Brain bases of reading and language. I am conducting research on the brain bases of language and reading in two labs: with Ken Pugh and his many collaborators at Haskins Laboratories, and with Jeff Binder, Language Imaging Lab, Medical College of Wisconsin.
Neural noise in developmental dyslexia: The idea that “noisy” processing in parts of the reading network is a primary mechanism in developmental dyslexia dates from the modeling work I did with Michael Harm in 1999 and experiments with Frank Manis, Zhong-lin Lu, and Anne Sperling at USC. The evidence for the neural bases of noisy processing is now accumulating rapidly. It mainly involves anomalies in the structure and functioning of white matter tracts linking reading and language related areas. “Noise” involves several phenomena: more variable responses to stimuli; less reliable signal propagation via white matter tracts; impaired learning from experience. These anomalies have been linked to high concentrations of the neurotransmitters choline and glutamate, and to susceptibility genes that affect their expression.
Bases of the “achievement gap”. Why are literacy levels consistently lower for African American children compared to whites? Poverty is certainly one major cause, but there are gaps at all SES levels. With Julie Washington (Georgia State University) and colleagues at UW, we have been examining an additional factor, dialect variation. Many African American children speak a dialect (AAE) that differs from the “standard” or “mainstream” dialect spoken in school. The linguistic validity and richness of AAE is not at issue. Rather, the socialcultural fact that AAE is not the dialect of instruction creates a more complex learning experience for dialect speakers. Children have to learn to accommodate the school dialect while learning to read and write and do arithmetic. Children who use the same dialect at home and in school do not have this additional overload. The playing field is not level, yet everyone is assessed against the same achievement standards. A “gap” results, other factors (such as SES) aside. Our research suggests that the gap could be reduced via changes in curriculum and assessment.
