Cognitive aging and categorical representations in visual working memory

A traditional view on cognitive aging is that visual working memory (VWM) capacity declines in older adults. Recent work has shown that visual information can be stored in VWM in different forms of representations. Specifically, VWM becomes more reliant on categorical representations as compared to continuous representations as memory load increases. Here, we replicated these findings and tested whether this holds for older adults. Participants memorized one to four colors; after a delay, an arrow pointed at the location of the color that needed to be reported. We used an extended mixture model to examine the extent to which memory responses were biased in the direction of the category prototypes. Our results showed that for both younger and older adults, VWM became more biased towards category prototypes with increasing memory load. Importantly, we found no difference in the extent to which VWM was biased towards category prototypes between younger and older adults. However, older adults showed an overall lower precision as compared to younger adults. Taken together, our results demonstrated that both younger and older adults became more reliant on categorical representations with increasing memory load; importantly, the extent to which categorical representations were involved in maintaining VWM information was insensitive to age.