Strategic prioritisation enhances young and older adults' visual feature binding in working memory

Young (18-33 yrs) and older (60-90 yrs) adults’ ability to retain visual feature bindings in working memory was assessed, as was the extent to which memory could be enhanced using strategic prioritisation. The task involved sequentially presenting three coloured shapes, followed by a test probe in the form of an individual colour or shape, and participants were asked to recall the accompanying feature. Based on previous evidence, the earlier sequential objects are most vulnerable to forgetting, and in older adults this is especially so for the middle object. In Experiment 1, participants were instructed either to focus on all objects equally, or to prioritise a particular object in the array that was deemed more valuable (i.e. more points would be awarded if that object was probed and recalled correctly). As older adults may not be as strategically flexible as young adults, they might differentially benefit from instructions to focus attention on certain objects, especially for the most vulnerable ones. As expected, young adults outperformed older adults overall. A general recency effect was also found, and the poorest performance was observed at the middle serial position. Additionally, both age groups were equally able to prioritise an object in visual working memory, with the largest effects observed at the most vulnerable middle position. Experiment 2 investigated the potential effect of increasing encoding time. This replicated the findings from Experiment 1, but further showed that, under these conditions, processing speed does not limit older adults’ ability to benefit from strategic prioritisation.