The Reading System
The Reading system
Men started using symbols as a means for communication 32000 years ago. A cave in Chau vet south of France is beautifully marked with paintings of horses, lions and tigers but also other symbolic forms such as hand paintings and crosses, which were discovered in Lascaux.
Writing was invented 5400 years ago and it quickly took many forms. The Egyptians hieroglyphs, cuneiform, the Maya and Chinese are some examples of radical inventions that had never been anticipated by anything in our evolution. In these inventions we see how highly sophisticated the brain is in its ability to create writing systems, so although writing is a recent cultural invention and shows a large degree of cultural variation, reading acquisition is not. Right from birth the brain acquires sophisticated concepts of objects, space, linguistic structures, social relations …and so on, that is why we are able to read because we inherit an efficient recognition system with enough plasticity to learn new shapes and relevant connections to link them to existing language areas.
Let’s begin to examine the reading brain, a word in the brain is represented as a visual object which is encoded right at the back of the brain, an area specialised for recognising faces, objects as well as words. A little bit to the front in the fusiform gyrus we have the visual word form, an area which has become attuned to the shape of the letters and the strings that form our words in any given orthographic system. From here the information is then transmitted to other localised parts responsible for word pronunciation and articulation and access to meaning. It is important to note that all the parts that activate in a reading brain are not completely known at the moment. Furthermore the visual word form arears are seen to be activated by spoken language in children before they begin to read and even in children six months of age! The area that draws much attention though is the visual word form area (the brain’s letter box) which is an interface between the visual and the existing site for language acquisition.in other words, learning to read consists of creating a bridge between vision and language-the visual representation of written words and text corresponding to the sound and meaning.
To fully appreciate the reading acquisition, we need to understand that they are specific circuits that are involved in the task. If you look at dyslexic children learning to read, studies by Dehaene reveal that there is a possibility that some connections have failed to form complete circuits because there is a disorganisation in the more superior aspects of the temporal lobe. The consequence is that such children won’t develop the optimal visual representation of the strings of words in the inferior part of the temporal lobe.
However interesting studies show that rehabilitation of dyslexia can actually bring restoration to the part of the brain area needed for reading. This is to prove the plasticity of the brain which can compensate for deficits in children who lack normal structures for reading. Hence intervention in struggling learners is paramount to be performed at an young age when the circuit is maximally plastic, in older learners , recovery from dyslexia can occur but with reduced efficiency.
Bain changes induced by learning to read (Stanislas Dehaene).