Mental state attribution and the gaze cueing effect

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.

Agent-Object Relationships in Level-2 Visual Perspective Taking: An Eye-Tracking Study

Visual perspective taking (VPT) generates a shared frame of reference for understanding how the world appears to others. Whilst greater cognitive and neurophysiological demands are associated with increasing angular distance between the self and other is well documented, accompanying attentional characteristics are not currently understood. Furthermore, although age and group status have been shown to impact task performance, other important cues, such as the relationship between agents and objects, have not been manipulated. Therefore, 35 university students participated in an eye-tracking experiment where they completed a VPT task with agents positioned at a low or high angular disparity (45° or 135° respectively). The congruence between the age of the agent (child vs adult) and the object they are attending to (e.g., teddy-bear vs kettle) was also manipulated. Participants were required to respond to the direction of the object from the agent's position. The findings reveal more fixations and increased dwell-times on agents compared to objects, but this was moderated by the age of the task agent. Results also showed more attentional transitions between agents and objects at higher angular disparities. These results converge with behavioural and neurophysiological descriptions of task performance in previous studies. Furthermore, the congruency of the relationship between agents and objects also impacted attention shifting and response times, highlighting the importance of understanding how social cues and contexts can modulate VPT processes in everyday contexts and social interaction.

Mentalistic attention orienting triggered by android eyes

The eyes play a special role in human communications. Previous psychological studies have reported reflexive attention orienting in response to another individual's eyes during live interactions. Although robots are expected to collaborate with humans in various social situations, it remains unclear whether robot eyes have the potential to trigger attention orienting similarly to human eyes, specifically based on mental attribution. We investigated this issue in a series of experiments using a live gaze-cueing paradigm with an android. In Experiment 1, the non-predictive cue was the eyes and head of an android placed in front of human participants. Light-emitting diodes in the periphery served as target signals. The reaction times (RTs) required to localize the valid cued targets were faster than those for invalid cued targets for both types of cues. In Experiment 2, the gaze direction of the android eyes changed before the peripheral target lights appeared with or without barriers that made the targets non-visible, such that the android did not attend to them. The RTs were faster for validly cued targets only when there were no barriers. In Experiment 3, the targets were changed from lights to sounds, which the android could attend to even in the presence of barriers. The RTs to the target sounds were faster with valid cues, irrespective of the presence of barriers. These results suggest that android eyes may automatically induce attention orienting in humans based on mental state attribution.

Testing the effects of gaze distractors with invariant spatial direction on attention cueing

In four experiments, we tested the boundary conditions of gaze cueing with reference to the resistance to suppression criterion of automaticity. Participants were asked to respond to peripheral targets preceded by a central gaze stimulus. Under one condition, gaze direction was random and uninformative with respect to target location (intermixed condition), as in the typical paradigm. Under another condition, gaze direction was uninformative and, crucially, it was also kept constant throughout the sequence of trials (blocked condition). In so doing, we aimed at maximally reducing the informative value of the gaze stimulus because gaze would not only be task-irrelevant but would also provide no sudden and unpredictable information. Across the four experiments, the results showed a strong gaze-cueing effect. More specifically, a comparable gaze cueing emerged under the blocked and intermixed conditions. These findings are consistent with the idea that gaze cueing is resistant to suppression and are discussed in relation to current views of the automaticity of gaze cueing.

Reading minds or reading scripts? De-intellectualising theory of mind

Understanding the origins of human social cognition is a central challenge in contemporary science. In recent decades, the idea of a 'Theory of Mind' (ToM) has emerged as the most popular way of explaining unique features of human social cognition. This default view has been progressively undermined by research on 'implicit' ToM, which suggests that relevant precursor abilities may already be present in preverbal human infants and great apes. However, this area of research suffers from conceptual difficulties and empirical limitations, including explanatory circularity, over-intellectualisation, and inconsistent empirical replication. Our article breaks new ground by adapting 'script theory' for application to both linguistic and non-linguistic agents. It thereby provides a new theoretical framework able to resolve the aforementioned issues, generate novel predictions, and provide a plausible account of how individuals make sense of the behaviour of others. Script theory is based on the premise that pre-verbal infants and great apes are capable of basic forms of agency-detection and non-mentalistic goal understanding, allowing individuals to form event-schemata that are then used to make sense of the behaviour of others. We show how script theory circumvents fundamental problems created by ToM-based frameworks, explains patterns of inconsistent replication, and offers important novel predictions regarding how humans and other animals understand and predict the behaviour of others.

Gaze-Triggered Communicative Intention Compresses Perceived Temporal Duration

Eye gaze communicates a person's attentional state and intentions toward objects. Here we demonstrate that this important social signal has the potential to distort time perception of gazed-at objects (N = 70 adults). By using a novel gaze-associated learning paradigm combined with the time-discrimination task, we showed that objects previously associated with others' eye gaze were perceived as significantly shorter in duration than the nonassociated counterparts. The time-compression effect cannot be attributed to general attention allocation because it disappeared when objects were associated with nonsocial attention cues (i.e., arrows). Critically, this effect correlated with observers' autistic traits and vanished when the gazing agent's line of sight was blocked by barriers, reflecting the key role of intention processing triggered by gaze in modulating time perception. Our findings support the existence of a special mechanism tuned to social cues, which can shape our perception of the outer world in time domains.

Can the robot "see" what I see? Robot gaze drives attention depending on mental state attribution

Mentalizing, where humans infer the mental states of others, facilitates understanding and interaction in social situations. Humans also tend to adopt mentalizing strategies when interacting with robotic agents. There is an ongoing debate about how inferred mental states affect gaze following, a key component of joint attention. Although the gaze from a robot induces gaze following, the impact of mental state attribution on robotic gaze following remains unclear. To address this question, we asked forty-nine young adults to perform a gaze cueing task during which mental state attribution was manipulated as follows. Participants sat facing a robot that turned its head to the screen at its left or right. Their task was to respond to targets that appeared either at the screen the robot gazed at or at the other screen. At the baseline, the robot was positioned so that participants would perceive it as being able to see the screens. We expected faster response times to targets at the screen the robot gazed at than targets at the non-gazed screen (i.e., gaze cueing effect). In the experimental condition, the robot's line of sight was occluded by a physical barrier such that participants would perceive it as unable to see the screens. Our results revealed gaze cueing effects in both conditions although the effect was reduced in the occluded condition compared to the baseline. These results add to the expanding fields of social cognition and human-robot interaction by suggesting that mentalizing has an impact on robotic gaze following.

I see you, you see me: the impact of social presence on social interaction processes in autistic and non-autistic people

Environments that require social interaction are complex, challenging and sometimes experienced as overwhelming by autistic people. However, all too often theories relating to social interaction processes are created, and interventions are proposed, on the basis of data collected from studies that do not involve genuine social encounters nor do they consider the perception of social presence to be a potentially influential factor. In this review, we begin by considering why face-to-face interaction research is important in this field. We then discuss how the perception of social agency and social presence can influence conclusions about social interaction processes. We then outline some insights gained from face-to-face interaction research conducted with both autistic and non-autistic people. We finish by considering the impact of social presence on cognitive processes more broadly, including theory of mind. Overall, we demonstrate that choice of stimuli in studies assessing social interaction processes has the potential to substantially alter conclusions drawn. Ecological validity matters and social presence, in particular, is a critical factor that fundamentally impacts social interaction processes in both autistic and non-autistic people. This article is part of a discussion meeting issue 'Face2face: advancing the science of social interaction'.

Both the domain-general and the mentalising processes affect visual perspective taking

People's attention cannot help being affected by what others are looking at. The dot-perspective task has been often employed to investigate this visual attentional shift. In this task, participants are presented with virtual scenes with a cue facing some targets and must judge how many targets are visible from their own or the cue perspective. Typically, this task shows an interference pattern: Participants record slower reaction times (RTs) and more errors when the cue is facing away from the targets. Interestingly, this occurs also when participants take their own perspective. Two accounts contend the explanation of this interference. The mentalising account focuses on the social relevance of the cue, while the domain-general account focuses on the directional features of the cue. To investigate the relative contribution of the two accounts, we developed a Social_Only cue, a cue having only social features and compared its effects with a Social+Directional cue, which had both social and directional features. Results show that while the Social+Directional cue generates the typical interference pattern, the Social_Only cue does not generate interference in the RTs, only in the error rate. We advance an integration between the mentalising and the domain-general accounts. We suggest that the dot-perspective task requires two processes: an orienting process, elicited by the directional features of the cue and measured by the RTs, and a decisional process elicited by the social features of the cue and measured also by the error rate.

Gaze cueing, mental States, and the effect of autistic traits

The ability to interpret and follow the gaze of our social partners is an integral skill in human communication. Recent research has demonstrated that gaze following behaviour is influenced by theory of mind (ToM) processes. However, it has yet to be determined whether the modulation of gaze cueing by ToM is affected by individual differences, such as autistic traits. The aim of this experiment was to establish whether autistic traits in neurotypical populations affect the mediation of gaze cueing by ToM processes. This study used a gaze cueing paradigm within a change detection task. Participants' perception of a gaze cue was manipulated such that they only believed the cue to be able to 'see' in one condition. The results revealed that participants in the Low Autistic Traits group were significantly influenced by the mental state of the gaze cue and were more accurate on valid trials when they believed the cue could 'see'. By contrast, participants in the High Autistic Traits group were also more accurate on valid trials, but this was not influenced by the mental state of the gaze cue. This study therefore provides evidence that autistic traits influence the extent to which mental state attributions modulate social attention in neurotypical adults.

Human but not robotic gaze facilitates action prediction

Do people ascribe intentions to humanoid robots as they would to humans or non-human-like animated objects? In six experiments, we compared people’s ability to extract non-mentalistic (i.e., where an agent is looking) and mentalistic (i.e., what an agent is looking at; what an agent is going to do) information from gaze and directional cues performed by humans, human-like robots, and a non-human-like object. People were faster to infer the mental content of human agents compared to robotic agents. Furthermore, although the absence of differences in control conditions rules out the use of non-mentalizing strategies, the human-like appearance of non-human agents may engage mentalizing processes to solve the task. Overall, results suggest that human-like robotic actions may be processed differently from humans’ and objects’ behavior. These findings inform our understanding of the relevance of an object’s physical features in triggering mentalizing abilities and its relevance for human–robot interaction.

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People differently ascribe mental content to human-like and non-human-like agents

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A human-like shape may automatically engage mentalizing processes

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Human actions are interpreted faster than non-human actions

Irrelevant Robot Signals in a Categorization Task Induce Cognitive Conflict in Performance, Eye Trajectories, the N2 ERP-EEG Component, and Frontal Theta Oscillations

Understanding others' nonverbal behavior is essential for social interaction, as it allows, among others, to infer mental states. Although gaze communication, a well-established nonverbal social behavior, has shown its importance in inferring others' mental states, not much is known about the effects of irrelevant gaze signals on cognitive conflict markers during collaborative settings. Here, participants completed a categorization task where they categorized objects based on their color while observing images of a robot. On each trial, participants observed the robot iCub grasping an object from a table and offering it to them to simulate a handover. Once the robot "moved" the object forward, participants were asked to categorize the object according to its color. Before participants were allowed to respond, the robot made a lateral head/gaze shift. The gaze shifts were either congruent or incongruent with the object's color. We expected that incongruent head cues would induce more errors (Study 1), would be associated with more curvature in eye-tracking trajectories (Study 2), and induce larger amplitude in electrophysiological markers of cognitive conflict (Study 3). Results of the three studies show more oculomotor interference as measured in error rates (Study 1), larger curvatures eye-tracking trajectories (Study 2), and higher amplitudes of the N2 ERP of the EEG signals as well as higher event-related spectral perturbation amplitudes (Study 3) for incongruent trials compared with congruent trials. Our findings reveal that behavioral, ocular, and electrophysiological markers can index the influence of irrelevant signals during goal-oriented tasks.

Hidden intentions: Visual awareness prioritizes perceived attention even without eyes or faces

Eye contact is a powerful social signal, and it readily captures attention. Recent work has suggested that direct gaze is prioritized even unconsciously: faces rendered invisible via interocular suppression enter awareness faster when they look directly at (vs. away from) you. Such effects may be driven in a relatively low level way by the special visual properties of eyes, per se, but here we asked whether they might instead arise from the perception of a deeper property: being the focus of another agent's attention and/or intentions. We report five experiments which collectively explore whether visual awareness also prioritizes distinctly non-eye-like stimuli that nevertheless convey directedness. We first showed that directed (vs. averted) 'mouth' shapes also break through into awareness faster, after being rendered invisible by continuous flash suppression - a direct 'gaze' effect without any eyes. But such effects could still be specific to faces (if not eyes), so we next asked whether the prioritization of directed intentions would still occur even for stimuli that have no faces at all. In fact, even simple geometric shapes can be seen as intentional, as when numerous randomly scattered cones are all consistently pointing at you. And indeed, even such directed (vs. averted) cones entered awareness faster - a direct 'gaze' effect without any facial cues. Additional control experiments ruled out effects of both symmetry and response biases. We conclude that the perception of directed intentions is sufficient to boost objects into awareness, and that putative eye-contact effects might instead reflect more general phenomena of 'mind contact'.

Investigating facilitatory versus inhibitory effects of dynamic social and non-social cues on attention in a realistic space

This study aimed to investigate the facilitatory versus inhibitory effects of dynamic non-predictive central cues presented in a realistic environment. Realistic human-avatars initiated eye contact and then dynamically looked to the left, right or centre of a table. A moving stick served as a non-social control cue and participants localised (Experiment 1) or discriminated (Experiment 2) a contextually relevant target (teapot/teacup). The cues movement took 500 ms and stimulus onset asynchronies (SOA, 150 ms/300 ms/500 ms/1000 ms) were measured from movement initiation. Similar cuing effects were seen for the social avatar and non-social stick cue across tasks. Results showed facilitatory processes without inhibition, though there was some variation by SOA and task. This is the first time facilitatory versus inhibitory processes have been directly investigated where eye contact is initiated prior to gaze shift. These dynamic stimuli allow a better understanding of how attention might be cued in more realistic environments.

Does gaze direction of fearful faces facilitate the processing of threat? An ERP study of spatial precuing effects

Eye gaze is very important for attentional orienting in social life. By adopting the event-related potential (ERP) technique, we explored whether attentional orienting of eye gaze is modulated by emotional congruency between facial expressions and the targets in a spatial cuing task. Faces with different emotional expressions (fearful/angry/happy/neutral) directing their eye gaze to the left or right were used as cues, indicating the possible location of subsequent targets. Targets were line drawings of animals, which could be either threatening or neutral. Participants indicated by choice responses whether the animal would fit inside a shoebox in real life or not. Reaction times to targets were faster after valid compared with invalid cues, showing the typical eye gaze cuing effect. Analyses of the late positive potential (LPP) elicited by targets revealed a significant modulation of the gaze cuing effect by emotional congruency. Threatening targets elicited larger LPPs when validly cued by gaze in faces with negative (fearful and angry) expressions. Similarly, neutral targets showed larger LPPs when validly cued by faces with neutral expressions. Such effects were not present after happy face cues. Source localization in the LPP time window revealed that for threatening targets, the activity of right medial frontal gyrus could be related to a larger gaze-orienting effect for the fearful than the angry condition. Our findings provide electrophysiological evidence for the modulation of gaze cuing effects by emotional congruency.

Evolution of social attentional cues: Evidence from the archerfish

Social cues such as gaze, head, and body orientation are essential for the survival of any social animal. The gaze cuing paradigm is a well-studied experimental manipulation, employed to detect automatic attentional shifts in humans. To the best of our knowledge, no previous study has tested non-primates in a paradigm that is similar to the one typically used on humans. Herein, three archerfish observed a conspecific picture oriented toward the right or the left, followed unpredictably by a visual target presented in the socially cued or un-cued location. Similar to the pattern observed in humans, fish demonstrated faster reaction times for targets presented at the socially cued location. Results suggest that social cues may have an early evolutionary origin and can elicit automatic attentional orienting even in species without a visual cortex.

Social information rapidly prioritizes overt but not covert attention in a joint spatial cueing task

Coordinating actions with others is crucial for our survival. Our ability to see what others are seeing and to align our visual attention with them facilitates these joint actions. In the present research, we set out to increase our understanding of such joint attention by investigating the extent to which social information would be able to prioritize overt (when moving the eyes to attend) and covert (when shifting attention without eye movements) attention in a joint spatial cueing task. Participants saw a cue and detected a target at the same or a different location alongside an unseen partner of either higher or lower social rank. In a novel twist, participants were led to believe that the cue was connected to the gaze location of their partner. In Experiment 1, where participants were told to not move their eyes (covert attention), the partner's social rank did not change how quickly participants detected targets. But in Experiment 2, where participants were free to move their eyes naturally (overt attention), inhibition of return effects (slower responses to cued than uncued targets) were modulated by their partner's social rank. These social top-down effects occurred already at a short SOA of 150 ms. Our findings suggest that overt attention might provide a key tool for joint action, as it is penetrable for social information at the early stages of information processing.

Attention in naïve psychology

In everyday life, mentalizing is nested in a rich context of cognitive faculties and background information that potentially contribute to its success. Yet, we know little about these modulating effects. Here we propose that humans develop a naïve psychological model of attention (featured as a goal-dependent, intentional relation to the environment) and use this to fine-tune their mentalizing attempts, presuming that the way people represent their environment is influenced by the cognitive priorities (attention) their current intentions create. The attention model provides an opportunity to tailor mental state inferences to the temporary features of the agent whose mind is in the focus of mentalizing. The ability to trace attention is an exceptionally powerful aid for mindreading. Knowledge about the partner's attention provides background information, however being grounded in his current intentions, attention has direct relevance to the ongoing interaction. Furthermore, due to its causal connection to intentions, the output of the attention model remains valid for a prolonged but predictable amount of time: till the evoking intention is in place. The naïve attention model theory is offered as a novel theory on social attention that both incorporates existing evidence and identifies new directions in research.

Perspective-Taking: In Search of a Theory

Perspective-taking has been one of the central concerns of work on social attention and developmental psychology for the past 60 years. Despite its prominence, there is no formal description of what it means to represent another’s viewpoint. The present article argues that such a description is now required in the form of theory—a theory that should address a number of issues that are central to the notion of assuming another’s viewpoint. After suggesting that the mental imagery debate provides a good framework for understanding some of the issues and problems surrounding perspective-taking, we set out nine points that we believe any theory of perspective-taking should consider.

Visual Attentional Bias Induced by Face Direction

The effect of spatial cueing on eye gaze has been confirmed by a large number of studies, but the effect of spatial cueing on face direction and the impact of eye gaze on this effect are less known. In four experiments, we investigated the attentional bias induced by face direction. A modified paradigm of spatial cueing was adopted with stimuli that were static faces rotated by 90 or 45° to the left or right from the frontal view. To control the effect of eyes, face stimuli with eyes open and those with eyes closed were both used in each experiment. In Experiment 1, the facial cue (face rotated by 90°) and target were presented simultaneously, and the stimulus onset asynchrony (SOA) between the facial cue and target was set to be 300, 600, and 900 ms in Experiments 2 (face rotated by 90°), 3 (inverted face rotated by 90°), and 4 (face rotated by 45°), respectively. The response time of detecting the target position was recorded. The spatial cueing effects were nonsignificant in Experiment 1, in which the cue and target were presented simultaneously. However, significant spatial cueing effects of face direction were found in Experiments 2 and 3, in which the upright and inverted faces rotated by 90° were adopted, respectively, in both the eyes open and eyes closed conditions. In addition, we did not find an effect of spatial cueing with the face rotated by 45° (Experiment 4). Our results indicate that face direction can bias visual attention. This effect might not be based on the holistic processing of faces.

Examining joint attention with the use of humanoid robots-A new approach to study fundamental mechanisms of social cognition

This article reviews methods to investigate joint attention and highlights the benefits of new methodological approaches that make use of the most recent technological developments, such as humanoid robots for studying social cognition. After reviewing classical approaches that address joint attention mechanisms with the use of controlled screen-based stimuli, we describe recent accounts that have proposed the need for more natural and interactive experimental protocols. Although the recent approaches allow for more ecological validity, they often face the challenges of experimental control in more natural social interaction protocols. In this context, we propose that the use of humanoid robots in interactive protocols is a particularly promising avenue for targeting the mechanisms of joint attention. Using humanoid robots to interact with humans in naturalistic experimental setups has the advantage of both excellent experimental control and ecological validity. In clinical applications, it offers new techniques for both diagnosis and therapy, especially for children with autism spectrum disorder. The review concludes with indications for future research, in the domains of healthcare applications and human-robot interaction in general.

Mechanisms for the Cognitive Processing of Attractiveness in Adult and Infant Faces: From the Evolutionary Perspective

Research on the cognitive processing of facial attractiveness has mainly focused on adult faces. Recent studies have revealed that the cognitive processing of facial attractiveness in infant faces is not the same as that in adult faces. Therefore, it is necessary to summarize the evidence on the processing of facial attractiveness in each kind of face and compare their underlying mechanisms. In this paper, we first reviewed studies on the cognitive processing of facial attractiveness in adult faces, including attentional and mnemonic processing, and then discussed the underlying mechanisms. Afterward, studies on facial attractiveness in infant faces were reviewed, and the underlying mechanisms were also discussed. Direct comparisons between the two kinds of cognitive processing were subsequently made. The results showed that the mechanisms for the processing of attractiveness in adult faces and infant faces are mainly motivated by the perspectives of mate selection and raising offspring, respectively, in evolutionary psychology. Finally, directions for future research are proposed.

The closing of the theory of mind: A critique of perspective-taking

Theory of mind (ToM) is defined as the ability to attribute mental states to oneself and others and is often said to be one of the cornerstones of efficient social interaction. In recent years, a number of authors have suggested that one particular ToM process occurs spontaneously in that it is rapid and outside of conscious control. This work has argued that humans efficiently compute the visual perspective of other individuals. In this article, we present a critique of this notion both on empirical and theoretical grounds. We argue that the experiments and paradigms that purportedly demonstrate spontaneous perspective-taking have not as yet convincingly demonstrated the existence of such a phenomenon. We also suggest that it is not possible to represent the percept of another person, spontaneous or otherwise. Indeed, the perspective-taking field has suggested that humans can represent the visual experience of others. That is, going beyond assuming that we can represent another's viewpoint in anything other than symbolic form. In this sense, the field suffers from the same problem that afflicted the "pictorial" theory in the mental imagery debate. In the last section we present a number of experiments designed to provide a more thorough assessment of whether humans can indeed represent the visual experience of others.

The Role of Perspective Taking on Attention: A Review of the Special Issue on the Reflexive Attentional Shift Phenomenon

Attention is a process that alters how cognitive resources are allocated, and it allows individuals to efficiently process information at the attended location. The presence of visual or auditory cues in the environment can direct the focus of attention toward certain stimuli even if the cued stimuli are not the individual’s primary target. Samson et al. demonstrated that seeing another person in the scene (i.e., a person-like cue) caused a delay in responding to target stimuli not visible to that person: “alter-centric intrusion.” This phenomenon, they argue, is dependent upon the fact that the cue used resembled a person as opposed to a more generic directional indicator. The characteristics of the cue are the core of the debate of this special issue. Some maintain that the perceptual-directional characteristics of the cue are sufficient to generate the bias while others argue that the cuing is stronger when the cue has social characteristics (relates to what another individual can perceive). The research contained in this issue confirms that human attention is biased by the presence of a directional cue. We discuss and compare the different studies. The pattern that emerges seems to suggest that the social relevance of the cue is necessary in some contexts but not in others, depending on the cognitive demand of the experimental task. One possibility is that the social mechanisms are involved in perspective taking when the task is cognitively demanding, while they may not play a role in automatic attention allocation.

Perceptual sensitivity is modulated by what others can see

Previous work has established that social cues such as the direction of others' gaze or their perspective on a scene may influence one's own perceptual judgments. However, up until now it has remained unclear whether such influences are exerted at a perceptual or decisional locus, as most previous studies have used response times as their primary dependent measure. Here, we asked whether perceptual sensitivity is also dependent on social cognition. To test this hypothesis, we asked participants to evaluate whether low-contrast Gabor patterns embedded in noise were visible from either their own or an avatar's perspective. Across three experiments, we found that observers' detection performance was increased if an avatar also shared perception of the stimulus location. By leveraging signal detection modelling, we show that this effect is driven by a change in perceptual sensitivity (d'), independent of decisional or response interference. Furthermore, by "blindfolding" the avatar, we show that the boosting effect of shared perception on detection sensitivity is only obtained when the participant believes the avatar can also see the stimulus, ruling out an influence of low-level directional cues. We interpret these results within a framework in which the avatar's perspective boosts top-down spatial attention by prioritising particular spatial locations at which perception is shared. In summary, we reveal that perceptual sensitivity is modulated by the perspective of others.

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.

Attribution of vision and knowledge in 'spontaneous perspective taking'

Theory of mind is a ubiquitous notion that permeates many aspects of social cognition. A recent application has been in the context of 'spontaneous perspective taking' in which responses to target stimuli are facilitated if a human agent, present in a display, sees the same stimuli as an experimental participant. In the present work, we replicated results from a paradigm purporting to show such perspective taking in which participants tend to judge an ambiguous number from the position of an agent. We find, however (in Experiment 1) that this effect still occurs even when the agent cannot see the number due to an occluding object. This, therefore, does not support the perspective-taking hypothesis. An alternative explanation to the theory of mind account is posited in which the agent acts as a reference point that cues the observer to view the critical stimuli from that position and in the direction to which the agent faces. We test this hypothesis in Experiments 2 and 3, and show that non-human reference points can generate perspective-taking-like data. Overall, these results do not support the theory of mind account of previous studies.

Mental attribution is not sufficient or necessary to trigger attentional orienting to gaze

Attention can be shifted in the direction that another person is looking, but the role played by an observer's mental attribution to the looker is controversial. And whether mental attribution to the looker is sufficient to trigger an attention shift is unknown. The current study introduces a novel paradigm to investigate this latter issue. An actor is presented on video turning his head to the left or right before a target appears, randomly, at the gazed-at or non-gazed at location. Time to detect the target is measured. The standard finding is that target detection is more efficient at the gazed-at than the nongazed-at location, indicating that attention is shifted to the gazed-at location. Critically, in the current study, an actor is wearing two identical masks - one covering his face and the other the back of his head. Thus, after the head turn, participants are presented with the profile of two faces, one looking left and one looking right. For a gaze cuing effect to emerge, participants must attribute a mental state to the actor - as looking through one mask and not the other. Over the course of four experiments we report that when mental attribution is necessary, a shift in social attention does not occur (i.e., mental attribution is not sufficient to produce a social attention effect); and when mental attribution is not necessary, a shift in social attention does occur. Thus, mental attribution is neither sufficient nor necessary for the occurrence of an involuntary shift in social attention. The present findings constrain future models of social attention that wish to link gaze cuing to mental attribution.

On the role of eye contact in gaze cueing

Most experimental protocols examining joint attention with the gaze cueing paradigm are "observational" and "offline", thereby not involving social interaction. We examined whether within a naturalistic online interaction, real-time eye contact influences the gaze cueing effect (GCE). We embedded gaze cueing in an interactive protocol with the iCub humanoid robot. This has the advantage of ecological validity combined with excellent experimental control. Critically, before averting the gaze, iCub either established eye contact or not, a manipulation enabled by an algorithm detecting position of the human eyes. For non-predictive gaze cueing procedure (Experiment 1), only the eye contact condition elicited GCE, while for counter-predictive procedure (Experiment 2), only the condition with no eye contact induced GCE. These results reveal an interactive effect of strategic (gaze validity) and social (eye contact) top-down components on the reflexive orienting of attention induced by gaze cues. More generally, we propose that naturalistic protocols with an embodied presence of an agent can cast a new light on mechanisms of social cognition.

Visual attention and action: How cueing, direct mapping, and social interactions drive orienting

Despite considerable interest in both action perception and social attention over the last 2 decades, there has been surprisingly little investigation concerning how the manual actions of other humans orient visual attention. The present review draws together studies that have measured the orienting of attention, following observation of another's goal-directed action. Our review proposes that, in line with the literature on eye gaze, action is a particularly strong orienting cue for the visual system. However, we additionally suggest that action may orient visual attention using mechanisms, which gaze direction does not (i.e., neural direct mapping and corepresentation). Finally, we review the implications of these gaze-independent mechanisms for the study of attention to action. We suggest that our understanding of attention to action may benefit from being studied in the context of joint action paradigms, where the role of higher level action goals and social factors can be investigated.

Can Monetary Reward Modulate Social Attention?

Selective visual attention is a primary cognitive function, which allows the selection of the most relevant stimuli in the environment by prioritizing their processing. Several studies showed that this process can be influenced by both social signals, such as gaze direction (i.e., the Gaze Cueing Effect, GCE) and by the motivational valence of gratifying stimuli, such as monetary rewards. The aim of this study was to explore whether GCE could be modulated by a monetary reward. To this end, we created an experiment in which participants performed a gaze cuing task before and after an implicit learning task aiming to induce an association between gaze direction and monetary reward (experimental condition), or after a perceptual task (control condition). Statistical analyses were conducted following both a frequentist and a Bayesian approach. Results supported previous findings showing the presence of the GCE, i.e., faster responses in congruent trials when the target appeared in the gazed-at location. Interestingly, our results did not reveal significant differences among the conditions. Therefore, contrary to what was reported by previous attentional orienting studies with non-social stimuli, monetary reward does not seem to be able to modulate (or interfere with) the orienting of attention mediated by gaze direction as measured by the GCE. Taken together our results suggest that social signals such as gaze direction have a greater impact than monetary reward in orienting selective attention.

Attention to faces and gaze-following in social anxiety: preliminary evidence from a naturalistic eye-tracking investigation

Social attentional biases are a core component of social anxiety disorder, but research has not yet determined their direction due to methodological limitations. Here we present preliminary findings from a novel, dynamic eye-tracking paradigm allowing spatial-temporal measurement of attention and gaze-following, a mechanism previously unexplored in social anxiety. 105 participants took part, with those high (N = 27) and low (N = 25) in social anxiety traits (HSA and LSA respectively) entered into the analyses. Participants watched a video of an emotionally-neutral social scene, where two actors periodically shifted their gaze towards the periphery. HSA participants looked more at the actors' faces during the initial 2s than the LSA group but there were no group differences in proportion of first fixations to the face or latency to first fixate the face, although HSA individuals' first fixations to the face were shorter. No further differences in eye movements were found, nor in gaze-following behaviour, although these null effects could potentially result from the relatively small sample. Findings suggest attention is biased towards faces in HSA individuals during initial scene inspection, but that overt gaze-following may be impervious to individual differences in social anxiety. Future research should seek to replicate these effects.

Reasoning About Visibility in Mirrors: A Comparison Between a Human Observer and a Camera

Human observers make errors when predicting what is visible in a mirror. This is true for perception with real mirrors as well as for reasoning about mirrors shown in diagrams. We created an illustration of a room, a top-down view, with a mirror on a wall and objects (nails) on the opposite wall. The task was to select which nails were visible in the mirror from a given position (viewpoint). To study the importance of the social nature of the viewpoint, we divided the sample ( N = 108) in two groups. One group ( n = 54) were tested with a scene in which there was the image of a person. The other group ( n = 54) were tested with the same scene but with a camera replacing the person. Participants were instructed to think about what would be captured by a camera on a tripod. This manipulation tests the effect of social perspective-taking in reasoning about mirrors. As predicted, performance on the task shows an overestimation of what can be seen in a mirror and a bias to underestimate the role of the different viewpoints, that is, a tendency to treat the mirror as if it captures information independently of viewpoint. In terms of the comparison between person and camera, there were more errors for the camera, suggesting an advantage for evaluating a human viewpoint as opposed to an artificial viewpoint. We suggest that social mechanisms may be involved in perspective-taking in reasoning rather than in automatic attention allocation.

Mental State Attributions Mediate the Gaze Cueing Effect

Understanding the mental states of our social partners allows us to successfully interact with the world around us. Mental state attributions are argued to underpin social attention, and have been shown to modulate attentional orienting to social cues. However, recent research has disputed this claim, arguing that this effect may arise as an unintentional side effect of study design, rather than through the involvement of mentalising processes. This study therefore aimed to establish whether the mediation of gaze cueing by mental state attributions generalises beyond the specific experimental paradigm used in previous research. The current study used a gaze cueing paradigm within a change detection task, and the gaze cue was manipulated such that participants were aware that the cue-agent was only able to 'see' in one condition. The results revealed that participants were influenced by the mental state of the cue-agent, and were significantly better at identifying if a change had occurred on valid trials when they believed the cue-agent could 'see'. The computation of the cue-agent's mental state therefore mediated the gaze cueing effect, demonstrating that the modulation of gaze cueing by mental state attributions generalises to other experimental paradigms.

I Don't See It Your Way: The Dot Perspective Task Does Not Gauge Spontaneous Perspective Taking

Data from studies employing the dot-perspective task have been used to support the theory that humans are capable of automatically computing the visual perspective of other individuals. Recent work has challenged this interpretation, claiming instead that the results may arise through the automatic reorienting of attention triggered by observed head and gaze cues. The two experiments reported here offer a stronger test of the perspective taking account by replacing the computer-generated avatars used in previous research with, respectively, photo-realistic stimuli and socially co-present individuals in a "live", face-to-face version of the task. In each study observers were faster to judge the number of dots in a display when either a digitized image depicting a human "gazer" (Experiment 1), or a socially co-present gazer (Experiment 2) could see the same number of dots as the observer, than when the number of dots visible to each was different. However, in both experiments this effect was also obtained in conditions where barriers clearly occluded the gazers' view of the target dots so that the perspectives of participants and gazers were always different. These results offer no support for the idea that participants are engaged in spontaneous perspective taking in the dot perspective task. It is argued that, instead, the results are likely caused by a spontaneous redirection of a viewer's attention by the observed gazes, which is unlikely to involve representations of the gazer's mental state.

'Spontaneous' visual perspective-taking mediated by attention orienting that is voluntary and not reflexive

Experiments revealing 'spontaneous' visual perspective-taking are conventionally interpreted as demonstrating that adults have the capacity to track simple mental states in a fast and efficient manner ('implicit mentalising'). A rival account suggests that these experiments can be explained by the general purpose mechanisms responsible for reflexive attentional orienting. Here, we report two experiments designed to distinguish between these competing accounts. In Experiment 1, we assessed whether reflexive attention orienting was sufficient to yield findings interpreted as spontaneous perspective-taking in the 'avatar task' when the protocol was adapted so that participants were unaware that they were taking part in a perspective-taking experiment. Results revealed no evidence for perspective-taking. In Experiment 2, we employed a Posner paradigm to investigate the attentional orienting properties of the avatar stimuli. This revealed cue-validity effects only for longer stimulus onset asynchronies, which indicates a voluntary rather than reflexive shift in spatial attention. Taken together, these findings suggest that attentional orienting does indeed contribute to performance in the Samson et al. avatar task. However, attention orienting appears to be voluntary rather than reflexive, indicating that the perspective-taking phenomenon measured may be less spontaneous than first reported.

Investigating gaze processing in euthymic bipolar disorder: Impaired ability to infer mental state and intention, but preservation of social attentional orienting

Euthymic bipolar disorder (BD) has been associated with subtle impairment in face processing. However, it is not known whether their difficulties extend to the processing of gaze. In the present study, two tasks, both of which rely on the ability to make use of the eye region of a pictured face, were used: the Reading the Mind in the Eyes test and the Eye-gaze cueing task. Compared to healthy controls, BD patients were impaired at judging mental state from images of the face but showed normal susceptibility to the direction of gaze as an attentional cue. These findings suggest that BD patients present selective gaze processing impairment, limited to the sensitivity to intention and emotion. This impairment could account at least partially for the higher levels of interpersonal problems generally observed in BD.

Social Beliefs and Visual Attention: How the Social Relevance of a Cue Influences Spatial Orienting

We are highly tuned to each other's visual attention. Perceiving the eye or hand movements of another person can influence the timing of a saccade or the reach of our own. However, the explanation for such spatial orienting in interpersonal contexts remains disputed. Is it due to the social appearance of the cue—a hand or an eye—or due to its social relevance—a cue that is connected to another person with attentional and intentional states? We developed an interpersonal version of the Posner spatial cueing paradigm. Participants saw a cue and detected a target at the same or a different location, while interacting with an unseen partner. Participants were led to believe that the cue was either connected to the gaze location of their partner or was generated randomly by a computer (Experiment 1), and that their partner had higher or lower social rank while engaged in the same or a different task (Experiment 2). We found that spatial cue‐target compatibility effects were greater when the cue related to a partner's gaze. This effect was amplified by the partner's social rank, but only when participants believed their partner was engaged in the same task. Taken together, this is strong evidence in support of the idea that spatial orienting is interpersonally attuned to the social relevance of the cue—whether the cue is connected to another person, who this person is, and what this person is doing—and does not exclusively rely on the social appearance of the cue. Visual attention is not only guided by the physical salience of one's environment but also by the mental representation of its social relevance.

Attentional interference is modulated by salience not sentience

Spatial cueing of attention occurs when attention is oriented by the onset of a stimulus or by other information that creates a bias towards a particular location. The presence of a cue that orients attention can also interfere with participants' reporting of what they see. It has been suggested that this type of interference is stronger in the presence of socially-relevant cues, such as human faces or avatars, and is therefore indicative of a specialised role for perspective calculation within the social domain. However, there is also evidence that the effect is a domain-general form of processing that is elicited equally with non-social directional cues. The current paper comprises four experiments that systematically manipulated the social factors believed necessary to elicit the effect. The results show that interference persists when all social components are removed, and that visual processes are sufficient to explain this type of interference, thus supporting a domain-general perceptual interpretation of interference.

Spontaneous Perspective Taking in Humans?

A number of social cognition studies posit that humans spontaneously compute the viewpoint of other individuals. This is based on experiments showing that responses are shorter when a human agent, located in a visual display, can see the stimuli relevant to the observer's task. Similarly, responses are slower when the agent cannot see the task-relevant stimuli. We tested the spontaneous perspective taking theory by incorporating it within two classic visual cognition paradigms (i.e., the flanker effect and the Simon effect), as well as reassessing its role in the gaze cueing effect. Results showed that these phenomena (e.g., the Simon effect) are not modulated according to whether a gazing agent can see the critical stimuli or not. We also examined the claim that previous results attributed to spontaneous perspective taking are due to the gazing agent's ability to shift attention laterally. Results found no evidence of this. Overall, these data challenge both the spontaneous perspective taking theory, as well as the attentional shift hypothesis.

Intergroup visual perspective-taking: Shared group membership impairs self-perspective inhibition but may facilitate perspective calculation

Reasoning about what other people see, know, and want is essential for navigating social life. Yet, even neurodevelopmentally healthy adults make perspective-taking errors. Here, we examined how the group membership of perspective-taking targets (ingroup vs. outgroup) affects processes underlying visual perspective-taking. In three experiments using two bases of group identity (university affiliation and minimal groups), interference from one's own differing perspective (i.e., egocentric intrusion) was stronger when responding from an ingroup versus an outgroup member's perspective. Spontaneous perspective calculation, as indexed by interference from another's visual perspective when reporting one's own (i.e., altercentric intrusion), did not differ across target group membership in any of our experiments. Process-dissociation analyses, which aim to isolate automatic processes underlying altercentric-intrusion effects, further revealed negligible effects of target group membership on perspective calculation. Meta-analytically, however, there was suggestive evidence that shared group membership facilitates responding from others' perspectives when self and other perspectives are aligned.

Controlling attention to gaze and arrows in attention deficit hyperactivity disorder

The aim of this research was to assess implicit processing of social and non-social distracting cues in children with ADHD. Young people with ADHD and matched controls were asked to classify target words (LEFT/RIGHT) which were accompanied by a distracter eye-gaze or arrow. Typically developing participants showed evidence of interference effects from both eye-gaze and arrow distracters. In contrast, the ADHD group showed evidence of interference effects from arrow but failed to show interference from eye-gaze. This absence of interference effects from eye-gaze observed in the participants with ADHD may reflect an attentional impairment in attending to socially relevant information.