Facial expressions of threat influence perceived gaze direction in 8 year-olds

Masked face is looking at me: Face mask increases the feeling of being looked at during the COVID-19 pandemic

Background

As the COVID-19 global pandemic unfolded, governments recommended wearing face masks as a protective measure. Recent studies have found that a face mask influences perception; but how it affects social perception, especially the judgment of being looked at, is still unknown. This study investigated how wearing a mask influences the judgment of gaze direction by conducting a cone of direct gaze (CoDG) task.

Methods

In Experiment 1, three types of masked faces were considered to investigate whether the effect of masks on CoDG is modulated by mask types. Experiment 2 was to further validate the results of Experiment 1 by adding a learning phase to help participants better distinguish N95 and surgical masks. Furthermore, to investigate whether the effect of masks derives from its social significance, a face with only the eye-region (a mouth-cut face) was used as the stimuli in Experiment 3.

Results

The results of Experiment 1 found that wearing masks widens the CoDG, irrespective of the mask type. Experiment 2 replicated the results of Experiment 1. Experiment 3 found that the CoDG of N95-masked faces was wider than the mouth-cut and non-masked faces, while no significant difference existed between the CoDG of mouth-cut and non-masked faces, illustrating that the influence of wearing masks on CoDG was due to high-level social significance rather than low-level facial feature information.

Conclusion

The results show that face mask increases the feeling of being looked at during the COVID-19 Pandemic. The present findings are of significance for understanding the impact of wearing masks on human social cognition in the context of COVID-19.

Fear-specific leftward bias in gaze direction judgment

Previous studies have shown that humans have a left spatial attention bias in cognition and behaviour. However, whether there exists a leftward perception bias of gaze direction has not been investigated. To address this gap, we conducted three behavioural experiments using a forced-choice gaze direction judgment task. The point of subjective equality (PSE) was employed to measure whether there was a leftward perception bias of gaze direction, and if there was, whether this bias was modulated by face emotion. The results of experiment 1 showed that the PSE of fearful faces was significantly positive as compared to zero and this effect was not found in angry, happy, and neutral faces, indicating that participants were more likely to judge the gaze direction of fearful faces as directed to their left-side space, namely a leftward perception bias. With the response keys counterbalanced between participants, experiment 2a replicated the findings in experiment 1. To further investigate whether the gaze direction perception variation was contributed by emotional or low-level features of faces, experiment 2b and 3 used inverted faces and inverted eyes, respectively. The results revealed similar leftward perception biases of gaze direction in all types of faces, indicating that gaze direction perception was biased by emotional information in faces rather than low-level facial features. Overall, our study demonstrates that there a fear-specific leftward perception bias in processing gaze direction. These findings shed new light on the cerebral lateralization in humans.

Intranasal oxytocin enhances the perception of ambiguous averted gaze in women but not in men

BACKGROUND

Perceiving accurately that others are looking away from us (averted gaze) is as important, for social interactions, as perceiving that others are looking at us (direct gaze). However, previous studies have revealed that when the deflection angle of averted gaze is small, individuals tend to falsely perceive it as direct gaze. Oxytocin (OXT) has been shown to increase orientation to the eye region. Therefore, a critical question is whether and how OXT would facilitate the perception of ambiguous averted gaze.

OBJECTIVES

The present study aimed to measure the effects of OXT on the performance of males and females in distinguishing ambiguous averted gaze from direct gaze of different emotional faces.

METHODS

In a double-blind placebo-controlled crossover experiment, 48 participants were presented successively two emotional faces with direct gaze (defined as 0, indicating the center of the eye) or averted gaze (defined as ±4, indicating the corner of the eye; +4 means that the iris moves 4 steps to the right; and -4 means that the iris moves 4 steps to the left) following intranasal oxytocin or placebo treatment and asked to make judgments on whether or not the two faces were the same in terms of identity. The interference effect of gaze direction was calculated by subtracting the mean accuracy and reaction time in the congruent gaze condition from those in the incongruent gaze condition. The logic of the measurement was if intranasal OXT would facilitate the detection of ambiguous averted gaze, we would observe a larger interference effect in the gaze incongruent condition compared with the gaze congruent condition, leading to longer RT or/and lower accuracy for identification judgment in the gaze incongruent condition.

RESULTS

While there were no OXT effects in accuracy, we found a significant interaction between treatment, sex, and gaze congruency in reaction times. That is, following OXT as compared to placebo, women displayed stronger interference of gaze direction, whereas in men no significant difference was observed. Besides, this interaction did not vary across different emotional expressions.

CONCLUSIONS

Our findings provide the first evidence for sex-dependent effects of OXT on the perception of ambiguous averted gaze. Given potential therapeutic applications of OXT to patients with developmental and psychiatric disorders, who are characterized as atypical in encoding gaze features, the findings suggest that rather different treatment outcomes could be anticipated in males and females.

Opposing sex-dependent effects of oxytocin on the perception of gaze direction

BACKGROUND

Gaze direction is an important cue of the eye region. Previous studies have revealed that oxytocin (OXT) increases orienting to the eye region of face. However, little has been known about the effect of OXT in men and women on the perception of gaze direction particularly when associated with different emotions.

OBJECTIVES

We investigated how oxytocin would affect gaze direction judgments for threatening, angry, and neutral facial expressions and whether this effect would be modulated by observers' sex.

METHODS

We used the cone of direct gaze (CoDG) task. Participants were required to judge the gaze direction of face between directed and averted gaze.

RESULTS

Results showed opposing sex-dependent effects of OXT such that OXT, as compared with placebo, tended to decrease the CoDG in men but increase it in women. The CoDG was marginally wider in men than in women in the placebo condition, and however, this difference was abolished following OXT treatment. We also found that the perception of gaze direction varied as a function of emotional expression such that the CoDG for angry and neutral faces was wider than that for fearful faces and the CoDG for angry faces was marginally wider than that for neutral ones. However, there was no significant interaction between treatment and facial expression.

CONCLUSIONS

Our findings provide the first evidence for sex-dependent effects of OXT on gaze direction perception, suggesting that OXT attenuates the self-referential judgment of gaze directions of others in men and enhances it in women despite differentiated emotions of faces.

Are you looking my way? Ostracism widens the cone of gaze

Ostracized individuals demonstrate an increased need for belonging. To satisfy this need, they search for signals of inclusion, one of which may be another person's gaze directed at oneself. We tested if ostracized, compared to included, individuals judge a greater degree of averted gaze as still being direct. This range of gaze angles still viewed as direct has been dubbed “the cone of (direct) gaze”. In the current research, ostracized and included participants viewed friendly-looking face stimuli with direct or slightly averted gaze (0°, 2°, 4°, 6°, and 8° to the left and to the right) and judged whether stimulus persons were looking at them or not. Ostracized individuals demonstrated a wider gaze cone than included individuals.

Trait Anxiety Impacts the Perceived Gaze Direction of Fearful But Not Angry Faces

Facial expression and gaze direction play an important role in social communication. Previous research has demonstrated the perception of anger is enhanced by direct gaze, whereas, it is unclear whether perception of fear is enhanced by averted gaze. In addition, previous research has shown the anxiety affects the processing of facial expression and gaze direction, but hasn't measured or controlled for depression. As a result, firm conclusions cannot be made regarding the impact of individual differences in anxiety and depression on perceptions of face expressions and gaze direction. The current study attempted to reexamine the effect of the anxiety level on the processing of facial expressions and gaze direction by matching participants on depression scores. A reliable psychophysical index of the range of eye gaze angles judged as being directed at oneself [the cone of direct gaze (CoDG)] was used as the dependent variable in this study. Participants were stratified into high/low trait anxiety groups and asked to judge the gaze of angry, fearful, and neutral faces across a range of gaze directions. The result showed: (1) the perception of gaze direction was influenced by facial expression and this was modulated by trait anxiety. For the high trait anxiety group, the CoDG for angry expressions was wider than for fearful and neutral expressions, and no significant difference emerged between fearful and neutral expressions; For the low trait anxiety group, the CoDG for both angry and fearful expressions was wider than for neutral, and no significant difference emerged between angry and fearful expressions. (2) Trait anxiety modulated the perception of gaze direction only in the fearful condition, such that the fearful CoDG for the high trait anxiety group was narrower than the low trait anxiety group. This demonstrated that anxiety distinctly affected gaze perception in expressions that convey threat (angry, fearful), such that a high trait anxiety level modulated the impact of indirectly threatening expressions (fearful), and did not influence responses to directly threatening expression (angry). These findings partially support the shared signal hypothesis.

Assessing early processing of eye gaze in schizophrenia: measuring the cone of direct gaze and reflexive orienting of attention

INTRODUCTION

The accurate discrimination of another person's eye-gaze direction is vital as it provides a cue to the gazer's focus of attention, which in turn supports joint attention. Patients with schizophrenia have shown a "direct gaze bias" when judging gaze direction. However, current tasks do not dissociate an early perceptual bias from high-level top-down effects. We investigated early stages of gaze processing in schizophrenia by measuring perceptual sensitivity to fine deviations in gaze direction (i.e., the cone of direct gaze: CoDG) and ability to reflexively orient to locations cued by the same deviations.

METHODS

Twenty-four patients and 26 controls completed a CoDG discrimination task that used realistic direct-face images with six fine degrees of deviation (i.e., 3, 6 or 9 pixels to the left and right) and direct gaze, and a gaze cueing task that assessed reflexive orienting to the same fine-grained deviations.

RESULTS

Our data showed patients exhibited no impairment in gaze discrimination, nor did we observe a reduced orienting response.

CONCLUSIONS

These results suggest that while patients may suffer deficits associated with interpreting another person's gaze, the earliest processes concerned with detecting averted gaze and reflexively orienting to the gazed-at location are intact.

Emotion Unchained: Facial Expression Modulates Gaze Cueing under Cognitive Load

Direction of eye gaze cues spatial attention, and typically this cueing effect is not modulated by the expression of a face unless top-down processes are explicitly or implicitly involved. To investigate the role of cognitive control on gaze cueing by emotional faces, participants performed a gaze cueing task with happy, angry, or neutral faces under high (i.e., counting backward by 7) or low cognitive load (i.e., counting forward by 2). Results show that high cognitive load enhances gaze cueing effects for angry facial expressions. In addition, cognitive load reduces gaze cueing for neutral faces, whereas happy facial expressions and gaze affected object preferences regardless of load. This evidence clearly indicates a differential role of cognitive control in processing gaze direction and facial expression, suggesting that under typical conditions, when we shift attention based on social cues from another person, cognitive control processes are used to reduce interference from emotional information.

How Long Did You Look At Me? The Influence of Gaze Direction on Perceived Duration and Temporal Sensitivity

Faces that exhibit emotionally negative expressions in mutual gaze have been shown to induce a dilation of perceived duration. The influence of gaze by itself on duration judgments, however, has rarely been investigated. We argue for a social interaction hypothesis, according to which humans should be highly accurate and precise (sensitive) when processing the temporal dynamics of mutual gaze. In three experiments, we investigated whether the direction of observed gaze affects perceived duration and temporal sensitivity. In Experiment 1, subjects did indeed estimate the duration of direct gaze more accurately as compared to the duration of averted gaze. In Experiments 2 and 3, subjects had to categorize direct and averted gaze stimuli as being short or long in duration (temporal bisection). Experiment 2 found temporal sensitivity (but not mean duration judgments) to be improved in cases of mutual gaze. In Experiment 3, the effect of mutual gaze on prolonged subjective duration did replicate, however, it was rather small. Moreover, temporal precision was not improved in the case of naturalistic stimuli. In sum, effects of mutual gaze on duration judgments are rather weak, and cannot be attributed to arousal, as such ratings did not differ between direct and averted gaze stimuli.

Eye contact perception in the West and East: a cross-cultural study

This study investigated whether eye contact perception differs in people with different cultural backgrounds. Finnish (European) and Japanese (East Asian) participants were asked to determine whether Finnish and Japanese neutral faces with various gaze directions were looking at them. Further, participants rated the face stimuli for emotion and other affect-related dimensions. The results indicated that Finnish viewers had a smaller bias toward judging slightly averted gazes as directed at them when judging Finnish rather than Japanese faces, while the bias of Japanese viewers did not differ between faces from their own and other cultural backgrounds. This may be explained by Westerners experiencing more eye contact in their daily life leading to larger visual experience of gaze perception generally, and to more accurate perception of eye contact with people from their own cultural background particularly. The results also revealed cultural differences in the perception of emotion from neutral faces that could also contribute to the bias in eye contact perception.

The influences of face inversion and facial expression on sensitivity to eye contact in high-functioning adults with autism spectrum disorders

We examined the influences of face inversion and facial expression on sensitivity to eye contact in high-functioning adults with and without an autism spectrum disorder (ASD). Participants judged the direction of gaze of angry, fearful, and neutral faces. In the typical group only, the range of directions of gaze leading to the perception of eye contact (the cone of gaze) was narrower for upright than inverted faces. In both groups, the cone of gaze was wider for angry faces than for fearful or neutral faces. These results suggest that in high-functioning adults with ASD, the perception of eye contact is not tuned to be finer for upright than inverted faces, but that information is nevertheless integrated across expression and gaze direction.