Training-Induced Changes in Dual -Task fMRI Activation in Young and Old Adults

105 p.Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2005.We conducted a series of studies to examine the neural correlates of training-related improvements in dual-task processing in older and younger adults. The first study consisted of untrained younger adults with the goal to discriminate between cortical regions involved in preparing to make more than one response from those involved in the management and execution of two tasks. To assess this, we employed a blocked event-related functional magnetic resonance imaging (fMRI) design. We found that the dual-task elicited a network of cortical regions including the left and right inferior frontal gyrus, anterior cingulate, parietal cortex, and basal ganglia. These results argue that a variety of neural regions are involved in the coordination of performing multiple concurrent tasks even after minimizing task-preparatory processes. In the second study we examined training-related changes in cortical activity in the same dual-task paradigm in the hope of (a) assessing the direction and meaning of the changes, and (b) addressing shortcomings of previous training studies. Two fMRI sessions, one before training and one after training, were performed on both a control group and a training group. We found that most regions involved in dual-task processing before training showed reductions in activation after training indicating increased neural efficiency in dual-task processing. The third study employed the same dual-task training paradigm in a sample of older adults (>55 years old). The goal of this study was to investigate (a) whether cognitive and neural decline could be reversed in older adults through minimal amounts of training, and (b) whether an improvement in behavioral performance would result in smaller age differences in cortical activation. As predicted, we found that training-induced performance improvements were correlated with a significant increase in hemispheric asymmetry and a reduction in age-differences in ventral and dorsal prefrontal cortex. These results indicate that cognitive training programs can reliably alter the functioning of the older and younger adult brain and reduce age-differences in activation.U of I OnlyRestricted to the U of I community idenfinitely during batch ingest of legacy ETD