Abstract
Gaze is widely considered a good proxy for spatial attention. We address whether such "overt attention" is related to other attention measures in natural scenes, and to what extent laboratory results on eye movements transfer to real-world gaze orienting. We find that the probability of a target to be detected in a rapid-serial-visual-presentation task correlates with its probability to be fixated during prolonged viewing, and that both measures are similarly affected by modifications to the target's contrast. This shows a direct link between covert attention in time and overt attention in space for natural stimuli. Especially in the context of computational vision, the probability of an item to be fixated ("salience") is frequently equated with its "importance", the probability of it being recalled during scene description. While we confirm a relation between salience and importance, we dissociate these measures by changing an item's contrast: whereas salience is affected by the actual features, importance is driven by the observer's expectations about these features based on scene statistics. Using a mobile eye-tracking device we demonstrate that eye-tracking experiments in typical laboratory conditions have limited predictive power for real-world gaze orienting. Laboratory data fail to measure the substantial effects of implicit tasks that are imposed on the participant by the environment to avoid severe costs (e.g., tripping over) and typically fail to include the distinct contributions of eye, head and body for orienting gaze. Finally, we provide some examples for applications of mobile gaze-tracking for ergonomic workplace design and aiding medical diagnostics.
Meeting abstract presented at VSS 2014