Remember: The Science of Memory and the Art of Forgetting

“Making a memory literally changes your brain.”

All memories go through four stages before becoming a long-term memory. First, your brain needs to translate the senses of what it sees, smells, hears, feels, and what you paid attention to into the neurologic language in order to encode it. 

Next, it consolidates the info with associations made and bundles this memory together. It is then stored in specific pathways and neurons in the brain. Lastly, we have retrieval. This is the ability to remember what we previously thought and experienced through our prior associated connections. 

Our “working memory,” which lasts around 15-30s, is the first part of this encoding process. However, to trigger the rest of the process and be stored as long-term memory, it must be significant to us (emotional, new, surprising, etc.), and we must pay attention. Then, the memory passes through the hippocampus, solidifying its parts into a cohesive whole. 

Once the memory is weaved with its unique associations via the hippocampus, it will light up the same brain regions that were originally activated before when you next recall it.

“Muscle memories are remarkably stable and can be called back into play even after sitting on the bench for decades.”

How frustrating would it be to recall how to drive a car every time you go to work? Or remember where each note on a piano was every time you wanted to play it? It would be very difficult to be able to sing or read the sheet music all at once. 

This is where muscle memory comes in. It’s all about remembering how to execute actions and activities, such as riding a bike or swinging a golf club a certain way. Muscle memory is unique in its ability to first be a deliberate thought on how to do an action and later an unconscious memory of connected fluid movement(s). 

What makes it really special is that it does not go through the hippocampus to consolidate the memory but instead the basal ganglia. Muscle memory is important as it helps us free up some brain space instead of relearning how to do the same movements. 

Essentially, brains take a shortcut, so you don’t need to rethink these movements again, but they first need to be repeated the same way and practiced to become subconscious.

“In fact, prospective memory is so poorly supported by our neural circuitry and so steeped in failure, it can be thought of as a kind of forgetting rather than a kind of memory.”

When you tell yourself to remember to call your friend at 3 pm tomorrow, you’re using a memory called prospective memory. It is a type of future memory for a specific time and place to be recalled later. 

However, this sort of memory isn’t reliable without strong environmental cues. For example, you could go to the grocery store for milk and then completely forget about it once you’re there. Once home, you might open the fridge to get some cookies and milk only to realize you forgot to buy some! Or you might have a meeting at 9 am, only to forget about it because you were distracted by an interesting article. Since you didn’t notice the time, you completely forgot the meeting.

“In addition to the stuff you know, there is the stuff that happened.”

The two most common memory types we often associate with memory are episodic and semantic memories. Semantic memories have no place and time and are the facts we remember, such as six times six equals thirty-six or that blueberries are blue. They hold our personal data, such as knowing what color of eyes we have, our birthday, our phone number, height, name, etc. 

Episodic memories are memories that have a time, place, and what and where. They are personal to you and your experience. This includes your first kiss, that time you embarrassed yourself, your first job, that time you got food poisoned, and other meaningful memories. 

Episodic memories create your autobiographical memory, the story of your life. Semantic memories and episodic memories that aren’t often retrieved tell the brain they aren’t meaningful, and thus, we can forget about them.

“Forgetting happens. If you stress about it, it will happen more.”

When people think of memory, they tend not to focus on the part of forgetfulness or forgetting. Although, a huge part of remembering is forgetting. Our brains have an amazing capacity to remember and forget the irrelevant, important, or exciting details to us. 

You can help your memories with certain techniques, but you can also impair your brain’s capacity to remember with stress. Short-term stress can help remember, but only the stressor's object and not many outside details. Chronic stress, on the other hand, is detrimental to memory.

Under chronic stress, the body is in a constant flight or fight mode—even if the “threat” is psychological, such as a deadline. Too much stress can cause an inability to focus or process what is going on, hinder recall of stored memories, and worse, hamper the ability to store memories. The hippocampus limits neurogenesis (making new neurons) when chronic stress is present. In an intriguing study done with women ages 38 to 60, those who reported chronic stress had an increased chance of Alzheimer’s up to 65%!