It has been claimed that adults with a history of reading disability show differential patterns of brain activity compared to normal readers. What aspects of these patterns are confounded with task difficulty? A novel Non-word Rhyme Task with four levels of difficulty has been devised such that normal readers' performance can be reduced to the level of dyslexic readers. A group of 10 dyslexic and 10 normal readers will be tested using magnetoencephalography (MEG) during performance of the Non-word Rhyme Task. Brain activity patterns will be compared for the two easiest levels for dyslexic readers, and the two hardest levels for normal readers. This will indicate whether some of the differences in the patterns of brain activation between normal and dyslexic readers are eliminated when both groups are equally challenged. Reading groups will also be compared at only the easiest level of difficulty where dyslexic readers perform more poorly than the normal readers. This information will affect interpretation of the neural signatures that may someday be used for diagnosis of subtypes of dyslexia.
| Frye, Richard E; Fisher, Janet McGraw; Witzel, Thomas et al. (2008) Objective phonological and subjective perceptual characteristics of syllables modulate spatiotemporal patterns of superior temporal gyrus activity. Neuroimage 40:1888-901 |
