Reward-based prioritization and perceptual feature effects on attentional flexibility in working memory

The focus of attention (FoA) is a resource within working memory (WM) assumed to hold limited information in a highly accessible state. Recent evidence suggests the FoA can flexibly adjust to hold early, middle, or terminal memory representations in a highly active state with adequate motivation. When a high-reward item is present, the FoA can be redirected to flexibly adjust and select prioritized items, leading to improved performance. This has been termed the prioritization effect. This finding has been demonstrated across prior investigations that have consistently used the color red to indicate the high-reward stimulus. The salience of the stimulus may alternatively explain the prioritization effect in that the salient item may have an easier time entering WM. Salience could influence memory performance through better encoding. The current study aims to test the effect of feature-based confounds (pop-out effect) on reward-based prioritization by using a probe-recognition task and alternating the color of the to-be-prioritized item. Four colors (red, green, blue, magenta) were used, and the color assigned to a higher point-value was randomized between subjects. Our results showed that the prioritization effect was still evident even when salience (pop-out) was controlled. Regardless of the color used there was a performance benefit for the prioritized list position. Comparisons with prior studies indicate that visual pop-out, while not necessary for prioritization, may help facilitate stronger reward effects. Raw trial-level data, statistical analysis, and task code are available in the Open Science Framework (OSF) repository ( https://osf.io/xsc34/overview ). The experiment was not preregistered.