Foraging with your eyes: a novel task to study cognitive strategies involved in (visual) foraging behaviour.

In this study we introduce a new gaze-contingent visual foraging task in which participants searched through an environment by looking at trees displayed on a computer screen. If the looked-at tree contained a fruit item, the item became visible and was collected. In each trial, the participant's task was to forage for a defined number of fruit items. In two experiments, fruit items were either randomly distributed about the trees (dispersed condition) or organised in one large patch (patchy condition). In the second experiment, we addressed the role of memory for foraging by including a condition that did not require memorising which trees had already been visited by changing their appearance (tree fading). Foraging performance was superior in the patchy as compared to the dispersed condition and benefited from tree-fading. In addition, with further analyses on search behaviour, these results suggest (1) that participants were sensitive to the distribution of resources, (2) that they adapted their search/foraging strategy accordingly, and (3) that foraging behaviour is in line with predictions derived from foraging theories, specifically area-restricted search, developed for large scale spatial foraging. We therefore argue that the visual search task presented shares characteristics and cognitive mechanisms involved in successful large-scale search and foraging behaviour and can therefore be successfully employed to study these mechanisms.