Abstract
Accumulating evidence demonstrates that selection history influences the allocation of attention. However, it is unclear how visual working memory (VWM), which is tightly connected to attention, is influenced by selection history. The aim of present study was to investigate the influence of encoding history on VWM encoding. By incorporating task switching into an attribute amnesia task, participants’ encoding history for stimulus identity was manipulated and its corresponding influence on VWM performance was tested. In Experiment 1, while participants in the selection history group switched between reporting the color of a target digit among letters and the identity of a target letter among digits, participants in the no selection history group only reported the color of the target regardless of whether it was a letter or a digit. Then participants in both groups were unexpectedly asked to report the identity of a target digit. The results showed that memory performance in this surprise test was significantly better in the selection history group. Experiment 2 was identical to the no selection history condition in Experiment 1 except that the letter task was excluded, thus removing the task switching demand. Compared to the no selection history group in Experiment 1, memory performance for the surprise test was improved, indicating that the increased attentional demands in target identification associated with task switching does not help but actually hinders encoding of target identify into VWM. Experiment 3 was identical to Experiment 2 except that there was no mention of identity as a probed feature in task instruction; a similar pattern of results was obtained, clarifying that verbal instruction does not have a crucial influence on participants’ performance, which is mainly driven by prior experience in the task. Collectively, these results lend unique insights into how selection history influences the encoding of stimulus features into VWM.