Never underestimate the power of visualisation. It may sound like a self-help mantra, but a growing body of evidence shows that mental imagery can accelerate learning and improve performance of all sorts of skills. For athletes and musicians, “going through the motions,” or mentally rehearsing the movements in the mind, is just as effective as physical training, and motor imagery can also help stroke patients regain function of their paralysed limbs.
For most of us, visual imagery is essential for memory, daydreaming and imagination. But some people apparently lack a mind’s eye altogether, and find it impossible to conjure up such visual images – and their inability to do so may affect their ability to learn and their educational performance. Firefox co-creator Blake Ross recently described how it feels to be blind in your mind, and his surprise at the revelation that other people can visualise things. “I can’t ‘see’ my father’s face or a bouncing blue ball, my childhood bedroom or the run I went on ten minutes ago,” he wrote on Facebook. “I thought ‘counting sheep’ was a metaphor. I’m 30 years old and I never knew a human could do any of this. And it is blowing my goddamned mind.” Neurologists believe aphantasia affects approximately 2% of the population, or one in 50 people We’ve known that some people cannot visualise things in their mind’s eye since the 1880s, when the controversial psychologist Francis Galton – one of the pioneers of eugenics – published a paper called Statistics of Mental Imagery. Galton set out to “define the different degrees of vividness with which different persons have the faculty of recalling familiar scenes under the form of mental pictures”. He asked his scientific colleagues to think of their breakfast table and describe to him the vividness of their impressions, and found this ability varied markedly – some individuals could draw up a mental image just as brilliant as the scene itself, whereas others could only conjure up an extremely dim image, or none at all. Today, neurologists refer to this inability to form mental images as “congenital aphantasia” – from the Greek words a, meaning “without”, and phantasia, meaning “a capacity to form mental images” – and they believe it affects approximately 2% of the population, or one in 50 people. Remarkably, though, aphantasics do experience visual imagery in their dreams, so it seems that only voluntary visualisation is affected. In the classroom, mental imagery seems to be especially important for reading comprehension and learning word meanings, and, according to at least to one theory, is a cornerstone for literacy. Dual-coding theory, put forward by Allan Paivio of the University of Western Ontario in 1971, distinguishes between verbal and non-verbal thought processes, and places mental imagery as the primary form of non-verbal representation. Thus, information is stored in two different ways – verbally and visually – and although these two codes are independent of one another, and can each be used alone, they can also interact to enhance learning and recall. Dual-coding theory has its limitations, the main one being the assumption that thought processes are based on nothing but words and images. Nevertheless, numerous studies published since the early 1970s confirm that mental imagery does indeed play an important role in how schoolchildren acquire literacy skills. The work shows, for example, that mental imagery helps eight-year-olds remember what they read, and that students who are asked to create mental images during word memory tasks learn two and a half times as much as those who are told merely to repeat the words they need to remember. Verbal recall and visual images do appear to be separate but related, and while the ability to use imagery is not directly related to measures of intelligence, vocabulary, and reading comprehension, the spontaneous use of imagery helps children to learn and understand prose. More recently, other studies have shown that mental imagery can help students grasp abstract concepts, and that encouraging students to use imagery can improve their understanding of such concepts. One study shows that using mental imagery helps primary school pupils learn and understand new scientific words, and that their subjective reports of the vividness of their images is closely related to the extent to which imagery enhances their learning. Visualisation techniques are also helpful for the teaching and learning of mathematics and computer science, both of which involve an understanding of the patterns within numbers, and creating mental representations of the spatial relationships between them. Aphantasia could possibly affect how students revise for exams, too. Using mind maps is one common strategy, which has been shown to effectively help them retain and recall information, and merely visualising the appropriate page of their revision notes can also help them to recall the information on it. It follows, then, that an inability to create mental images would hinder students’ abilities to use such strategies. Although aphantasia was first recognised more than one hundred years ago, there has been very little systematic research on the phenomenon, and so we still know very little about it. For example, are people with aphantasia able to imagine sounds or touch sensations, or does the condition affect imagery in senses other than vision? Galton alluded to this in his original 1880 paper, concluding that “the missing faculty seems to be replaced so serviceably by other modes of conception… Men who declare themselves entirely deficient in the power of seeing mental pictures can nevertheless give life-like descriptions of what they have seen.” Regardless, research into visual imagery would seem to suggest that students with aphantasia are likely to experience difficulties with learning, but as yet there is no research confirming that this is the case. “We know that children with aphantasia tend not to enjoy descriptive texts, and this may well influence their reading comprehension,” says neurologist Adam Zeman of the University of Exeter who, together with his colleagues, gave the condition its name last year. “But there isn’t any evidence directly linking it to learning disabilities yet.” Zeman adds that people with aphantasia may be able to form visual images, but just don’t have conscious access to them. “The story really is still at the early stages, so the implications for education haven’t been explored,” he says. Researchers use questionnaires to determine the vividness of mental images, and people’s scores on these tests are closely correlated to measures of activity in visual brain regions. Thus, it may be possible to objectively measure individual differences or variations in the vividness of people’s mental images, and to identify students who have aphantasia. If it becomes clear that the condition does in fact impinge on children’s ability to learn, it may then be possible to devise alternative learning strategies for them. Get involved with the Use your head series by joining the discussion on #useyourhead