Stella Wernicke¹ (), Paul M Bays¹; ¹University of Cambridge

In visuospatial working memory (VSWM), two kinds of location information can contribute to recall: egocentric, defined relative to the observer, and allocentric, defined by the spatial relationships between objects. Previous work (Aagten-Murphy & Bays, 2019) found that resources for storing information from these two sources are limited, but independent. In adults, VSWM declines with age, but whether the two memory systems deteriorate equally is not known. To disentangle the contributions of ego- and allocentric processing to age-related VSWM decline, 40 young (18–30 years) and 40 older (60–70 years) neurotypical healthy adults completed an online VSWM task. In each trial, three colored disks were presented at random locations. After a brief delay, one stimulus was cued by its color, and participants reported its remembered location. Additionally, a larger gray disk, serving as a visual landmark, was either present throughout the entire trial (LM-PRESENT; 96 trials) or only during stimulus presentation (LM-ENCODING; 48 trials). We fit the data with a model in which only egocentric location information is available in LM-ENCODING, but this is optimally combined with allocentric information about location relative to the landmark for LM-PRESENT. Allocentric precision is assumed to peak at the location of the landmark and decline with increasing distance from it, while egocentric precision is independent of stimulus–landmark distance. This model fit the data better than models assuming allocentric information was integrated in both conditions or neither. While egocentric memory fidelity was lower in older than in younger adults (BF10 = 325), there was evidence against age-related differences in peak allocentric precision (BF10 = 0.359) and its decline with distance (BF10 = 0.530). These results suggest that allocentric VSWM is relatively preserved with age, whereas egocentric memory degrades more strongly. Future research could investigate the neural basis of this dissociation and contrast healthy aging to neurodegenerative disorders.

Acknowledgements: SW received a PhD scholarship from the Foundation of German Businesses, financed by the German Federal Ministry of Research, Technology, and Space. Additional support was provided through a research prize for research expenses from the Wilhelm Woort Foundation for Aging Research awarded to SW. The authors declare no conflicts of interest.