We can view learning as multi-representational. We might, for example, learn through reading or listening, but we may also use diagrams, charts, schematics or video. When describing the working memory model I can refer to the different systems, such as the phonological loop and central executive and explain what they are for. But, in this particular case, it’s also going to be useful if I can draw a diagram so that you can better grasp how these systems slot together and work with each other.
More often than not, the written or verbal description will be paired with a diagram, the ubiquitous PowerPoint presentation that’s sent thousands of eager young students into a deep slumber. It’s clear by now that the human brain is capable of processing information in a number of ways, or through different modalities. We can hear something, read something (and hear what we read in our heads), but we can also gain a great deal of information from other sources. We associate a green man at a crossing as an indication we can cross the road safely, and when we learn to drive we also have to become familiar with a variety of symbols that represent the rules of the road. Similarly, building blueprints or electrical diagrams form some kind of representation in our minds. You might recall drawing a diagram of a volcano or the water cycle when you were at school and might even have used self-generated images when you revised for an upcoming exam, such as a mind-map. They can also be used a form of retrieval practice, for example, by presenting a blank diagram and asking the learner to label the different components.
During the 1960s, Canadian psychologist Allan Paivio made an interesting yet seemingly simple observation that would have an important influence on learning. He discovered that people found it easier to remember concrete nouns that can be imagined compared to abstract nouns where images are harder to come by. If I were to present to you a list of words containing only the latter (words like truth, justice, liberty, ambiguity) you would find it more difficult to recall these later, but if I gave you a list of words like tree, car, river or house you would stand a much better chance. Indeed, if you were presented with a list of words containing both concrete and abstract nouns, you’ll recall more of the former than the latter. This makes intuitive sense and might explain the effectiveness of certain mnemonic strategies employed by contestants at the world memory championships. We can, of course, represent a term such as justice symbolically, perhaps using the image of a scales or of Lady Justice, the blindfolded figure who holds the scales of justice in one hand a sword in the other. This kind of image to represent an abstract concept is generally referred to as a symbolic code, while a drawing of a dog to represent and actual dog is known as an analogue code.
In addition, studies using mental chronometry (the measure of the amount of time it takes to carry out various cognitive tasks) find that the ability to mentally rotate objects in the mind hasten the ability to compare shapes for similarity. If, for example, I was to show you a set of three-dimensional shapes (two of which were the same, only viewed from a different angle) and ask you to identify the matching pair, success on the task would correlate with your ability to hold the representation of the shape in your mind and rotate it until it matched one of the other shapes. This suggests that our ability to hold the image in our minds eye (our ability to imagine something) can help us learn. Experiments such as those involving mental rotation, led Paivio to propose that the human cognitive system codes information in two ways, reflecting the unique ability of our cognitive architecture to deal simultaneously with both language and nonverbal objects and events, a notion that became known as the dual coding theory. Paivio went on to propose that the language system can deal directly with linguistic input and output, that is, speech and writing, while at the same time serving a symbolic function with respect to nonverbal objects, events and behaviours (see the figure below). This implies that there are two cognitive subsystems; one specialised to deal with the representation and processing of nonverbal objects and events (images) and one specialised to deal with language. Dual coding theory would suggest that images are encoded differently to non-images. This then suggests that pairing a word with an image representing that word, will result in a much stronger memory trace, because it’s essentially been encoded twice. But the advantages don’t stop there, and there is ample evidence suggesting that learning using both images and auditory materials externalises information for problem solving (Zhang and Norman, 1994). What this means is that complex tasks can be visualised, and by doing this there is less stress placed on our cognitive resources; load is, therefore, optimised.
Being presented with information in two modalities may, therefore, help us recall the information later, but what about generating our own images? In a study from 2018, researchers at the University of Waterloo in Canada discovered that drawing simple pictures might be more effective than taking notes or copying information from the board, the so-called drawing effect. Myra Fernandes found that participants asked to produce a quick (4 second) drawing of items in a list of words had significantly better recall of the words than those who wrote them down multiple times. Initially, volunteers were given lists of simple words, such as truck or shoe, but later trials included more complex concepts such as isotope and spore where participants were expected to recall the definition. Even with the increased complexity of the words, recall remained higher in the drawing condition than in the condition where participants copied out the definitions.
Furthermore, another study (again from 2018), concluded that older adults who take up drawing could also see significant improvements in their memory. Retention of new information typically declines as people age due to deterioration of critical brain structures involved in memory, particularly the hippocampus and frontal lobes. However, visuospatial processing regions of the brain, involved in representing images and pictures, are mostly intact in normal ageing and in dementia.
But why should drawing a concept make it easier to recall later? The most likely explanation is that drawing requires elaboration on the meaning of the term by translating the concept into a new form. This is consistent with the levels of processing theory of Craik and Lockhart because elaboration results in deeper cognitive processing. This view is also consistent with other theories of learning, for example, Deep Learning (see, for example, Marton and Säljö), Meaningful Learning (Ausubel) and Generative Learning (for example, Fiorella and Mayer, or see this excellent short guide from Mark and Zoe Enser), as well as the ICAP (Interactive, Constructive, Active, Passive) paradigm of Chi and Wylie. For more on Dual Coding and teaching, see Oliver Caviglioli‘s Dual Coding with Teachers.
Finally, when learners use drawings to retrieve understood material, their new learning can be enhanced by connecting it with what they already know. In addition, Wetzels, Kester, and Van Merriënboer (2011) conclude that drawing may be effective at activating prior knowledge as the visual form reduces the load on memory, supports perceptual processing and makes relationships more explicit.