Assessing visual STM in infants and adults: eye movements and pupil dynamics reflect memory maintenance

Though previous work has demonstrated substantial short-term memory (STM) development in the first year of life (e.g., Ross-Sheehy, S., Oakes, L. M., & Luck, S. J. 2003. The development of visual short-term memory capacity in Infants. Child Development, 74(6), 1807–1822. doi:10.1046/j.1467-8624.2003.00639.x), limitations in infant-based procedures make it difficult to assess the continuity of STM mechanisms from infancy though adulthood. The goal of the current work is to present data collected from both infants and adults using a novel STM assessment task. Eye-tracking was used to capture gaze and pupillometry in 5-, 8- and 11-month-old infants and adults (n?=?176). Infant data replicate and extend previous findings demonstrating clear evidence of STM improvement from 5- to 11-months-of-age. Analysis of adult data reveal qualitatively similar patterns of responding, and additionally reveal several behavioural markers of STM accuracy including pupil dilation, saccade count, and switching. These results suggest that change-detection tasks recruit similar memory mechanisms in both infants and adults, and further suggest that visual dynamics may provide important new continuous measures of STM from infancy through adulthood.