Effects of peripheral eccentricity and head orientation on gaze discrimination

This is an Accepted Manuscript of an article published by Taylor & Francis in Social Neuroscience on 13 Jan 2015, available online: http://www.tandfonline.com/10.1080/13506285.2014.990545.Visual search tasks support a special role for direct gaze in human cognition, while classic gaze judgement 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 fieldparticipants 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 judgements, 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

The final publication is available at Springer via https://dx.doi.org/10.3758/s13414-015-0961-y.The present study used an inhibition of return (IOR) spatial cueing paradigm to examine how gaze direction and head orientation modulate attention capture for human faces. Target response time (RT) was measured after the presentation of a peripheral cue, which was either a face (with frontfacing or averted gaze, in either frontal head view or averted head view) or a house (control). Participants fixated on a centred cross at all times and responded via button press to a peripheral target after a variable stimulus onset asynchrony (SOA) from the stimulus cue. At the shortest SOA (150 ms), RTs were shorter for faces than houses, independent of an IOR response, suggesting a cue-based RT advantage elicited by faces. At the longest SOA (2400 ms), a larger IOR magnitude was found for faces compared to houses. Both the cue-based RT advantage and later IOR responses were modulated by gaze-head congruency; these effects were strongest for frontal gaze faces in frontal head view, and for averted gaze faces in averted head view. Importantly, participants were not given any specific information regarding the stimuli, nor were they told the true purpose of the study. These findings indicate that the congruent combination of head and gaze direction influence the exogenous attention capture of faces during inhibition of return.These findings indicate that the congruent combination of head and gaze direction influence the exogenous attention capture of faces during inhibition of return.||the Ontario government (Early Researcher Award||ER11-08-172), the Canada Foundation for Innovation (CFI, #213322)||and the Canada Research Chair (CRC, #959-213322) program to RJI||as well as by a doctoral NSERC grant to KNN

Effects of Gender and Gaze Direction on the Visual Exploration of Male and Female Bodies

The present study used eye-tracking to investigate whether a model’s gaze direction influences the way observers look at the entire body of the model and how this interacts with the observer and the model’s gender. Participants viewed individual male and female computer agents during both a free-viewing task and a rating task to evaluate the attractiveness of each character. The results indicated that both male and female participants primarily gazed at the models’ faces. Participants also spent more time scanning the face when rating the attractiveness of each model. Observers tended to scan faces with a direct gaze longer than faces with an averted gaze for both the free-viewing and attractiveness rating tasks. Lastly, participants evaluated models with a direct gaze as more attractive than models with an averted gaze. As these results occurred for pictures of computer agents, and not actual people, this suggests that direct gaze, and faces in general, are powerful for engaging attention. In summary, both task requirements and gaze direction modified face viewing preference

The Effects of Eye Gaze and Head Orientation On Covert Attention Capture

The direction of someone’s eye gaze plays a fundamental role during social interactions and may function to capture and engage attention in the environment. Research has shown that direct eye gaze can preferentially attract visuospatial attention compared to averted gaze, while other research has shown that the congruency between head orientation and gaze direction plays a central role in determining where a person is looking. The majority of previous research examining the perception of gaze direction has predominantly measured overt attention, either through visual search paradigms, or other gaze judgment tasks when targets are directly fixated. However, it is unknown whether gaze direction can be accurately discriminated using covert attention, when stimuli are located outside the focus of attention. This thesis presents a series of studies examining whether and to what extent gaze direction and head orientation capture covert attention in the periphery. Chapter 2 contained four experiments examining gaze detection in the horizontal periphery. Individual faces with a direct- or an averted gaze were flashed for 150 ms across various horizontal eccentricities along the visual field while participants judged whether the face was looking straight or to the side. Fixation on a centred cross was enforced using an eye-tracker, ensuring the use of covert attention. Gaze detection speed and accuracy varied with stimulus type and eccentricity. Accurate gaze detection was achieved all the way to ±10.5° eccentricity when face photographs were highly symmetrical and controlled for visual contrast and luminance (Experiment 1a), but only to ±4.5° eccentricity when using natural face photographs (Experiments 1b, 1c, and 1d). By ±3º of eccentricity, head orientation started biasing gaze judgments, and this bias increased with eccentricity so that beyond central vision gaze judgment was primarily made on the basis of head orientation. However, when presented at the fovea, direct gaze was generally detected faster than averted gaze. Results also suggested a facilitated processing of frontal heads with direct gaze in both central and peripheral vision. Chapter 3 contained three experiments that examined gaze detection in the vertical periphery. These experiments used the same paradigm as in Chapter 2, except with presenting stimuli across various vertical eccentricities (only natural face photographs were used). Gaze was detected above chance level up to ±3° eccentricity when using frontal heads (Experiment 2a), but over ±6° eccentricity when using deviated heads (Experiment 2b); Experiment 2b also showed that head orientation did not play a strong role in biasing gaze judgments. However, it was demonstrated that, beyond foveal vision, head orientation influenced gaze judgments when both head orientations were tested together (Experiment 2c), and that gaze was discriminated accurately only within central vision (~3°-4.5° eccentricity). Again, there was a special processing of frontal heads with direct gaze. Chapter 4 contained two experiments that investigated how gaze direction and head orientation influenced attention capture using an inhibition of return (IOR) spatial cueing paradigm. Target response time (RT) was measured after the presentation of a stimulus cue (150 ms situated 4.5° horizontally to either left or right of fixation), which was either a face (with direct- or averted gaze) or a house (control). Participants fixated on a centred cross at all times and responded via button press to a peripheral target after a variable stimulus onset asynchrony (SOA) from the stimulus cue. At the shortest SOA (150 ms), RTs were shorter for faces than houses, independent of an IOR response, suggesting a priming effect elicited by faces. At the longest SOA (2400 ms), a larger IOR magnitude was found for faces compared to houses. Both the priming effect and later IOR responses were modulated by gaze-head congruency; these effects were strongest for direct gaze faces with frontal heads (Experiment 3a), and for averted gaze faces with deviated heads (Experiment 3b). Overall, the series of studies in this thesis indicate that gaze direction and head orientation can be powerful social cues for capturing and engaging attention, and both contribute to gaze detection in the environment, but their roles differ with eccentricity

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

To view the final version of this © SAGE publication go here: https://dx.doi.org/10.1177/0301006616686989Previous 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.This work was supported by NSERC (Discovery grant #418431)CFI (#213322)and the Canada Research Chair (CRC) program (#959-213322) to R. J. I.and by a Queen Elizabeth II Graduate Scholarship in Science and Technology to A. P

Direct gaze facilitates rapid orienting to faces: evidence from express saccades and saccadic potentials

Direct gaze is a crucial signal in human social communication, which is known to attract visual attention and modulate a wide range of behaviours. The present study investigated whether direct gaze facilitates rapid orienting to faces, which is important for adaptive on-line communication, and its neural correlates. Fifteen participants performed a rapid orienting task, in which they were instructed to saccade to peripherally presented buildings or faces containing direct or averted gaze as quickly as possible. Electroencephalographic recordings were made during the task. Shorter express saccade latencies were found for faces with direct gaze, compared to averted gaze or buildings, while no significant difference was found between faces with averted gaze and buildings. Furthermore, saccade-locked event-related potential (ERP) amplitudes in parieto-occipital areas discriminated faces with direct gaze from buildings and faces with averted gaze corroborating behavioural results. These results show that detection of direct gaze facilitates rapid orienting to faces

The influence of top-down modulation on the processing of direct gaze

Gaze or eye contact is one of the most important non-verbal social cues, which is fundamental to human social interactions. To achieve real time and dynamic face-to-face communication, our brain needs to process another person's gaze direction rapidly and without explicit instruction. In order to explain fast and spontaneous processing of direct gaze, the fast-track modulator model (Senju & Johnson, 2009) was proposed. Here, we review recent developments in gaze processing research in the last decade to extend the fast-track modulator model. In particular, we propose that task demand or top-down modulation could play a more crucial role at gaze processing than formerly assumed. We suggest that under different task demands, top-down modulation can facilitate or interfere with the direct gaze effects for early visual processing. The proposed modification of the model extends the role of task demand and its implication on the direct gaze effect, as well as the need to better control for top-down processing in order to better disentangle the role of top-down and bottom-up processing on the direct gaze effect

The Role of Emotional Expression and Eccentricity on Gaze Perception

The perception of another’s gaze direction and facial expression complements verbal communication and modulates how we interact with other people. However, our perception of these two cues is not always accurate, even when we are looking directly at the person. In addition, in many cases social communication occurs within groups of people where we can’t always look directly at every person in the group. Here, we sought to examine how the presence of other people influences our perception of a target face. We asked participants to judge the direction of gaze of the target face as either looking to their left, to their right or directly at them, when the face was viewed on its own or viewed within a group of other identity faces. The target face either had an angry or a neutral expression and was viewed directly (foveal experiment), or within peripheral vision (peripheral experiment). When the target was viewed within a group, the flanking faces also had either neutral or angry expressions and their gaze was in one of five different directions (from averted leftwards to averted rightwards in steps of 10°). When the target face was viewed foveally there was no effect of target emotion on participants’ judgments of its gaze direction. There was also no effect of the presence of flankers (regardless of expression) on the perception of the target gaze. When the target face was viewed peripherally, participants judged its direction of gaze to be direct over a wider range of gaze deviations than when viewed foveally, and more so for angry faces than neutral faces. We also find that flankers (regardless of emotional expression) did not influence performance. This suggests that observers judge that angry faces were looking at them over a broad range of gaze deviations in the periphery only, possibly resulting from increased uncertainty about the stimulus