The effect of head turn on the perception of gaze

When Attentional and Politeness Demands Clash: The Case of Mutual Gaze Avoidance and Chin Pointing in Quiahije Chatino

Pointing with the chin is a practice attested worldwide: it is an effective and highly recognizable device for re-orienting the attention of the addressee. For the chin point to be observed, the addressee must attend carefully to the movements of the sender’s head. This demand comes into conflict with the politeness norms of many cultures, since these often require conversationalists to avoid meeting the gaze of their interlocutor, and can require them to look away from their interlocutor’s face and head. In this paper we explore how the chin point is successfully used in just such a culture, among the Chatino indigenous group of Oaxaca, Mexico. We analyze interactions between multiple dyads of Chatino speakers, examining how senders invite visual attention to the pointing gesture, and how addressees signal that attention, while both participants avoid stretches of mutual gaze. We find that in the Chatino context, the senior (or higher-status) party to the conversation is highly consistent in training their gaze away from their interlocutor. This allows their interlocutor to give visual attention to their face without the risk of meeting the gaze of a higher-status sender, and facilitates close attention to head movements including the chin point.

Abstracts in Spanish and Quiahije Chatino are published as appendices.

Se incluyen como apéndices resúmenes en español y en el chatino de San Juan Quiahije.

SonG ktyiC reC inH, ngyaqC skaE ktyiC noE ndaH sonB naF ngaJ noI ngyaqC loE ktyiC reC, ngyaqC ranF chaqE xlyaK qoE chaqF jnyaJ noA ndywiqA renqA KchinA KyqyaC.

Exploring Critical Components of Physician-Patient Communication: A Qualitative Study of Lay and Professional Perspectives

(1) Background: The ability to communicate with patients and their relatives is a crucial skill for a physician. Unfortunately, many physicians and medical students are not well-equipped in this area. Therefore, this study aims to better understand the views on critical components of physician-patient communication to improve their skills. (2) Methods: This qualitative study utilized focus group discussions (FGDs) and in-depth interviews (IDIs). Through a purposive sampling technique, 32 medical students and physicians from the Faculty of Medicine and Health Sciences, Universiti Putra Malaysia (FMHS UPM) and Universiti Putra Malaysia Teaching Hospital (HPUPM), as well as patients and relatives from government and private hospitals or clinics were recruited. All sessions were audio-recorded, transcribed, and analyzed thematically. (3) Results: Seven themes were identified: professionalism, content of communication, verbal, non-verbal and paraverbal communication skills, environment, and visual communication. Good eye contact, providing treatment plans, and ensuring patient privacy and confidentiality were emphasized by physicians and medical students. In comparison, patients and relatives focused on the prognosis of disease, physician's empathy and advice, and physician's skills in building rapport with their patients and relatives. (4) Conclusion: The critical components that were highlighted by both professionals and laymen in the study should be practiced to ensure effective communication between physician and patient. There were different expectations in terms of the content of information between both groups. Patients and relatives were more interested in the physician's advice regarding their diet, care plans, physical activities, and daily routine. They were also focused on the prognosis of the disease, which indicates how quickly they would get better. Meanwhile, physicians and medical students were concentrating on management and treatment strategies, such as what additional procedures should be considered and what medications might work best for their patients. We also found that the patients and relatives had a lack of awareness on confidentiality issues. These findings provide an insight on the improvement of medical training and patient education to improve patient care. Patients have a right to privacy protection, and physicians should be well trained to carry out all procedures and treatment plans to ensure patients are treated with respect.

Gaze perception from head and pupil rotations in 2D and 3D: Typical development and the impact of autism spectrum disorder

The study of gaze perception has largely focused on a single cue (the eyes) in two-dimensional settings. While this literature suggests that 2D gaze perception is shaped by atypical development, as in Autism Spectrum Disorder (ASD), gaze perception is in reality contextually-sensitive, perceived as an emergent feature conveyed by the rotation of the pupils and head. We examined gaze perception in this integrative context, across development, among children and adolescents developing typically or with ASD with both 2D and 3D stimuli. We found that both groups utilized head and pupil rotations to judge gaze on a 2D face. But when evaluating the gaze of a physically-present, 3D robot, the same ASD observers used eye cues less than their typically-developing peers. This demonstrates that emergent gaze perception is a slowly developing process that is surprisingly intact, albeit weakened in ASD, and illustrates how new technology can bridge visual and clinical science.

Recognizing Students and Detecting Student Engagement with Real-Time Image Processing

With COVID-19, formal education was interrupted in all countries and the importance of distance learning has increased. It is possible to teach any lesson with various communication tools but it is difficult to know how far this lesson reaches to the students. In this study, it is aimed to monitor the students in a classroom or in front of the computer with a camera in real time, recognizing their faces, their head poses, and scoring their distraction to detect student engagement based on their head poses and Eye Aspect Ratios. Distraction was determined by associating the students’ attention with looking at the teacher or the camera in the right direction. The success of the face recognition and head pose estimation was tested by using the UPNA Head Pose Database and, as a result of the conducted tests, the most successful result in face recognition was obtained with the Local Binary Patterns method with a 98.95% recognition rate. In the classification of student engagement as Engaged and Not Engaged, support vector machine gave results with 72.4% accuracy. The developed system will be used to recognize and monitor students in the classroom or in front of the computer, and to determine the course flow autonomously.

How does gaze to faces support face-to-face interaction? A review and perspective

Gaze-where one looks, how long, and when-plays an essential part in human social behavior. While many aspects of social gaze have been reviewed, there is no comprehensive review or theoretical framework that describes how gaze to faces supports face-to-face interaction. In this review, I address the following questions: (1) When does gaze need to be allocated to a particular region of a face in order to provide the relevant information for successful interaction; (2) How do humans look at other people, and faces in particular, regardless of whether gaze needs to be directed at a particular region to acquire the relevant visual information; (3) How does gaze support the regulation of interaction? The work reviewed spans psychophysical research, observational research, and eye-tracking research in both lab-based and interactive contexts. Based on the literature overview, I sketch a framework for future research based on dynamic systems theory. The framework holds that gaze should be investigated in relation to sub-states of the interaction, encompassing sub-states of the interactors, the content of the interaction as well as the interactive context. The relevant sub-states for understanding gaze in interaction vary over different timescales from microgenesis to ontogenesis and phylogenesis. The framework has important implications for vision science, psychopathology, developmental science, and social robotics.

Quantifying the Wollaston Illusion

In the early 19th century, William H. Wollaston impressed the Royal Society of London with engravings of portraits. He manipulated facial features, such as the nose, and thereby dramatically changed the perceived gaze direction, although the eye region with iris and eye socket had remained unaltered. This Wollaston illusion has been replicated numerous times but never with the original stimuli. We took the eyes (pupil and iris) from Wollaston's most prominent engraving and measured their perceived gaze direction in an analog fashion. We then systematically added facial features (eye socket, eyebrows, nose, skull, and hair). These features had the power to divert perceived gaze direction by up to 20°, which confirms Wollaston's phenomenal observation. The effect can be thought of as an attractor effect, that is, cues that indicate a slight change in head orientation have the power to divert perceived gaze direction.

Turning Heads: The Effects of Face View and Eye Gaze Direction on the Perceived Attractiveness of Expressive Faces

We investigated whether the perceived attractiveness of expressive faces was influenced by head turn and eye gaze towards or away from the observer. In all experiments, happy faces were consistently rated as more attractive than angry faces. A head turn towards the observer, whereby a full-face view was shown, was associated with relatively higher attractiveness ratings when gaze direction was aligned with face view (Experiment 1). However, preference for full-face views of happy faces was not affected by gaze shifts towards or away from the observer (Experiment 2a). In Experiment 3, the relative duration of each face view (front-facing or averted at 15°) during a head turn away or towards the observer was manipulated. There was benefit on attractiveness ratings for happy faces shown for a longer duration from the front view, regardless of the direction of head turn. Our findings support previous studies indicating a preference for positive expressions on attractiveness judgements, which is further enhanced by the front views of faces, whether presented during a head turn or shown statically. In sum, our findings imply a complex interaction between cues of social attention, indicated by the view of the face shown, and reward on attractiveness judgements of unfamiliar faces.

Perceiving gaze from head and eye rotations: An integrative challenge for children and adults

Gaze is an emergent visual feature. A person's gaze direction is perceived not just based on the rotation of their eyes, but also their head. At least among adults, this integrative process appears to be flexible such that one feature can be weighted more heavily than the other depending on the circumstances. Yet it is unclear how this weighting might vary across individuals or across development. When children engage emergent gaze, do they prioritize cues from the head and eyes similarly to adults? Is the perception of gaze among individuals with autism spectrum disorder (ASD) emergent, or is it reliant on a single feature? Sixty adults (M = 29.86 years-of-age), thirty-seven typically developing children and adolescents (M = 9.3 years-of-age; range = 7-15), and eighteen children with ASD (M = 9.72 years-of-age; range = 7-15) viewed faces with leftward, rightward, or direct head rotations in conjunction with leftward or rightward pupil rotations, and then indicated whether the face was looking leftward or rightward. All individuals, across development and ASD status, used head rotation to infer gaze direction, albeit with some individual differences. However, the use of pupil rotation was heavily dependent on age. Finally, children with ASD used pupil rotation significantly less than typically developing (TD) children when inferring gaze direction, even after accounting for age. Our approach provides a novel framework for understanding individual and group differences in gaze as it is actually perceived-as an emergent feature. Furthermore, this study begins to address an important gap in ASD literature, taking the first look at emergent gaze perception in this population.

The center of attention: Metamers, sensitivity, and bias in the emergent perception of gaze

A person's gaze reveals much about their focus of attention and intentions. Sensitive perception of gaze is thus highly relevant for social interaction, especially when it is directed toward the viewer. Yet observers also tend to overestimate the likelihood that gaze is directed toward them. How might the visual system balance these competing goals, maximizing sensitivity for discriminating gazes that are relatively direct, while at the same time allowing many gazes to appear as if they look toward the viewer? Perceiving gaze is an emergent visual process that involves integrating information from the eyes with the rotation of the head. Here, we examined whether the visual system leverages emergent representation to balance these competing goals. We measured perceived gaze for a large range of pupil and head combinations and found that head rotation has a nonlinear influence on a person's apparent direction of looking, especially when pupil rotations are relatively direct. These perceptual distortions could serve to expand representational space and thereby enhance discriminability of gazes that are relatively direct. We also found that the emergent perception of gaze supports an abundance of direct gaze metamers-different combinations of head and pupil rotations that combine to generate the appearance of gaze directed toward the observer. Our results thus demonstrate a way in which the visual system flexibly integrates information from facial features to optimize social perception. Many gazes can be made to look toward you, yet similar gazes need not appear alike.

Asymmetry in Gaze Direction Discrimination Between the Upper and Lower Visual Fields

Previous research has shown that gaze direction can only be accurately discriminated within parafoveal limits (∼5° eccentricity) along the horizontal visual field. Beyond this eccentricity, head orientation seems to influence gaze discrimination more than iris cues. The present study examined gaze discrimination performance in the upper visual field (UVF) and lower visual field (LVF), and whether head orientation affects gaze judgments beyond parafoveal vision. Direct and averted gaze faces, in frontal and deviated head orientations, were presented for 150 ms along the vertical meridian while participants maintained central fixation during gaze discrimination judgments. Gaze discrimination was above chance level at all but one eccentricity for the two gaze-head congruent conditions. In contrast, for the incongruent conditions, gaze was discriminated above chance only from -1.5° to +3°, with an asymmetry between the UVF and LVF. Beyond foveal vision, response rates were biased toward head orientation rather than iris eccentricity, occurring in the LVF for both head orientations, and in the UVF for frontal head views. These findings suggest that covert processing of gaze direction involves the integration of eyes and head cues, with congruency of these two social cues driving response differences between the LVF and the UVF.

The Effect of Head Orientation on Perceived Gaze Direction: Revisiting Gibson and Pick (1963) and Cline (1967)

Two biases in perceived gaze direction have been observed when eye and head orientation are not aligned. An overshoot effect indicates that perceived gaze direction is shifted away from head orientation (i.e., a repulsive effect), whereas a towing effect indicates that perceived gaze direction falls in between head and eye orientation (i.e., an attraction effect). In the 60s, three influential papers have been published with respect to the effect of head orientation on perceived gaze direction (Gibson and Pick, 1963; Cline, 1967; Anstis et al., 1969). Throughout the years, the results of two of these (Gibson and Pick, 1963; Cline, 1967) have been interpreted differently by a number of authors. In this paper, we critically discuss potential sources of confusion that have led to differential interpretations of both studies. At first sight, the results of Cline (1967), despite having been a major topic of discussion, unambiguously seem to indicate a towing effect whereas Gibson and Pick’s (1963) results seem to be the most ambiguous, although they have never been questioned in the literature. To shed further light on this apparent inconsistency, we repeated the critical experiments reported in both studies. Our results indicate an overshoot effect in both studies.

Differences in the Judged Direction of Gaze From Heads Imaged in 3-D versus 2-D

Observers viewed a model imaged on an LCD monitor in 3-D or 2-D as she gazed at points along a horizontally oriented meter stick from a distance of 80 cm. Her head was either straight or turned 20 degrees to the side, and for each head orientation, her gaze was straight, 10 degrees, or 20 degrees to the side, with her eyes individually open, both open, or both closed. For images in which both eyes were closed, the observers pointed along the same meter stick to where they judged her head to be pointed. When one or both eyes were open they judged where she appeared to be gazing. Gaze from the 2-D images agreed with previous studies. A comparison of the results from the 2-D versus 3-D images showed that the judgments were virtually identical for gaze from the straight versus turned head in all combinations of straight versus averted gaze, eyes individually open versus both open. The judgments were also virtually identical for head point. This suggests that 2-D studies that have used procedures similar to those described in this study may be applied to real world 3-D gaze perception.

Perceiving where another person is looking: the integration of head and body information in estimating another person's gaze

The process through which an observer allocates his/her attention based on the attention of another person is known as joint attention. To be able to do this, the observer effectively has to compute where the other person is looking. It has been shown that observers integrate information from the head and the eyes to determine the gaze of another person. Most studies have documented that observers show a bias called the overshoot effect when eyes and head are misaligned. That is, when the head is not oriented straight to the observer, perceived gaze direction is sometimes shifted in the direction opposite to the head turn. The present study addresses whether body information is also used as a cue to compute perceived gaze direction. In Experiment 1, we observed a similar overshoot effect in both behavioral and saccadic responses when manipulating body orientation. In Experiment 2, we explored whether the overshoot effect was due to observers assuming that the eyes are oriented further than the head when head and body orientation are misaligned. We removed horizontal eye information by presenting the stimulus from a side view. Head orientation was now manipulated in a vertical direction and the overshoot effect was replicated. In summary, this study shows that body orientation is indeed used as a cue to determine where another person is looking.

Dual-route model of the effect of head orientation on perceived gaze direction

Previous studies on gaze perception have identified 2 opposing effects of head orientation on perceived gaze direction—1 repulsive and the other attractive. However, the relationship between these 2 effects has remained unclear. By using a gaze categorization task, the current study examined the effect of head orientation on the perceived direction of gaze in a whole-head condition and an eye-region condition. We found that the perceived direction of gaze was generally biased in the opposite direction to head orientation (a repulsive effect). Importantly, the magnitude of the repulsive effect was more pronounced in the eye-region condition than in the whole-head condition. Based on these findings, we developed a dual-route model, which proposes that the 2 opposing effects of head orientation occur through 2 distinct routes. In the framework of this dual-route model, we explain and reconcile the findings from previous studies, and provide a functional account of attractive and repulsive effects and their interaction.

Effects of Peripheral Eccentricity and Head Orientation on Gaze Discrimination

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.

Was Rembrandt strabismic?

PURPOSE

We studied a set of Rembrandt's self-portraits to reassess a previous claim, based on measurements of the centration of his painted irises, that Rembrandt had a large exotropia.

METHODS

Of the 24 self-portraits that Rembrandt painted, with significant ocular detail to give an impression of the direction of his gaze, we scanned 10; the five with the largest difference in centration between the irises and the five with the smallest difference. The right and left eyes in each image were then occluded using Photoshop to produce two additional images that gave monocular gaze. Thirty observers then judged where the portraits appeared to be gazing within the plane of their face.

RESULTS

Although our observers did judge a significant outward deviation for gaze between the two eyes, part of this was caused by an outward deviation from central by the presumably nonstrabismic eye. Any greater amount of outward deviation from the "strabismic" than the nonstrabismic eye can then be explained by a gaze overshoot induced by head turn, painting with a mirror, and angle kappas. In addition, Rembrandt's apparent strabismus is seen only in those portraits painted during a few years early in his career, and portraits that Rembrandt and his students produced of other presumably nonstrabismic individuals often give a similar impression of strabismus.

CONCLUSIONS

There are several factors that can explain why some of Rembrandt's self-portraits make him look strabismic without concluding that he actually was. Rembrandt and his students may also have painted this appearance as an artistic style.

Accurate gaze direction measurements with free head movement for strabismus angle estimation

We present the Delft Assessment Instrument for Strabismus in Young children (DAISY) a device designed to measure angles of strabismus in young children fast and accurately. DAISY allows for unrestrained head movements by the mean of a triple camera vision system that simultaneously estimates the head rotation and the eye pose. The device combines two different methods to record bilateral eye position: corneal reflections (Purkinje images) and pupillary images. Detailed results are provided on three orthotropic subjects (age 25-27). Three different conditions were tested: 1) gaze ahead, 2) gaze ahead with different head rotations, and 3) fixed head with different eye positions. Systematic errors occurred between subjects that need further study. The system reached sufficient accuracy to be applied for the measurement of angles of strabismus, almost independent from the head pose.

The Effect of Head Turn and Illumination on the Perceived Direction of Gaze

Thirty observers judged the direction of monocular and binocular gaze from a model's LCD-imaged head when the head, gaze, and illumination were either straight or turned 20.6° to the side. The judged direction of binocular eye contact from a turned head was judged to go past the direction of the observer, while judged monocular gaze from the eye toward the observer followed that for binocular gaze. Although judged monocular gaze from the eye away from the observer also passed the observer, it did so by a smaller amount. The judged direction of binocular gaze in the same direction as the head turn was judged to pass the direction of the head turn. The judged direction of monocular gaze from the eye away from the observer was nearly true, but the judged direction of monocular gaze from the eye toward the observer was judged as closer to the observer than true. Illumination of the model's head from the side made the direction of both head turn and gaze appear to move away from the direction of the light source. These results are discussed in connection with angle k and the perceived direction of head turn.

Stare in the crowd: frontal face guides overt attention independently of its gaze direction

Whether or not a stare in the midst of many faces can guide visual attention is a controversial issue. Two experiments are reported that investigate the hypothesis that visual attention is guided toward a frontal face in the search for a stare among faces with varied head angles. The participants were required to search for a face with a direct gaze in a context where the target could be at any of various head angles and the target's head angle was unpredictable in one trial. The search performance was better for a frontal-face target than for deviated-face targets. Furthermore, eye-movement analyses revealed that a frontal-face stimulus tended to be initially fixated prior to deviated-face stimuli, and many of the initially fixated frontal-face stimuli had an averted gaze. The findings suggest that a frontal face guides overt attention independently of its gaze direction in the search for a stare in a crowd. The validity of prioritising a frontal face in order to find a direct gaze among faces and the characteristics of a human-face detection system are discussed.

Research in visual pattern recognition: the enduring legacy of studies from the 1960s

This article highlights some research in visual pattern perception that was published in the American Journal of Psychology in the 1960s. Although visual perception research has changed substantially since then, and the term visual pattern recognition is no longer in widespread use, the six articles presented here are some of the most influential of those published by the Journal in its long history. The research is described with an emphasis on how a particular publication influenced others and the field in general.

Perceived direction of gaze from eyes with dark vs. light irises

PURPOSE

Much of the previous research on the perceived direction of gaze has not specified eye color or pupil visibility. This study tests whether the lightness or darkness of a gazer's irises (typically brown vs. blue) affects their perceived direction of gaze.

METHODS

Twenty-five observers judged the direction of horizontal gaze from a model whose LCD-imaged head gazed toward points on the plane of the observer's face. The model's head was displayed with its natural brown irises and also with its irises digitally altered to look blue without pupils, blue with centered pupils, and blue with nasally decentered pupils. True gaze location was compared with the judged gaze location for each type of iris.

RESULTS

For all iris types, observers judged that monocular gaze was biased outward from its true direction for all gaze locations, including central, whereas binocular gaze was close to centered and had a greater slope. Blue eyes with no pupil and blue eyes with a centered pupil exaggerated this perceived outward deviation for monocular gaze but binocular gaze remained the same. When the pupils were nasally decentered by a typical amount, straight monocular as well as binocular gaze appeared to be centered.

CONCLUSIONS

The direction of monocular gaze from eyes that differ in the darkness of their irises is perceived differently, and, within the blue irises, small differences in pupil centration made surprisingly large differences in the perceived directions of gaze.

Differences in the perception of monocular and binocular gaze

PURPOSE

The judged direction of side gaze from a straight head is known to be biased from its true direction. This study reports the specific biases in the perceived direction of gaze from right, left, or both eyes when targets are in the plane of the observer or in a plane in front of the observer. Theories are discussed about the ocular cues that are used to determine the perceived direction of gaze.

METHODS

Two sets of 16 observers judged the direction of gaze from each of two models whose LCD-imaged heads gazed toward points that were either on the plane of the observers' faces or on a plane that was midway between the models and observers.

RESULTS

For both distant and near targets, straight monocular gaze from the right and left eyes appeared to be mildly exotropic, as expected from the positive angle kappa of the models, but straight binocular gaze appeared orthotropic. However, when binocular gaze was toward the side, the perceived direction of gaze differed significantly between the two eyes, and for this condition, the perception of binocular gaze followed that of the abducting eye.

CONCLUSION

When the perceived directions of monocular gaze from the two eyes do not agree, the perceived direction of binocular gaze resolves this conflict by matching that of the abducting eye.