Regional cerebral blood flow (rCBF) in normal readers: bilateral activation with narrative text

Based on recent evidence that suggests a more active participation of the right cerebral hemisphere in reading, this exploratory study examined changes in regional cerebral blood flow (rCBF) in three normal subjects during the reading of controlled narrative text. Narrative text presumably activates all neurocognitive processes important in reading including the semantic, pragmatic, emotional, and imagery components. Because of the small number of subjects, percentage change over a baseline at rest condition in rCBF during reading was compared to test/retest variability in control subjects. Effect size was also considered. The results indicated statistically significant bilateral central posterior activation during reading. These findings are consistent with an evolving model of bilateral language representation in which subcortical structures and right hemispheric systems are functionally and anatomically tied to the dominant left hemispheric language centers.