Age-related differences in memory-encoding fMRI responses after accounting for decline in vascular reactivity

摘要: BOLD fMRI has provided a wealth of information about the aging brain. A common finding is that posterior regions brain manifest an age-related decrease in activation while anterior show increase. Several neurocognitive models have been proposed to interpret these findings. However, one issue not sufficiently considered date signal based on vascular responses secondary neural activity. Thus above findings could be part due change, especially view expected decline health with age. In present study, we aim examine differences memory-encoding response context aging. One hundred and thirty healthy subjects ranging from 20 89 years old underwent scene-viewing task and, same session, cerebrovascular reactivity (CVR) was measured each subject using CO2-inhalation task. Without accounting for influence changes, task-activated showed typical visual cortex medial temporal lobe (MTL), but manifested increase right inferior frontal gyrus (IFG). individuals, CVR reduction observed all regions. We then used previously normalization approach calculate CVR-corrected signal, which defined as uncorrected divided by CVR. Based now seen both left sides IFG; no additionally model-based data CVR, again suggested change two regions, MTL