Feature integration theory in non-humans: Spotlight on the archerfish

The ability to visually search, quickly and accurately, for designated items in cluttered environments is crucial for many species to ensure survival. Feature integration theory, one of the most influential theories of attention, suggests that certain visual features that facilitate this search are extracted pre-attentively in a parallel fashion across the visual field during early visual processing. Hence, if some objects of interest possess such a feature uniquely, it will pop out from the background during the integration stage and draw visual attention immediately and effortlessly. For years, visual search research has explored these ideas by investigating the conditions (and visual features) that characterize efficient versus inefficient visual searches. The bulk of research has focused on human vision, though ecologically there are many reasons to believe that feature integration theory is applicable to other species as well. Here we review the main findings regarding the relevance of feature integration theory to non-human species and expand it to new research on one particular animal model - the archerfish. Specifically, we study both archerfish and humans in an extensive and comparative set of visual-search experiments. The findings indicate that both species exhibit similar behavior in basic feature searches and in conjunction search tasks. In contrast, performance differed in searches defined by shape. These results suggest that evolution pressured many visual features to pop out for both species despite cardinal differences in brain anatomy and living environment, and strengthens the argument that aspects of feature integration theory may be generalizable across the animal kingdom.