Towards the Origins of Dyslexia

This chapter highlights the origins of dyslexia. The problems of dyslexia have been addressed by theorists from a bewildering variety of backgrounds—experimental psychologists, educationalists, geneticists, neurophysiologists, neuroanatomists, statisticians, and cognitive scientists. Each discipline has brought a different perspective and contributed a range of intriguing findings that should eventually fit together to complete the jigsaw connecting the genes with the brain with the mind. This chapter discusses different studies whose results established that a phonological deficit alone was not capable of accounting for the range of deficits found. There was strong evidence of an automatization deficit on motor balance, and the automatization deficit hypothesis appeared capable of explaining not only the balance deficits but also the phonological deficit and the established problems of working memory. However, the automatization deficits are best seen also as a symptom of some deeper underlying cause. The lack of a deficit for simple reactions, taken together with the appearance of a deficit in even the simplest choice reactions, suggest that the most likely cause is some problem within the central brain processes, most probably in the hypothetical inner loop for information transmission between different brain modules.