The world is full of opportunities, and life is short. There are far more potentially awesome and/or merely fun experiences to enjoy than there is time to enjoy them. For example, I want to review the notes from my biology class today, and I want to read for my literature and history class and solve a handful of math problems. I want to play some intramural soccer, chat with my friends, go fishing and to the museum exhibit, play my favorite video game, learn to play the guitar and the ocarina; and I want to watch season three of whatever on Netflix. But there is not enough time for me to do all these things in one afternoon. So, what do I do? Multitask.
Multitasking sounds like a great idea. It is an efficient way to live life to its fullest, we reassure ourselves. Despite our protestations and insistence, most of us intuitively know, however, that studying while watching Netflix, carrying on six conversations on Snapchat and having a quick peek at our favorite YouTube bloggers every 15 minutes is not as effective as undistracted, focused concentration on the single task of studying. There have been many studies completed that provide a clear explanation for why repeated, focused study for relatively short intervals (about 20 minutes) is so much more effective than studying while doing other things.
There are at least a couple of different ways to discuss this. We could consider task-switching, but today we will examine working memory capacity (WMC). WMC and Cognitive Load Theory are transforming the way people approach teaching and learning. The cool thing is that these theories are based on a relatively simple and easily understood model of the human mind, as I explain below.
We can think of memory as having three parts: sensory memory, working memory and long-term memory. Let’s start with sensory memory. We are constantly bombarded with sensory information all the time, but most of this is not that important to us, and our mind simply filters it out. Sensory memory holds onto what we see and hear for a moment or two—just long enough for us to decide if the information or event is something we should pay attention to. Once we decide to pay attention, the information moves into working memory and we begin to process it.
Working memory is where most learning occurs. It’s not really a place, but for analogy’s sake, you can think of working memory as a place where long-term memories, prior experiences and knowledge brought forward to process the information coming from your senses into your mind. Existing knowledge is used to recognize, identify and interpret the new information. This is happening right now—as your knowledge of the English language and many other things are used to process the symbols on this newsprint and assemble meaning.
Our long-term memory is amazing. We seem to be able to recall near-infinite amounts of knowledge—especially when given a little prodding by incoming sensory information. There is no known limit to how much of that vast store of information we can access at any given moment. Unfortunately, perhaps, the same is not true for our working memory. In fact, our working memory can process only about four pieces of new information at any one time. This characteristic of human cognitive architecture creates a bottleneck in our ability to learn. The implications of this limitation for studying are quite clear. If I would like to take these math formulas before me and store them in my long-term memory, then it behooves me to focus all of my very limited working memory capacity on the task at hand. If I try to memorize and understand the water cycle, while also trying to carry on a conversation with my friends and watch a movie, I will likely overburden the limitations of my working memory. What will be processed will likely be the easy stuff—the casual conversations and the funny cat memes. The more complex and more abstract pieces of information—i.e., what you are trying to study—will be processed much less effectively, if at all.
So, although many of us want to live deliberately and fully, to not waste a moment of this wonderful opportunity, to suck out all the marrow of life, multitasking might function as an alluring siren, leading us astray. Gurus from Henry David Thoreau to Thich Nhat Hanh have emphasized the value of mindfulness and attending to one thing at a time. Cognitive science supports this approach in a variety of ways. One of those is being a more effective learner. Techniques for effective studying will be developed further in the next installation of The Science of Learning, where we will examine retrieval and test anxiety. Happy studying
