Gaze matters: On the nature of the reverse congruency effect.

Eye-gaze plays a central role in social interactions and can elicit orienting of attention in an observer. Recent evidence has shown differences in inducing attentional shifting between eye-gaze stimuli compared to non-social stimuli (e.g., 'arrows'). For example, in a spatial Stroop task, while arrows induce a standard congruency effect (faster reaction times for congruent compared to incongruent trials), eye-gaze stimuli elicit a reversed congruency effect (faster reaction times for incongruent compared to congruent trials). Our study aims to further explore the explanation for the reverse congruency effect related to joint attention: on incongruent trials, specifically for eye-gaze stimuli, the peripheral stimulus is pointing towards the object to which participants' attention is expected to be allocated (i.e., the fixation). Participants (N = 60) were asked to discriminate the direction indicated by the target (arrow or eye-gaze stimuli), which can appear to the left or right of a central fixation point. Participants were instructed to keep their eyes at fixation and to ignore the location in which the target could appear. To further explore the joint-attention assumption, we manipulated the central fixation point (i.e., the object of joint focus), which, within trials, could be either a meaningful real-life object or a symbolic cross. The results replicate previous studies, showing a standard congruency effect for arrow stimuli and a reverse congruency effect for eye-gaze stimuli, for both the symbolic cross and the meaningful real-life object fixation points. Ongoing research is still exploring the nature of this result.