An expectation-based memory deficit in aging

Memory performance can be enhanced by expectations regarding the appearance of ensuing stimuli. Here, we investigated the influence of stimulus-category expectation on memory performance in aging, and used fMRI to explore age-related alterations in associated neural mechanisms. Unlike younger adults, who demonstrated both working memory (WM) and long-term memory (LTM) performance benefits for face stimuli when this stimulus category was expected, older adults did not exhibit these memory benefits. Concordantly, older adults did not exhibit expectation-period activity modulation in visual association cortex (i.e., fusiform face area (FFA)), unlike youger adults. However, within the older population, individuals who demonstrated face-expectation memory benefits also exhibited expectation-period FFA activity modulation equivalent to younger adults. The older cohort also displayed diminished expectation-related functional connectivity between regions of the prefrontal cortex and the FFA, relative to younger adults, suggesting that network alterations underlie the absence of expectation-mediated cortical modulation and memory benefits. This deficit may have broader consequences for the effective utilization of predictive cues to guide attention and engender optimal cognitive performance in older individuals. (C) 2011 Elsevier Ltd. All rights reserved.