Spatial discrimination in task-driven attention

Visual attention is becoming an increasingly imperative capability to endow computer vision systems and autonomous agents with. Starting from a biological inspired model of attention, we present an experiment aimed to study selective attention in 3D space. Depth has been proved to be an important feature affecting the way attention is deployed when observing a scene. We studied preferential scanning paths and fixation zones in a task-driven wandering of the tutor gaze over a scene where multiple targets had been disposed on different depth planes. We supposed that selective attention would aggregate targets in cliques that maximize utility, minimizing meanwhile visual effort produced when passing from closer planes to further planes or between different cluttered locations. By means of a purposely designed machine, we stored visual and motor data of the tutor´s head; we clustered different scanning paths of the gaze shifts according to velocity and space criteria to determine a preference model of attentional shifts and fixations. We propose subsequently a utility model that can formalize acquired information and establish a vision-based attentional framework for robots. We show that an interpretation of task-driven gaze orienting based on the presented preference criteria correctly accounts for the studied behaviours, as further reported in the literature