Fortunes and misfortunes of political leaders reflected in the eyes of their electors

Can masked gaze and arrow stimuli elicit overt orienting of attention? A registered report

Viewing an averted gaze can elicit saccades towards the corresponding location. Here, the automaticity of this gaze-following behaviour phenomenon was further tested by exploring whether such an effect can be detected in response to briefly-presented masked averted gazes. Participants completed an oculomotor interference task consisting of making leftward/rightward saccades according to a symbolic instruction cue. Crucially, either a task-irrelevant averted-gaze face or an arrow (i.e., a non-social control stimulus) was also presented in different blocks of trials. Faces and arrows were presented for either 1000 ms, or 8 ms and then backward-masked, to reduce the likelihood of conscious processing. Worse oculomotor performance emerged when the saccade direction did not match (vs match) that suggested by the task-irrelevant gaze/arrow stimuli in the unmasked condition. However, in the masked condition, no oculomotor interference occurred for any task-irrelevant stimulus. Results enrich knowledge about boundary conditions for gaze/arrow-driven orienting using ecological attention measures.

Are there quantitative differences between eye-gaze and arrow cues? A meta-analytic answer to the debate and a call for qualitative differences

Gaze acts from an early age as a cue to orient attention and, thereafter, to infer our social partners' intentions, thoughts, and emotions. Variants of the attentional orienting paradigm have been used to study the orienting capabilities associated to eye gaze. However, to date, it is still unclear whether this methodology truly assesses "social-specific" processes exclusively involved in attention to eye-gaze or the operation of domain-general attentional processes. The present study provides a comprehensive meta-analysis indicating that eye-gaze and non-social directional stimuli, such as arrows, produce equivalent attentional effects. This result casts doubt on the potential utility of the classic cueing task in revealing social-specific processes. On the other hand, we review behavioral evidence suggesting that eye-gaze stimuli may induce higher-order social processes when more specific experimental procedures that analyze qualitative rather than quantitative differences are used. These findings point to an integrated view in which domain-general and social specific processes both contribute to the attentional mechanisms induced by eye-gaze direction. Finally, some proposals about the social components specifically triggered by eye-gaze stimuli are discussed.

Misleading Robot Signals in a Classification Task Induce Cognitive Load as Measured by Theta Synchronization Between Frontal and Temporo-parietal Brain Regions

As technological advances progress, we find ourselves in situations where we need to collaborate with artificial agents (e.g., robots, autonomous machines and virtual agents). For example, autonomous machines will be part of search and rescue missions, space exploration and decision aids during monitoring tasks (e.g., baggage-screening at the airport). Efficient communication in these scenarios would be crucial to interact fluently. While studies examined the positive and engaging effect of social signals (i.e., gaze communication) on human-robot interaction, little is known about the effects of conflicting robot signals on the human actor's cognitive load. Moreover, it is unclear from a social neuroergonomics perspective how different brain regions synchronize or communicate with one another to deal with the cognitive load induced by conflicting signals in social situations with robots. The present study asked if neural oscillations that correlate with conflict processing are observed between brain regions when participants view conflicting robot signals. Participants classified different objects based on their color after a robot (i.e., iCub), presented on a screen, simulated handing over the object to them. The robot proceeded to cue participants (with a head shift) to the correct or incorrect target location. Since prior work has shown that unexpected cues can interfere with oculomotor planning and induces conflict, we expected that conflicting robot social signals which would interfere with the execution of actions. Indeed, we found that conflicting social signals elicited neural correlates of cognitive conflict as measured by mid-brain theta oscillations. More importantly, we found higher coherence values between mid-frontal electrode locations and posterior occipital electrode locations in the theta-frequency band for incongruent vs. congruent cues, which suggests that theta-band synchronization between these two regions allows for communication between cognitive control systems and gaze-related attentional mechanisms. We also find correlations between coherence values and behavioral performance (Reaction Times), which are moderated by the congruency of the robot signal. In sum, the influence of irrelevant social signals during goal-oriented tasks can be indexed by behavioral, neural oscillation and brain connectivity patterns. These data provide insights about a new measure for cognitive load, which can also be used in predicting human interaction with autonomous machines.

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.

Cross-cultural asymmetries in oculomotor interference elicited by gaze distractors belonging to Asian and White faces

The averted gaze of others triggers reflexive attentional orienting in the corresponding direction. This phenomenon can be modulated by many social factors. Here, we used an eye-tracking technique to investigate the role of ethnic membership in a cross-cultural oculomotor interference study. Chinese and Italian participants were required to perform a saccade whose direction might be either congruent or incongruent with the averted-gaze of task-irrelevant faces belonging to Asian and White individuals. The results showed that, for Chinese participants, White faces elicited a larger oculomotor interference than Asian faces. By contrast, Italian participants exhibited a similar oculomotor interference effect for both Asian and White faces. Hence, Chinese participants found it more difficult to suppress eye-gaze processing of White rather than Asian faces. The findings provide converging evidence that social attention can be modulated by social factors characterizing both the face stimulus and the participants. The data are discussed with reference to possible cross-cultural differences in perceived social status.

Inhibitory Theta Burst Stimulation Highlights the Role of Left aIPS and Right TPJ during Complementary and Imitative Human-Avatar Interactions in Cooperative and Competitive Scenarios

Competitive and cooperative interactions are based on anticipation or synchronization with the partner's actions. Both forms of interaction may either require performing imitative or complementary movements with respect to those performed by our partner. We explored how parietal regions involved in the control of imitative behavior (temporo-parietal junction, TPJ), goal coding and visuo-motor integration (anterior intraparietal sulcus, aIPS) contribute to the execution of imitative and complementary movements during cooperative and competitive interactions. To this aim, we delivered off-line non-invasive inhibitory brain stimulation to healthy individuals' left aIPS and right TPJ before they were asked to reach and grasp an object together with a virtual partner by either performing imitative or complementary interactions. In different blocks, participants were asked to compete or cooperate with the virtual partner that varied its behavior according to cooperative or competitive contexts. Left aIPS and right TPJ inhibition impaired individuals' performance (i.e., synchrony in cooperative task and anticipation in competition) during complementary and imitative interactions, respectively, in both cooperative and competitive contexts, indicating that aIPS and TPJ inhibition affects own-other action integration and action imitation (that are different in complementary vs imitative interactions) more than action synchronization or anticipation (that are different in cooperative vs competitive contexts).

Competence-based social status and implicit preference modulate the ability to coordinate during a joint grasping task

Studies indicate that social status influences people's social perceptions. Less information is available about whether induced social status influences dyadic coordination during motor interactions. To explore this issue, we designed a study in which two confederates obtained high or low competence-based status by playing a game together with the participant, while the participant always occupied the middle position of the hierarchy. Following this status-inducing phase, participants were engaged in a joint grasping task with the high- and low-status confederates in different sessions while behavioural (i.e., interpersonal asynchrony and movement start time) indexes were measured. Participants' performance in the task (i.e., level of interpersonal asynchrony) when interacting with the low-status partner was modulated by their preference for him. The lower participants' preference for a low- relative to a high-status confederate, the worse participants' performance when interacting with the low-status confederate. Our results show that participants' performance during motor interactions changes according to the social status of the interaction partner.

Social attention across borders: A cross-cultural investigation of gaze cueing elicited by same- and other-ethnicity faces

The gaze-cueing effect is a robust phenomenon which illustrates how attention can be shaped by social factors. In four experiments, the present study explored the interaction between the ethnic membership of the participant and that of the face providing the gaze cue. Firstly, we aimed to further investigate the differential impact of White, Black, and Asian faces on the gaze-cueing effect in White individuals. Secondly, we aimed to explore, for the first time, the impact of faces belonging to different ethnicities on gaze cueing in Chinese participants. The results allowed to rule out alternative accounts and showed that White participants exhibit a gaze-cueing effect for White and Asian faces, but not for Black faces, consistent with previous studies. As regards Chinese participants, the overall findings suggested a stronger gaze-cueing effect for White faces than for Asian faces. The results are discussed with reference to differences in the perceived social status of the various groups, pointing to the need of taking into account different cultural contexts.

Early saccade planning cannot override oculomotor interference elicited by gaze and arrow distractors

Humans tend to perform reflexive saccades according to the eye-gaze direction of other individuals. Here, in two experiments, we tested whether preparing a saccade before the onset of a task-irrelevant averted-gaze stimulus can abolish this form of gaze-following behavior. At the beginning of each trial, participants received the instruction to prepare for a leftward or a rightward saccade. This was provided either on a trial-by-trial basis (Experiment 1) or was maintained constant within a whole block of trials (Experiment 2). Then, a central fixation spot changed in color, acting as a "go" signal to perform the saccade. Simultaneously with the go-signal onset, a task-irrelevant distractor face looked either leftwards or rightwards. In so doing, no temporal overlapping was likely to occur between saccade preparation and the presentation of the distractor. Arrows were also employed as non-social control stimuli. In both experiments - and regardless of the distractor type - saccadic latencies were smaller when both the instruction and the distractor conveyed the same spatial vector, rather than the opposite. Taken together, these results suggest that an early preparation of saccades is not sufficient to override the oculomotor interference effects elicited by both social and non-social distractors.

Oculomotor behavior tracks the effect of ideological priming on deception

The decision to lie to another person involves a conflict between one's own and others' interest. Political ideology may foster self-promoting or self-transcending values and thus may balance or fuel self vs. other related conflicts. Here, we explored in politically non-aligned participants whether oculomotor behavior may index the influence on moral decision-making of prime stimuli related to left and right-wing ideologies. We presented pictures of Italian politicians and ideological words in a paradigm where participants could lie to opponents with high vs. low socio-economic status to obtain a monetary reward. Results show that left-wing words decreased self-gain lies and increased other-gain ones. Oculomotor behavior revealed that gazing longer at politicians' pictures led participants to look longer at opponent's status-related information than at game's outcome-related information before the decision. This, in turn, caused participants to lie less to low status opponents. Moreover, after lying, participants averted their gaze from high status opponents and maintained it towards low status ones. Our results offer novel evidence that ideological priming influences moral decision-making and suggest that oculomotor behavior may provide crucial insights on how this process takes place.

Eye contact boosts the reflexive component of overt gaze following

Establishing eye contact with an individual can subsequently lead to a stronger gaze-mediated orienting effect. However, studies exploring this phenomenon have, so far, only assessed manual responses and focused on covert attention - namely, without eye movements. Here, in two experiments, we explored for the first time whether eye contact can also impact on overt attention in an oculomotor task. This approach has two main advantages, in that it relies on more sensitive, online measures of attention allocation and it better mimics real life settings. Participants performed leftwards and rightwards eye movements in response to a central cue. Furthermore, a task-irrelevant central face established - or not - eye contact with the participant, and then averted its gaze either leftwards or rightwards. Hence, eye movement direction was either congruent or incongruent with that of the gaze stimulus. In both experiments, a gaze following behaviour emerged - specifically, smaller saccadic latencies and a greater accuracy emerged on congruent than on incongruent trials - but its magnitude was not modulated by eye contact. However, in Experiment 2 - in which the different eye contact conditions were presented intermixed rather than blocked, thus making eye contact contextually salient - eye contact led to an overall decrement of saccadic latencies and enhanced the reflexive component of gaze following. Taken together, these results provide novel evidence indicating that eye contact can impact on both eye movements programming and overt gaze following mechanisms, at least when eye contact is made contextually salient.

Modulation of preference for abstract stimuli following competence-based social status primes

In the present study, we measured whether competence-related high and low social status attributed to two unknown individuals affects participants' implicit reactivity to abstract stimuli associated to the identity of the same individuals. During a status-inducing procedure, participants were asked to play an interactive game with two (fake) players coded as high vs low status based on their game competence. Before and after the game, a modified version of the Affective Misattribution Procedure (AMP) was administered in which the players' faces were used as primes. The evaluation target, as is typical to AMP, was a Chinese ideogram. There were two different presentation timings for the prime image: 75 ms and 17 ms. After the status-inducing procedure, the evaluation targets preceded by the high-status prime (i.e. best player's face) were rated as more pleasant than those preceded by the low-status prime (i.e. worst player's face). This effect was only found, however, for the 75 ms lasting prime. Moreover, explicit ratings of the primes showed that the high-status player was rated as more intelligent, competent and dominant than the low status one. These results indicate that implicit preference and explicit evaluation of unacquainted individuals are rapidly modulated by competence-based social status attribution, thus hinting at the plastic nature of social categorization and, relatedly, the malleability of visual preference.

Bound to the group and blinded by the leader: ideological leader-follower dynamics in a trust economic game

Understanding the dynamics of trustworthiness in ideological contexts could influence human societies, affect electoral campaigns and ultimately impact democracy. We tested trust behaviour towards political leaders in a sample of 121 opposing/supporting voters assigned as trustors in an iterative trust game (TG). In two experiments, a famous Italian conservative leader (i.e. Silvio Berlusconi) or a famous non-politician were used as trustees in a predefined un/trustworthy TG, while trustors believed that mathematical algorithms reproduced trustee's real behaviour. Results revealed that depending on the group, voters either relied on the situation and adjusted to the behaviour of the out-group leader (in our case left-wing voters), or on their disposition for group-loyalty with respect for authority, thus failing to adjust to the behaviour of the in-group leader (in our case right-wing voters). Our findings suggest that: (i) complex voter-leader relations in politics are reflected in the simple trustor-trustee financial interactions from behavioural economics, and (ii) being bound to one's group and one's leader may affect the trust economic decisions of the followers.

Left Threatened by Right: Political Intergroup Bias in the Contemporary Italian Context

Using different evaluation targets (i.e., politicians' pictures, ideological words, items referring to features attributed to political ingroup/outgroup) we characterized the intergroup bias among political groups in the Italian context (Study 1-2-3) and tested a model that may account for the bias itself (Study 3). For all evaluation targets, left-wing participants - compared to right-wing participants - showed a greater intergroup bias, expressing more negative emotions toward the outgroup. The process was influenced by a greater perceived threat of the outgroup. Conversely, right-wing participants expressed the bias only when presented with ideological words. Our results provide a detailed description of how intergroup bias in Italy is differently expressed by the two ideological groups depending on the targets used to represent the political counterpart. Moreover, the results show that the stronger bias expressed by left-wing participants is driven by perceived threat of the outgroup.