Inter- and Intra-Hemispheric Age-Related Remodeling in Visuo-Spatial Working Memory

Area of Science:

• Neuroscience
• Cognitive Psychology
• Gerontology

Background:

• Event-related potential (ERP) analysis in electroencephalography (EEG) studies has revealed age-related changes in visuo-spatial working memory (vWM).
• Existing models like Hemispheric Asymmetry Reduction in Older Adults (HAROLD) and Posterior-Anterior Shift in Aging (PASA) suggest older adults recruit additional brain areas.
• A detailed temporal analysis of these age-related neural dynamics is needed.

Purpose of the Study:

• To investigate the temporal dynamics of age-related neural activations during visuo-spatial working memory (vWM).
• To examine how these activations align with the HAROLD and PASA models across different stages of cognitive processing.
• To characterize the time course of neural recruitment in older adults compared to younger adults during a vWM task.

Main Methods:

• A data-driven, whole-scalp electroencephalography (EEG) analysis was employed.
• Younger (N=36) and older adults (N=35) performed a delayed match-to-sample vWM task.
• Neural activity was analyzed across different stages of stimulus processing (retention and retrieval).

Main Results:

• Behaviorally, younger adults outperformed older adults.
• Older adults exhibited supplementary bilateral posterior (HAROLD-like) and frontal (PASA-like) activations, particularly under higher memory loads.
• These age-related supplementary activations were dynamic, varying across retention and retrieval stages, with HAROLD-like activity prominent in retention and PASA-like in both.

Conclusions:

• Age-related neural changes in vWM are not uniform across all cognitive processing stages.
• The findings support and extend the HAROLD and PASA models by detailing their temporal dynamics in vWM.
• Older adults exhibit distinct, time-dependent neural recruitment strategies during visuo-spatial working memory tasks.