| During social interactions, people’s eyes convey a wealth of information about their direction of attention and their emotional and mental states. Especially, direction of eye gaze is an important indicator of another individual’s focus of attention. The study of how we process other people’s gaze direction is a fascinating topic across diverse fields within psychology and neuroscience. Recent studies showed that observing another person’s averted eye gaze leads to automatic shift of attention to the same object and facilitates subsequent early visual processing. This phenomenon is termed as’Joint attention’. Joint attention processing proceeds through two main processes:gaze perception and gaze following. Gaze perception refers to analysis of the perceptual features of a gaze cue. By contrast, gaze following refers to the tendency of observers to shift attention to locations looked at by others, which is indicated by gaze cueing effect (GCE). Most of researchers maintained that the latter process relied on the former (serial model). They hold the idea that mechanisms involved in gaze perception precede those involved in attentional cueing from gaze. However, other studies suggested that gaze perception and gaze following might involve dissociable mechanisms (parallel model). As Doherty et al. (2009) reported in young children, it was possible for gaze following to occur in the absence of precise gaze perception. Thus, it remains unclear what role the gaze perception plays in gaze following behavior. To solve this problem, here we focused on the processing stages of gaze perception and the role of gaze perception on gaze following. We hypothesized those different processing stages of gaze perception play separate role in the gaze following behavior. According to this hypothesis, the early visual analysis of gaze direction precedes the gaze following, while the conscious coding of gaze direction and gaze cueing effect operate in parallel.The present study aimed to investigate the processing stages of gaze perception and figure out the relationship between gaze perception and gaze following. It was consisted of three parts. By manipulating the perceptual loads and spatial attention, the first part investigated the processing mechanisms of direct and averted gaze adaptation effects. In the second part, a gaze adaptation technique and a gaze cueing paradigm were combined to investigate the role of gaze perception in gaze following behavior. Finally, utilizing interocular suppression (or continuous flash suppression, CFS) to render faces with averted gaze invisible, the third part explored whether averted gaze cue influence gaze direction perception and shift observers’attention outside conscious awareness.The main findings of this study are as follows:(1) There are different processing mechanisms between direct gaze and averted gaze perception. Although the high perceptual load task exhausted all attentional resources, direct gaze direction could be perceived, with a significant gaze adaptation effect. By contrast, averted gaze perception needs more attentional resources and requires focused attention.(2) During the processing stages of gaze perception, the discrimination between direct and averted gaze is necessary for gaze cueing effect. If observers’perception of averted gaze cue was impaired by perceptual adaptation, then it might not elicit spatial orienting effects.(3) Gaze perception and gaze following involve dissociable mechanisms under unconscious condition. Although averted gaze direct (left or right gaze) could not be extracted in the invisible condition, suppressed gaze cue leads to reflexive shifts of attention. Furthermore, only female exhibited a reliable gaze cueing effect in the invisible condition, but male failed to show any cueing effects. Thus, there is a gender difference in the unconscious gaze-triggered attention orienting. |
