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P3‐169: Functional neuroimaging of prose recall in healthy and pathological aging
Author(s) -
Johnson David,
Wang Clarice
Publication year - 2012
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2012.05.1389
Subject(s) - comprehension , neurocognitive , recall , psychology , cognition , dementia , narrative , cognitive psychology , neuroimaging , episodic memory , audiology , developmental psychology , neuroscience , medicine , disease , linguistics , pathology , philosophy
activity patterns on functional MRI (fMRI) tasks in nondemented older adults. Individuals with Alzheimer’s Disease (AD) show abnormal patterns of brain activation when doing learning and memory tasks in fMRI. We investigated whether higher levels of physical fitness might positivelymediate brain activation in both healthy elderly and AD individuals during a learning and memory fMRI paradigm.Methods: Twenty-three older adults (12 AD, 11 nondemented) completed maximal exercise testing and an fMRI session. Peak oxygen consumption (VO 2 peak) was used as a measure of cardiorespiratory fitness. Structural and functional imaging was performed. Functional imaging included a visual memory task which they were asked recall if they had seen an image in a set standardized indoor and outdoor visual scenes they were previously exposed to. BOLD images were rigid-body transformed to the first image, slice timing corrected (sinc-interpolation), normalized to MNI space, and smoothed using an 8mm FWHM Gaussian kernel. Group differences were explored and VO 2 peak was regressed against activation maps, controlling for age. Activation maps were masked to regions of high gray matter probability across each group and a threshold for significance was set at P<0.001, k>1⁄45 for these exploratory analyses. Results: Across all individuals, bilateral visual cortex fusiform gyrus and right dorsolateral prefrontal cortex were active during picture recall. Individuals without dementia showed increased activation in right temporal pole, hippocampus/ parahippocampus and left middle temporal lobe compared to individuals with AD during the recall task. In the nondemented group, better fitness (higher VO 2 peak) was associated with less activation of left middle temporal lobe during recall. In the AD group, better fitness was associated with less activation of left cerebellum during recall, a region previously reported to show increase activation in AD during recall tasks. Conclusions: Previous studies have identified associations between fitness levels and brain activation during cognitive tasks. Our results extend these findings to suggest that regional recruitment during visual recall may be modulated both by dementia and fitness level. These findings support further investigation of the effects of fitness and exercise training on memory in the earliest stages of dementia.