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Published on: September 18, 2021
A neural mechanism underlying memory failure in older adults
W Dale Stevens1, Lynn Hasher, Kimberly S Chiew
1Department of Psychology, Harvard University, Cambridge, Massachusetts 02138, USA. dstevens@wjh.harvard.edu
Summary
Older adults experience memory decline due to impaired inhibition of distractions. This study reveals increased activity in distraction-related brain regions in older adults during unsuccessful memory encoding, unlike younger adults.
Area of Science:
- Neuroscience
- Cognitive Psychology
- Aging Research
Background:
- Older adults exhibit memory deficits, particularly in recall and recognition, linked to difficulties inhibiting irrelevant information during memory encoding.
- Functional magnetic resonance imaging (fMRI) studies have explored successful memory encoding in aging, but the neural basis of memory failures remains unclear.
Purpose of the Study:
- To investigate the neural mechanisms underlying memory failures in older adults during unsuccessful encoding.
- To identify brain regions associated with distraction and their functional connectivity in aging memory processes.
Main Methods:
- Utilized functional magnetic resonance imaging (fMRI) to compare brain activity between younger and older adults during successful and unsuccessful memory encoding tasks.
- Analyzed activation patterns in encoding-related, distraction-mediating, and default mode brain regions.
- Examined functional connectivity between these identified brain regions.
Main Results:
- Both age groups showed reduced activation in memory encoding regions during unsuccessful encoding.
- Older adults, but not younger adults, exhibited increased activity in distraction-related areas (auditory cortex, left prefrontal cortex) during unsuccessful encoding.
- These distraction-related regions were functionally connected with default mode network areas in older adults.
Conclusions:
- Older adults' memory failures may stem from heightened distraction and increased environmental monitoring, potentially hindering the suppression of default mode activity.
- Impaired inhibition of task-irrelevant input, exacerbated by the fMRI environment, contributes to memory decline in aging.
- Findings offer insights into the neural basis of age-related memory deficits and have implications for fMRI research in neurocognitive aging.
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