Journal Article

Age differences in behavioral and neural correlates of proactive interference: Disentangling the role of overall working memory performance

Mader, Irina, Kaller, Christoph P., Loosli, Sandra V., Rahm, Benjamin, Weiller, Cornelius, Unterrainer, Josef M.

2016

Overview

Reliable performance in working memory (WM) critically depends on the ability to resist proactive interference (PI) from previously relevant WM contents. Both WM performance and PI susceptibility are subject to cognitive decline at older adult age. However, the behavioral and neural processes underlying these co-evolving developmental changes and their potential interdependencies are not yet understood. Here, we investigated PI using a recent-probes WM paradigm and functional MRI in a cross-sectional sample of younger (n=18, 10 female, 23.4±2.7years) and older adults (n=18, 10 female, 70.2±2.7years). As expected, older adults showed lower WM performance and higher PI susceptibility than younger adults. Resolution of PI activated a mainly bilateral frontal network across all participants. Significant interactions with age indicated reduced neural activation in older adults for PI resolution. A second analysis in a selection of younger and older adults (n=12 each) with matched WM performance also revealed significant differences in PI between both age groups and – on a descriptive level – again a hypo-activation of the older adults' PI network. But the differential effect of age on the neural PI effects did not reach significance in this smaller sample most likely to the reduced statistical power. However, given the highly similar patterns in both the overall and the WM-matched samples, we propose that the hypo-activation of the PI network in the older adults may not be attributable to age-related differences in overall WM performance, hence suggesting that higher PI susceptibility in older adult age does not directly depend on their lower WM performance. •Investigated age differences in working memory (WM) and proactive interference (PI)•Old adults show lower WM performance and more PI than younger adults.•Old adults show lower neural activation in frontal areas related to PI.•Lower PI performance and neural activation in older adults is independent from WM.•Cognitive and neural processing of PI appears to qualitatively differ at older age.

• Publisher: Elsevier Inc,Elsevier Limited
• Subject: Age / Age differences / Aged / Aging / Aging - physiology / Attention - physiology / Bias / Brain - physiology / Brain Mapping / Cross-Sectional Studies / Development / Female / Humans / Image Processing, Computer-Assisted / Inferior frontal gyrus / Inhibition / Magnetic Resonance Imaging / Male / Memory, Short-Term - physiology / Older people / Proactive interference / Studies / Working memory / Young Adult / Young adults