To evaluate task-induced regional activation, we have applied a verbal and a spatial task previously demonstrating regional activation with other methods.94,108,119 This study examined activation for a spatial task (judgment, of line orientation) compared with a. verbal reasoning task (analogies) in a sample of 29 healthy participants (15 men and 14 women). Task difficulty was manipulated. An image-based multisubject analysis was performed by registering Inhibitors,research,lifescience,medical the brains of the different

subjects. A well-characterized brain registration algorithm was used to register the Tl images from the different subjects to that of one particular subject. The registration transformation was also performed on the statistical images. Once registered, the statistics were summed across subjects and divided by the square root of the number of subjects, as is appropriate for independent, normally distributed variables. The statistical images were smoothed by convolution

with a Gaussian kernel with full width at half maximum Inhibitors,research,lifescience,medical of 12 mm and thresholded at a. P value of 0.05 corrected for multiple comparisons using the theory of Gaussian random fields. The activation map in Figure 7 121 indicates that the hypothesized left-lateralized Inhibitors,research,lifescience,medical changes were seen for the verbal task in click here posterior temporal and inferior parietal regions, while right-latcralizcd increase was seen for the spatial task in these regions. This imagebased analysis revealed a. distributed network of cortical regions, which expanded for the hard verbal task and became more circumscribed for the hard spatial task. This effect was more pronounced in men than in women. The task by hemisphere interactions for the hypothesized inferior parietal, superior temporal, and planum temporale regions Inhibitors,research,lifescience,medical were significant at an order Inhibitors,research,lifescience,medical of magnitude comparable to what we have obtained with other methods (all F<0.001 ).121 Thus, it. appears that spatial processing requires, for harder tasks, greater reliance on visual association cortex with minimal activation of other areas. Poorer performance in women may relate to continued reliance on supplementary

strategies, perhaps verbal, which are ineffective for the success on the harder over spatial items. Such studies may help elucidate neural substrates of cognitive strategies for problem solving. Effects of aging on regional activation in relation to cognitive strategics have not yet been examined with fMRI. Figure 7. Blood oxygenation level-dependent (BOLD) activation for men and women during performance of easy and hard verbal and spatial tasks. Reproduced from reference 121: Gur RC, Alsop D, Glahn D, et al. An fMRI study of sex differences in regional activation … The study of ovarian aging As is generally the case for age-related changes, the hormonal environment, can have pervasive effects that require scrutiny, not only during early development,122 but also during the perimenopausal phase.