Chimpanzees demonstrate a behavioural signature of human joint action.

The strength of human society can largely be attributed to the tendency to work together to achieve outcomes that are not possible alone. Effective social coordination benefits from mentally representing a partner's actions. Specifically, humans optimize social coordination by forming internal action models adapted to joint rather than individual task demands. To what extent do humans share the cognitive mechanisms that support optimal human coordination and collaboration with other species? An ecologically inspired joint handover-to-retrieve task was systematically manipulated across several experiments to assess whether joint action planning in chimpanzees reflects similar patterns to humans. Chimpanzees' chosen handover locations shifted towards the location of the experimenter's free or unobstructed hand, suggesting they represent the constraints of the joint task even though their individual half of the task was unobstructed. These findings indicate that chimpanzees and humans may share common cognitive mechanisms or predispositions that support joint action.

Enhancing surgical performance in cardiothoracic surgery with innovations from computer vision and artificial intelligence: a narrative review.

When technical requirements are high, and patient outcomes are critical, opportunities for monitoring and improving surgical skills via objective motion analysis feedback may be particularly beneficial. This narrative review synthesises work on technical and non-technical surgical skills, collaborative task performance, and pose estimation to illustrate new opportunities to advance cardiothoracic surgical performance with innovations from computer vision and artificial intelligence. These technological innovations are critically evaluated in terms of the benefits they could offer the cardiothoracic surgical community, and any barriers to the uptake of the technology are elaborated upon. Like some other specialities, cardiothoracic surgery has relatively few opportunities to benefit from tools with data capture technology embedded within them (as is possible with robotic-assisted laparoscopic surgery, for example). In such cases, pose estimation techniques that allow for movement tracking across a conventional operating field without using specialist equipment or markers offer considerable potential. With video data from either simulated or real surgical procedures, these tools can (1) provide insight into the development of expertise and surgical performance over a surgeon's career, (2) provide feedback to trainee surgeons regarding areas for improvement, (3) provide the opportunity to investigate what aspects of skill may be linked to patient outcomes which can (4) inform the aspects of surgical skill which should be focused on within training or mentoring programmes. Classifier or assessment algorithms that use artificial intelligence to 'learn' what expertise is from expert surgical evaluators could further assist educators in determining if trainees meet competency thresholds. With collaborative efforts between surgical teams, medical institutions, computer scientists and researchers to ensure this technology is developed with usability and ethics in mind, the developed feedback tools could improve cardiothoracic surgical practice in a data-driven way.

Social gaze cueing elicits facilitatory and inhibitory effects on movement execution when the model might act on an object.

Social cues, such as eye gaze and pointing fingers, can increase the prioritisation of specific locations for cognitive processing. A previous study using a manual reaching task showed that, although both gaze and pointing cues altered target prioritisation (reaction times [RTs]), only pointing cues affected action execution (trajectory deviations). These differential effects of gaze and pointing cues on action execution could be because the gaze cue was conveyed through a disembodied head; hence, the model lacked the potential for a body part (i.e., hands) to interact with the target. In the present study, the image of a male gaze model, whose gaze direction coincided with two potential target locations, was centrally presented. The model either had his arms and hands extended underneath the potential target locations, indicating the potential to act on the targets (Experiment 1), or had his arms crossed in front of his chest, indicating the absence of potential to act (Experiment 2). Participants reached to a target that followed a nonpredictive gaze cue at one of three stimulus onset asynchronies. RTs and reach trajectories of the movements to cued and uncued targets were analysed. RTs showed a facilitation effect for both experiments, whereas trajectory analysis revealed facilitatory and inhibitory effects, but only in Experiment 1 when the model could potentially act on the targets. The results of this study suggested that when the gaze model had the potential to interact with the cued target location, the model's gaze affected not only target prioritisation but also movement execution.

The role of primary motor cortex in manual inhibition of return: A transcranial magnetic stimulation study.

Inhibition of return (IOR) is a behavioural phenomenon characterised by longer response times (RTs) to stimuli presented at previously cued versus uncued locations. The neural mechanisms underlying IOR effects are not fully understood. Previous neurophysiological studies have identified a role of frontoparietal areas including posterior parietal cortex (PPC) in the generation of IOR, but the contribution of primary motor cortex (M1) has not been directly tested. The present study investigated the effects of single-pulse transcranial magnetic stimulation (TMS) over M1 on manual IOR in a key-press task where peripheral (left or right) targets followed a cue at the same or opposite location at different SOAs (100/300/600/1000 ms). In Experiment 1, TMS was applied over right M1 on a randomized 50% of trials. In Experiment 2, active or sham stimulation was provided in separate blocks. In the absence of TMS (non-TMS trials in Experiment 1 and sham trials in Experiment 2), evidence of IOR was observed in RTs at longer SOAs. In both experiments, IOR effects differed between TMS and non-TMS/sham conditions, but the effects of TMS were greater and statistically significant in Experiment 1 where TMS and non-TMS trials were randomly interspersed. The magnitude of motor-evoked potentials was not altered by the cue-target relationship in either experiment. These findings do not support a key role of M1 in the mechanisms of IOR but suggest the need for further research to elucidate the role of the motor system in manual IOR effects.

Evaluating the relative contributions of copying and reconstruction processes in cultural transmission episodes.

The ability to transmit information between individuals through social learning is a foundational component of cultural evolution. However, how this transmission occurs is still debated. On the one hand, the copying account draws parallels with biological mechanisms for genetic inheritance, arguing that learners copy what they observe and novel variations occur through random copying errors. On the other hand, the reconstruction account claims that, rather than directly copying behaviour, learners reconstruct the information that they believe to be most relevant on the basis of pragmatic inference, environmental and contextual cues. Distinguishing these two accounts empirically is difficult based on data from typical transmission chain studies because the predictions they generate frequently overlap. In this study we present a methodological approach that generates different predictions of these accounts by manipulating the task context between model and learner in a transmission episode. We then report an empirical proof-of-concept that applies this approach. The results show that, when a model introduces context-dependent embedded signals to their actions that are not intended to be transmitted, it is possible to empirically distinguish between competing predictions made by these two accounts. Our approach can therefore serve to understand the underlying cognitive mechanisms at play in cultural transmission and can make important contributions to the debate between preservative and reconstructive schools of thought.

The influence of location, ownership, and the presence of a coactor on the processing of objects.

Humans operate in complex environments where social interactions require individuals to constantly attend to people and objects around them. Despite the complexity of these interactions from a visuomotor perspective, humans can engage and thrive in social settings. The purpose of the current study was to examine the simultaneous influence of multiple social cues (i.e., ownership and the presence of a coactor) on the processing of objects. Participants performed an object-based compatibility task in the presence and absence of a coacting confederate. Participants indicated whether pictures of mugs (that were either self-owned or unowned) were upright or inverted. The pictures appeared at one of 2 locations (a near or far location relative to the participant) on a computer screen laid flat on (parallel to) the tabletop. When present, the coactor stood on the opposite side of the screen/table. Analysis of response times (RTs) indicated that the processing of objects was influenced by the object's ownership status, the presence of the coactor, and where the object was located on the screen. Specifically, RTs for pictures of self-owned mugs were shorter than unowned mugs, but only when the pictures were located at the near location. Further, the presence of a confederate resulted in shorter RTs for pictures located at the near but not the far location. These findings suggest that when objects were placed at the far location, the additional social cues of ownership and social context did not influence visuomotor processing of the objects. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Self-bias effect: movement initiation to self-owned property is speeded for both approach and avoidance actions.

Recall of, and physical interaction with, self-owned items is privileged over items owned by other people (Constable et al. in Cognition 119(3):430-437, 2011; Cunningham et al. in Conscious Cognit 17(1):312-318, 2008). Here, we investigate approach (towards the item), compared with avoidance (away from the item) movements to images of self- and experimenter-owned items. We asked if initiation time and movement duration of button-press approach responses to self-owned items are associated with a systematic self-bias (overall faster responses), compared with avoidance movements, similar to findings of paradigms investigating affective evaluation of (unowned) items. Participants were gifted mugs to use, and after a few days they completed an approach-avoidance task (Chen and Bargh in Pers Soc Psychol Bull 25(2):215-224, 1999; Seibt et al. in J Exp Soc Psychol 44:713-720, 2008; Truong et al. in J Exp Psychol Hum Percept Perform 42(3), 375-385, 2016) to images of their own or the experimenter's mug, using either congruent or incongruent movement direction mappings. There was a self-bias effect for initiation time to the self-owned mug, for both congruent and incongruent mappings, and for movement duration in the congruent mapping. The effect was abolished in Experiment 2 when participants responded based on a shape on the handle rather than mug ownership. We speculate that ownership status requires conscious processing to modulate responses. Moreover, ownership status judgements and affective evaluation may employ different mechanisms.

Sticking together? Re-binding previous other-associated stimuli interferes with self-verification but not partner-verification.

The self-prioritisation and we-prioritisation effects can be observed through faster responses to self-stimuli (self and group) than non-self-stimuli. It remains uncertain if we-prioritisation extends to individual members of one's own group. In light of recent work that implicates memory-based processes in identity-prioritisation effects, the present experiment was developed to determine whether a task-partner's identity relevant information also benefits from an enhanced representation, despite conflicting evidence of partner-prioritisation. To this end, pairs of participants were recruited to perform a joint task. Each partner was assigned a shape and a stranger was also assigned a shape. Participants then completed a shape-to-label matching task where one participant responded if a shape and a label pair matched and the other responded if the shape and a label pair did not match. Halfway through the task the associated identities were switched such that the same shapes and labels were reassigned. Overall, a standard self-prioritisation effect was observed with match-responders making faster responses to self- over partner- and stranger-stimuli. After identities were remapped a decrement in performance was observed for self-trials relative to baseline self-responses. Conversely, responses were faster to partner- and stranger-stimuli relative to baseline performance for each stimulus type. Thus, no evidence was observed for an enhanced representation for task-partner-associated identities. However, an interaction between old and new memory traces for self- and other-associated identities does seem to interfere with self-retrieval and self-verification processes.

It goes with the territory: Ownership across spatial boundaries.

Previous studies have shown that people are faster to process objects that they own as compared with objects that other people own. Yet object ownership is embedded within a social environment that has distinct and sometimes competing rules for interaction. Here we ask whether ownership of space can act as a filter through which we process what belongs to us. Can a sense of territory modulate the well-established benefits in information processing that owned objects enjoy? In 4 experiments participants categorized their own or another person's objects that appeared in territories assigned either to themselves or to another. We consistently found that faster processing of self-owned than other-owned objects only emerged for objects appearing in the self-territory, with no such advantage in other territories. We propose that knowing whom spaces belong to may serve to define the space in which affordances resulting from ownership lead to facilitated processing. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Susceptibility to the fusion illusion is modulated during both action execution and action observation.

Many researchers have proposed that when an individual observes the actions of another individual, the observer simulates the action using many of the same neural areas that are involved in action production. The present study was designed to test this simulation hypothesis by comparing the perception of multisensory stimuli during both the execution and observation of an aiming action. The present work used the fusion illusion - an audio-visual illusion in which two visual stimuli presented with one auditory stimulus are erroneously perceived as being one visual stimulus. Previous research has shown that, during action execution, susceptibly to this illusion is reduced early in the execution of the movement when visual information may be more highly weighted than other sensory information. We sought to determine whether or not a non-acting observer of an action showed a similar reduction in susceptibility to the fusion illusion. Participants fixated a target and either executed or observed a manual aiming movement to that target. Audiovisual stimuli were presented at 0, 100, or 200 ms relative to movement onset and participants reported the number of perceived flashes after the movement was completed. Analysis of perceived flashes revealed that participants were less susceptible to the fusion illusion when the stimuli were presented early (100 ms) relative to later in the movement (200 ms). Critically, this pattern emerged in both execution and observation tasks. These findings support the hypothesis that observers simulate the performance of the actor and experience comparable real-time alterations in multisensory processing.

Relevant for us? We-prioritization in cognitive processing.

Humans are social by nature. We ask whether this social nature operates as a lens through which individuals process the world even in the absence of immediate interactions or explicit goals to collaborate. Is information that is potentially relevant to a group one belongs to ("We") processed with priority over information potentially relevant to a group one does not belong to ("They")? We conducted three experiments using a modified version of Sui, He, and Humphreys' (2012) shape-label matching task. Participants were assigned to groups either via a common preference between assigned team members (Experiment 1) or arbitrarily (Experiment 2). In a third experiment, only personal pronouns were used. Overall, a processing benefit for we-related information (we-prioritization) occurred regardless of the type of group induction. A final experiment demonstrated that we-prioritization did not extend to other individual members of a short-term transitory group. We suggest that the results reflect an intrinsic predisposition to process information "relevant for us" with priority, which might feed into optimizing collaborative processes. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Probing the time course of facilitation and inhibition in gaze cueing of attention in an upper-limb reaching task.

Previous work has revealed that social cues, such as gaze and pointed fingers, can lead to a shift in the focus of another person's attention. Research investigating the mechanisms of these shifts of attention has typically employed detection or localization button-pressing tasks. Because in-depth analyses of the spatiotemporal characteristics of aiming movements can provide additional insights into the dynamics of the processing of stimuli, in the present study we used a reaching paradigm to further explore the processing of social cues. In Experiments 1 and 2, participants aimed to a left or right location after a nonpredictive eye gaze cue toward one of these target locations. Seven stimulus onset asynchronies (SOAs), from 100 to 2,400 ms, were used. Both the temporal (reaction time, RT) and spatial (initial movement angle, IMA) characteristics of the movements were analyzed. RTs were shorter for cued (gazed-at) than for uncued targets across most SOAs. There were, however, no statistical differences in IMAs between movements to cued and uncued targets, suggesting that action planning was not affected by the gaze cue. In Experiment 3, the social cue was a finger pointing to one of the two target locations. Finger-pointing cues generated significant cueing effects in both RTs and IMAs. Overall, these results indicate that eye gaze and finger-pointing social cues are processed differently. Perception-action coupling (i.e., a tight link between the response and the social cue that is presented) might play roles in both the generation of action and the deviation of trajectories toward cued and uncued targets.

It is not in the details: Self-related shapes are rapidly classified but their features are not better remembered.

Self-prioritization is a robust phenomenon whereby judgments concerning self-representational stimuli are faster than judgments toward other stimuli. The present paper examines if and how self-prioritization causes more vivid short-term memories for self-related objects by giving geometric shapes arbitrary identities (self, mother, stranger). In Experiment 1 participants were presented with an array of the three shapes and required to retain the location and color of each in memory. Participants were then probed regarding the identity of one of the shapes and subsequently asked to indicate the color of the probed shape or an unprobed shape on a color wheel. Results indicated no benefit for self-stimuli in either response time for the identification probe or for color fidelity in memory. Yet, a cuing benefit was observed such that the cued stimulus in the identity probe did have higher fidelity within memory. Experiments 2 and 3 reduced the cognitive load by only requiring that participants process the identity and color of one shape at a time. For Experiment 2, the identity probe was memory-based, whereas the stimulus was presented alongside the identity probe for Experiment 3. Results demonstrated a robust self-prioritization effect: self-related shapes were classified faster than non-self-shapes, but this self-advantage did not lead to an increase in the fidelity of memory for self-related shapes' colors. Overall, these results suggest that self-prioritization effects may be restricted to an improvement in the ability to recognize that the self-representational stimulus is present without devoting more perceptual and short-term memory resources to such stimuli.

I before U: Temporal order judgements reveal bias for self-owned objects.

A multitude of studies demonstrate that self-relevant stimuli influence attention. Self-owned objects are a special class of self-relevant stimuli. If a self-owned object can indeed be characterised as a self-relevant stimulus then, consistent with theoretical predictions, a behavioural effect of ownership on attention should be present. To test this prediction, a task was selected that is known to be particularly sensitive measure of the prioritisation of visual information: the temporal order judgement. Participants completed temporal order judgements with pictures of "own" and "experimenter" owned objects (mugs) presented on either side of a central fixation cross. There was a variable onset delay between each picture, ranging between 0 ms and 105 ms, and participants were asked to indicate which mug appeared first. The results indicated a reliable change in the point of subjective simultaneity (PSS) in favour of their own mug. Such a change in the PSS was not observed for two groups of participants who were exposed to a mug but did not keep the mug. A further experiment indicated that the source of the bias in PSS was more consistent with a criterion shift or top-down attentional prioritisation rather than a perceptual bias. These findings suggest that ownership, beyond mere-touch, mere-choice, or familiarity, leads to prioritised processing and responses, but the mechanism underlying the effect is not likely to be perceptual in nature.

"Two Minds Don't Blink Alike": The Attentional Blink Does Not Occur in a Joint Context.

Typically, when two individuals perform a task together, each partner monitors the other partners' responses and goals to ensure that the task is completed efficiently. This monitoring is thought to involve a co-representation of the joint goals and task, as well as a simulation of the partners' performance. Evidence for such "co-representation" of goals and task, and "simulation" of responses has come from numerous visual attention studies in which two participants complete different components of the same task. In the present research, an adaptation of the attentional blink task was used to determine if co-representation could exert an influence over the associated attentional mechanisms. Participants completed a rapid serial visual presentation task in which they first identified a target letter (T1) and then detected the presence of the letter X (T2) presented one to seven letters after T1. In the individual condition, the participant identified T1 and then detected T2. In the joint condition, one participant identified T1 and the other participant detected T2. Across two experiments, an attentional blink (decreased accuracy in detecting T2 when presented three letters after T1) was observed in the individual condition, but not in joint conditions. A joint attentional blink may not emerge because the co-representation mechanisms that enable joint action exert a stronger influence at information processing stages that do not overlap with those that lead to the attentional blink.

The influence of intrapersonal sensorimotor experiences on the corticospinal responses during action-observation.

The coupling of perception and action has been strongly indicated by evidence that the observation of an action primes a response in the observer. It has been proposed that these primed responses may be inhibited when the observer is able to more closely distinguish between self- and other-generated actions - the greater the distinction, then the greater the inhibition of the primed response. This self-other distinction is shown to be enhanced following a period of visual feedback of self-generated action. The present study was designed to examine how sensorimotor experiences pertaining to self-generated action affect primed responses from observed actions. Single-pulse transcranial magnetic stimulation was used to investigate corticospinal activity elicited during the observation of index- and little-finger actions before and after training (self-generated action). For sensorimotor training, participants executed finger movements with or without visual feedback of their own movement. Results showed that the increases in muscle-specific corticospinal activity elicited from action-observation persisted after training without visual feedback, but did not emerge following training with visual feedback. This inhibition in corticospinal activity during action-observation following training with vision could have resulted from the refining of internal models of self-generated action, which then led to a greater distinction between "self" and "other" actions.

Right away: A late, right-lateralized category effect complements an early, left-lateralized category effect in visual search.

According to the Sapir-Whorf hypothesis, learned semantic categories can influence early perceptual processes. A central finding in support of this view is the lateralized category effect-namely, the finding that categorically different colors (e.g., blue and green hues) can be discriminated faster than colors within the same color category (e.g., different hues of green), especially when they are presented in the right visual field. Because the right visual field projects to the left hemisphere, this finding has been popularly couched in terms of the left-lateralization of language. However, other studies have reported bilateral category effects, which has led some researchers to question the linguistic origins of the effect. Here we examined the time course of lateralized and bilateral category effects in the classical visual search paradigm by means of eyetracking and RT distribution analyses. Our results show a bilateral category effect in the manual responses, which is combined of an early, left-lateralized category effect and a later, right-lateralized category effect. The newly discovered late, right-lateralized category effect occurred only when observers had difficulty locating the target, indicating a specialization of the right hemisphere to find categorically different targets after an initial error. The finding that early and late stages of visual search show different lateralized category effects can explain a wide range of previously discrepant findings.

Eye movements may cause motor contagion effects.

When a person executes a movement, the movement is more errorful while observing another person's actions that are incongruent rather than congruent with the executed action. This effect is known as "motor contagion". Accounts of this effect are often grounded in simulation mechanisms: increased movement error emerges because the motor codes associated with observed actions compete with motor codes of the goal action. It is also possible, however, that the increased movement error is linked to eye movements that are executed simultaneously with the hand movement because oculomotor and manual-motor systems are highly interconnected. In the present study, participants performed a motor contagion task in which they executed horizontal arm movements while observing a model making either vertical (incongruent) or horizontal (congruent) movements under three conditions: no instruction, maintain central fixation, or track the model's hand with the eyes. A significant motor contagion-like effect was only found in the 'track' condition. Thus, 'motor contagion' in the present task may be an artifact of simultaneously executed incongruent eye movements. These data are discussed in the context of stimulation and associative learning theories, and raise eye movements as a critical methodological consideration for future work on motor contagion.

Ownership Status Influences the Degree of Joint Facilitatory Behavior.

When engaging in joint activities, humans tend to sacrifice some of their own sensorimotor comfort and efficiency to facilitate a partner's performance. In the two experiments reported here, we investigated whether ownership-a socioculturally based nonphysical feature ascribed to objects-influenced facilitatory motor behavior in joint action. Participants passed mugs that differed in ownership status across a table to a partner. We found that participants oriented handles less toward their partners when passing their own mugs than when passing mugs owned by their partners (Experiment 1) and mugs owned by the experimenter (Experiment 2). These findings indicate that individuals plan and execute actions that assist their partners but do so to a smaller degree if it is the individuals' own property that the partners intend to manipulate. We discuss these findings in terms of underlying variables associated with ownership and conclude that a self-other distinction can be found in the human sensorimotor system.