Dyslexia, learning, and the brain - Roderick Nicolson

Dyslexia research has made dramatic progress since the mid-1980s. Once
discounted as a "middle-class myth," dyslexia is now the subject of a
complex -- and confusing -- body of theoretical and empirical research. In
Dyslexia, Learning, and the Brain, leading dyslexia researchers
Roderick Nicolson and Angela Fawcett provide a uniquely broad and coherent analysis
of dyslexia theory. Unlike most dyslexia research, which addresses the question
"what is the cause of the reading disability called dyslexia?" the
authors' work has addressed the deeper question of "what is the cause of the
learning disability that manifests as reading problems?" This perspective
allows them to place dyslexia research within the much broader disciplines of
cognitive psychology and cognitive neuroscience and has led to a rich framework,
including two established leading theories, the automatization deficit account
(1990) and the cerebellar deficit hypothesis (2001).

Nicolson and
Fawcett show that extensive evidence has accumulated to support these two theories
and that they may be seen as subsuming the established phonological deficit account
and sensory processing accounts. Moving to the explanatory level of neural systems,
they argue that all these disorders reflect problems in some component of the
procedural learning system, a multiregion system including major components of
cortical and subcortical regions. The authors' answer to the fundamental question
"what is dyslexia?" offers a challenge and motivation for research
throughout the learning disabilities, laying the foundations for future
progress.