Gaze following in multiagent contexts: Evidence for a quorum-like principle

Not to follow because of distrust: perceived trust modulates the gaze cueing effect

In social life, people spontaneously form stable trustworthiness impressions from faces. However, the precise role of extracting trustworthiness information remains unclear. This study aims to elucidate whether discerning facial trustworthiness influences social interactions. Specifically, it explores the gaze cueing effect (GCE), wherein individuals exhibit quicker responses to targets appearing in the direction of gaze compared to other locations. Given conflicting perspectives in existing literature regarding the potential modulation of trustworthiness on the GCE, two plausible hypotheses are proposed to explain divergent result patterns. The reflexive hypothesis posits that the GCE operates automatically. In contrast, the flexible hypothesis underscores the potential modulatory role of trustworthiness in the GCE. To provide a comprehensive understanding of whether trustworthiness modulates the GCE, we employed face stimuli incorporating trustworthiness information within Posner' s cue-target task. The findings of Experiment 1 revealed that the perception of trustworthiness indeed influenced the GCE. Specifically, when facial stimuli were perceived as trustworthy, they elicited a more pronounced GCE compared to untrustworthy stimuli. This modulation effect was replicated using a different stimulus set in Experiment 2. In Experiment 3, we employed the same stimuli as in Experiment 2, setting the trustworthiness information to baseline as a control experiment. The results demonstrated that the trustworthiness modulation effect disappeared, indicating its specificity to the trustworthiness attribute of the stimuli rather than other characteristics. Collectively, these findings lend support to the flexible hypothesis, highlighting that the extraction of trustworthiness information plays a pivotal role in modulating the GCE, consequently influencing social interactions.

The who and the where: Attention to identities and locations in groups

While it is widely accepted that the single gaze of another person elicits shifts of attention, there is limited work on the effects of multiple gazes on attention, despite real-world social cues often occurring in groups. Further, less is known regarding the role of unequal reliability of varying social and nonsocial information on attention. We addressed these gaps by employing a variant of the gaze cueing paradigm, simultaneously presenting participants with three faces. Block-wise, we manipulated whether one face (Identity condition) or one location (Location condition) contained a gaze cue entirely predictive of target location; all other cues were uninformative. Across trials, we manipulated the number of valid cues (number of faces gazing at target). We examined whether these two types of information (Identity vs. Location) were learned at a similar rate by statistically modelling cueing effects by trial count. Preregistered analyses returned no evidence for an interaction between condition, number of valid faces, and presence of the predictive element, indicating type of information did not affect participants' ability to employ the predictive element to alter behaviour. Exploratory analyses demonstrated (i) response times (RT) decreased faster across trials for the Identity compared with Location condition, with greater decreases when the predictive element was present versus absent, (ii) RTs decreased across trials for the Location condition only when it was completed first, and (iii) social competence altered RTs across conditions and trial number. Our work demonstrates a nuanced relationship between cue utility, condition type, and social competence on group cueing.

Mechanisms of group-hunting in vertebrates

Group-hunting is ubiquitous across animal taxa and has received considerable attention in the context of its functions. By contrast much less is known about the mechanisms by which grouping predators hunt their prey. This is primarily due to a lack of experimental manipulation alongside logistical difficulties quantifying the behaviour of multiple predators at high spatiotemporal resolution as they search, select, and capture wild prey. However, the use of new remote-sensing technologies and a broadening of the focal taxa beyond apex predators provides researchers with a great opportunity to discern accurately how multiple predators hunt together and not just whether doing so provides hunters with a per capita benefit. We incorporate many ideas from collective behaviour and locomotion throughout this review to make testable predictions for future researchers and pay particular attention to the role that computer simulation can play in a feedback loop with empirical data collection. Our review of the literature showed that the breadth of predator:prey size ratios among the taxa that can be considered to hunt as a group is very large (<100 to >102 ). We therefore synthesised the literature with respect to these predator:prey ratios and found that they promoted different hunting mechanisms. Additionally, these different hunting mechanisms are also related to particular stages of the hunt (search, selection, capture) and thus we structure our review in accordance with these two factors (stage of the hunt and predator:prey size ratio). We identify several novel group-hunting mechanisms which are largely untested, particularly under field conditions, and we also highlight a range of potential study organisms that are amenable to experimental testing of these mechanisms in connection with tracking technology. We believe that a combination of new hypotheses, study systems and methodological approaches should help push the field of group-hunting in new directions.

Social Isolation Affects the Mimicry Response in the Use of Smartphones : An Ethological Experiment during the COVID-19 Pandemic

Humans are social animals that rely on different ways to interact with each other. The COVID-19 pandemic strongly changed our communication strategies. Because of the importance of direct contact for our species, we predict that immediately after the forced social isolation, people were more prone to engage in direct rather than in virtual interactions, thus showing a lower mimicry response in the use of smartphones. In a non-longitudinal study, we collected behavioral data under naturalistic contexts and directly compared the data of the mimicry response gathered immediately following the Italian lockdown (May-September 2020) with those gathered one year later (May-October 2021). Contrary to our expectations, the mimicry response in the use of smartphones was higher immediately after the lockdown than a year later. Probably the large use of these devices during the lockdown translated into a greater sensitivity to be affected by others' smartphone manipulation. Indeed, social isolation modified, at least in the short term, the ways we interact with others by making us more prone to engage in "virtual" social interactions. The bright side of the coin unveiled by our findings is that the effect seems to diminish over time. The large behavioral dataset analyzed here (1,608 events; 248 people) also revealed that the mimicry response in the use of smartphones was higher between familiar subjects than between strangers. In this view, mimicry in manipulating smartphones can be considered an example of joint action that fosters behavioral synchrony between individuals that, in the long-term, can translate into the formation of social bonding.

Influences of eye gaze cues on memory and its mechanisms: The function and evolution of social attention

During evolution, humans have formed a priority perceptual preference for others’ gazes. The gaze direction of others is called the gaze cue, conveying environmental information, a critical non-verbal communication in early humans. Recently, empirical evidence has indicated that gaze cues can affect high-level cognitive processes, such as memory. Unlike non-social cues (e.g., arrows), gaze cues elicit special social attention. Research determining the underlying mechanisms suggests that social intention influences observers’ visual attention and influences their memory. This article provides a brief review of the current state of research on the relationship between gaze cues and memory. Future studies should focus on multiple gaze cues, the social nature of gaze cues, and clinical research.

Evidence for a two-step model of social group influence

Social group influence plays an important role in societally relevant phenomena such as rioting and mass panic. One way through which groups influence individuals is by directing their gaze. Evidence that gaze following increases with group size has typically been explained in terms of strategic processes. Here, we tested the role of reflexive processes. In an ecologically valid virtual reality task, we found that participants were more likely to follow the group’s gaze when more people looked, even though they knew the group provided no relevant information. Interestingly, participants also sometimes changed their mind after starting to follow the gaze of the group, indicating that automatic imitation can be overruled by strategic processes. This suggests that social group influence is best explained by a two-step model in which bottom-up imitative processes first elicit a reflexive tendency to imitate, before top-down strategic processes determine whether to execute or inhibit this reflex.

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Groups influence human behavior in two stages

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First, groups elicit a reflexive tendency to imitate

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Second, strategic processes decide to execute or inhibit this reflex

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Social group conformity may be more automatic than previously thought

Standing out from the crowd: Both cue numerosity and social information affect attention in multi-agent contexts

Groups of people offer abundant opportunities for social interactions. We used a two-phase task to investigate how social cue numerosity and social information about an individual affected attentional allocation in such multi-agent settings. The learning phase was a standard gaze-cuing procedure in which a stimulus face could be either uninformative or informative about the upcoming target. The test phase was a group-cuing procedure in which the stimulus faces from the learning phase were presented in groups of three. The target could either be cued by the group minority (i.e., one face) or majority (i.e., two faces) or by uninformative or informative stimulus faces. Results showed an effect of cue numerosity, whereby responses were faster to targets cued by the group majority than the group minority. However, responses to targets cued by informative identities included in the group minority were as fast as responses to targets cued by the group majority. Thus, previously learned social information about an individual was able to offset the general enhancement of cue numerosity, revealing a complex interplay between cue numerosity and social information in guiding attention in multi-agent settings.

Understanding joint action: Current theoretical and empirical approaches

Joint actions are omnipresent, ranging from a handshake between two people to the coordination of groups of people playing in an orchestra. We are highly skilled at coordinating our actions with those of others to reach common goals and rely on this ability throughout our daily lives. What are the social, cognitive and neural processes underlying this ability? How do others around us influence our task representations? How does joint action influence interpersonal interactions? How do language and gesture support joint action? What differentiates joint action from individual action? This article forms an introductory editorial to the field of joint action. It accompanies contributions to the special issue entitled "Current Issues in Joint Action Research". The issue brings together conceptual and empirical approaches on different topics, ranging from lower-level issues such as the link between perception and joint action, to higher-level issues such as language as a form of joint action.

Tracking multiple perspectives: Spontaneous computation of what individuals in high entitative groups see

Perspective-taking ability is crucial for supporting social interactions. It has been widely suggested that the calculation of an individual's perspective is spontaneous. Nevertheless, people typically engage with more than one individual, and computing what individuals in a crowd see is important. The current study explored whether people spontaneously compute the perspectives of individuals displayed in a crowd. The classic visual perspective-taking task was adopted, but the picture of the room was presented with four human avatars facing two walls. The results showed that if the crowd of individuals was treated as a high entitative group, when none of the perspectives of the individuals contained the same number of discs as that from the perspective of the participant, the judgment of the participant's perspective was slower than when a proportion of the perspectives of the individuals displayed in the crowd were consistent with the participant's perspective, even if the perspectives of the multiple individuals in a crowd were not explicitly noticed. This altercentric intrusion effect was not present when the crowd had low entitativity. These findings were replicated by using different methods to operationalize group entitativity. Hence, this study demonstrates that spontaneously tracking the perspectives of individuals displayed in a crowd has a boundary condition and that people can spontaneously compute what individuals in high entitative groups see.

Prior attentional bias is modulated by social gaze

Focusing attention is a key cognitive skill, but how the gaze of others affects engaged attention remains relatively unknown. We investigated if participants' attentional bias toward a location is modulated by the number of people gazing toward or away from it. We presented participants with a nonpredictive directional cue that biased attention towards a specific location. Then, any number of four stimulus faces turned their gaze toward or away from the attended location. When all the faces looked at the attended location participants increased their commitment to it, and response time to targets at that location were speeded. When most or all of the faces looked away from the attended location, attention was withdrawn, and response times were slowed. This study reveals that the gaze of others can penetrate one's ability to focus attention, which in turn can be both beneficial and costly to one's responses to events in the environment.

Incidental learning of group trust: Predictive gaze cue matters

Human gaze is a subtle cue to deliver information and helps impression formation in social interactions. People automatically follow the gaze direction of others and shift their attention accordingly, as well as determine the trustworthiness of others based on the predictable validity of their gaze behavior, yet it remains unclear how this works at the collective level. Therefore, the current study is the first to explore the incidental learning of trust from a group’s gaze behavior. To simulate different patterns of perceiving collective information in real life, two ways of presenting group member gazes were used in the object categorization task, the simultaneous way in Experiment 1 and the sequential way in Experiment 3, and a sampling strategy was ruled out in Experiment 2. Converging findings in experiments demonstrated a typical gaze-cueing effect, and more importantly, the Predictive-valid group obtained more trust compared to the Predictive-invalid group. To enrich and expand the applicability of the incidental trust learning effect from gazes, the current study provides supportive evidence at the collective level, confirming that humans have an efficient capability to process gaze information of groups.

ERP evidence on how gaze convergence affects social attention

How people process gaze cues from multiple others is an important topic but rarely studied. Our study investigated this question using an adapted gaze cueing paradigm to examine the cueing effect of multiple gazes and its neural correlates. We manipulated gaze directions from two human avatars to be either convergent, created by the two avatars simultaneously averting their gazes to the same direction, or non-convergent, when only one of the two avatars shifted its gaze. Our results showed faster reaction times and larger target-congruency effects following convergent gazes shared by the avatars, compared with the non-convergent gaze condition. These findings complement previous research to demonstrate that observing shared gazes from as few as two persons is sufficient to enhance gaze cueing. Additionally, ERP analyses revealed that (1) convergent gazes evoked both left and right hemisphere N170, while non-convergent gazes evoked N170 mainly in the hemisphere contralateral to the cueing face; (2) effects of target congruency on target-locked N1 and P3 were modulated by gaze convergence. These findings shed light on temporal features of the processing of multi-gaze cues.

How attention gates social interactions

Social interactions are at the core of social life. However, humans selectively choose their exchange partners and do not engage in all available opportunities for social encounters. In this review, we argue that attentional systems play an important role in guiding the selection of social interactions. Supported by both classic and emerging literature, we identify and characterize the three core processes-perception, interpretation, and evaluation-that interact with attentional systems to modulate selective responses to social environments. Perceptual processes facilitate attentional prioritization of social cues. Interpretative processes link attention with understanding of cues' social meanings and agents' mental states. Evaluative processes determine the perceived value of the source of social information. The interplay between attention and these three routes of processing places attention in a powerful role to manage the selection of the vast amount of social information that individuals encounter on a daily basis and, in turn, gate the selection of social interactions.