Eye contact facilitates awareness of faces during interocular suppression

Abstract

Eye contact captures attention and receives prioritized visual processing. Here we asked whether eye contact might be processed outside conscious awareness. Faces with direct and averted gaze were rendered invisible using interocular suppression. In two experiments we found that faces with direct gaze overcame such suppression more rapidly than faces with averted gaze. Control experiments ruled out the influence of low-level stimulus differences and differential response criteria. These results indicate an enhanced unconscious representation of direct gaze, enabling the automatic and rapid detection of other individuals making eye contact with the observer.Keywords: Eye contact, gaze processing, binocular rivalry, interocular suppression, unconscious processing UNCONSCIOUS EYE CONTACT 2 IntroductionEye contact is a salient visual signal for a large number of species. In many vertebrates, the rapid perception of eye contact supports the effective detection of potential predators (Emery, 2000). By contrast, in human and non-human primates eye contact is a pivotal element in complex social behavior and therefore receives privileged visual processing and modulates cognitive processes. Given the special perceptual status of direct gaze as well as the proposed involvement of subcortical structures in mediating this eye contact effect, we asked whether the processing of eye contact might occur automatically, even outside of conscious awareness. We used continuous flash suppression (CFS;Tsuchiya & Koch, 2005) to render faces with direct or averted gaze invisible at the beginning of each trial. CFS is a recently developed variant of binocular rivalry in which a stimulus presented to one eye is suppressed from awareness by dynamic Mondrian-like masks flashed to the other eye. The potency of stimuli to overcome such interocular suppression and break into awareness is regarded as an index of unconscious processing (Costello, Jiang, Baartman, McGlennen, & He, 2009;Jiang, Costello, & He, 2007;Tsuchiya, Moradi, Felsen, Yamazaki, & Adolphs, 2009; Yang & Yeh, in press;Yang, Zald, & Blake, 2007;Zhou, Jiang, He, & Chen, 2010). Accordingly, enhanced unconscious processing of direct gaze would be reflected in shorter suppression periods of faces with direct gaze compared to faces with averted gaze.

Look at them and they will notice you: Distractor-independent attentional capture by direct gaze in change blindness

“…However, facial stimuli (Kikuchi et al, 2009;Lyyra, Mäkelä, et al, 2014;Ro et al, 2001) and their emotional expressions seem to form an exception, and our results suggest that gaze direction may also be implicitly represented in a manner that can exert a similar bottom-up influence speeding up recovery from change blindness. This is also in line with studies using interocular suppression (Akechi et al, 2014;Chen & Yeh, 2012;Stein et al, 2011) and studies using visual search (Conty et al, 2006;Doi et al, 2009;Senju et al, 2005;Shirama, 2012;Von Grünau & Anston, 1995). In visual search, however, the search advantage for direct gaze has been contested as being confounded by the attention-grabbing effect of the gaze directions of the distractor faces.…”

“…Yokoyama et al (2011) already observed a similar direct gaze advantage for change detection using both schematic faces with frontal-views and with rotated head-views, the latter with non-symmetrical direct gaze stimuli in the change blindness paradigm. Similarly, in interocular suppression, the facilitated awareness of direct gaze relative to averted gaze is observed for face stimuli with both frontal/symmetrical (Chen & Yeh, 2012) and rotated/asymmetrical head orientation (Stein et al, 2011). Nevertheless, eye contact perception in laterally rotated head stimuli would not completely correspond to the present findings.…”

“…This finding would be akin to corresponding findings in interocular suppression, in which a target stimulus is presented to one eye, and conscious perception of the target is delayed by a dynamic high contrast mask presented to the other eye. This delay is found to be shortened for direct gaze, i.e., it breaks to consciousness faster than averted gaze (Akechi et al, 2014;Chen & Yeh, 2012;Stein, Senju, Peelen, & Sterzer, 2011). In interocular suppression, however, it is not clear which cognitive functions contribute to the quickened breakthrough of direct gaze to consciousness, and the role of attention in this phenomenon has not been studied directly (see, e.g., Sterzer, Stein, Ludwig, Rothkirch, & Hesselmann, 2014).…”

Melodic sound enhances visual awareness of congruent musical notes, but only if you can read music

“…After all, in other circumstances suppression durations of a visual stimulus are impacted by the properties of that stimulus, including its physical characteristics (9), its configural properties (30,66), its affective connotation (67,68), its lexical familiarity (32), and its social connotation (69). However, in all these instances the features defining the suppressed stimulus are plausibly being registered and remain available for analysis (70), albeit with reduced fidelity or signal strength (34).…”

Effects of peripheral eccentricity and head orientation on gaze discrimination

“…One visual search study reported better discrimination of direct than averted gaze looking characters situated in the visual periphery (Palanica & Itier, 2011). Other studies using change detection (e.g., Yokoyama et al, 2011) and interocular suppression (e.g., Stein et al, 2011;Yokoyama et al, 2013) also support the view of a preferential processing of direct gaze in faces presented covertly. However, these studies did not manipulate the eccentricity at which those faces were presented or the direction of the face.…”