Coding of featural information in visual working memory in 2.5-year-old toddlers

The number of objects that infants can remember in visual working memory (VWM) increases rapidly during the first few years of life (Kaldy & Leslie, 2005; Ross-Sheehy, Oakes, & Luck, 2003). However, less is understood about the representational format of VWM: whether storage is determined by fixed-precision memory slots, or the allocation of a limited continuous resource. In the current study, we adapted the Delayed Match Retrieval eye-tracking paradigm (Kaldy, Guillory, & Blaser, 2016), to test 2.5-year-old toddlers' ability to remember three object-location bindings when the to-be-remembered objects were all unique (Experiment 1) versus when they shared features such as color or shape (Experiment 2). 2.5-year-olds succeeded in Experiment 1, but only performed marginally better than chance in Experiment 2. Interestingly, when incorrect, participants in Experiment 2 were no more likely to select a decoy item that shared a feature with the target item. It seems that the increased similarity of to-be-remembered objects did not impair memory for the objects directly, but instead increased the likelihood of catastrophic forgetting.