The Neuroscience of Memory: How does our Brain remember and forget?

Joy from Inside Out looking at the memory trays in Headquarters (Vox)

Our brain is a storage box full of both cherished memories and some memories that we kind of don't want to remember. I know that we can all think of a few memories that fit the latter category. I believe that an integral part of being human is being able to recall our memories and cherish them. So, how does our brain store, retrieve, and sometimes forget memories? It's not too complicated once we break it down.

The first step in the creation of memory in the human brain is the hippocampus. What's the hippocampus? It's a seahorse-shaped structure located deep in the brain whose job is memory formation. When we're experiencing something new, like eating new food, viewing a world wonder, or smelling a new perfume, our hippocampus springs into action. It quickly processes and stores this novel information in a temporary form called short-term memory. 

From Dory's short-term memory, we go to the long-term storage facility like Mike Ross's through a process called memory consolidation. In this process, information is gradually transferred from the hippocampus to other parts of the brain. 

Obviously, we have some memories that are stronger than others. This is because of how our senses come into play. Sensory inputs, like smell and taste, trigger electrical and chemical signals in our brains. As these signals travel through the brain, they form new neural connections and reinforce existing ones. This is also called synaptic plasticity, and it's this unique trait of the brain that is the anchor of strong memory formation. The bottom line is, the more frequently and intensely we encounter a certain experience, the stronger the neural connections become, which results in longer-lasting memories.

Now that our memories are in long-term storage, how do we get them back? Basically, the way we retrieve our memories is by going through the same encoding pathways that our brain went through while the brain was actually creating the memories in the first place. This is done through little cues. For example, some years ago, I went with my friends to the mall and I smelled this decadent vanilla perfume. Now, if I smell that vanilla perfume again, then I'll most likely remember the mall trip that I went on so many years ago.

Ever forgot an important math formula during a test? I bet you have. Just as our brains retrieve our memories, they can also forget them. This usually happens in two ways: one is decay, where memories fade over time if they're not frequently accessed or reinforced, and two is interference, which happens when new information disrupts the retrieval of older memories or vice versa. Forgetting things is super important though. This way, our brain holds only the memories and information that are relevant to us. 

As we continue to explore the neural intricacies of memory, we gain insights into what makes us uniquely human. Each memory, is a piece of the puzzle, contributing to the rich tapestry of our existence. So, the next time you find yourself reminiscing about the past or struggling to recall a name, take a moment to appreciate the wonder of the brain's memory system—a delicate orchestra of neurons orchestrating the symphony of our lives.

Sources:

https://qbi.uq.edu.au/brain-basics/memory/where-are-memories-stored

https://dornsife.usc.edu/news/stories/how-memories-are-formed/

https://www.hopkinsmedicine.org/health/wellness-and-prevention/inside-the-science-of-memory