Spatial cueing by social versus nonsocial directional signals

Unmasking social attention: The key distinction between social and non-social attention emerges in disengagement, not engagement

The debate surrounding whether social and non-social attention share the same mechanism has been contentious. While prior studies predominantly focused on engagement, we examined the potential disparity between social and non-social attention from both perspectives of engagement and disengagement, respectively. We developed a two-stage attention-shifting paradigm to capture both attention engagement and disengagement. Combining results from five eye-tracking experiments, we supported that the disengagement of social attention markedly outpaces that of non-social attention, while no significant discrepancy emerges in engagement. We uncovered that the faster disengagement of social attention came from its social nature by eliminating alternative explanations including broader fixation distribution width, reduced directional salience in the peripheral visual field, decreased cue-object categorical consistency, reduced perceived validity, and faster processing time. Our study supported that the distinction between social and non-social attention is rooted in attention disengagement, not engagement.

Attentional spatial cueing of the stop-signal affects the ability to suppress behavioural responses

The ability to adapt to the environment is linked to the possibility of inhibiting inappropriate behaviours, and this ability can be enhanced by attention. Despite this premise, the scientific literature that assesses how attention can influence inhibition is still limited. This study contributes to this topic by evaluating whether spatial and moving attentional cueing can influence inhibitory control. We employed a task in which subjects viewed a vertical bar on the screen that, from a central position, moved either left or right where two circles were positioned. Subjects were asked to respond by pressing a key when the motion of the bar was interrupted close to the circle (go signal). In about 40% of the trials, following the go signal and after a variable delay, a visual target appeared in either one of the circles, requiring response inhibition (stop signal). In most of the trials the stop signal appeared on the same side as the go signal (valid condition), while in the others, it appeared on the opposite side (invalid condition). We found that spatial and moving cueing facilitates inhibitory control in the valid condition. This facilitation was observed especially for stop signals that appeared within 250ms of the presentation of the go signal, thus suggesting an involvement of exogenous attentional orienting. This work demonstrates that spatial and moving cueing can influence inhibitory control, providing a contribution to the investigation of the relationship between spatial attention and inhibitory control.

Neural basis of social attention: common and distinct mechanisms for social and nonsocial orienting stimuli

Social and nonsocial directional stimuli (such as gaze and arrows, respectively) share their ability to trigger attentional processes, although the issue of whether social stimuli generate other additional (and unique) attentional effects is still under debate. In this study, we used the spatial interference paradigm to explore, using functional magnetic resonance imaging, shared and dissociable brain activations produced by gaze and arrows. Results showed a common set of regions (right parieto-temporo-occipital) similarly involved in conflict resolution for gaze and arrows stimuli, which showed stronger co-activation for incongruent than congruent trials. The frontal eye field showed stronger functional connectivity with occipital regions for congruent as compared with incongruent trials, and this effect was enhanced for gaze as compared with arrow stimuli in the right hemisphere. Moreover, spatial interference produced by incongruent (as compared with congruent) arrows was associated with increased functional coupling between the right frontal eye field and a set of regions in the left hemisphere. This result was not observed for incongruent (as compared with congruent) gaze stimuli. The right frontal eye field also showed greater coupling with left temporo-occipital regions for those conditions in which larger conflict was observed (arrow incongruent vs. gaze incongruent trials, and gaze congruent vs. arrow congruent trials). These findings support the view that social and nonsocial stimuli share some attentional mechanisms, while at the same time highlighting other differential effects. Highlights Attentional orienting triggered by social (gaze) and nonsocial (arrow) cues is comparable. When social and nonsocial stimuli are used as targets, qualitatively different behavioral effects are observed. This study explores the neural bases of shared and dissociable neural mechanisms for social and nonsocial stimuli. Shared mechanisms were found in the functional coupling between right parieto-temporo-occipital regions. Dissociable mechanisms were found in the functional coupling between right frontal eye field and ipsilateral and contralateral occipito-temporal regions.

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.

Are you paying attention to me? The effect of social presence on spatial attention to gaze and arrows

Prior research has shown that the presence of another individual and type of attention cue (social gaze vs. nonsocial arrow) can modulate attention, with little done to integrate the two. We thus investigate the role of two social presence factors when completing a joint cueing task with either social (gaze) or nonsocial (arrow) cues. Familiarity was operationalized as participants engaged in a prompted conversation either before (n = 60 dyads) or after (n = 59 dyads) the task. To determine the effect of previous responder identity on attention, we contrasted trials where participants responded twice in a row (same responder) with switch trials (different responder), along with whether the previous target was in the same or a different location. Although familiarity only affected global speed and not magnitudes of cueing, we did find that attention to gaze and arrows was differentially affected by previous responder and previous target location. Specifically, for gaze cues muted cueing effects occurred for trials where the previous responder was different, while for arrow cues there was less muting of the cueing effect regardless of previous responder. Taken together, previous responder and previous target location both modulated attention, with the effect on attention dependent on the type of cue, gaze, or arrow.

Social Attention: Developmental Foundations and Relevance for Autism Spectrum Disorder

The use of the term "social attention" (SA) in the cognitive neuroscience and developmental psychopathology literature has increased exponentially in recent years, in part motivated by the aim to understand the early development of autism spectrum disorder (ASD). Unfortunately, theoretical discussions around the term have lagged behind its various uses. Here, we evaluate SA through a review of key candidate SA phenotypes emerging early in life, from newborn gaze cueing and preference for face-like configurations to later emerging skills such as joint attention. We argue that most of the considered SA phenotypes are unlikely to represent unique socioattentional processes and instead have to be understood in the broader context of bottom-up and emerging top-down (domain-general) attention. Some types of SA behaviors (e.g., initiation of joint attention) are linked to the early development of ASD, but this may reflect differences in social motivation rather than attention per se. Several SA candidates are not linked to ASD early in life, including the ones that may represent uniquely socioattentional processes (e.g., orienting to faces, predicting others' manual action goals). Although SA may be a useful superordinate category under which one can organize certain research questions, the widespread use of the term without proper definition is problematic. Characterizing gaze patterns and visual attention in social contexts in infants at elevated likelihood of ASD may facilitate early detection, but conceptual clarity regarding the underlying processes at play is needed to sharpen research questions and identify potential targets for early intervention.

Does Eye Gaze Uniquely Trigger Spatial Orienting to Socially Relevant Information? A Behavioral and ERP Study

Using behavioral and event-related potential (ERP) measures, the present study examined whether eye gaze triggers a unique form of attentional orienting toward threat-relevant targets. A threatening or neutral target was presented after a non-predictive gaze or an arrow cue. In Experiment 1, reaction times indicated that eye gaze and arrow cues triggered different attention orienting towards threatening targets, which was confirmed by target-elicited P3b latency in Experiment 2. Specifically, for targets preceded by arrow and gaze cues, P3b peak latency was shorter for neutral targets than threatening targets. However, the latency differences were significantly smaller for gaze cues than for arrow cues. Moreover, target-elicited N2 amplitude indicated a significantly stronger cue validity effect of eye gaze than that of arrows. These findings suggest that eye gaze uniquely triggers spatial attention orienting to socially threatening information.

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.

A question of (perfect) timing: A preceding head turn increases the head-fake effect in basketball

In many kinds of sports, deceptive actions are frequently used to hamper the anticipation of an opponent. The head fake in basketball is often applied to deceive an observer regarding the direction of a pass. To perform a head fake, a basketball player turns the head in one direction, but passes the ball to the opposite direction. Several studies showed that reactions to passes with head fakes are slower and more error-prone than to passes without head fakes (head-fake effect). The aim of a basketball player is to produce a head-fake effect for as large as possible in the opponent. The question if the timing of the deceptive action influences the size of the head-fake effect has not yet been examined systematically. The present study investigated if the head-fake effect depends on the temporal lag between the head turn and the passing movement. To this end, the stimulus onset asynchrony between head turn, and pass was varied between 0 and 800 ms. The results showed the largest effect when the head turn precedes the pass by 300 ms. This result can be explained better by facilitating the processing of passes without head fake than by making it more difficult to process passes with a head fake. This result is discussed regarding practical implications and conclusions about the underlying mechanism of the head–fake effect in basketball are drawn.

Hand, but not foot, cues generate increases in salience at the pointed-at location

One line of research has indicated that directional social cues, such as eye gaze and pointed fingers, increase the salience of spatial locations or objects in a relatively involuntary manner (social cueing effect). A separate line of research has indicated that the compatibility between the body part that is observed by an actor primes and facilitates responses with a similar body part more than a dissimilar body part (body-part compatibility effect). The present experiment investigated whether or not social cueing effects were modulated by the relationship between the responding effector and the body part observed as the cue. To this end, non-predictive directional hand or foot cues were presented 100 or 1000 ms prior to a target. On different blocks of trials, participants (n = 19) executed discrete hand-button and foot-pedal responses to the location of a target to examine the influence of cue-effector body-part compatibility on social cueing effects. Response times (RTs) of both hand and foot responses were shorter to cued targets than to uncued targets when hand cues were used. No cueing effects emerged when foot cues were used, regardless of the responding effector. These results suggest changes in salience following social cues are determined by the body part used as the cue and are not modulated by the compatibility between the limb used as the cue and effector. Overall, the social relevance and learned use of a cue seem more pertinent than body-part matching of a stimulus type and response effector in social cueing.

The understanding of congruent and incongruent referential gaze in 17-month-old infants: an eye-tracking study comparing human and robot

Several studies have shown that the human gaze, but not the robot gaze, has significant effects on infant social cognition and facilitate social engagement. The present study investigates early understanding of the referential nature of gaze by comparing-through the eye-tracking technique-infants' response to human and robot's gaze. Data were acquired on thirty-two 17-month-old infants, watching four video clips, where either a human or a humanoid robot performed an action on a target. The agent's gaze was either turned to the target (congruent) or opposite to it (incongruent). The results generally showed that, independent of the agent, the infants attended longer at the face area compared to the hand and target. Additionally, the effect of referential gaze on infants' attention to the target was greater when infants watched the human compared to the robot's action. These results suggest the presence, in infants, of two distinct levels of gaze-following mechanisms: one recognizing the other as a potential interactive partner, the second recognizing partner's agency. In this study, infants recognized the robot as a potential interactive partner, whereas ascribed agency more readily to the human, thus suggesting that the process of generalizability of gazing behaviour to non-humans is not immediate.

How do infants and adults process communicative events in real time?

Speech allows humans to communicate and to navigate the social world. By 12 months, infants recognize that speech elicits appropriate responses from others. However, it is unclear how infants process dynamic communicative scenes and how their processing abilities compare with those of adults. Do infants, like adults, process communicative events while the event is occurring or only after being presented with the outcome? We examined 12-month-olds' and adults' eye movements as they watched a Communicator grasp one (target) of two objects. During the test event, the Communicator could no longer reach the objects, so she spoke or coughed to a Listener, who selected either object. Infants' and adults' patterns of looking to the actors and objects revealed that both groups immediately evaluated the Communicator's speech, but not her cough, as communicative and recognized that the Listener should select the target object only when the Communicator spoke. Furthermore, infants and adults shifted their attention between the actors and the objects in very similar ways. This suggests that 12-month-olds can quickly process communicative events as they occur with adult-like accuracy. However, differences in looking reveal that 12-month-olds process slower than adults. This early developing processing ability may allow infants to learn language and acquire knowledge from communicative interactions.

Automaticity of social cues: The influence of limiting cognitive resources on head orientation cueing

Our ability to communicate effectively often relies on being able to shift our focus of attention to align with that of another person. This so-called “social attention” reflects the use of cues such as gaze, pointing and head orientation to infer the attentional focus of others. An important, but unresolved, question is whether these socially relevant cues automatically direct attention in observers, or whether cognitive resources shape this process. An additional issue is that existing work has almost exclusively examined eye gaze cues, thus potentially limiting the generalizability of this work across types of social cues. To examine these issues, the present research investigates the influence of limiting resource availability (using a concurrent memory load) on the ability of an oriented head cue to direct attention. The results indicate that reducing resource availability increases the impact of the head cue on attentional orienting – the opposite pattern to that obtained with gaze cues. This outcome suggests that resource availability does not affect all social cues the same, and that caution is warranted in drawing broad conclusions about mechanisms underlying social cueing of attention without appropriate comparisons across multiple types of social cues.

Conflict Tasks of Different Types Divergently Affect the Attentional Processing of Gaze and Arrow

The present study explored the attentional processing mechanisms of gaze and arrow cues in two different types of conflict tasks. In Experiment 1, participants performed a flanker task in which gaze and arrow cues were presented as central targets or bilateral distractors. The congruency between the direction of the target and the distractors was manipulated. Results showed that arrow distractors greatly interfered with the attentional processing of gaze, while the processing of arrow direction was immune to conflict from gaze distractors. Using a spatial compatibility task, Experiment 2 explored the conflict effects exerted on gaze and arrow processing by their relative spatial locations. When the direction of the arrow was in conflict with its spatial layout on screen, response times were slowed; however, the encoding of gaze was unaffected by spatial location. In general, processing to an arrow cue is less influenced by bilateral gaze cues but is affected by irrelevant spatial information, while processing to a gaze cue is greatly disturbed by bilateral arrows but is unaffected by irrelevant spatial information. Different effects on gaze and arrow cues by different types of conflicts may reflect two relatively distinct specific modes of the attentional process.

Trial-by-trial modulations in the orienting of attention elicited by gaze and arrow cues

Recent findings suggested that the orienting of attention towards gazed at locations (i.e., the gaze cueing effect) could result from the conflict emerging in incongruent trials between the spatial information conveyed by gaze direction and the target spatial position. In two experiments, we assessed this hypothesis by investigating whether this effect is influenced by the same trial-by-trial modulations that are reported in a spatial conflict task, i.e., the Simon task. In Experiment 1, we compared the trial-by-trial modulations emerging in the Simon task with those emerging in a gaze cueing task, while in Experiment 2, we compared gaze and arrows cues. Trial-by-trial modulations were evident in both tasks. In the Simon task, correspondence sequence affected both corresponding and noncorresponding responses, this resulting in a larger Simon effect when the preceding trial was corresponding and an absent effect when the preceding trial was noncorresponding. Differently, in the gaze cueing task, congruence sequence affected only congruent responses with faster responses when the preceding trial was congruent compared to when it was incongruent, resulting in a larger gaze cuing effect when the preceding trial was congruent. Same results were evident with nonpredictive arrow cues. These findings speak against a spatial conflict account.

Social attention directs working memory maintenance

Visual working memory (vWM) performance is enhanced when a memorized object is cued after encoding. This so-called retro-cue effect is typically observed with a predictive (80% valid), retrospective cue. The current study examined whether a nonpredictive (50% valid) retro-cue can similarly enhance internal memory representations in cases where the cue conveys social signals. To this end, gaze cues were presented during the retention interval of a change-detection task, which are capable to engender a mutual attentional focus of two individuals towards one location. In line with our prediction, Experiment 1 demonstrated that a polygon presented at the gazed-at location was remembered better than that at both non-gazed and gazed-away locations. Experiments 2 and 3 showed that low-level motion cues did not elicit attentional orienting in a comparable manner as the gaze cue, and these differences in cuing were found to be reliable and independent of memory load. Furthermore, the gaze retro-cue effect disappeared when the face was inverted (Experiment 4). In sum, these results clearly show that sharing the focus of another individual establishes a point of reference from which visual information is restored with priority, suggesting that a gaze retro-cue leads to social attention, thus, modulating vWM maintenance in a reflexive, automatic manner.

Gaze and Arrows: The Effect of Element Orientation on Apparent Motion is Modulated by Attention

In two experiments we investigated whether stimuli that elicit automatic orienting of attention (i.e., arrow or averted gaze) could drive apparent motion perception in one of two possible directions, modulating the effect of a low-level property (the orientation of elements along the motion direction). To this end, the competing motion paradigm was used, in which at time 1, a stimulus appears in the center of the display, and at time 2, two other stimuli appear in different spatial locations. Three kinds of stimuli with eight possible orientations were used in separate blocks; (1) a line; (2) an arrow; and, (3) an averted gaze. First, since the three stimuli present in the display at time 2 should be perceived to be located at the same distance (i.e., equidistant), the threshold for perceived equidistance was calculated for each participant and then used as the customized inter-stimulus distance. Participants were asked to press the button corresponding to the direction of the perceived motion. Results show a preference for collinear motion (motions between elements oriented along the motion direction), with a higher percentage of responses for gaze and arrow stimuli. In Experiment 1, a difference between gaze- and arrow-stimuli was observed. Apparent motion was seen towards the collinear position more often for gaze than for arrow when the stimulus was pointing to the vertical directions, while the opposite was true when the stimulus was pointing to the horizontal directions. In Experiment 2, where the lightness contrast between the gaze and the background was reduced, no difference between gaze- and arrow-stimuli emerged. We interpret our results as due to the social and biological value of gaze, which solved a possible ambiguity between gaze direction and the directions conveyed by the figural properties of the contrasted background in Experiment 1. These findings are consistent with the idea that stimuli known to automatically orient visual attention modulate motion perception.

Feature and motion-based gaze cuing is linked with reduced social competence

Gaze following is a fundamental ability that plays an important role in human social function. However, the link between these two processes remains elusive. On the one hand, typically developing persons show robust gaze following in laboratory cuing tasks. On the other hand, investigations with individuals with autism suggest that reduced social competence in this population may partly reflect an atypical access to social information through attending to perceptual changes that normally accompany gaze shifts, like luminance or motion transients. Here we investigated if gaze cuing in typically developing individuals was modulated by similar task-irrelevant perceptual changes. In Experiment 1, a social gaze cue was presented with or without a luminance change. In Experiment 2, a social gaze cue was presented together with a motion cue. Both experiments indicated reduced magnitudes of gaze cuing in persons with low social competence on trials containing an irrelevant perceptual change. This suggests that similarly to individuals with autism, typically developing persons with low social competence also utilize idiosyncratic perceptual changes in the environment to access social content, revealing strong links between basic gaze following abilities and a range of social competence within typical individuals.

Moving Single Dots as Primes for Static Arrow Targets

In response priming, responses are typically faster and more accurate if the prime calls for the same response as the target (i.e., compatible trials) than when primes and targets trigger different responses (i.e., incompatible trials). With moving rows-of-dots as primes for static arrow targets, participants instead responded faster to incompatible targets with longer SOAs (stimulus onset asynchrony, > 200 ms). Until now, it is unclear whether this effect is specific to the material. In the present research, a single moving dot was used as a prime. Further, we analyzed compatibility effects depending on reaction times (RTs). Positive compatibility effects in reaction times were found with an SOA of 147 ms and even with a relatively long SOA of 360 ms; for very long SOAs (800-1,200 ms), negative effects were found. We interpreted this as evidence that the specific type of motion is irrelevant for the occurrence of a negative compatibility effect.

Automatic attentional orienting to other people's gaze in schizophrenia

Explicit tests of social cognition have revealed pervasive deficits in schizophrenia. Less is known of automatic social cognition in schizophrenia. We used a spatial orienting task to investigate automatic shifts of attention cued by another person's eye gaze in 29 patients and 28 controls. Central photographic images of a face with eyes shifted left or right, or looking straight ahead, preceded targets that appeared left or right of the cue. To examine automatic effects, cue direction was non-predictive of target location. Cue-target intervals were 100, 300, and 800 ms. In non-social control trials, arrows replaced eye-gaze cues. Both groups showed automatic attentional orienting indexed by faster reaction times (RTs) when arrows were congruent with target location across all cue-target intervals. Similar congruency effects were seen for eye-shift cues at 300 and 800 ms intervals, but patients showed significantly larger congruency effects at 800 ms, which were driven by delayed responses to incongruent target locations. At short 100-ms cue-target intervals, neither group showed faster RTs for congruent than for incongruent eye-shift cues, but patients were significantly slower to detect targets after direct-gaze cues. These findings conflict with previous studies using schematic line drawings of eye-shifts that have found automatic attentional orienting to be reduced in schizophrenia. Instead, our data indicate that patients display abnormalities in responding to gaze direction at various stages of gaze processing-reflected by a stronger preferential capture of attention by another person's direct eye contact at initial stages of gaze processing and difficulties disengaging from a gazed-at location once shared attention is established.

Can we resist another person's gaze?

Adaptive adjustments of strategies are needed to optimize behavior in a dynamic and uncertain world. A key function in implementing flexible behavior and exerting self-control is represented by the ability to stop the execution of an action when it is no longer appropriate for the environmental requests. Importantly, stimuli in our environment are not equally relevant and some are more valuable than others. One example is the gaze of other people, which is known to convey important social information about their direction of attention and their emotional and mental states. Indeed, gaze direction has a significant impact on the execution of voluntary saccades of an observer since it is capable of inducing in the observer an automatic gaze-following behavior: a phenomenon named social or joint attention. Nevertheless, people can exert volitional inhibitory control on saccadic eye movements during their planning. Little is known about the interaction between gaze direction signals and volitional inhibition of saccades. To fill this gap, we administered a countermanding task to 15 healthy participants in which they were asked to observe the eye region of a face with the eyes shut appearing at central fixation. In one condition, participants were required to suppress a saccade, that was previously instructed by a gaze shift toward one of two peripheral targets, when the eyes were suddenly shut down (social condition, SC). In a second condition, participants were asked to inhibit a saccade, that was previously instructed by a change in color of one of the two same targets, when a change of color of a central picture occurred (non-social condition, N-SC). We found that inhibitory control was more impaired in the SC, suggesting that actions initiated and stopped by social cues conveyed by the eyes are more difficult to withhold. This is probably due to the social value intrinsically linked to these cues and the many uses we make of them.

The Microstructure of Action Perception in Infancy: Decomposing the Temporal Structure of Social Information Processing

In this article, we review recent evidence of infants' early competence in perceiving and interpreting the actions of others. We present a theoretical model that decomposes the timeline of action perception into a series of distinct processes that occur in a particular order. Once an agent is detected, covert attention can be allocated to the future state of the agent (priming), which may lead to overt gaze shifts that predict goals (prediction). Once these goals are achieved, the consequence of the agents' actions and the manner in which the actions were performed can be evaluated (evaluation). We propose that all of these processes have unique requirements, both in terms of timing and cognitive resources. To understand more fully the rich social world of infants, we need to pay more attention to the temporal structure of social perception and ask what information is available to infants and how this changes over time.

ERP evidence for selective drop in attentional costs in uncertain environments: challenging a purely premotor account of covert orienting of attention

Several studies have proved that the reliability of endogenous spatial cues linearly modulates the reaction time advantage in the processing of targets at validly cued vs. invalidly cued locations, i.e. the "validity effect". This would imply that with non-predictive cues, no "validity effect" should be observed. However, contrary to this prediction, one could hypothesize that attentional benefits by valid cuing (i.e. the RT advantage for validly vs. neutrally cued targets) can still be maintained with non-predictive cues, if the brain were endowed with mechanisms allowing the selective reduction in costs of reorienting from invalidly cued locations (i.e. the reduction of the RT disadvantage for invalidly vs. neutrally cued targets). This separated modulation of attentional benefits and costs would be adaptive in uncertain contexts where cues predict at chance level the location of targets. Through the joint recording of manual reaction times and event-related cerebral potentials (ERPs), we have found that this is the case and that relying on non-predictive endogenous cues results in abatement of attentional costs and the difference in the amplitude of the P1 brain responses evoked by invalidly vs. neutrally cued targets. In contrast, the use of non-predictive cues leaves unaffected attentional benefits and the difference in the amplitude of the N1 responses evoked by validly vs. neutrally cued targets. At the individual level, the drop in costs with non-predictive cues was matched with equivalent lateral biases in RTs to neutrally and invalidly cued targets presented in the left and right visual field. During the cue period, the drop in costs with non-predictive cues was preceded by reduction of the Early Directing Attention Negativity (EDAN) on posterior occipital sites and by enhancement of the frontal Anterior Directing Attention Negativity (ADAN) correlated to preparatory voluntary orienting. These findings demonstrate, for the first time, that the segregation of mechanisms regulating attentional benefits and costs helps efficiency of orienting in "uncertain" visual spatial contexts characterized by poor probabilistic association between cues and targets.

Differential activation of frontoparietal attention networks by social and symbolic spatial cues

Perception of both gaze-direction and symbolic directional cues (e.g. arrows) orient an observer's attention toward the indicated location. It is unclear, however, whether these similar behavioral effects are examples of the same attentional phenomenon and, therefore, subserved by the same neural substrate. It has been proposed that gaze, given its evolutionary significance, constitutes a 'special' category of spatial cue. As such, it is predicted that the neural systems supporting spatial reorienting will be different for gaze than for non-biological symbols. We tested this prediction using functional magnetic resonance imaging to measure the brain's response during target localization in which laterally presented targets were preceded by uninformative gaze or arrow cues. Reaction times were faster during valid than invalid trials for both arrow and gaze cues. However, differential patterns of activity were evoked in the brain. Trials including invalid rather than valid arrow cues resulted in a stronger hemodynamic response in the ventral attention network. No such difference was seen during trials including valid and invalid gaze cues. This differential engagement of the ventral reorienting network is consistent with the notion that the facilitation of target detection by gaze cues and arrow cues is subserved by different neural substrates.

Neural correlates of the spatial and expectancy components of endogenous and stimulus-driven orienting of attention in the Posner task

Voluntary orienting of visual attention is conventionally measured in tasks with predictive central cues followed by frequent valid targets at the cued location and by infrequent invalid targets at the uncued location. This implies that invalid targets entail both spatial reorienting of attention and breaching of the expected spatial congruency between cues and targets. Here, we used event-related functional magnetic resonance imaging (fMRI) to separate the neural correlates of the spatial and expectancy components of both endogenous orienting and stimulus-driven reorienting of attention. We found that during endogenous orienting with predictive cues, there was a significant deactivation of the right Temporal-Parietal Junction (TPJ). We also discovered that the lack of an equivalent deactivation with nonpredictive cues was matched to drop in attentional costs and preservation of attentional benefits. The right TPJ showed equivalent responses to invalid targets following predictive and nonpredictive cues. On the contrary, infrequent-unexpected invalid targets following predictive cues specifically activated the right Middle and Inferior Frontal Gyrus (MFG-IFG). Additional comparisons with spatially neutral trials demonstrated that, independently of cue predictiveness, valid targets activate the left TPJ, whereas invalid targets activate both the left and right TPJs. These findings show that the selective right TPJ activation that is found in the comparison between invalid and valid trials results from the reciprocal cancelling of the different activations that in the left TPJ are related to the processing of valid and invalid targets. We propose that left and right TPJs provide "matching and mismatching to attentional template" signals. These signals enable reorienting of attention and play a crucial role in the updating of the statistical contingency between cues and targets.

Human social attention: A new look at past, present, and future investigations

The present review examines the neural-behavioral correlates of human social attention, with special regard to the neural mechanisms involved in processing gaze information and the functional impact of gaze direction on the spatial orienting of attention. Our review suggests that there is strong evidence that specific brain systems are preferentially biased toward processing gaze information, yet this specificity is not mirrored by the behavioral data as measured in highly controlled model attention tasks such as the Posner cueing paradigm. In less controlled tasks, however, such as when observers are left free to select what they want to attend, they focus on people and their eyes, consistent with one's intuition and with the neural evidence that eyes are special. We discuss a range of implications of these data, including that much is to be gained by examining brain and behavioral processes to social stimuli as they occur in complex real-world settings.

Emotional attention: effects of emotion and gaze direction on overt orienting of visual attention

In the present study we considered the two factors that have been advocated for playing a role in emotional attention: perception of gaze direction and facial expression of emotions. Participants performed an oculomotor task in which they had to make a saccade towards one of the two lateral targets, depending on the colour of the fixation dot which appeared at the centre of the computer screen. At different time intervals (stimulus onset asynchronies, SOAs: 50,100,150 ms) following the onset of the dot, a picture of a human face (gazing either to the right or to the left) was presented at the centre of the screen. The gaze direction of the face could be congruent or incongruent with respect to the location of the target, and the expression could be neutral or angry. In Experiment 1 the facial expressions were presented randomly in a single block, whereas in Experiment 2 they were shown in separate blocks. Latencies for correct saccades and percentage of errors (saccade direction errors) were considered in the analyses. Results showed that incongruent trials determined a significantly higher percentage of saccade direction errors with respect to congruent trials, thus confirming that gaze direction, even when task-irrelevant, interferes with the accuracy of the observer's oculomotor behaviour. The angry expression was found to hold attention for a longer time with respect to the neutral one, producing delayed saccade latencies. This was particularly evident at 100 ms SOA and for incongruent trials. Emotional faces may then exert a modulatory effect on overt attention mechanisms.

Selective attention to threatening faces in delusion-prone individuals

INTRODUCTION

Selective attention to threat-related information has been associated with clinical delusions in schizophrenia and nonclinical delusional ideation in healthy individuals. However, it is unclear whether biased attention for threat reflects early engagement effects on selective attention, or later difficulties in disengaging attention from perceived threat. The present study examined which of these processes operate in nonclinical delusion-prone individuals.

METHODS

A total of 100 psychologically healthy participants completed the Peters et al. (1999) Delusions Inventory (PDI). Twenty-two scoring in the upper quartile (high-PDI group) and 22 scoring in the lower quartile (low-PDI group) completed a modified dot-probe task. Participants detected dot-probes appearing 200, 500, or 1250 ms after an angry-neutral face pair or a happy-neutral face pair.

RESULTS

High-PDI individuals responded faster to dot-probes presented in the same location as angry compared to happy faces at the short 200 ms stimulus onset asynchrony (SOA), but only when the emotional faces were presented to the left visual field. At the two longer SOAs (500 ms, 1250 ms), the high-PDI group were also faster to respond to dot-probes presented in the same location as angry compared to happy faces and slower to respond to dot-probes presented in different spatial locations to angry (vs. happy) faces. The latter effects were seen whether emotional faces were presented to the left or the right visual field.

CONCLUSIONS

Results support the operation of emotion-selective engagement and defective disengagement for threat-related facial expressions (i.e., anger) in delusion-prone individuals.