What the brain thinks while reading

If men and women sometimes seem like they come from different planets, the difference in how their brains go about reading may help explain just how far apart those planets are. Husband-and-wife team of pediatric neurologist Bennett A. Shaywitz, M.D., and developmental pediatrician Sally E. Shaywitz, M.D., together with their team of investigators, electrified the neuroscientific world when they reported in 1995 in the journal Nature that female subjects had areas in both brain hemispheres active during reading while male subjects had only one. This was the first time functional differences in the brains of men and women had been shown. While it demonstrates important anatomical differences between the brains, it also may help explain why neurologists report that women with strokes tend to recover language abilities more rapidly than men.

The Shaywitzs' finding was in fact a byproduct of a much larger investigation of reading and language usage designed to identify neurological differences in the brains of non-impaired readers and those with dyslexia. "We're developing a much more in-depth picture of how the brain works in non-impaired readers and people with reading difficulties," says Robert K. Fulbright, M.D., director of clinical fMRI and a collaborator with the Shaywitzs.

Use of language for reading is an enormously complex mental activity involving motor-speech areas and language reception regions in the brain. Investigators ask study subjects to sound out nonsense words projected on a screen that is reflected to them while they undergo functional imaging. Areas of activation are then overlapped with anatomical scans. The results of each subject are "averaged" out to create a common brain space to account for individual differences in size and anatomy. The researchers are analyzing the data to determine differences between non-impaired readers and those with disabilities. Eventually, clinicians will diagnose children with various learning disabilities early on and begin treatment to prevent a lifetime of difficulties. "Reading disability is a circumscribed deficit surrounded by strengths," says Dr. Sally Shaywitz, professor of pediatrics and a faculty member in the Child Study Center. [Bennett Shaywitz is a professor with appointments in pediatrics, neurology and the Child Study Center.] "You need to identify those strengths, make the child aware of those strengths, and then maximize them to help overcome the disability."