Abstract
Detecting where other individuals are allocating their gaze is crucial for humans and other primates when assessing their intention to initiate gaze contact. Previous literature has shown the different contributions of gaze and head orientation to gaze contact discrimination in the center and periphery of the visual field. However, to the best our knowledge, all previous studies have assessed this using static images. In the current study we evaluated the contribution of the eye and the head to gaze discrimination by using 3D face models to test participants in a 3-forced choice gaze discrimination task ranging up to 18° of visual angle eccentricity. First we accessed discrimination performance with eye & head aligned (congruent), while in the second experiment we dissociated the orientation of eye & head (incongruent). Lastly we added motion cues in forms of saccadic eye movement to the stimuli tested before and repeated the experiments. Our findings show gaze discrimination errors increase as a function of eccentricity and are significantly greater when eye and head position are incongruent (paired-sample t-test p=0.03, 0.01, 0.01 at 9°, 14° and 18° of eccentricity respectively, df=8) This increase in error was shown to be attributed to an increased reliance on head orientation as a cue for gaze discrimination at larger eccentricities. Lastly, addition of motion cues in form of saccadic eye movement facilitated gaze discrimination in the periphery as well as in the center (paired sample t-test: p=0.03 for 0° of eccentricity in congruent condition, p=0.009 for 9° of eccentricity in incongruent condition, df=7 for all). Our study provides the first model of gaze discrimination that incorporates motion cues and assesses its contribute to gaze contact.
Meeting abstract presented at VSS 2018