The Science of Memory

Illustration by Elizabeth Dettmann

Memory is a complex and often misunderstood part of ourselves. In taking a closer look at how memory works, we can use it to our advantage in practical situations, such as exams.

How Does Memory Work?

Matt Altobelli, fourth year Psychology student, said, "Memory is the cognitive storage place for all of your past experiences and knowledge."

"Memory is the cognitive storage place for all of your past experiences and knowledge."

Within this storage space there are connections between neurons, the cells that transmit information, called synapses. Synapses get stronger or weaker depending on how often you are exposed to the event. For example, if you bake cupcakes every weekend, eventually you won’t have to look at the recipe to know how many eggs you need. This also explains why it’s hard to remember someone’s name after just one introduction.

The information processing model of memory states that when we are exposed to something, we encode the information, store it and then retrieve the information at a later date. First, encoding is when we receive and process information. Second, we create a record of the encoded information and maintain its place in our storage for an unidentified period of time. Lastly, we call back our stored information. We have to locate the information in our brain and return it to our consciousness. This happens in response to a “cue.”

A cue is a reminder that facilitates the retrieval of information. If you see a dog in the park, you’ll remember that you have to feed your dog when you get home — in other words, you are using a cue to retrieve information. There are two types of retrieval: recall and recognition. Recall pulls information from your memory with little external cues. An example of this would be fill-in-the-blank or short answer test questions. Recognition matches a piece of information with a fact that is already stored. This would be multiple choice or matching test questions.

Pulling information is often done unconsciously. An example of this is semantic priming. Altobelli explained semantic priming with a sub-example: the word “bird” automatically brings certain words and pictures to your mind. In response to “bird,” our memory pulls “feathers” and “wings.”

Types of Memory

You have many different types of memory. There are three initial branches: sensory, short-term and long-term. Sensory memory is the ability to retain impressions of sensory information even once the original stimulus has ended. Think of lighting a sparkler. It might look like the sparkler is leaving a trail of light as you move it; that’s your sensory memory.

Your short-term memory (STM) is your working memory. Your STM can only hold a few items and it lasts for about 20 seconds. Information in your short-term memory can be moved to long-term memory by rehearsal. An example of this is when someone tells you their phone number, and you continue to repeat it to yourself until you can write it down. If someone interrupts your rehearsal of information h, you can easily forget it.

Your long-term memory (LTM) encompasses everything in our lives. This includes what we learned in third grade to important phone numbers and even the conversation you had with your best friend yesterday. We have 100 billion nerve cells in our brain; each of those cells can make 10,000 connections to other nerve cells. Therefore, our brains have a nearly endless capacity for information. Some memories can last from the time they were created until we die while other memories can be easily lost.

Forgetting

Forgetting is somewhat of an abstract concept, and scientists only have theories as to how we forget information. Half the information we hear goes in one ear and out the other. After attending class, you’ll remember roughly 60 percent of the information you learned, and that’s if you were paying attention the entire time. After that, the information you’ve retained grows exponentially smaller. By the next day, you’ll only remember 30 percent, and it continues to get smaller by the day.

There are a few theories scientists have as to how and why we forget information.

First is an encoding failure; this is the failure to process information, which means it was never in your memory to begin with.

Second is memory trace decay; this refers to the loss of memory due to the passage of time. If you aren’t using the information regularly, your brain will cut the connections you have to the information. This is prominent in language learning. I took four years of French in high school, but because I haven’t utilized those skills in three years, I’ve lost most of my knowledge regarding the language.

Lastly is the interference theory. This is the failure to remember due to the interference of other information. There are two types of interference: proactive and retroactive. Proactive interference is when old information is blocking the learning of new information. For example, if you’re trying to learn Spanish and already know French, your French knowledge will often get in the way of you learning Spanish. Retroactive interference is when your new knowledge blocks you from remembering your old knowledge. Back to the language example, your new Spanish knowledge prevents you from remembering your past French knowledge.

Amnesia is another phenomenon that causes people to forget things. There are three different types of amnesia: retrograde, anterograde and infantile.

Retrograde is the loss of memory from everything before the point of trauma; this would be the case if you experienced blunt force trauma.

Anterograde is the loss of memory from everything after the trauma. An example of this is black-outs due to alcohol consumption.

Infantile is the inability to retrieve any memories before the age of three. Some people may disagree and think that they remember their first and second birthday. However, those memories have been found to not be real and merely constructed from stories and photos.

Altobelli explained that there is quite a controversy among psychologists surrounding the idea of forgetting. He explained that some believe we don’t forget anything and that our associations with the information just becomes loose. There is an unlimited amount of storage space for memories, but the bonds often fade. This happens if memories aren’t used; you will no longer have the ability to recall them.

"[Psychologists] don’t know the mechanism behind it. The memory might be gone, or it might just be the bonds that fades," he said.

If associations are lost so easily, does that mean memory is malleable?

Is Memory Malleable?

Sir Frederic Bartlett, a psychologist from the 1900s, is quoted as saying, “ ... Remembering is more like making up a story than it is like reading one printed in a book ... Every memory is a blend of knowledge and inference.”

Altobelli agreed that our memories are susceptible to change and that our memories are often altered, revised or influenced by new information.

“Every time you recall, you change [your memory] based on your current emotion,” stated Altobelli. “Memories are malleable.”

Our memories change based on our moods or new events that occur. Old memories can be encoded with new memories so you believe they happened at the same time.

Many are under the impression that our memories are a video recording of events from our personal past. That isn’t the case. This is highlighted by the Misinformation Effect, which states that eyewitnesses really can’t remember the event because of post-event information.

What Affects Your Memory?

There are quite a few things that affect our memory. If you’re well-rested, in a calm environment and with a lot of cognitive resources available, you’re in a prime state to learn and retain information.

There are two types of stress that can affect your memory: eustress and distress. Eustress is useful. An example would be deadlines; deadlines keep you motivated and on task.

“[Eustress] increases your ability to study and helps you get stuff done,” Altobelli said.

Distress, on the other hand, is overwhelming. This includes things such as ineffective studying at 2 a.m,  procrastination and putting work off until the deadline.

“Some stress can be good; stress will help to a degree, and then you’ll go sharply down,” explained Altobelli.

This is highlighted by the Yerkes-Dodson curve. Stress keeps you motivated to a point, but then it becomes debilitating and nothing gets done.

How to Improve Your Memory

There are a variety of ways you can take control of your learning and remember content more effectively. Altobelli argues that the best way to retain content is through association and state.

“If you can link the concept to something that’s important to you, you’ll recall the information faster,” Altobelli said.

"If you can link the concept to something that's important to you. you'll recall the information faster."

In terms of state, you should try and replicate your study space in exams. If you were chewing gum while you were studying, chew gum at the exam. Try and study in the same location that you’re to take the exam in if at all possible.

Another important technique is handwriting your notes. Many students prefer taking notes electronically because it’s faster and you conserve resources. However, according to Suzanne McMillan, coordinator of Success Courses at the Academic Success Center (ASC), research has found taking notes by hand is beneficial for a variety of reasons.

“It forces your brain to process the information at a different level,” explained McMillan. “When you’re typing, you’re thinking about what you’re typing, but you’re often recording it verbatim. You can’t write as quick as you type. You think about what is most important.”

Altobelli agreed and explained that when handwriting notes, you have to process the information, recall it and write it down in a different way to keep up with the professor.

“You process the information twice; it’s more likely to go to your long-term memory,” Altobelli said.

Another important aspect is frequency. Take your favorite video game or sport for example. If you only practice it once in a while, you’ll only have a certain amount of success, according to McMillan. Your memory works the same way. If you take notes in class and then don’t review the material until the test three weeks later, you won’t remember much. You should work on the content often to strengthen your neural networks.

“Work on the content daily even if it’s 10 to 15 minutes,” McMillan said.

You should also try previewing your notes before class. Take five to 10 minutes to look at your notes from the last class, as well as preview what’s coming up. See what you already know and what questions you already have.

“This will make a more productive class for you,” McMillan said.

In terms of studying, there are a few things to remember. Don’t just reread your notes; it’s not productive. According to McMillan, you should make something out of your notes. Take the concepts you’ve learned and “squish” them together in a way that makes it meaningful to you.

"[If you’ve] worked with [the material] frequently and made long-term connections, it’s harder for you to forget because you’ve strengthened your neural networks,” McMillan explained. “This should make test prep somewhat painless.”

You should not cram before an exam. You will not retain the information, and doing well on the exam might become out-of-reach. Deep sleep is where you solidify connections to information you’ve learned. Therefore, if you stay up all night studying for an exam, you won’t remember everything you've studied the next day because you didn’t sleep enough.

The science of memory is just as vast as our brains, but it’s not impossible to learn how to take advantage of it. If we take what we've learned about how memory works, and what we've learned about the best ways to retain information in our LTM, we can better succeed in college and in life.