Object-intrinsic oddities draw early saccades

Abstract

The authors investigated whether anomalous information in the periphery of a scene attracts saccades when the anomaly is not distinctive in its low-level visual properties. Subjects viewed color photographs for 8 s while their eye movements were monitored. Each subject saw 2 photographs of different scenes. One photograph was a control scene in which familiar objects appeared in their canonical form. In the other picture, objects were altered in a way that rendered them deviant without introducing any obvious changes in low-level visual saliency. In Experiment 1, these alterations involved rotating an object in an unnatural fashion (e.g., an inverted head on a portrait, a truck parked on its front end). In Experiment 2, colors were distributed over objects in a way that was either reasonable or anomalous (e.g., a green cup vs. a green hand). Subjects fixated the anomalous items earlier (both in time and in order of fixations) than the nondistorted objects, suggesting that violations of canonical form are detected peripherally and can affect the likelihood of fixating an item.