Effects of peripheral eccentricity and head orientation on gaze discrimination

Abstract

Visual search tasks support a special role for direct gaze in human cognition, while classic gaze judgment tasks suggest the congruency between head orientation and gaze direction plays a central role in gaze perception. Moreover, whether gaze direction can be accurately discriminated in the periphery using covert attention is unknown. In the present study, individual faces in frontal and in deviated head orientations with a direct or an averted gaze were flashed for 150 ms across the visual field; participants focused on a centred fixation while judging the gaze direction. Gaze discrimination speed and accuracy varied with head orientation and eccentricity. The limit of accurate gaze discrimination was less than ±6° eccentricity. Response times suggested a processing facilitation for direct gaze in fovea, irrespective of head orientation, however, by ±3° eccentricity, head orientation started biasing gaze judgments, and this bias increased with eccentricity. Results also suggested a special processing of frontal heads with direct gaze in central vision, rather than a general congruency effect between eye and head cues. Thus, while both head and eye cues contribute to gaze discrimination, their role differs with eccentricity.

Eye gaze and head orientation modulate the inhibition of return for faces

“…Although the effect of gaze-head congruency on IOR magnitudes was not as consistent across head orientations, these findings indicate that the congruent face stimuli (i.e., frontal heads with frontal gaze and averted heads with averted gaze) may have captured more initial attention than the incongruent face stimuli, when compared to houses, thus leading to a larger inhibition of target responses when subsequent targets were placed in those previous locations that contained the congruent facial stimuli. These results are in line with other research demonstrating that head orientation strongly affects gaze discrimination (Itier et al, 2007a(Itier et al, , 2007bLangton, 2000;Seyama & Nagayama, 2005;Todorović, 2009), especially when stimuli are presented beyond foveal vision (Palanica & Itier, 2015). If we assume that stronger initial exogenous attention capture leads to a larger inhibition of return (Posner & Cohen, 1984), then these findings also support the proposed Direction of Attention Detector (Perrett & Emery, 1994), which integrates social information from the eyes and head, and preferentially captures attention for congruently oriented facial stimuli compared to incongruently oriented facial stimuli.…”

“…It has been shown that head orientation strongly influences gaze discrimination (Itier et al, 2007a(Itier et al, , 2007bLangton, 2000;Seyama & Nagayama, 2005;Todorović, 2009), especially when stimuli are presented beyond foveal vision (Palanica & Itier, 2015), as in the current study. In line with the DAD hypothesis that eye and head cues are integrated to better capture attention, it was predicted that congruent gaze-head stimuli (i.e., frontal heads with a frontfacing gaze and averted heads with an averted gaze) should capture more reflexive attention than incongruent gaze-head stimuli (i.e., frontal heads with averted gaze and averted heads with frontal gaze).…”

“…A stimulus cue was then presented for 150 ms, the center of which was situated 4.5°to the left or to the right of fixation. From Palanica and Itier (2015), it was shown that gaze direction could be discriminated at this eccentricity, across head orientations, using covert attention. Following a variable cue-target SOA of 150 ms, 3 300 ms, 800 ms, 1, 200 ms, or 2,400 ms, a response target (a black asterisk (*) symbol, 0.8°× 0.8°of visual angle) appeared to the left or to the right at the same eccentricity as the center of the stimulus cue for 1,000 ms regardless of whether a response was made or not.…”

“…Furthermore, the congruency of one's eye gaze direction and their head orientation can capture attention better than if one's eye gaze and head orientation are incongruent or misaligned with each other. For example, reaction times (RTs) to discriminate gaze direction are shorter when the eyes and head are oriented in the same direction than when they are oriented in different directions (Itier et al, 2007a(Itier et al, , 2007bLangton, 2000;Palanica & Itier, 2015;Seyama & Nagayama, 2005;Todorović, 2009). People generally align their heads and eye direction to grab another person's attention or to orient the observer's attention to some other specific place/person.…”

“…Although the majority of research examining how gaze and/or head orientation captures visuospatial attention has used explicit gaze discrimination tasks (e.g., Burton et al, 2009;Loomis et al, 2008;Palanica & Itier, 2015;Yokoyama et al, 2014), another way to study how attention is captured is by using an inhibition of return (IOR; Posner & Cohen, 1984) cueing paradigm. The phenomenon of IOR refers to the finding that after attention has been exogenously cued and then withdrawn from a location, attention is inhibited to return to that region, and there is delayed responding to stimuli subsequently presented at that cued location relative to previously uncued locations (Klein, 2000).…”