Modulations of one's sense of agency during human-machine interactions: A behavioural study using a full humanoid robot.

Although previous investigations reported a reduced sense of agency when individuals act with traditional machines, little is known about the mechanisms underpinning interactions with human-like automata. The aim of this study was twofold: (1) to investigate the effect of the machine's physical appearance on the individuals' sense of agency and (2) to explore the cognitive mechanisms underlying the individuals' sense of agency when they are engaged in a joint task. Twenty-eight participants performed a joint Simon task together with another human or an automated artificial system as a co-agent. The physical appearance of the automated artificial system was manipulated so that participants could cooperate either with a servomotor or a full humanoid robot during the joint task. Both participants' response times and temporal estimations of action-output delays (i.e., an implicit measure of agency) were collected. Results showed that participants' sense of agency for self- and other-generated actions sharply declined during interactions with the servomotor compared with the human-human interactions. Interestingly, participants' sense of agency for self- and other-generated actions was reinforced when participants interacted with the humanoid robot compared with the servomotor. These results are discussed further.

Motor Coordination and Strategic Cooperation in Joint Action.

Naturalistic joint action between two agents typically requires both motor coordination and strategic cooperation. However, these two fundamental processes have systematically been studied independently. We presented 50 dyads of adult participants with a novel collaborative task that combined different levels of motor noise with different levels of strategic noise, to determine whether the sense of agency (the experience of control over an action) reflects the interplay between these low-level (motor) and high-level (strategic) dimensions. We also examined how dominance in motor control could influence prosocial behaviors. We found that self-agency was particularly dependent on motor cues, whereas joint agency was particularly dependent on strategic cues. We suggest that the prime importance of strategic cues to joint agency reflects the co-representation of coagents' interests during the task. Furthermore, we observed a reduction in prosocial strategies in agents who exerted dominant motor control over joint action, showing that the strategic dimension of human interactions is also susceptible to the influence of low-level motor characteristics.

Agents' pivotality and reward fairness modulate sense of agency in cooperative joint action.

The sense of agency (SoA) experienced in joint action is an essential subjective dimension of human cooperativeness, but we still know little about the specific factors that contribute to its emergence or alteration. In the present study, dyads of participants were instructed to coordinate their key presses to move a cursor up to a specific target (i.e., to achieve a common goal). We applied random deviations on the cursor's trajectory to manipulate the motor fluency of the joint action, while the agents' motor roles were either balanced (i.e., equivalent) or unbalanced (i.e., one agent contributed more than the other), making the agents more or less pivotal to the joint action. Then, the final outcomes were shared equally, fairly (i.e., reflecting individual motor contributions) or arbitrarily in an all-or-none fashion, between the co-agents. Self and joint SoA were measured through self-reports about feeling of control, that is, using judgment of (felt) control (JoC), and electrodermal activity was recorded during the whole motor task. We observed that self and joint JoC were reduced in the case of low motor fluency, pointing out the importance of sensorimotor cues for both I- and we-modes. Moreover, while self JoC was reduced in the low pivotality condition (i.e., low motor role), joint JoC was significantly enhanced when agents' roles and rewards were symmetrical (i.e. equal). Skin conductance responses to rewards were impacted by the way outcomes were shared between partners (i.e., fairly, equally or arbitrarily) but not by the individual gains, which demonstrates the sensitivity of low-level physiological reactions to external signs of fairness. Skin conductance level was also reduced in the fair context, where rewards were shared according to individual motor contributions, relative to the all-or-none context, which could mirror the feeling of effective responsibility and control over actions' outcomes.

The sense of agency in human-human vs human-robot joint action.

Kinesthesis pertains to the perception of moving body parts, while the sense of agency refers to the experience of controlling one's action-effects. Based on previous work, we hypothesized that the sense of agency would decrease in joint action with a robot compared to a human partner. Pairs of participants were jointly manipulating two interconnected haptic devices enabling them to feel each other's forces. Unbeknown to participants, their partner was sometimes replaced by a robot. The sense of agency was assessed using intentional binding, which refers to a contraction of perceived time between an action and its effect for intentional actions, and participants' judgment of their contribution to joint action. Participants judged their contribution as higher when they were initiating action and when they were paired with the robot. By contrast, intentional binding occurred only with a human partner. This outcome supports the hypothesis that human-robot joint action hinders intentional binding.

Alterations of agency in hypnosis: A new predictive coding model.

Hypnotic suggestions can lead to altered experiences of agency, reality, and memory. The present work is primarily concerned with alterations of the sense of agency (SoA) following motor suggestions. When people respond to the suggestion that their arm is rising up all by itself, they usually have a feeling of passivity for their action. The mechanisms leading to such alterations of the SoA are still controversial. We propose a theoretical model based on the framework of predictive coding: The view that the brain constantly generates hypotheses that predict sensory input at varying levels of abstraction and minimizes prediction errors either by updating its prior hypotheses-perceptual inference-or by modifying sensory input through action-active inference. We argue that suggested motor behavior and the experience of passivity accompanying it can be accounted for in terms of active inference. We propose that motor suggestions optimize both proprioceptive predictions and actual proprioceptive evidence through attentional modulation. The comparison between predicted and actual sensory evidence leads to highly precise prediction errors that call for an explanation. The motor suggestion readily supplies such an explanation by providing a prior of nonagency to the subject. We present this model in detail and discuss how it relates to, and differs from, other recent models of hypnosis. We compare its predictions with the predictions derivable from these other models. We also discuss the potential application of our predictive account to reality and memory alterations in hypnosis and offer an explanation of interindividual differences in hypnotic suggestibility. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Intentions: The dynamic hierarchical model revisited.

Ten years ago, one of us proposed a dynamic hierarchical model of intentions that brought together philosophical work on intentions and empirical work on motor representations and motor control (Pacherie, 2008). The model distinguished among Distal intentions, Proximal intentions, and Motor intentions operating at different levels of action control (hence the name DPM model). This model specified the representational and functional profiles of each type of intention, as well their local and global dynamics, and the ways in which they interact. A core insight of the model was that action control is the result of integrated, coordinated activity across these levels of intention. Since the proposal of the model, empirical and theoretical works in philosophy and cognitive science have emerged that would seem to support and expand on this central insight. In particular, an updated understanding of the nature of sensorimotor processing and motor representations, as well as of how the different levels of intention and control interface and interact, allows for the further specification and precisification of the original DPM model. This article is categorized under: Philosophy > Psychological Capacities Psychology > Motor Skill and Performance Philosophy > Action.

Action co-representation and the sense of agency during a joint Simon task: Comparing human and machine co-agents.

Recent studies have suggested that individuals are not able to develop a sense of joint agency during joint actions with artificial systems. We sought to examine whether this lack of joint agency is linked to individuals' inability to co-represent the machine-generated actions. Fifteen participants observed or performed a Simon response time task either individually, or jointly with another human or a computer. Participants reported the time interval between their response (or the co-actor response) and a subsequent auditory stimulus, which served as an implicit measure of participants' sense of agency. Participants' reaction times showed a classical Simon effect when they were partnered with another human, but not when they collaborated with a computer. Furthermore, participants showed a vicarious sense of agency when co-acting with another human agent but not with a computer. This absence of vicarious sense of agency during human-computer interactions and the relation with action co-representation are discussed.

Corrigendum: Predictive Mechanisms Are Not Involved the Same Way during Human-Human vs. Human-Machine Interactions: A Review.

[This corrects the article on p. 52 in vol. 11, PMID: 29081744.].

Predictive Mechanisms Are Not Involved the Same Way during Human-Human vs. Human-Machine Interactions: A Review.

Nowadays, interactions with others do not only involve human peers but also automated systems. Many studies suggest that the motor predictive systems that are engaged during action execution are also involved during joint actions with peers and during other human generated action observation. Indeed, the comparator model hypothesis suggests that the comparison between a predicted state and an estimated real state enables motor control, and by a similar functioning, understanding and anticipating observed actions. Such a mechanism allows making predictions about an ongoing action, and is essential to action regulation, especially during joint actions with peers. Interestingly, the same comparison process has been shown to be involved in the construction of an individual's sense of agency, both for self-generated and observed other human generated actions. However, the implication of such predictive mechanisms during interactions with machines is not consensual, probably due to the high heterogeneousness of the automata used in the experimentations, from very simplistic devices to full humanoid robots. The discrepancies that are observed during human/machine interactions could arise from the absence of action/observation matching abilities when interacting with traditional low-level automata. Consistently, the difficulties to build a joint agency with this kind of machines could stem from the same problem. In this context, we aim to review the studies investigating predictive mechanisms during social interactions with humans and with automated artificial systems. We will start by presenting human data that show the involvement of predictions in action control and in the sense of agency during social interactions. Thereafter, we will confront this literature with data from the robotic field. Finally, we will address the upcoming issues in the field of robotics related to automated systems aimed at acting as collaborative agents.

Neural coding of prior expectations in hierarchical intention inference.

The ability to infer other people's intentions is crucial for successful human social interactions. Such inference relies on an adaptive interplay of sensory evidence and prior expectations. Crucially, this interplay would also depend on the type of intention inferred, i.e., on how abstract the intention is. However, what neural mechanisms adjust the interplay of prior and sensory evidence to the abstractness of the intention remains conjecture. We addressed this question in two separate fMRI experiments, which exploited action scenes depicting different types of intentions (Superordinate vs. Basic; Social vs. Non-social), and manipulated both prior and sensory evidence. We found that participants increasingly relied on priors as sensory evidence became scarcer. Activity in the medial prefrontal cortex (mPFC) reflected this interplay between the two sources of information. Moreover, the more abstract the intention to infer (Superordinate > Basic, Social > Non-Social), the greater the modulation of backward connectivity between the mPFC and the temporo-parietal junction (TPJ), resulting in an increased influence of priors over the intention inference. These results suggest a critical role for the fronto-parietal network in adjusting the relative weight of prior and sensory evidence during hierarchical intention inference.

Reduced sensitivity to social priors during action prediction in adults with autism spectrum disorders.

An extensive amount of evidence has documented a diminished ability to predict and understand other people's action in individuals with autism spectrum disorders (ASD). Recently, two theoretical accounts, the "Hypo-priors" and the "Aberrant precision" hypotheses, have suggested that attenuated Bayesian priors or an imbalance of the precision ascribed to sensory evidence relative to prior expectations may be responsible for the atypical perceptual experience and difficulties with action understanding in ASD. In the present study, we aimed to directly investigate whether difficulties in the appreciation of others' intentions can be accounted for by abnormal interaction between these two types of information: (i) the sensory evidence conveyed by movement kinematics, and (ii) the observer's expectations, acquired from past experience or derived from prior knowledge. To test this hypothesis, we contrasted the ability to infer Non-Social and Social intentions in adults with and without ASD, using a series of tasks in which both sensory evidence and prior expectations were manipulated. The results showed that attenuated effect of prior expectations in ASD individuals does not result from a generalized impairment in mentalizing, but one confined to social intentions. Attenuated priors in the social domain predicted the severity of clinical symptoms in the area of social interaction. Importantly, however, we found that reduced priors in the social domain could be compensated by ASD through observational learning, i.e. through deriving statistical regularities from observed behaviours. This capacity to balance reduced social expectations by learning inversely correlated with the severity of repetitive and stereotyped behaviours. Collectively, these findings suggest that adults with ASD exhibit a disturbance in the inferential mechanism that integrates sensory evidence into prior beliefs to produce accurate inferences about other people's intentions.

Perceptual hysteresis as a marker of perceptual inflexibility in schizophrenia.

People with schizophrenia are known to exhibit difficulties in the updating of their current belief states even in the light of disconfirmatory evidence. In the present study we tested the hypothesis that people with schizophrenia could also manifest perceptual inflexibility, or difficulties in the updating of their current sensory states. The presence of perceptual inflexibility might contribute both to the patients' altered perception of reality and the formation of some delusions as well as to their social cognition deficits. Here, we addressed this issue with a protocol of auditory hysteresis, a direct measure of sensory persistence, on a population of stabilized antipsychotic-treated schizophrenia patients and a sample of control subjects. Trials consisted of emotional signals (i.e., screams) and neutral signals (i.e., spectrally-rotated versions of the emotional stimuli) progressively emerging from white noise - Ascending Sequences - or progressively fading away in white noise - Descending Sequences. Results showed that patients presented significantly stronger hysteresis effects than control subjects, as evidenced by a higher rate of perceptual reports in Descending Sequences. The present study thus provides direct evidence of perceptual inflexibility in schizophrenia.

The phenomenology of controlling a moving object with another person.

The phenomenology of controlling what one perceives is influenced by a combination of sensory predictions and inferential processes. While it is known that external perturbations can reduce the sense of control over action effects, there have been few studies investigating the impact of intentional co-actors on the sense of control. In three experiments, we investigated how individuals' judgments of control (JoC) over a moving object were influenced by sharing control with a second person. Participants used joysticks to keep a cursor centered on a moving target either alone or with a co-actor. When both participants' actions had similar perceptual consequences, JoC ratings were highest when self-generated movements were the only influence on the cursor, while the appearance of sharing control with a second person decreased JoC ratings. By contrast, when participants performed complementary actions with perceptually distinctive consequences, JoC ratings were highest when both participants were able to influence the cursor. The phenomenology of control during joint action is influenced by low-level visuomotor correlations, the presence of competing causal influences, and group-level performance.

Out of nowhere: thought insertion, ownership and context-integration.

We argue that thought insertion primarily involves a disruption of the sense of ownership for thoughts and that the lack of a sense of agency is but a consequence of this disruption. We defend the hypothesis that this disruption of the sense of ownership stems from a failure in the online integration of the contextual information related to a thought, in particular contextual information concerning the different causal factors that may be implicated in their production. Loss of unity of consciousness, manifested by incoherent subjective experiences is a general phenomenal characteristic of schizophrenia. This loss of coherence has been hypothesized to reflect a generalized deficit of contextual information integration not conveyed by, but related to, a target event. This deficit is manifested across many cognitive domains. We argue that it is also manifested in the process of thinking itself, resulting in causally decontextualized thoughts that are experienced as inserted thoughts.

Delusions and metacognition in patients with schizophrenia.

INTRODUCTION: The aim of the present study was to explore the basis of the strong feeling of conviction and the high resistance to change characteristic of delusions and to test whether patients with schizophrenia suffering from delusions have specific metacognitive impairments when compared to both patients without delusions and healthy controls. METHODS: 14 actively delusional patients with schizophrenia, 14 nondelusional patients, and 14 healthy subjects were administered two measures assessing different aspects of metacognition: an emotional metacognitive version of the WCST adapted from Koren et al. (2004) and the Beck Cognitive Insight Scale. RESULTS: Relative to both healthy controls and nondelusional patients, delusional participants were specifically impaired on metacognitive measures of free choice improvement and global monitoring. This was correlated with high self-certainty on the BCIS relative to nondelusional patients. CONCLUSIONS: Our results suggest that metacognitive impairments play an important role in the maintenance of delusional beliefs. It may therefore be important to adapt remediation strategies to the metacognitive profiles of patients.

Mentalizing under influence: abnormal dependence on prior expectations in patients with schizophrenia.

An impaired ability to appreciate other people's mental states is a well-established and stable cognitive deficit in schizophrenia, which might explain some aspects of patients' social dysfunction. Yet, despite a wealth of literature on this topic, the basic mechanisms underlying these impairments are still poorly understood, and their links with the clinical dimensions of schizophrenia remain unclear. The present study aimed to investigate the extent to which patients' impaired ability to appreciate other people's intentions (known as mentalizing) may be accounted for by abnormal interaction between the two types of information that contribute to this ability: (i) the sensory evidence conveyed by movement kinematics; and (ii) the observer's prior expectations. We hypothesized that this is not a generalized impairment, but one confined to certain types of intentions. To test this assumption, we designed four tasks in which participants were required to infer either: (i) basic intentions (i.e. the simple goal of a motor act); (ii) superordinate intentions (i.e. the general goal of a sequence of motor acts); (iii) social basic; or (iv) social superordinate intentions (i.e. simple or general goals achieved within the context of a reciprocal interaction). In each of these tasks, both prior expectations and sensory information were manipulated. We found that patients correctly inferred non-social, basic intentions, but experienced difficulties when inferring non-social superordinate intentions and both basic and superordinate social intentions. These poor performances were associated with two abnormal patterns of interaction between prior expectations and sensory evidence. In the non-social superordinate condition, patients relied heavily on their prior expectations, while disregarding sensory evidence. This pattern of interaction predicted the severity of 'positive' symptoms. Social conditions prompted exactly the opposite pattern of interaction: patients exhibited weaker dependence on prior expectations while relying strongly on sensory evidence, and this predicted the severity of 'negative' symptoms. We suggest both these patterns can be accounted for by a disturbance in the Bayesian inferential mechanism that integrates sensory evidence (conveyed by movement kinematics) into prior beliefs (about others' mental states and attitudes) to produce accurate inferences about other people's intentions.

What are they up to? The role of sensory evidence and prior knowledge in action understanding.

Explaining or predicting the behaviour of our conspecifics requires the ability to infer the intentions that motivate it. Such inferences are assumed to rely on two types of information: (1) the sensory information conveyed by movement kinematics and (2) the observer's prior expectations--acquired from past experience or derived from prior knowledge. However, the respective contribution of these two sources of information is still controversial. This controversy stems in part from the fact that "intention" is an umbrella term that may embrace various sub-types each being assigned different scopes and targets. We hypothesized that variations in the scope and target of intentions may account for variations in the contribution of visual kinematics and prior knowledge to the intention inference process. To test this hypothesis, we conducted four behavioural experiments in which participants were instructed to identify different types of intention: basic intentions (i.e. simple goal of a motor act), superordinate intentions (i.e. general goal of a sequence of motor acts), or social intentions (i.e. intentions accomplished in a context of reciprocal interaction). For each of the above-mentioned intentions, we varied (1) the amount of visual information available from the action scene and (2) participant's prior expectations concerning the intention that was more likely to be accomplished. First, we showed that intentional judgments depend on a consistent interaction between visual information and participant's prior expectations. Moreover, we demonstrated that this interaction varied according to the type of intention to be inferred, with participant's priors rather than perceptual evidence exerting a greater effect on the inference of social and superordinate intentions. The results are discussed by appealing to the specific properties of each type of intention considered and further interpreted in the light of a hierarchical model of action representation.

The phenomenology of action: a conceptual framework.

After a long period of neglect, the phenomenology of action has recently regained its place in the agenda of philosophers and scientists alike. The recent explosion of interest in the topic highlights its complexity. The purpose of this paper is to propose a conceptual framework allowing for a more precise characterization of the many facets of the phenomenology of agency, of how they are related and of their possible sources. The key assumption guiding this attempt is that the processes through which the phenomenology of action is generated and the processes involved in the specification and control of action are strongly interconnected. I argue in favor of a three-tiered dynamic model of intention, link it to an expanded version of the internal model theory of action control and specification, and use this theoretical framework to guide an analysis of the contents, possible sources and temporal course of complementary aspects of the phenomenology of action.

The anarchic hand syndrome and utilization behavior: a window onto agentive self-awareness.

Two main approaches can be discerned in the literature on agentive self-awareness: a top-down approach, according to which agentive self-awareness is fundamentally holistic in nature and involves the operations of a central-systems narrator, and a bottom-up approach that sees agentive self-awareness as produced by lowlevel processes grounded in the very machinery responsible for motor production and control. Neither approach is entirely satisfactory if taken in isolation; however, the question of whether their combination would yield a full account of agentive self-awareness remains very much open. In this paper, I contrast two disorders affecting the control of voluntary action: the anarchic hand syndrome and utilization behavior. Although in both conditions patients fail to inhibit actions that are elicited by objects in the environment but inappropriate with respect to the wider context, these actions are experienced in radically different ways by the two groups of patients. I discuss how top-down and bottom-up processes involved in the generation of agentive self-awareness would have to be related in order to account for these differences.