Age-related functional compensation in novelty and relational encoding of scenes : a brain activation and functional connectivity study
Leow, Dayton Wei Yang
Date of Issue2015
School of Humanities and Social Sciences
Past neuroimaging studies have demonstrated the functional involvement of bilateral inferior frontal gyrus (IFG), hippocampus and parahippocampus in novelty and relational encoding of scenes. Age-related reduction in hippocampal/parahippocampal (posterior brain region) activity and increase IFG (anterior brain region) activation is often found; which is representative of the posterior-to-anterior shift in aging (PASA) model. This study utilized functional MRI-task sensitive to novelty and relational encoding of indoor/outdoor scenes to examine the age-related changes in brain activation and IFG-hippocampus/parahippocampus functional connectivity, among high/low performing older adults and young adults, for PASA effect and the support for its compensatory function. Functional scans of 33 old adults and 48 young adults were analyzed at the group level, in terms of whole brain activation and seed-to-voxel functional connectivity, focusing on the IFG, hippocampus and parahippocampus. Significant parahippocampal activation was generally found in high/low performing older adults and young adults for novelty and relational encoding of scenes. No significant hippocampus/parahippocampus-to-IFG shift in aging effect was found. However, functional connectivity results generally revealed an age-related increase in IFG-hippocampus/parahippocampus functional connectivity for both novelty and relational encoding of scenes, which served a compensatory function for high performing older adults. The present findings pose theoretical contribution to the research in aging.
Final Year Project (FYP)
Nanyang Technological University