Abstract
The gaze is directed to various locations in the visual field from moment to moment for acquiring information necessary to recognize the external environment. Previous studies showed that the gaze is directed frequently to spatial locations with high saliency defined by lower-order visual features, suggesting that the visual system assigns the higher priority in spatial domain to fixate salient locations. However, it remains unclear whether gaze priority also exists in temporal domain and what characteristics of visual information dominates temporal gaze priority. To resolve this question, we recorded eye movements of human observers while they saw natural scene images and investigated visual information of gazed locations over time. Natural scene images were selected from large image databases (Mottaghi et al., 2014; Zhou et al., 2016) such that a number of presented object categories was as large as possible ( > 100 categories). In this study, we particularly focused on difference in temporal priority of the gaze toward objects in the scene images and quantified the time course of gaze attraction for each object category after the onset of the image presentation. Results showed that the time course of gaze attraction varied with the object category. Hierarchical clustering revealed that there were at least two distinct clusters consisting of multiple object categories: a cluster attracting the gaze in the early period and the opposite one. These clusters appeared to disagree with conventional categories in superordinate levels. Control analyses further confirmed that variation in the time course of gaze attraction could not be explained by difference in saliency defined by lower-order visual features. These results suggest that the gaze is attracted fast to particular object categories and the temporal priority could be explained by higher-order visual features rather than lower-order visual features.
Meeting abstract presented at VSS 2018