Differential BOLD Hemodynamics in Young and Elderly: Emphasis on Post-Stimulus Undershoot
Gopinath K, Wierenga C, Conway T, Crosson B, Briggs R
Differences in the BOLD hemodynamic response, with particular emphasis on the post-stimulus undershoot, were studied between young adults (20 subjects; 20-34 yrs) and elderly (20 subjects; 68-84 yrs) populations, using a semantic picture naming task. Young adults exhibited significantly greater magnitude of the post-stimulus undershoot than elderly adults in a number of areas in the brain. These areas also exhibited correlated differences in the amplitude and width of the positive BOLD response. The elderly showed greater undershoot magnitudes in a few areas, often correlated with a greater positive BOLD HDR amplitude.