Evidence Accumulation Rate Moderates the Relationship between Enriched Environment Exposure and Age-Related Response Speed Declines
- Méadhbh Brosnan1,2,3,4,5,
- Daniel J. Pearce1,
- Megan H. O’Neill1,
- Gerard M. Loughnane7,8,
- Bryce Fleming1,
- Shou-Han Zhou6,
- Trevor Chong1,
- Anna C. Nobre2,3,4,
- Redmond G. O Connell1,7, and
- Mark A. Bellgrove1
- 1Turner Institute for Brain and Mental Health and School of Psychological Sciences, Monash University, Melbourne, Victoria 3800, Australia
- 2Department of Experimental Psychology, University of Oxford, Oxford OX2 6GG, United Kingdom
- 3Oxford Centre for Human Brain Activity, University of Oxford, Oxford OX3 7JX, United Kingdom
- 4Wellcome Centre for Integrative Neuroimaging, University of Oxford, Oxford OX3 9DU, United Kingdom
- 5School of Psychology, University College Dublin, Dublin 2, Ireland
- 6Department of Psychology, James Cook University, Brisbane, Queensland 4000, Australia
- 7School of Business, National College of Ireland, Dublin 1, Ireland
- 8Trinity College Institute of Neuroscience and School of Psychology, Trinity College Dublin, Dublin 2, Ireland
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Author contributions: M.B., M.H.O., and M.A.B. designed research; D.J.P., M.H.O., and B.F. performed research; M.B., G.M.L., R.G.O., and M.B. contributed unpublished reagents/analytic tools; M.B., D.J.P., M.H.O., G.M.L., B.F., S.-H.Z., and R.G.O. analyzed data; M.B., D.J.P., T.C., A.C.N., and M.A.B. wrote the paper.
Abstract
Older adults exposed to enriched environments (EEs) maintain relatively higher levels of cognitive function, even in the face of compromised markers of brain health. Response speed (RS) is often used as a simple proxy to measure the preservation of global cognitive function in older adults. However, it is unknown which specific selection, decision, and/or motor processes provide the most specific indices of neurocognitive health. Here, using a simple decision task with electroencephalography (EEG), we found that the efficiency with which an individual accumulates sensory evidence was a critical determinant of the extent to which RS was preserved in older adults (63% female, 37% male). Moreover, the mitigating influence of EE on age-related RS declines was most pronounced when evidence accumulation rates were shallowest. These results suggest that the phenomenon of cognitive reserve, whereby high EE individuals can better tolerate suboptimal brain health to facilitate the preservation of cognitive function, is not just applicable to neuroanatomical indicators of brain aging but can be observed in markers of neurophysiology. Our results suggest that EEG metrics of evidence accumulation may index neurocognitive vulnerability of the aging brain.
Significance Statement Response speed in older adults is closely linked with trajectories of cognitive aging. Here, by recording brain activity while individuals perform a simple computer task, we identify a neural metric that is a critical determinant of response speed. Older adults exposed to greater cognitive and social stimulation throughout a lifetime could maintain faster responding, even when this neural metric was impaired. This work suggests EEG is a useful technique for interrogating how a lifetime of stimulation benefits brain health in aging.
- aging
- cognitive reserve
- decision-making
- enriched environments
- neurocognitive resilience
- response speed
- Received November 15, 2021.
- Revision received July 10, 2023.
- Accepted July 20, 2023.
- Copyright © 2023 Brosnan et al.
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