Alpha phase dynamics predict age-related visual working memory decline.

Alpha oscillations (7-14Hz) are modulated in response to visual temporal and spatial cues. However, the neural response to alerting cues is less explored, as is how this response is affected by healthy aging. Using scalp EEG, we examined how visual cortical alpha activity relates to working memory performance. Younger (20-30 years) and older (60-70 years) participants were presented with a visual alerting cue uninformative of the position or size of a lateralized working memory array. Older adults showed longer response times overall and reduced accuracy when memory load was high. Older adults had less consistent cue-evoked alpha phase resetting than younger adults, which predicted worse performance. Alpha phase prior to memory array presentation predicted response time, but the relationship between phase and response time was weaker in older adults. These results suggest that changes in alpha phase dynamics, especially prior to presentation of task-relevant stimuli, potentially contribute to age-related cognitive decline.
(Copyright © 2016 Elsevier Inc. All rights reserved.)