Bill's story

This is Bill's story, told by his adoptive mother Sarah. Bill was born and raised in Bamako Mali and suffered terribly in the education system there. In 2008 Sarah reached out to Dyslexia International.

Bill was diagnosed with dyslexia and dyscalculia. This was a huge relief in itself because it allowed Sarah and Bill to understand the issues that needed to be addressed.

Bill and Sarah now live in London and Bill is enjoying school.

Reading in Western scripts and in Chinese … and the importance of hand movements

It has long been debated whether the neural circuits for reading in, say, French, which is an alphabetic language, and in Chinese, which is a logographic language, are radically different.

Previous studies had suggested that there was a radical difference but Stanislas Dehaene and colleagues have published a paper in the journal Proceedings of the National Academy of Sciences*, US, indicating otherwise, provided that cross-cultural confounds are controlled for. One such confound is the great memory load needed for Chinese characters. More precisely, they used dynamic handwritten stimuli in a cursive style rather than letter strings with a static roman typography such as that you are reading in now. It is suggested that a fast neural pathway automatically recovers the intended visually perceived handwritten traces in both languages.

At the microscopic level, as would be expected, restricted neural networks are found better tuned to specific graphic shapes and sounds for the different languages but at the macroscopic level their findings suggest universal mechanisms in pre-existing innate networks. In fact there are two networks: one for the analysis of shape and another which decodes motor gestures. A motor memory for writing in Chinese is not specific to that culture because it also plays a general role in the acquisition of literacy in French; however it is more activated in Chinese than in French presumably owing to the fact that the Chinese have to memorize a huge number of characters. The environment, that is teaching, then fine-tunes and balances these networks specifically for each language as literacy is taught. Culture does matter but the brain is plastic and adaptable, significantly more so in children.

Take-home message for teachers: These experiments lend strong support for multisensory methods of teaching, especially for children with dyslexia.

Stanislas Dehaene is a speaker at the forthcoming Oxford-Kobe conference.

            * December 12, Volume 109, pages 20762 - 20767

http://www.oxfordkobe.com/

In both French and Chinese a character may be presented whole or a compound of dynamic movements. For instance, ‘a’ is in fact written in a different way with a forward movement first to form the arc and then a backward movement to complete the upright. Chinese characters are also formed with forward and backward movements but the researchers were attempting to discover what happens when this effect is shown dynamically rather than when the complete character is presented statically.

The subjects were in France, near Paris, and Taiwan, where a modified form of Mandarin Chinese is spoken. Complex combinations of tests were run in two types of experiment. The first, a behavioural test, used a research paradigm known as ‘priming’. A stimulus is flashed briefly on a screen, followed by a mask then a target character or word presented statically or dynamically and reaction times recorded. The quicker reaction time shows that the target has been swiftly detected. The second type deployed functional magnetic resonance imaging (fMRI) to capture areas of the brain activated by specific tasks. This method is not used to determine the speed of the reaction but where it is taking place.

The conclusions of the studies are as follows.

There was support for the view that the brain uses motor patterns of hand-writing gestures in order to perceive the shapes of letters.

There is a distributed network of regions in the brain, which is fast, automatic and is activated in fluent reading. There is no difference across different cultures. Interestingly, elements of this network are also found in the perception of hand movements in non-human primates, indicating a long lineage for this ability.

In summary, when the expert reading network has been well trained it actually uses two distinct pathways in all cultures but with fine-grained modifications depending on the orthography. There is a visual word-from area, ‘reading by eye’, and another area in a specific area that decodes gestures, ‘reading by hand’. The authors write:

‘… recent developmental data show that reading acquisition is facilitated when young children are taught to write or finger-trace the letter shapes compared with classical grapho-phonemic teaching without a haptic [touch] component ... Conversely, fMRI of normal and dyslexic children also suggests that reading difficulties lead to a greater reliance on [a specific area in the left hemisphere], suggesting partial compensation through the gesture system ...’