UCLA

The goal of this dissertation was to examine the scope and development of early visual short-term memory (VSTM) abilities in 6–12-month-old infants. Study 1 investigated individual- and age-related differences across three unique VSTM tasks by examining the effect of increased delay on memory performance. Results suggest longer-term memory processes are quantifiable utilizing 500-1250 ms delays by 8 months with the Change Detection paradigm and spatial- attention cueing processes are quantifiable by 10 months with the Delayed Response paradigm. Performance improved from 6-12 months and longer delays impaired performance. Study 2 examined whether fragile VSTM abilities were responsible for infants’ A-Not-B error, a phenomenon often observed when searching for an object hidden at one of two locations (A and B). Six to 12-month-olds were assessed on a looking A-Not-B task as well as on Delayed Response and Change Detection to assess links between performance. Individual differences in VSTM performance were not predictive of A-Not-B error performance, providing evidence that VSTM accounts may not solely provide explanation of A-Not-B error. Study 3 assessed whether individual differences in 8-month-olds’ neural band power was predictive of their VSTM performance. Infants’ continuous EEG was recording during Change Detection as well as during a baseline resting-state. Results suggest the early alpha band modulates VSTM performance, with decreases in alpha band power shown for higher performers and increases in alpha band power shown for lower performers, relative to baseline. Theta band power was not found to be related to VSTM performance. These outcomes help inform the understanding of infant VSTM and its emergence throughout early development.