In our case, however, since the learner is presented with only the visual stream and is not in the presence of the speaker, attention is mediated by visual saliency alone, and not by cues received from the speaker's gaze.
to simulate gaze-based visual attention, we follow the assumption of Perceptual Theory of Mind (Mukerjee and Sarkar, 2007), that the salient features that our cognitive agent discovers through image processing, would also be salient for the speaker involved in the associated commentaries, letting us correlate the visual and linguistic elements coherently.