Student using a laptop
September 16, 2020
5 mins read

The science of why we forget what we (just) learned

Okay, I just read this page in my Biochem textbook—but I don’t remember anything. Can somebody tell me what a “protein” is? Alpha helix who? *Calls a friend* The prof said that in class? You sure?!

I figured I’d do myself (and my friends) a favour if I got better at remembering what I just learned. 

So, I reached out to 2 Psychology professors—Dr. Peter Graf, Director of the Memory & Cognition Lab, and Dr. Daniela Palombo, Principal Investigator of the Memory & Imagination Lab. Both professors have backgrounds in cognitive science, with a particular focus on memory.

Dr. Peter Graf

Dr. Peter Graf 

Dr. Daniela Palombo

Dr. Daniela Palombo

What is memory?

According to Dr. Graf, memory is the capacity to “think, reflect, and reason,” as well as an evolutionary adaptation. 

“It’s an application that allows us to benefit from the experiences that we have, and prevents us from doing what’s harmful to us," he explained.

The process underlying the creation of a memory is also very curious. As Dr. Palombo described, it involves 3 steps:

  1. Encoding: taking in new information
  2. Storage: maintaining it over time
  3. Retrieval: recalling it at a later date

Both profs explained that the brain rewires itself whenever a new long-term memory gets made. To elaborate, Dr. Graf referred to this quote from the late Canadian neuroscientist Donald Hebb: 

“Neurons that fire together, wire together.” 

In other words:

  • Thinking about and/or learning something activates particular neurons
  • When certain neurons get activated simultaneously, they connect with one another to form stronger networks
  • So, whenever only some of the same neurons are activated, the entire network will get activated—and this is recall

Then, what is forgetting?

“Forgetting is certainly frustrating—for students and professors alike!” Dr. Palombo said. “But forgetting is a normal, adaptive process.”

The human brain occupies a fascinating evolutionary in-between of remembering and forgetting. In many cases, we keep only the gist of our the expense of holding onto specific details. In fact, forgetting can be attributed to the presence of interfering memories and the fading of memories.

To paraphrase Dr. Palombo, gaining new information can interfere with your memories of old information, when the two are similar. One possibility is that the neural circuitry associated with the old memories gets rewired and harder to access and retrieve later—resulting in what we know as forgetting.

As for how memories fade, Ebbinghaus’s Forgetting Curve is a fantastic example. Dr. Graf explained what the curve means: 

“Within hours of a class, most of what was heard, seen, or discussed is forgotten; what you’ve lost are the details. If you take notes throughout a class and look at them 24 hours later, I bet you that you won't have a clue what a huge portion of those notes are about. You might ask, ‘Why did I write this?’”

Some ways to curb the “Forgetting Curve” 

1. Stagger out review sessions
Rectangle staggering out

“For students who want to retain information for a final exam, they should space their learning out by several weeks,” Dr. Palombo advised. “Longer spaces lead to longer retention.”

She refers to this approach as the “spacing effect,” where students’ performance on tests “improve when the intervals between successive study sessions leading up to these exams are increased,” relative to “massed practice”—a.k.a. studying lots of material in one session.

According to Dr. Palombo, we (as students) also lean towards rereading material as a study method. But when we simply read through content, we might feel like we’ve mastered it—when we actually haven’t processed it deeply. In fact, reviewing notes for the first time before an exam is basically like learning new material at that point.

Instead, we should spend more time doing practice problems, as testing our knowledge helps us understand where we’re still a little rusty. So, consider trying Dr. Graf’s recommended study schedule:

  • 1st review (within 2 to 5 hours of the class)
    • Revisit your notes and:
      • Fill in what you might’ve missed writing down in class
      • Add details from other sources, like the textbook
      • Jot down questions in the margin 
  • 2nd review (1 or 2 days later)
  • 3rd review (1 week later)
  • Pre-exam review

Dr. Graf warns against reviewing right after class, however, as you might not pay close attention to the details when the material’s still fresh in your mind.

2. Test yourself in environments similar to the exam environment
Illustration of a desk flatlay

To boost your memory, consider: 

  • Practicing the material in an environment similar to the one you’ll be in during the exam. You could even try studying or writing practice exams in the room where you’ll be taking the exam.
  • Trying to feel the same way you probably would during the exam, e.g. anxious (a tip from Dr. Graf!)
  • Studying without music (unless your prof plans to play music during the exam)
3. Make connections with what you know

“A deeper processing of information leads to better retention,” said Dr. Palombo. “When you are first encoding new information, try to relate that new information to things you already know.”

Connecting the points

But Dr. Graf and Dr. Palombo warn that sometimes what we think is forgetting might result from another cause...beyond the Forgetting Curve. 

“Occasionally, what people might think is forgetting is [actually] not forgetting,” Dr. Graf pointed out. “It is that we never really learned it.”

Meet the troublemaker—“inattentional blindness”

“We have the innate tendency to respond and automatically pay attention to everything that’s novel,” said Dr. Graf. “So as we get older, a large part of what we encounter in everyday life is no longer new, and we’re no longer automatically paying attention as much.”

This lack of attention is attributed to inattentional blindness, Dr. Graf said. It can come from our minds being preoccupied with thoughts irrelevant to the task at hand, which is why we can read something but have no recollection of what we’ve just read. 

Some ways to be more attentive

To avoid having to read and reread material when not very much seems to get in, Dr. Graf and Dr. Palombo suggest you try the following in class—and during studying:

  • Boost your energy levels by getting enough exercise and sleep
  • Identify things you’ve learned before and connect new knowledge to what you already know 
  • Write down questions you have in the margins of your notes—and get the answers ASAP, not the night before an exam
  • Have a notepad nearby when you’re studying—so when you think of an unrelated task, jot it down instead of reaching for your phone and risking other distractions!

Pro tip: To know if you’ve really got the material down, try explaining it in your own words to somebody else.

Try these tips on curbing the curve and attuning your attention so you can Love Remember Actually!

For an informative read, Dr. Palombo recommends checking out this 19-page paper by Dr. Eric Eich, UBC Psychology Professor, Vice-Provost, and Associate Vice-President Academic Affairs.

And, of course, head to the Navigating Online Learning series to get even more tips on learning effectively (digitally)—today!