The emergence of UHD video format induces larger screens and involves a wider stimulated visual angle. Therefore, its effect on visual attention can be questioned since it can impact quality assessment, metrics but also the whole chain of video processing and creation. Moreover, changes in visual attention from different viewing conditions challenge visual attention models. In this paper, we present a comparative study of visual attention and viewing behavior on three video datasets in SD, HD and UHD conditions. Then, we propose and assess an improvement for video visual attention models by applying a stimulated visual angle dependent center model.