An fMRI investigation on simple multiplication in younger and older adults

Abstract

Objective To investigate the cortical activation patterns and their correlation with behavioristics during simple multiplication in Chinese younger and older adults. Methods Functional magnetic resonance imaging (fMRI) was performed as healthy younger and older participants resolving arithmetic and control problems. Results Totally 39 right-handed healthy adults were recruited in this study, including 19 (11 females, 8 males) younger and 20 (12 females, 8 males) older subjects. Age (P = 0.000) was significantly different between 2 groups, and no significant difference was observed in years of education (P = 0.125) and IQ scores (P = 0.921). The accuracy for simple multiplication (P = 0.880) and control task (P = 0.142) were not significantly different between 2 groups, however differences were observed in reaction time for experimental (P = 0.005) and control (P = 0.000) tasks. In younger group, activation in right hemisphere included inferior parietal lobule with an extending to the intraparietal sulcus and superior/middle temporal gyrus, precentral gyrus, premotor cortex and prefrontal cortex. Activation of supramarginal gyrus, angular gyrus, temporal lobe was found in the left. And activation in medial cingulate gyrus, precuneus, parahippocampal gyrus, uncus, and supplementary motor area (SMA) was also observed. In older group, supramarginal gyrus, inferior parietal lobule, precentral gyrus, premotor cortex and prefrontal cortex were activated in the right hemisphere. Left angular gyrus, supramarginal gyrus, precentral gyrus, premotor cortex, insula and prefrontal cortex were also activated, as well as cingulate gyrus, paracentral lobule and prefrontal cortex in the medial part. The conjunction analysis of the fMRI data revealed in a distributed network consisting of inferior parietal area, precuneus, precentral/postcentral gyrus and prefrontal lobe, as well as some subcortical areas. Conclusions The major components of the network subserving simple multiplication are not significantly affected by advancing age, in addition activation in older people concentrates to task related parietal area.

doi: 10.3969/j.issn.1672-6731.2014.03.010