Characterising neural signatures of successful aging: Electrophysiological correlates of preserved episodic memory in older age

Brain Cogn. 2015 Jul:97:40-50. doi: 10.1016/j.bandc.2015.04.002. Epub 2015 May 24.

Abstract

While aging is associated with a gradual decline in memory, substantial preservation of function is observed in certain individuals and dissecting this heterogeneity is paramount to understanding successful aging. A cohort of elderly individuals were classified according to their level of memory preservation and administered a test of episodic memory in which participants were cued to learn or simply read each word and then to identify previously presented items in a delayed recognition phase. Mathematical modelling revealed that relatively preserved memory function was specifically linked to a faster rate of memorial evidence accumulation (drift rate). Analysis of event-related potentials at encoding revealed that high-performing elderly exhibited signals over parietal regions that discriminated between words to be learned vs. read for an additional 300-ms compared to young subjects suggesting a compensatory encoding mechanism that was absent in the low-performing group. At recognition, parietal signals associated with recollection processes discriminated previously learned words from read words in the young and high-performing old but not in low-performing old. These results reveal that successful aging is associated with specific adaptive neural markers during both encoding and retrieval.

Keywords: Encoding; Episodic memory; Event-related potentials; Neural compensation; Recognition; Successful aging.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Aged
  • Aging / physiology*
  • Brain / physiology*
  • Cues
  • Electroencephalography
  • Evoked Potentials / physiology
  • Female
  • Humans
  • Learning
  • Male
  • Memory, Episodic*
  • Parietal Lobe / physiology
  • Prefrontal Cortex / physiology
  • Reading*
  • Verbal Learning / physiology*
  • Young Adult