The limits of visual working memory in children: Exploring prioritization and recency effects with sequential presentation

Recent research has demonstrated that, when instructed to prioritize a serial position in visual working memory, adults are able to boost performance for this selected item, at a cost to non- prioritized items (e.g. Hu et al., 2014). While executive control appears to play an important role in this ability, the increased likelihood of recalling the most recently presented item (i.e. the recency effect) is relatively automatic, possibly driven by perceptual mechanisms. In three experiments 7 to 10-year-old’s ability to prioritize items in working memory was investigated using a sequential visual task (total N = 208). The relationship between individual differences in working memory and performance on the experimental task was also explored. Participants were unable to prioritize the first (Experiments 1 & 2) or final (Experiment 3) item in a 3-item sequence, while large recency effects for the final item were consistently observed across all experiments. The absence of a priority boost across three experiments indicates that children may not have the necessary executive resources to prioritize an item within a visual sequence, when directed to do so. In contrast, the consistent recency boosts for the final item indicate that children show automatic memory benefits for the most recently encountered stimulus. Finally, for the baseline condition in which children were instructed to remember all three items equally, additional working memory measures predicted performance at the first and second but not the third serial position, further supporting the proposed automaticity of the recency effect in visual working memory.