Science of Learning: Basics of Memory

I love memory. It is a part of cognitive psychology, and I found it one of the most fascinating aspects of cognition (I ended up studying attention, but I still love memory).

Often, educational reformers will talk with some derision about the role of memory in education. All students (in today's world) are expected to do is memorize and regurgitate. Although that defines much of modern schooling – memorize for another test – remembering information is critical for the purposes of learning. So, I’ll talk about memory, how it is structured, how it works, and the role memory needs to play in learning. I’ll be relying heavily on the thinking of Robert Bjork here because he’s the real expert (in my eyes).

How we think of memory

Our common sense view of memory is that memory is like this:

…past experiences of differing duration and intensity leave impressions or traces in the brain that are like footprints of differing depths in the sand. And such traces or footprints are subject to blurring over time, becoming harder to read as a function of retention interval and intervening event (Bjork 1994).

We just know that this explains what memory is from our own, subjective experiences. Memories are encoded much the same as sounds of pictures are laid down on a tape, or bits are aligned in a memory stick or hard drive. Over time, the tape corrodes or the bits get a bit jumbled, and it becomes harder and harder to pull a real memory out of the fog. Footprints in the sand, slowly being washed away.

Common sense memory is the memory that is worked within education. If memories are like footprints in the sand, just keep going over and over the beach (drill and drill, or study and study), and the footprints are driven deeper and deeper into the sand and get harder and harder to wash away.

Unfortunately, for generations of learners, that’s not exactly the reality of how memory is structured. The table below illustrates just how complicated memory really is according to memory researchers. These distinctions can be confusing to understand, especially when you consider that they don’t really stand alone, but often overlap in what they are and what they do.

Sensory <-> Short-term

Short-term                     <->                     Long-term

Semantic                         <->                     Episodic

Declarative                     <->                     Procedural

Stimulus-driven             <->                     Conceptually Driven

Explicit                            <->                     Implicit

Controlled                      <->                     Automatic Processes

Later, in this article, I’ll walk you through the pairs that are critical to formal learning so you can get a flavor of exactly how memory is structured and works. But first, we have to go over the goals of education – as far as memory is concerned.

The primary memory goals of formal learning should be long term goals. The first of these goals should be that the knowledge and skills acquired during the learning process should be stable and durable. This information or knowledge (information that has been transformed into a usable form) should be available at the end of the learning cycle (pass the test memory). However, it should also be available long afterward when what has been learned in the formal setting might be useful in some real world setting. Knowing how to multiply using fractions in a kitchen when altering a recipe is important, however formal education is usually focussed exclusively on a learner’s ability to pass a test (the first problem of transference – having the information available in another time, setting, or circumstance when it is needed).

A secondary (but vitally important) long-term goal of learning is that the knowledge and skills learned should be able to survive long periods of time when the knowledge or skills are not used, and be able to be recalled in a useful state when needed. Like riding a bike, once you learn, you can (usually) do it again after a long period of time when you have not ridden a bike. It is frustrating to know that you once knew how to do something, but can’t really remember how to use that knowledge to solve your present problem. Although this should be a goal in formal learning, it is a very difficult one to manage.

The final long-term memory goal that we have is the need to produce and have available a mental representation of the knowledge or skill that allows for flexible access to that information in different settings. This is the second problem of transference – being able to recognize that something you learned in a different context might be useful in the context you currently find yourself. Having a theoretical understanding of a lever doesn’t help if you don’t recognize when it might be useful to have that knowledge. This aspect of transference is one of the most difficult challenges for any kind of formal learning. Educators can (and should) provide examples of when what has been learned might be useful, but it would be impossible to provide a list (to be memorized and tested – of course) of every instance when a person might need to add some numbers together. Instead, what is hoped, is that a learner will master the skill of addition, and also recognize every instance in their lives when addition will help solve a current problem. Seems simple enough, but transference is one of the most challenging aspects of formal education.

Which brings us to our final question before exploring how memory actually works. What is it that we really want memory to do? When we answer that question, we are prepared to consider how memory works, and how we can work with memory to get it to do what we want it to. We want memory to store knowledge and skills that are available for retrieval whenever that knowledge or skill is needed in a situation or to solve a problem. We also want to be able to recognize when any knowledge or skill is appropriate to apply to that situation or problem.