Decisions about objects in real-world scenes are influenced by visual saliency before and during their inspection

Geoffrey Underwood, Katherine Humphrey, Editha van Loon
2011 Vision Research  
Evidence from eye-tracking experiments has provided mixed support for saliency map models of inspection, with the task set for the viewer accounting for some of the discrepancies between predictions and observations. In the present experiment viewers inspected pictures of road scenes with the task being to decide whether or not they would enter a highway from a junction. Road safety observations have concluded that highly visible road users are less likely to be involved in crashes, suggesting
more » ... hat saliency is important in real-world tasks. The saliency of a critical vehicle was varied in the present task, as was the type of vehicle and the preferred vehicle of the viewer. Decisions were influenced by saliency, with more risky decisions when low saliency motorcycles were present. Given that the vehicles were invariably inspected, this may relate to the high incidence of "looked-but-failed-to-see" crashes involving motorcycles and to prevalence effects in visual search. Eye-tracking measures indicated effects of saliency on the fixation preceding inspection of the critical vehicle (as well as effects on inspection of the vehicle itself), suggesting that high saliency can attract an early fixation. These results have implications for recommendations about the conspicuity of vulnerable road users. 2 The terms saliency and conspicuity are used as equivalents here, but in the Itti and Koch (2000) model saliency is the aggregate of all operative conspicuity channels. So, the analysis of intensity conspicuity, colour conspicuity, motion conspicuity, etc., all contribute to the overall saliency map. Research on high visibility in applied setting such as road accident liability has tended to use the single term conspicuity to refer to any feature that increases the visibility of a road user, including changes to clothing and the vehicle itself, and temporary changes such as the use of daytime runninglights.
doi:10.1016/j.visres.2011.07.020 pmid:21820003 fatcat:gh7wllql25eqdpn667lo37jpra