Individuals vary in their overt attention preference for positive images consistently across time and stimulus types.

What humans look at strongly determines what they see. We show that individual differences in the tendency to look at positive stimuli are stable across time and across contents, establishing gaze positivity preference as a perceptual trait that determines the amount of positively valence stimuli individuals select for visual processing. Furthermore, we show that patients with major depressive disorder exhibit consistently low positivity preference before treatment. In a subset of patients, we also assessed the positivity preference after two months of treatment in which positivity gaze preference increased to levels similar to healthy individuals. We discuss the possible practical diagnostic applications of these findings, as well as how this general gaze-related trait may influence other behavioral and psychological aspects.

The validation of online webcam-based eye-tracking: The replication of the cascade effect, the novelty preference, and the visual world paradigm.

The many benefits of online research and the recent emergence of open-source eye-tracking libraries have sparked an interest in transferring time-consuming and expensive eye-tracking studies from the lab to the web. In the current study, we validate online webcam-based eye-tracking by conceptually replicating three robust eye-tracking studies (the cascade effect, n = 134, the novelty preference, n = 45, and the visual world paradigm, n = 32) online using the participant's webcam as eye-tracker with the WebGazer.js library. We successfully replicated all three effects, although the effect sizes of all three studies shrank by 20-27%. The visual world paradigm was conducted both online and in the lab, using the same participants and a standard laboratory eye-tracker. The results showed that replication per se could not fully account for the effect size shrinkage, but that the shrinkage was also due to the use of online webcam-based eye-tracking, which is noisier. In conclusion, we argue that eye-tracking studies with relatively large effects that do not require extremely high precision (e.g., studies with four or fewer large regions of interest) can be done online using the participant's webcam. We also make recommendations for how the quality of online webcam-based eye-tracking could be improved.

Attenuation of visual exploration following stress.

When we explore our surroundings, we frequently move our gaze to collect visual information. Studies have extensively examined gaze behavior in response to different visual scenes. Here, we examined how differences in an individual's state may affect visual exploration, for example, following acute stress. In this study, participants were exposed to either a psychosocial stressor-performing a public speaking task in front of a two-person committee-or a control condition absent stress induction. Elicitation of stress responses was validated using cortisol levels and subjective reports. Stress also led to an extended increase in pupil diameter (a proxy of arousal responses), suggesting it may also affect eye movements. Gaze behavior measures were taken prior and following the stress or control tasks. Acute stress attenuated visual exploration, reflected by fewer saccades and a smaller scanned area. Stress did not have a significant effect on either the tendency to look at social features or at salient regions of the images. These findings diverge from theoretical predictions suggesting that acute stress may facilitate social affiliative behaviors (e.g., Tend-and-Befriend theory). Reduced saccades and a smaller scanned area may be a possible mechanism explaining previous reports showing stress-related effects on various cognitive processes (e.g., visual working memory) that rely on visual exploration.

The robustness of individual differences in gaze preferences toward faces and eyes across face-to-face experimental designs and its relation to social anxiety.

Humans rely heavily on the visual and oculomotor systems during social interactions. This study examined individual differences in gaze behavior in two types of face-to-face social interactions: a screen-based interview and a live interview. The study examined how stable these individual differences are across scenarios and how it relates to individuals' traits of social anxiety, autism, and neuroticism. Extending previous studies, we distinguished between individuals' tendency to look at the face, and the tendency to look at the eyes if the face was fixated. These gaze measures demonstrated high internal consistencies (correlation between two halves of the data within a scenario) within both the screen-based and live interview scenarios. Furthermore, individuals who had a tendency to look more at the eyes during one type of interview tended to display the same behavior during the other interview type. More socially anxious participants looked less at faces in both scenarios, but no link with social anxiety was observed for the tendency to look at the eyes. This research highlights the robustness of individual variations in gaze behavior across and within interview scenarios, as well as the usefulness of measuring the tendency to look at faces separately from the tendency to look at eyes.

Do we know our visual preferences?

Humans differ in the amount of time they direct their gaze toward different types of stimuli. Individuals' preferences are known to be reliable and can predict various cognitive and affective processes. However, it remains unclear whether humans are aware of their visual gaze preferences and are able to report it. In this study, across three different tasks and without prior warning, participants were asked to estimate the amount of time they had looked at a certain visual content (e.g., faces or texts) at the end of each experiment. The findings show that people can report accurately their visual gaze preferences. The implications are discussed in the context of visual perception, metacognition, and the development of applied diagnostic tools based on eye tracking.

Empathy Modulates the Effect of Stress Reactivity on Generous Giving.

How does acute stress influence the degree to which we cooperate with others? Research on the effects of stress on social decision-making is guided by two seemingly contrasting theories. Acute stress may trigger a Fight-or-Flight response, manifested by increased anxiety, and more egocentric or selfish behavior. Alternatively, according to the Tend-and-Befriend model, acute stress may induce affiliative behaviors, marked by increased prosociality in an effort to seek and receive social support and protection. Extant studies on the topic do not provide consistent support for either pattern of behavior, with studies showing evidence for both Fight-or-Flight or Tend-and-Befriend like responses. One possibility, may be the nature of social responses to stressful situations differ as a function of the individual. In the current study, we demonstrate an example of such a person-by-situation interaction, showing that acute stress can cause either pro-social or selfish responses, contingent on individual differences in trait empathy. One hundred and twenty three participants (60 F) were assessed for trait empathy using the Interpersonal Reactivity Index; consequently, they underwent either the Trier Social Stress Test-a well-validated paradigm for eliciting acute psychosocial stress-or a non-stress inducing control condition. Following exposure to either the stress or control condition, participants played a one-shot Dictator Game to evaluate their generosity levels. Statistical analyses revealed that acute stress by itself did not affect the amount transferred in the Dictator Game. Rather, individual differences in trait empathy moderated the effects of stress on giving. Elevations in stress-induced cortisol resulted in more generous behavior, but only in individuals high in empathy. In contrast, in individuals low in empathy, a greater rise in stress-induced cortisol resulted in more selfish behavior. Effects were more pronounced in females than males. Our findings highlight the necessity of integrating personality traits as important moderators of the link between stress and sociality.

Many ways to see your feelings: Successful facial expression recognition occurs with diverse patterns of fixation distributions.

Facial expression recognition relies on the processing of diagnostic information from different facial regions. For example, successful recognition of anger versus disgust requires one to process information located in the eye/brow region, or in the mouth/nose region, respectively. Yet, how this information is extracted from the face is less clear. One widespread view, supported by cross-cultural experiments as well as neuropsychological case studies, is that the distribution of gaze fixations on specific diagnostic regions plays a critical role in the extraction of affective information. According to this view, emotion recognition is strongly related to the distribution of fixations to diagnostic regions. Alternatively, facial expression recognition may not rely merely on the exact patterns of fixations, but rather on other factors such as the processing of extrafoveal information. In the present study, we examined this matter by characterizing and using individual differences in fixation distributions during facial expression recognition. We revealed 4 groups of observers that differed in their distribution of fixations toward face regions in a robust and consistent manner. In line with previous studies, we found that different facial emotion categories evoked distinct distribution of fixations according to their diagnostic facial regions. However, individual distinctive patterns of fixations were not correlated with emotion recognition: individuals that strongly focused on the eyes, or on the mouth, achieved comparable emotion recognition accuracy. These findings suggest that extrafoveal processing may play a larger role in emotion recognition from faces than previously assumed. Consequently, successful emotion recognition can rise from diverse patterns of fixations. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Social evaluation under stress: Does acute stress affect social attributions and eye gaze?

Acute stress has been found to elicit pro-social, anti-social or null responses in humans. The causes for these contradicting findings are currently poorly understood, and may rise from subjects' characteristics, such as sex or hormonal status, as well as stimuli-based traits, such as group membership. In the current study, 120 subjects performed either the Trier Social Stress Test or a control (non-stress inducing) condition, followed by ranking displayed faces according to several attributes (e.g., trustworthiness, attractiveness, dominance). Participants' eye gaze was also tracked while viewing facial stimuli. We examined how acute stress interacts with participants' sex, female participants' hormonal status (hormonal contraceptives, early-follicular phase and mid-luteal phase), and the observed faces' social group (ethnicity-based in-group or out-groups). In general, frequentist and Bayesian analyses showed that acute stress exposure did not affect social attributions or gaze behavior, nor did it interact with subjects' sex or the group membership of the observed faces. Interestingly, sub-group analyses showed that in females, acute stress interacted with hormonal status to yield heterogenous anti-social effects, such as post-stress reductions in perceived trustworthiness in the early-follicular phase, and lower perceived attractiveness in the mid-luteal phase. Given the small sample sizes for the sub-groups, these results should be viewed as preliminary until further replicated. Our results highlight the necessity for large-scale studies, particularly in females, to further refine existing theories regarding the nature and contexts by which acute stress elicits changes in social cognition and behavior.

Not all fixations are created equal: The benefits of using ex-Gaussian modeling of fixation durations.

Various cognitive and perceptual factors have been shown to modulate the duration of fixations during visual exploration of complex scenes. The majority of these studies have only considered the mean of the distribution of fixation durations. However, this distribution is skewed to the right, so that an increase in the mean may be driven by a lengthening of all fixations (i.e., a right shift of the whole distribution) or only the relatively longer ones (i.e., a longer right tail of the distribution). To determine which factor is at play, the distribution can be modeled with an ex-Gaussian distribution, which is a convolution of a Gaussian and an exponential distribution. Here we demonstrate the usefulness of applying the ex-Gaussian model to empirical distributions of fixation durations and the reliability of its parameters across time. We demonstrate how the ex-Gaussian model had advantages over exclusive consideration of the mean, by showing that an increase in the mean can stem from specific changes in the components of the ex-Gaussian distribution. Specifically, the type of image leads to a change in the Gaussian component alone, indicating a right shift of the main mass of the distribution. By contrast, familiarity with the inspected image modifies the exponential component, and results in a more specific modulation of a subset of relatively long fixations. Hence, estimating the ex-Gaussian parameters may provide novel insights into the underlying processes that determine fixation duration and can contribute to the future development of process-based computational models of gaze behavior.

Role of Population Receptive Field Size in Complex Visual Dysfunctions: A Posterior Cortical Atrophy Model.

IMPORTANCE: The neuronal mechanism of visual agnosia and foveal crowding that underlies the behavioral symptoms of several classic neurodegenerative diseases, including impaired holistic perception, navigation, and reading, is still unclear. A better understanding of this mechanism is expected to lead to better treatment and rehabilitation. OBJECTIVE: To use state-of-the-art neuroimaging protocols to assess a hypothesis that abnormal population receptive fields (pRF) in the visual cortex underlie high-order visual impairments. DESIGN, SETTING, AND PARTICIPANTS: Between April 26 and November 21, 2016, patients and controls were recruited from the Hadassah-Hebrew University medical center in a cross-sectional manner. Six patients with posterior cortical atrophy (PCA) were approached and 1 was excluded because of an inability to perform the task. Participants underwent functional magnetic resonance imaging-based cortical visual field mapping and pRF evaluation and performed a masked repetition priming task to evaluate visuospatial perception along the eccentricity axis. The association between pRF sizes and behavioral impairments was assessed to evaluate the role of abnormal pRF sizes in impaired visual perception. Posterior cortical atrophy is a visual variant of Alzheimer disease that is characterized by progressive visual agnosia despite almost 20/20 visual acuity. Patients with PCA are rare but invaluable for studying visual processing abnormalities following neurodegeneration, as atrophy begins in visual cortices but initially spares other brain regions involved in memory and verbal communication. EXPOSURES: Participants underwent a magnetic resonance imaging scan. MAIN OUTCOMES AND MEASURES: Population receptive field sizes and their association with visual processing along the fovea-to-periphery gradient. RESULTS: Five patients with PCA (4 men [80%]; mean [SEM] age, 62.9 [3.5] years) were compared with 8 age-matched controls (1 man [25%]; mean [SEM] age, 63.7 [3.7] years) and demonstrated an atypical pRF mapping that varied along the eccentricity axis, which presented as abnormally small peripheral and large foveal pRFs sizes. Abnormality was seen in V1 (peripheral, 4.4° and 5.5°; foveal, 5.5° and 4.5° in patients and controls, respectively; P < .05) as well as in higher visual regions, but not in intermediate ones. Behaviorally, an atypical fovea-to-periphery gradient in visual processing was found that correlated with their pRF properties (r = 0.8; P < .01 for the correlation between pRF and behavioral fovea-to-periphery slopes). CONCLUSIONS AND RELEVANCE: High-order visuocognitive functions may depend on abnormalities in basic cortical characteristics. These results may fundamentally change approaches to rehabilitation in such conditions, emphasizing the potential of low-level visual interventions.

A novel perceptual trait: gaze predilection for faces during visual exploration.

Humans are social animals and typically tend to seek social interactions. In our daily life we constantly move our gaze to collect visual information which often includes social information, such as others' emotions and intentions. Recent studies began to explore how individuals vary in their gaze behavior. However, these studies focused on basic features of eye movements (such as the length of movements) and did not examine the observer predilection for specific social features such as faces. We preformed two test-retest experiments examining the amount of time individuals fixate directly on faces embedded in images of naturally occurring scenes. We report on stable and robust individual differences in visual predilection for faces across time and tasks. Individuals' preference to fixate on faces could not be explained by a preference for fixating on low-level salient regions (e.g. color, intensity, orientation) nor by individual differences in the Big-Five personality traits. We conclude that during visual exploration individuals vary in the amount of time they direct their gaze towards faces. This tendency is a trait that not only reflects individuals' preferences but also influences the amount of information gathered by each observer, therefore influencing the basis for later cognitive processing and decisions.