title: Common attentional constraints in visual foraging.
abstract: Predators are known to select food of the same type in non-random sequences or "runs" that are longer than would be expected by chance. If prey are conspicuous, predators will switch between available sources, interleaving runs of different prey types. However, when prey are cryptic, predators tend to focus on one food type at a time, effectively ignoring equally available sources. This latter finding is regarded as a key indicator that animal foraging is strongly constrained by attention. It is unknown whether human foraging is equally constrained. Here, using a novel iPad task, we demonstrate for the first time that it is. Participants were required to locate and touch 40 targets from 2 different categories embedded within a dense field of distractors. When individual target items "popped-out" search was organized into multiple runs, with frequent switching between target categories. In contrast, as soon as focused attention was required to identify individual targets, participants typically exhausted one entire category before beginning to search for the other. This commonality in animal and human foraging is compelling given the additional cognitive tools available to humans, and suggests that attention constrains search behavior in a similar way across a broad range of species.
authors: Faculty of Psychology, School of Health Sciences, University of Iceland, Reykjavik, Iceland.
authors: Árni
authors: Á
authors: Kristjánsson
authors: Faculty of Psychology, School of Health Sciences, University of Iceland, Reykjavik, Iceland.
authors: Ómar I
authors: ÓI
authors: Jóhannesson
authors: Department of Cognitive Science, Faculty of Media and Knowledge Sciences, University of Malta, Msida, Malta.
authors: Ian M
authors: IM
authors: Thornton
mesh_terms: D000328:Adult; D000818:Animals; D001288:Attention; D005260:Female; D006801:Humans; D008297:Male; D011235:Predatory Behavior / Q000502:physiology*; D014796:Visual Perception; D055815:Young Adult