@article {2655,
	title = {Assessing the precision of gaze following using a stereoscopic 3D virtual reality setting.},
	journal = {Vision Res},
	volume = {112},
	year = {2015},
	month = {2015 Jul},
	pages = {68-82},
	abstract = {<p>Despite the ecological importance of gaze following, little is known about the underlying neuronal processes, which allow us to extract gaze direction from the geometric features of the eye and head of a conspecific. In order to understand the neuronal mechanisms underlying this ability, a careful description of the capacity and the limitations of gaze following at the behavioral level is needed. Previous studies of gaze following, which relied on naturalistic settings have the disadvantage of allowing only very limited control of potentially relevant visual features guiding gaze following, such as the contrast of iris and sclera, the shape of the eyelids and--in the case of photographs--they lack depth. Hence, in order to get full control of potentially relevant features we decided to study gaze following of human observers guided by the gaze of a human avatar seen stereoscopically. To this end we established a stereoscopic 3D virtual reality setup, in which we tested human subjects{\textquoteright} abilities to detect at which target a human avatar was looking at. Following the gaze of the avatar showed all the features of the gaze following of a natural person, namely a substantial degree of precision associated with a consistent pattern of systematic deviations from the target. Poor stereo vision affected performance surprisingly little (only in certain experimental conditions). Only gaze following guided by targets at larger downward eccentricities exhibited a differential effect of the presence or absence of accompanying movements of the avatar{\textquoteright}s eyelids and eyebrows.</p>
},
	keywords = {Adult, Attention, Computer Simulation, Cues, Discrimination (Psychology), Eye Movements, Eyebrows, Eyelids, Female, Humans, Judgment, Male, Middle Aged, Young Adult},
	issn = {1878-5646},
	doi = {10.1016/j.visres.2015.04.015},
	author = {Atabaki, Artin and Marciniak, Karolina and Dicke, Peter W and Thier, Peter}
}
@article {2653,
	title = {Monkeys head-gaze following is fast, precise and not fully suppressible.},
	journal = {Proc Biol Sci},
	volume = {282},
	year = {2015},
	month = {2015 Oct 07},
	pages = {20151020},
	abstract = {<p>Human eye-gaze is a powerful stimulus, drawing the observer{\textquoteright}s attention to places and objects of interest to someone else ({\textquoteright}eye-gaze following{\textquoteright}). The largely homogeneous eyes of monkeys, compromising the assessment of eye-gaze by conspecifics from larger distances, explain the absence of comparable eye-gaze following in these animals. Yet, monkeys are able to use peer head orientation to shift attention ({\textquoteright}head-gaze following{\textquoteright}). How similar are monkeys{\textquoteright} head-gaze and human eye-gaze following? To address this question, we trained rhesus monkeys to make saccades to targets, either identified by the head-gaze of demonstrator monkeys or, alternatively, identified by learned associations between the demonstrators{\textquoteright} facial identities and the targets (gaze versus identity following). In a variant of this task that occurred at random, the instruction to follow head-gaze or identity was replaced in the course of a trial by the new rule to detect a change of luminance of one of the saccade targets. Although this change-of-rule rendered the demonstrator portraits irrelevant, they nevertheless influenced performance, reflecting a precise redistribution of spatial attention. The specific features depended on whether the initial rule was head-gaze or identity following: head-gaze caused an insuppressible shift of attention to the target gazed at by the demonstrator, whereas identity matching prompted much later shifts of attention, however, only if the initial rule had been identity following. Furthermore, shifts of attention prompted by head-gaze were spatially precise. Automaticity and swiftness, spatial precision and limited executive control characterizing monkeys{\textquoteright} head-gaze following are key features of human eye-gaze following. This similarity supports the notion that both may rely on the same conserved neural circuitry.</p>
},
	keywords = {Animals, Attention, Face, Head, learning, Macaca mulatta, Saccades, Vision, Ocular},
	issn = {1471-2954},
	doi = {10.1098/rspb.2015.1020},
	author = {Marciniak, Karolina and Dicke, Peter W and Thier, Peter}
}
