No matter what you do, travel is travel in visual foraging

In visual foraging, foragers collect multiple items from a series of visual displays (or “patches”). When the goal is to maximize the total or the rate of collection of target items, foragers must decide when to leave a depleted patch given that “traveling” from one patch to another incurs a temporal cost. In three experiments, we investigated whether the interposition of a secondary task during travel between patches in visual foraging altered patch-leaving behavior. Over the course of 10- or 30-minute experiments, participants foraged in simulated “berry patches” and traveled to the next patch at will. While they traveled, they either actively performed a secondary task or simply observed passing visual stimuli. Travel time was varied across conditions. The addition of a secondary task, regardless of its relevance to visual foraging, to traveling, or to both, did not impact patch-leaving times in the primary visual foraging task. In Experiment 1 and more weakly in Experiment 2, the patch-leaving decision was based on how long the travel took as predicted by the Marginal Value Theorem (MVT). In Experiment 3, however, patch-leaving did not depend on travel time. Participants ‘overharvested’ in a manner that suggests that they may have adopted rules different from those of MVT. Across all three experiments, patch-leaving did not depend on the nature of the travel.