Identifying key markers of visual short-term memory: How looking dynamics and physiology can inform
our interpretation of change detection

Visual short-term memory (STM) is a foundational component of general cognitive ability that develops rapidly during the first year of life. Currently, it is unknow if visual STM performance in infancy reflects a similar memory mechanism used by adults. This is due to significant differences in the tasks used to measure visual STM performance in infant and adults. The current project has identified key behavioral and physiological indexes of visual STM performance in infants by utilizing data collected from adult participants in a similar task. In Experiment 1, adult visual dynamics were assessed during a change-detection task, and several key behaviors identified. In Experiment 2, these behaviors were subsequently observed in infants and adults while performing a similar change-detection task. Experiment 3 then applied infant-specific adaptations to an adult change-detection procedure, and again, found significant similar patterns of responding. Experiment 4 proposed a novel visual STM assessment technique, shedding light on the extent to which infant performance is uniquely influenced by incidental attention to individual array items. Results demonstrated that the order of fixation affected subsequent performance on a change-detection task. Combined, these results have identified an informative metric for understanding change detection in both infant and adult populations and have provided researchers with a novel method of measuring a cornerstone of cognitive development, visual STM. Taken together, results from these tasks demonstrate that visual dynamics such as saccade count, run count, average fixation duration, and changes in pupil size may be an ideal means of assessing visual STM ability in both infants and adults.