Working memory (WM) is the aspect of our brain that manipulates information in the moment. It affects most everything we do in terms of learning. This creates a challenge, because working memory can only process around three to four bits of information at one time. As if that’s not enough, information in working memory lasts only around ten seconds. These conditions set up the phenomenon known as cognitive load. But let’s start at the beginning.
Working Memory: Small Capacity and Short Duration
The fact that our working memories have a small capacity and a short duration is what we are up against as people who want to learn and as learning experience designers.
Interactions Between Working Memory and Long-Term Memory
Unlike working memory, long-term memory appears to have an unlimited capacity. Information in long-term memory (LTM) is stored in schemas, which are mental structures we use to organize and structure knowledge. Schemas incorporate multiple elements of information into a single element with a specific function.
The interaction goes both ways. We construct new schemas in working memory so they can be integrated into existing knowledge in long-term memory. And existing knowledge in LTM is brought into working memory to help us understand the world. Otherwise, everything would be new all the time!
Working Memory is Vulnerable to Overload
As you have most likely experienced, sometimes learning involves great effort. That’s because working memory is quite vulnerable to overload. This occurs as we study increasingly complex subjects and perform increasingly complex tasks. As learning experience designers, we have to be aware of cognitive load, which refers to the total amount of mental activity imposed on working memory in any one instant.
What causes too much demand on working memory? One cause comes from an abundance of novel information. More information than a person can process. But high cognitive load is also strongly influenced by the number of elements in working memory that interact with each other. Often, complex learning is based on interacting elements that must be processed simultaneously. For example, learning to drive involves understanding how several elements simultaneously interact, such as considering the pressure required to brake, the amount to turn the steering wheel, staying alert to traffic conditions and making adjustments for weather conditions.
Intrinsic and Extraneous Cognitive Load
Not all cognitive load is bad. But a problem arises when the load exceeds the capacity of the person processing it. Cognitive Load Theory discusses two types of cognitive load: intrinsic and extraneous (or some call it extrinsic).
- Intrinsic Load. This type of cognitive load refers to the complexity of what you are learning. Consider the amount of new information and how it all interacts. Intrinsic cognitive load is an essential part of the learning task over which we don’t have control.
- Extraneous Load. If a learning experience is unnecessarily difficult or confusing, it results in extraneous cognitive load. That is, it uses up cognitive resources that learners could direct at the learning task. It is a result of poor learning design that can have a negative effect on learning. Extraneous load can interfere with the construction or automation of schemas.
What We Can Do
Two things that instructional designers can focus on to free working memory capacity are helping learners construct schemas and helping them automate schemas. Effective instructional design can help people combine elements of lower level schemas into higher-level schemas. This is one indicator of expertise. When a person is able to chunk multiple elements of information together, there is more working memory capacity available for solving problems and processing information.
In addition, one can automate schemas through repeatedly applying them. When we automate schemas, we no longer process them in working memory. Thus, they free working memory capacity for other activities. Some types of schemas that become automated are reading and driving a car.
As learners becomes increasingly familiar with content and skills, schemas change so that the information or task can be handled more efficiently by working memory. Our job is to facilitate this change in schemas, which ultimately, is what learning is all about. Listen to this interview with John Sweller, the developer of Cognitive Load Theory.
You may also want to read:
- 20 Facts About Working Memory
- Long-term Memory: A User’s Guide
- Novice Versus Expert Design Strategies
- The Novice Brain