed technologies to help us remember. But it’s as if we don’t need to work hard at remembering anymore. We've outsourced memory management to our devices and we’ve forgotten how. These devices have made our memories worse.
Cursive handwriting is going away in schools. Kids use computers instead. But we jeopardize losing the brain/mind connection to memory. And miss out on the creative benefits of writing long-hand.
Per Joshua Foer’s Ted Talk: Feats of Memory Anyone Can Do Memory champions use what psychologists call elaborative encoding techniques. In fMRI (functional magnetic resonance imaging) machines, different parts of our brains light up with spatial memory and navigation when memorizing numbers or faces. A normal MRI takes images of the brain’s structures. The scan makes sure everything is in the right place. Whereas fMRIs observe the brain while performing a specific function. They can “see” our thoughts and emotions.
Mr. Foer, a journalist, explained the Baker/baker paradox. Tell someone to remember a guy named Baker. Ask someone else to remember a person who is a baker. People will remember the latter because we put associational hooks allowing easier retrieval.
The whole trick to remembering better is creating a context or meaning to remember. The more sensory details the richer and more vivid the experience, and the more lasting the memory.
“At the most basic level, we remember when we pay attention, and figure out why it’s meaningful to us. We need to process deeply in order to remember.“
— Joshua Foer
Why did I have a red plaid, cool-to-the-touch, tinny-sounding lunch box? Why did I ask my mom for one? I wasn’t hungry. I didn’t want a snack at school. I wanted a lunch box to use on the other kids. When the boys hit me, I wanted to hit them back.
What I take away from that memory now is not only the fact that I wanted to defend myself, but that I learned to ask for help. My mother believed me and didn’t try to talk me out of it. She helped empower me to stand up for myself. And my mother told my grandmother who called the local paper.
Memories make us who we are. Our lives are the sum of our memories. The stories we tell ourselves and each other. At the end of the day, our legacy becomes the stories people tell about us.
What long-term memories expose who you are? What stories will people tell after you are gone?
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