Functional magnetic resonance imaging study of word recognition in normal elders

Four healthy, cognitively intact elders participated. Subjects underwent fMRI scanning while performing a word recognition task with an easy condition (low demand) and a difficult condition titrated to each subject's ability (titrated demand). Relative to low, titrated demand was associated with increased activation of the left medial frontal (cluster level P<.002), right superior temporal (P<.007) and right superior parietal cortices (P<.001). Increased activation of bilateral cortical areas by elders during the more challenging titrated demand compared with low demand may indicate recruitment of additional brain regions, enabling subjects to maintain performance despite increasing difficulty. Alternatively, the bilateral activation on this word recognition task may reflect compensatory use of right hemisphere networks.