How do individuals direct attention to valuable information in working memory tasks? Evidence from eye-tracking

There is robust evidence that individuals can direct their attention towards valuable information in working memory. However, the cognitive mechanisms underlying such effects are still under debate. Whilst attentional refreshing is considered to at least partially drive the effect, research has yet to establish whether other processes also contribute. One possibility is that participants preferentially encode high value information, creating a stronger representation relative to other information presented. We tested this hypothesis in two experiments. Participants completed a visual working memory task, which involved remembering the color of shapes for a brief period of time. During the encoding phase participants' eye movements were recorded to assess fixation behaviors. Participants were then presented with one shape and asked to report the color as accurately as possible on a color wheel. In Experiment 1, participants experienced trials where one particular item was more valuable (i.e., worth more notional points than the rest), or trials where all items were of equal value. In Experiment 2, each item within a trial differed in its value in a graded manner (i.e., 1–2–3-4 points). Across both experiments, participants exhibited the lowest recall error for the highest value information. Moreover, participants spent significantly longer fixating high value items during the encoding phase relative to other items, and often encoded high value items first. These eye movement behaviors partially mediated the effect of value on recall error. Taken together, these experiments rule out the possibility that maintenance mechanisms solely drive value-based prioritization effects, demonstrating an important role of attention during encoding.