Chapter 3 - The Neurobiological Bases of Reading Disability

Summary

This chapter considers the neurobiological bases of reading disability (dyslexia). These primarily concern the working of the brain and the nature and role of genetics (heritability). The first part of the chapter considers the development of the “reading brain,” describing key brain areas and their functions. The historical development of brain studies in reading disability from the early role of postmortems to present-day scanning techniques is outlined. The discussion of each of contemporary measurement approaches is split into two parts. Opening with work that focuses upon brain structure, discussion then considers brain functioning, particularly functional magnetic resonance imaging (fMRI). The second part of the chapter focuses upon the contribution of genetics to the dyslexia debate. In so doing, it considers both quantitative and more recent molecular approaches. The significant heritability of reading skill is discussed and the rudimentary knowledge base concerning the genetics of reading is acknowledged. The chapter concludes by noting that, despite significant scientific advances in both fields, neither current brain scanning techniques nor genetic analyses can be used to diagnose reading disability/dyslexia or inform practitioners about appropriate forms of intervention.