Intentional binding and the sense of agency: A review

Preliminary evidence for a selective agency-boosting effect of psychosocial stress

Sense of Agency (SoA) arises from the perception of being in control of one's own actions and their outcomes. Many contextual and individual difference variables have been found to influence the SoA. Here, we focused on elucidating the potential relationship between psychosocial stress and the SoA across two studies. Psychosocial stress was induced via the Trier Social Stress Test (TSST) and agency was assessed in a task involving production of a voluntary action that resulted in an auditory effect 100 ms, 400 ms or 700 ms later. In Study 1, we used an explicit self-reported measure of agency in the form of a perception of control rating, and in Study 2 we used an implicit measure of agency in the form of temporal estimates of the interval between an action and an effect, so called intentional binding (IB). The results of Study 1 (explicit) showed that undergoing the TSST relative to a control condition increased SoA for outcomes that occur after a 700 ms delay. However, this effect was weak and did not survive correction for multiple comparisons. In Study 2 (IB), temporal estimates in the stress condition were significantly shorter than those in the control condition, exclusively for action-effect time delays of 700 ms. We conclude that this increased IB for 700 ms delays after induction of psychosocial stress reflects a potential "stress-enabled agency boost", and that such an agency boost might be associated with the fight-or-flight stress response. Directions for future research are suggested.

Neurocomputational Mechanisms of Sense of Agency: Literature Review for Integrating Predictive Coding and Adaptive Control in Human-Machine Interfaces

BACKGROUND

The sense of agency (SoA)-the subjective experience of controlling one's own actions and their consequences-is a fundamental aspect of human cognition, volition, and motor control. Understanding how the SoA arises and is disrupted in neuropsychiatric disorders has significant implications for human-machine interface (HMI) design for neurorehabilitation. Traditional cognitive models of agency often fail to capture its full complexity, especially in dynamic and uncertain environments.

OBJECTIVE

This review synthesizes computational models-particularly predictive coding, Bayesian inference, and optimal control theories-to provide a unified framework for understanding the SoA in both healthy and dysfunctional brains. It aims to demonstrate how these models can inform the design of adaptive HMIs and therapeutic tools by aligning with the brain's own inference and control mechanisms.

METHODS

I reviewed the foundational and contemporary literature on predictive coding, Kalman filtering, the Linear-Quadratic-Gaussian (LQG) control framework, and active inference. I explored their integration with neurophysiological mechanisms, focusing on the somato-cognitive action network (SCAN) and its role in sensorimotor integration, intention encoding, and the judgment of agency. Case studies, simulations, and XR-based rehabilitation paradigms using robotic haptics were used to illustrate theoretical concepts.

RESULTS

The SoA emerges from hierarchical inference processes that combine top-down motor intentions with bottom-up sensory feedback. Predictive coding frameworks, especially when implemented via Kalman filters and LQG control, provide a mechanistic basis for modeling motor learning, error correction, and adaptive control. Disruptions in these inference processes underlie symptoms in disorders such as functional movement disorder. XR-based interventions using robotic interfaces can restore the SoA by modulating sensory precision and motor predictions through adaptive feedback and suggestion. Computer simulations demonstrate how internal models, and hypnotic suggestions influence state estimation, motor execution, and the recovery of agency.

CONCLUSIONS

Predictive coding and active inference offer a powerful computational framework for understanding and enhancing the SoA in health and disease. The SCAN system serves as a neural hub for integrating motor plans with cognitive and affective processes. Future work should explore the real-time modulation of agency via biofeedback, simulation, and SCAN-targeted non-invasive brain stimulation.

Influence of AI behavior on human moral decisions, agency, and responsibility

There is a growing interest in understanding the effects of human-machine interaction on moral decision-making (Moral-DM) and sense of agency (SoA). Here, we investigated whether the "moral behavior" of an AI may affect both moral-DM and SoA in a military population, by using a task in which cadets played the role of drone operators on a battlefield. Participants had to decide whether or not to initiate an attack based on the presence of enemies and the risk of collateral damage. By combining three different types of trials (Moral vs. two No-Morals) in three blocks with three type of intelligent system support (No-AI support vs. Aggressive-AI vs. Conservative-AI), we showed that participants' decisions in the morally challenging situations were influenced by the inputs provided by the autonomous system. Furthermore, by measuring implicit and explicit agency, we found a significant increase in the SoA at the implicit level in the morally challenging situations, and a decrease in the explicit responsibility during the interaction with both AIs. These results suggest that the AI behavior influences human moral decision-making and alters the sense of agency and responsibility in ethical scenarios. These findings have implications for the design of AI-assisted decision-making processes in moral contexts.

Recalibration of perceived agency transfers across modalities

We experience our actions and their sensory consequences as synchronous despite small sensorimotor delays. This is attained by an adaptation process in which the sensorimotor system recalibrates temporal discrepancies between actions and their feedback, as long as causality is maintained (i.e. feedback follows action). Predictive motor mechanisms boost action-feedback binding, aiding in adaptation. Sensorimotor temporal recalibration is therefore closely linked with perceived control over the action and its sensory feedback (sense of agency, SoA). Interestingly, recalibration can also transfer to another sense, indicating a generalized mechanism that adjusts the timing of action-feedback events. It is unclear whether recalibration of perceived agency is driven by a similar mechanism. Here, we investigated cross-modal transfer of perceived agency and simultaneity in a sensorimotor recalibration task. In an adaptation phase, participants executed button presses leading to an immediate or lagged (150 ms) occurrence of a Gabor patch. Subsequently, they were asked to make simultaneity or agency judgements for action-feedback pairs (Gabor patch or tone) with variable response-stimulus asynchronies (RSAs). We found adaptation of synchrony and agency judgements with transfer of recalibration for agency judgements. Our findings suggest flexible recalibration of perceived agency, suggesting SoA is not inferred solely on a match with modality-specific motor predictions.

Does perceived voluntariness of others' actions induce vicarious sense of agency? Evidence from human-robot interaction

Sense of Agency (SoA) is the feeling of control over one's actions and outcomes. People can experience "vicarious" SoA towards other agents, either other humans or artificial agents such as robots. A commonly used measure of implicit SoA is the Intentional Binding (IB) effect, which is stronger when the action is voluntary, relative to involuntary. However, it remains unclear whether this is true also for vicarious SoA. Thus, in three experiments, participants performed an IB task alone and with another agent, namely with another human (Experiment 1) or with the humanoid robot iCub (Experiments 2 and 3). The co-agents' actions were presented as voluntary or involuntary- triggered by a mechanical device. Participants reported the time of occurrence of self-generated actions, as well as the other's human actions (Experiment 1), the robot actions (Experiment 2) or robot outcomes (Experiment 3). Experiment 1 showed that both self- and vicarious IB occurred only when the actions were voluntary. In Experiment 2, IB for self-actions occurred only when voluntary, but vicarious IB over iCub's actions occurred irrespective of whether the action was presented as "voluntary" or "involuntary". Experiment 3 showed that IB over tone outcomes occurred for self-generated and robot actions. Our findings suggest that voluntariness of actions plays a role in the emergence of the IB affect (and, by extension, of SoA) only if predictive processes are at play. They also indicate that vicarious IB for robots is based on postdictive processes, and this, perceived voluntariness of the robot actions does not modulate the vicarious IB effect for robots.

Temporal binding during deliberate rule breaking

Rules are deeply ingrained in our cognition. The current study investigates the influence of rule breaking on explicit sense of agency as well as the implicit perceptual illusion of temporal binding. Participants completed a free choice task that involved following or breaking a predetermined rule. The task required pressing a key that matched to a visual stimulus which triggered a corresponding change after a delay. Participants estimated the delay as an index of temporal binding. The results showed similar levels of explicit agency for rule following and breaking. Temporal binding, by contrast, was indeed influenced by rule breaking; however, the relationship is complex. Specifically, participants had smaller interval estimates for rule following vs. breaking at the 100 ms delay, likely reflecting cognitive conflict during rule breaking, whereas this effect reversed for the 400 ms and 700 ms delays. We interpret our results in relation to the wider rule breaking and temporal binding literature.

A gaze into the void: Anticipatory saccades toward prevented events

It is an open question how prevented events are represented in the human cognitive system-are they represented like produced events or are they represented in a different format? Here, we propose that seemingly contradictory observations on this question can be unified by assuming different time courses for production and prevention actions. Evidence from two experiments in the anticipatory saccades paradigm supported this model. Specifically, our results suggest that prevented events might be represented like produced events during action selection and execution, whereas their representation dissolves rapidly during action monitoring. In other words, the representation of prevented events reflects a two-step process: An initial affirmative representation is followed by later negation. Preregistrations, data, and analysis scripts for all experiments are available online ( https://osf.io/m3veh/ ).

Neural correlates of the sense of agency in free and coerced moral decision-making among civilians and military personnel

The sense of agency, the feeling of being the author of one's actions and outcomes, is critical for decision-making. While prior research has explored its neural correlates, most studies have focused on neutral tasks, overlooking moral decision-making. In addition, previous studies mainly used convenience samples, ignoring that some social environments may influence how authorship in moral decision-making is processed. This study investigated the neural correlates of sense of agency in civilians and military officer cadets, examining free and coerced choices in both agent and commander roles. Using a functional magnetic resonance imaging paradigm where participants could either freely choose or follow orders to inflict a mild shock on a victim, we assessed sense of agency through temporal binding-a temporal distortion between voluntary and less voluntary decisions. Our findings suggested that sense of agency is reduced when following orders compared to acting freely in both roles. Several brain regions correlated with temporal binding, notably the occipital lobe, superior/middle/inferior frontal gyrus, precuneus, and lateral occipital cortex. Importantly, no differences emerged between military and civilians at corrected thresholds, suggesting that daily environments have minimal influence on the neural basis of moral decision-making, enhancing the generalizability of the findings.

Temporal binding: Task-dependent variations and reliability across experimental paradigms

Temporal binding refers to the subjective shortening of time between a cause and its effect compared with two unrelated events. The effect has been extensively explored over the past two decades and manifests across a robust range of paradigms, reflecting two distinct expressions of binding: (1) the subjective shortening of elapsed time between cause and effect and (2) the subjective attraction of cause and effect to each other. However, whether and how these binding expressions are related is still largely unknown. In this study, we report two experiments, employing four tasks (stimulus anticipation, Libet clock, interval estimation, and reproduction). We computed within and between session and task correlations across two (Experiment 1) and six (Experiment 2) sessions. Across both experiments, we successfully replicated temporal binding in temporal estimation, temporal reproduction, and the Libet clock, but not in stimulus anticipation. Good within-task and within-session reliability were observed, but reliability between sessions was poor. Correlation analyses revealed associations between binding effects measured via temporal estimation and temporal reproduction, underscoring task-dependent variations, in line with the suggestion that different temporal tasks tap into distinct facets of the temporal binding effect. This nuanced understanding contributes to refining experimental paradigms and advancing the comprehension of human temporal processing. The data, materials, and experiments from the present study are publicly available.

Atypical Impact of Action Effect Delay on Motor Performance in Autism

Atypical sensory perception and motor impairments are primary features of autism spectrum disorder (ASD) that indicate atypical development and predict social and non-social challenges. However, their link is poorly understood. Sensory perception is often integrated with motor processes when a sensory effect is temporally contiguous with the motor response. Such sensory-motor coupling further improves motor behavior. Previous studies indicate alterations in sensory perception of action-effect temporal contiguity in ASD, which bares the question of how it may impact motor performance. People diagnosed with ASD and typically developed (TD) participants performed a speeded reaction-time task previously established to capture the facilitating impact of action's perceptual effect on motor response selection. The sensitivity of this mechanism to delays in the effect was measured, manipulating the action-effect temporal contiguity in a within-subject design. An immediate action effect (compared to a No-effect condition) facilitated response selection in the TD group. This facilitation effect was evident in the ASD group but did not show the typical sensitivity to the effect delay. While in the TD group, RT was shorter in the short (225ms) compared to the long (675ms) action effect delay condition, this distinguished pattern was absent in the ASD group. The findings provide supporting evidence that atypical motor performance in ASD results, at least in part, from an altered sensory perception of action effect temporal contiguity. We discuss the results in light of the reduced perceptual specialization account in ASD and its potential for undermining adaptive sensorimotor processes.

The time course of Temporal Binding in social and nonsocial interactions

Temporal Binding (TB) is the subjective compression of action-effect intervals. While the effects of nonsocial actions are highly predictable, it is not the case when interacting with conspecifics, who often act under their own volition, at a time of their choosing. Given the relative differences in action-effect predictability in non-social and social interactions, it is plausible that TB and its properties differ across these situations. To examine this, in two experiments, we compared the time course of TB in social and nonsocial interactions, systematically varying action-effect intervals (200-2,100 ms). Participants were told they were (a) interacting with another person via a live webcam, who was in fact a confederate (social condition), (b) interacting with pre-recorded videos (nonsocial condition), or (c) observing two pre-recorded videos (control condition; Experiment 2). Results across experiments showed greater TB for social compared to nonsocial conditions, and the difference was proportional to the action-effect intervals. Further, in Experiment 1, TB was consistently observed throughout the experiment for social interactions, whereas nonsocial TB decreased from the first to the second half of the experiment. In Experiment 2, the nonsocial condition did not differ from control, whereas the social condition did, exhibiting enhanced binding. We argue these results suggest that the sociality of an interaction modulates the 'internal clock' of time perception.

Atypical implicit and explicit sense of agency in autism: A complete characterization using the cue integration approach

There exist indications that sense of agency (SoA), the experience of being the cause of one's own actions and actions' outcomes, is altered in autism. However, no studies in autism have simultaneously investigated the integration mechanisms underpinning both implicit and explicit SoA, the two levels of agency proposed by the innovative cue integration approach. Our study establishes a first complete characterization of SoA functioning in autism, by comparing age- and IQ-matched samples of autistic versus neurotypical adults. Intentional binding and judgments of agency were used to assess implicit and explicit SoA over pinching movements with visual outcomes. Sensorimotor and contextual cues were manipulated using feedback alteration and induced belief about the cause of actions' outcome. Implicit SoA was altered in autism, as showed by an overall abolished intentional binding effect and greater inter-individual heterogeneity. At the explicit level, we observed under-reliance on retrospective sensorimotor cues. The implicit-explicit dynamic was also altered in comparison to neurotypical individuals. Our results show that both implicit and explicit levels of SoA, as well as the dynamic between the two levels, present atypicalities in autism.

Influence of subjective social class and social mobility beliefs on self-focused attention: the mediating role of sense of control

We verified whether social class shapes different models of the self in China, by integrating individuals' social mobility beliefs and exploring the mediating effect of sense of control. Participants were randomly assigned to one of 2 (subjective social class: upper vs. low class) × 2 (social mobility beliefs: high vs. low mobility) manipulation conditions. They then completed the sense of control questionnaire and self-focused attention task. High mobility belief could alleviate the difference in perception among different subjective social classes and improve lower classes' control perception. Sense of control mediates subjective social class effects and social mobility beliefs on self-focused attention.

Visual information shows dominance in determining the magnitude of intentional binding for audiovisual outcomes

Intentional binding (IB) refers to the compression of subjective timing between a voluntary action and its outcome. In this study, we investigate the IB of a multimodal (audiovisual) outcome. We used a modified Libet clock while depicting a dynamic physical event (collision). Experiment 1 examined whether IB for the unimodal (auditory) event could be generalized to the multimodal (audiovisual) event, compared their magnitudes, and assessed whether the level of integration between modalities could affect IB. Planned contrasts (n = 42) showed significant IB effects for all types of events; the magnitude of IB was significantly weaker in both audiovisual integrated and audiovisual irrelevant conditions compared with auditory, with no difference between the integrated and irrelevant conditions. Experiment 2 separated the components of the audiovisual event to test the appropriate model describing the magnitude of IB in multimodal contexts. Planned contrasts (n = 42) showed the magnitude of IB was significantly weaker in both the audiovisual and visual conditions compared with the auditory condition, with no difference between the audiovisual and visual conditions. Additional Bayesian analysis provided moderate evidence supporting the equivalence between the two conditions. In conclusion, this study demonstrated that the IB phenomenon can be generalized to multimodal (audiovisual) sensory outcomes, and visual information shows dominance in determining the magnitude of IB for audiovisual events.

The impact of the degree of action voluntariness on sense of agency in saccades

Experiencing a sense of agency (SoA), the feeling of being in control over one's actions and their outcomes, typically requires intentional and voluntary actions. Prior research has compared the association of voluntary versus completely involuntary actions with the SoA. Here, we leveraged unique characteristics of oculomotor actions to partially manipulate the degree of action voluntariness. Participants performed either highly automatized prosaccades or highly controlled (voluntary) anti-saccades, triggering a gaze-contingent visual action effect. We assessed explicit SoA ratings and temporal action and effect binding as an implicit SoA measure. Anti-saccades were associated with stronger action binding compared to prosaccades, demonstrating a robust association between higher action voluntariness and a stronger implicit sense of action agency. We conclude that our manipulation of action voluntariness may have impacted the implicit phenomenological feeling of bodily agency, but it did not affect the SoA over effect outcomes or explicit agency perception.

Validation of the Italian Sense of Agency Scale and Its Relevance to Well-Being: An Iterative Bootstrap Approach

The Sense of Agency (SoA) refers to the subjective experience of controlling one's actions and the external events resulting from those actions. This study aimed to critically evaluate the construct validity, robustness, and clinical utility of the Sense of Agency Scale (SoAS) in an Italian-speaking population, using a data-driven approach to explore potential factor structures. A sample of 992 adults completed the SoAS alongside other validated psychological measures, allowing for a comprehensive analysis of the scale's psychometric properties. An iterative process of exploratory and confirmatory factor analyses (EFA and CFA) was implemented to assess both two-factor and bifactor models. A refined 10-item version of the SoAS was established, comprising two distinct factors: Sense of Positive Agency (SoPA, five items) and Sense of Negative Agency (SoNA, five items). The results favored a two-factor solution supported by satisfying fit indices, factor loadings, and stability. The revised scale demonstrated strong internal consistency, with McDonald's omega values of 0.79 (SoNA) and 0.87 (SoPA). This study extends the literature by providing evidence of the scale's convergent and divergent validity, with significant correlations in the expected directions with constructs such as sense of self, hopelessness, impulsiveness, psychosis-like experiences, and schizotypal traits. These findings support the revised SoAS as a reliable and valid measure for assessing the Sense of Agency and highlight its broader applicability in understanding psychological and psychopathological constructs.

Self-other distinction modulates the sense of self-agency during joint actions

In daily life interactions, we achieve goals with partners through tight temporal coordination or sequential joint efforts. Is our individual sense of control over shared outcomes (sense of self-agency) the same as the one experienced when we act alone? Do we explicitly and implicitly feel like we are fully in control of the motor act even if the goal is finally achieved by our partner? To address these questions, we measured explicit and implicit sense of self-agency in individual and (coordinated or sequential) interactive contexts. We studied 42 healthy adult participants during active/passive button presses aimed at turning on a light bulb. This goal could be achieved individually (Solo condition) or by interacting with a partner (Joint condition) synchronously (joint Coordination task) or sequentially (joint Sequential task). We collected trial-by-trial explicit judgments of self-agency. To quantify the intentional binding phenomenon, an index of implicit sense of agency, we also measured the perceived compression of the time interval between the active or passive movements and their outcomes. Explicit sense of agency: we observed decreased judgments of self-agency in Joint trials compared with the Solo ones in both the Coordination and Sequential tasks. Implicit sense of agency: in the Coordination task, we found a significant intentional binding effect only in Solo trials but not in Joint ones. For the Sequential task, however, a significant intentional binding was also present in the Joint condition. Our results indicate that the individual sense of agency is reduced during joint actions, yet this can be restored at an implicit level when the format of the motor interaction makes the individual contribution to goal achievement more obvious. We discuss these results considering current cognitive theories on motor awareness and interactions.

Previous experience of action-effect predictability and delay affect perceived agency and decision-making independently

The possible cognitive effect of sense of agency (SoA) has attracted increasing attention. Previous findings suggest that SoA has an effect on action control, time perception, and memory. Here we investigated whether SoA can also influence decision-making. We conducted two experiments, in which we induced high or low predictability by manipulating the contingency between keypresses (action) and ball movements (effect), before assessing SoA and risk-taking (in Experiment 1); and induced both predictability and short or long time delay of action-effect, before assessing SoA, risk-taking, and intertemporal decision-making (in Experiment 2). Higher predictability increased SoA and promoted risk-taking, but did not impact intertemporal decision-making; Shorter delay increased SoA and promoted Larger-Later options, but did not impact risk-taking decision-making. While our findings suggest that some decision-making processes are affected by the same factors as SoA is, we did not find any evidence for any direct impact of SoA on decision-making.

The Body Knows Better: Sensorimotor signals reveal the interplay between implicit and explicit Sense of Agency in the human mind

Sense of Agency (SoA) is the feeling of control over our actions. SoA has been suggested to arise from both implicit sensorimotor integration as well as higher-level decision processes. SoA is typically measured by collecting participants' subjective judgments, conflating both implicit and explicit processing. Consequently, the interplay between implicit sensorimotor processing and explicit agency judgments is not well understood. Here, we evaluated in one exploratory and one preregistered experiment (N = 60), using a machine learning approach, the relation between a well-known mechanism of implicit sensorimotor adaptation and explicit SoA judgments. Specifically, we examined whether subjective judgments of SoA and sensorimotor conflicts could be inferred from hand kinematics in a sensorimotor task using a virtual hand (VH). In both experiments participants performed a hand movement and viewed a virtual hand making a movement that could either be synchronous with their action or include a parametric temporal delay. After each movement, participants judged whether their actual movement was congruent with the movement they observed. Our results demonstrated that sensorimotor conflicts could be inferred from implicit motor kinematics on a trial by trial basis. Moreover, detection of sensorimotor conflicts from machine learning models of kinematic data provided more accurate classification of sensorimotor congruence than participants' explicit judgments. These results were replicated in a second, preregistered, experiment. These findings show evidence of diverging implicit and explicit processing for SoA and suggest that the brain holds high-quality information on sensorimotor conflicts that is not fully utilized in the inference of conscious agency.

Social exclusion in a virtual Cyberball game reduces the virtual hand illusion

Sense of ownership and agency are two important aspects of the minimal self, but how self-perception is affected by social conditions remains unclear. Here, we studied how social inclusion or exclusion of participants in the course of a virtual Cyberball game would affect explicit judgments and implicit measures of ownership and agency (proprioceptive drift, skin conductance responses, and intentional binding, respectively) in a virtual hand illusion paradigm, in which a virtual hand moved in or out of sync with the participants' own hand. Results show that synchrony affected all four measures. More importantly, this effect interacted with social inclusion/exclusion in the Cyberball game for both ownership and agency measure, showing that social exclusion reduces perceived agency and ownership.

Rejecting unfairness enhances the implicit sense of agency in the human brain

Sense of agency (SoA) describes the feeling of control over one's actions and their consequences. One proposed index of implicit SoA is temporal compression, which refers to the phenomenon that voluntary actions and their outcomes are perceived as closer in time than they actually are. The present study measured temporal compression in the social norm violation situation. In two experiments participants joined in an Ultimatum game (UG), in which they were presented with offers that varied in fairness and they could choose to accept or reject the offers by pressing buttons. A neutral sound would occur after their choices in the UG and the participants had to estimate the time interval between their button pressing and the occurrence of the sound, and EEG signals were recorded during the task. Experiment 1 demonstrated that rejecting unfair offers decreased the perceived interval between action and outcome compared to accepting fair offers, suggesting a higher level of SoA after rejecting unfair offers. Experiment 2 replicated these results and further revealed an attenuated N1 in response to the sound following rejections of unfairness. Taken together, these results highlight the importance of social norms in affecting people's behaviors and agency experiences.

Disturbance at the self-other boundary in schizophrenia: Linking phenomenology to clinical neuroscience

In this selective review, we describe the current neuroscientific literature on disturbances of the self-other boundary in schizophrenia as they relate to structural and experiential aspects of the self. Within these two broad categories, the structural self includes body ownership and agency, and the experiential self includes self-reflection, source monitoring, and self-referential and autobiographical memory. Further, we consider how disturbances in these domains link to the phenomenology of schizophrenia. We identify faulty internal predictive coding as a potential mechanism of disturbance in body ownership and agency, which results in susceptibility to bias (over- or under-attributing outcomes to one's own actions or intentions). This is reflected in reduced activity in the temporoparietal junction (TPJ), a heteromodal association area implicated in several aspects of self-other processing, as well as reduced fronto-parietal functional connectivity. Deficits of the experiential self in schizophrenia may stem from a lack of salience of self-related information, whereby the mental representation of self is not as rich as in healthy controls and therefore does not result in the same level of privileged processing. As a result, memory for self-referential material and autobiographical memory processes is impaired, which hinders creation of a cohesive life narrative. Impairments of the experiential self implicate abnormal activation patterns along the cortical midline, including medial prefrontal cortex and posterior cingulate/precuneus, as well as TPJ. In fact, TPJ appears to be involved in all the reviewed aspects of the self-other disturbance. We conclude with suggestions for future work, including implications for interventions with critical timing considerations.

The effect of electrical muscle stimulation on intentional binding and explicit sense of agency

The motivating question for this study is determining whether electrical muscle stimulation (EMS)-induced movements can extend the user's ability without reducing the sense of agency. Moreover, it is crucial to find the timing of the EMS application that is robust against individual differences and environmental changes. Previous studies have reported that the user-specific EMS-application timings, determined through explicit measures of sense of agency, would effectively shorten their reaction time in a push task while maintaining their sense of agency. However, no study has investigated EMS-application timings in relation to implicit measures of sense of agency. Intentional binding, an example of an implicit measure, refers to the phenomenon whereby the interval between an intentional action and the subsequent perceptual outcome is typically perceived to be shorter than the actual interval. By measuring this perceptual shift using a Libet clock, we have identified an EMS-application timing that accelerates the users' push action while maintaining their sense of agency. First, to conduct the EMS-application experiment while appropriately maintaining the intentional binding effect, we designed a new push task such that a pre-action, as the base timing of the EMS-application trigger, always occurs just before the push movement. (1) We showed the difference between the action-binding effect of EMS-induced involuntary movements and voluntary push movements. Subsequently, (2) we identified the EMS application timing that significantly shifted judgments of action tasks while accelerating voluntary movements. Additionally, (3) we demonstrated that the EMS application could accelerate user pushing movement while maintaining the sense of agency at this specific application time. The proposed EMS in the novel pushing setup was found to be robustly effective against individual and environmental changes.

Sense of agency at a temporally-delayed gaze-contingent display

The subjective feeling of being the author of one's actions and the subsequent consequences is referred to as a sense of agency. Such a feeling is crucial for usability in human-computer interactions, where eye movement has been adopted, yet this area has been scarcely investigated. We examined how the temporal action-feedback discrepancy affects the sense of agency concerning eye movement. Participants conducted a visual search for an array of nine Chinese characters within a temporally-delayed gaze-contingent display, blurring the peripheral view. The relative delay between each eye movement and the subsequent window movement varied from 0 to 4,000 ms. In the control condition, the window played a recorded gaze behavior. The mean authorship rating and the proportion of "self" responses in the categorical authorship report ("self," "delayed self," and "other") gradually decreased as the temporal discrepancy increased, with "other" being rarely reported, except in the control condition. These results generally mirror those of prior studies on hand actions, suggesting that sense of agency extends beyond the effector body parts to other modalities, and two different types of sense of agency that have different temporal characteristics are simultaneously operating. The mode of fixation duration shifted as the delay increased under 200-ms delays and was divided into two modes at 200-500 ms delays. The frequency of 0-1.5° saccades exhibited an increasing trend as the delay increased. These results demonstrate the influence of perceived action-effect discrepancy on action refinement and task strategy.

Measuring general sense of agency: a Japanese adaptation and validation of the sense of agency scale (J-SoAS)

The Sense of Agency (SoA) refers to the individual's perception of control over actions and their subsequent impact on the external environment. SoA encompasses multiple dimensions, such as implicit/local and explicit/general, which can be quantitatively assessed through cognitive tasks and psychometric questionnaires, respectively. The explicit and general aspect of SoA is commonly evaluated using the Sense of Agency Scale (SoAS). This study's objective is to adapt and validate a Japanese version of the Tapal-SoAS. To achieve this, we distributed an online survey in three stages, gathering data from 8,237 Japanese participants aged between their 20s and 60s. Our analysis confirmed the bifactorial structure identified in the original study: the Sense of Positive Agency (SoPA) and the Sense of Negative Agency (SoNA). Metrics pertaining to test-retest reliability, internal consistency, and construct validity reached satisfactory thresholds. Furthermore, the two-factor models demonstrated suitable fit across various age cohorts. The Japanese version of the SoAS (J-SoAS) shows potential for cross-cultural comparisons of explicit and general SoA, particularly between Western and Eastern populations, and among distinct age groups, including young adults and the elderly.

How aging shapes our sense of agency

The sense of agency refers to the feeling of controlling one's actions and their effects on the external environment. Here, we tested how the physiological process of aging affects the agency experience by taking advantage of a validated ecological experimental paradigm and exploring the different dimensions of agency. We tested 60 young and older adults during active and passive movements, causing, after a variable time delay, an external sensorial event. We collected overt agency judgments (i.e., explicit agency dimension), and we measured the perceived compression of the time interval between the active/passive movements and outcomes (to quantify the intentional binding phenomenon, an implicit index of agency). Our results indicate that the sense of agency significantly changes across the adult life span, with older participants exhibiting a reduced sense of agency, both at the explicit and implicit level. Crucially, the temporal dimension of the action outcome did not affect their agency experience. We suggest that elderly adults are more reliant on internal predictions, making them less sensitive to cognitive biases and external manipulations. We discuss these results in the domain of neurocognitive models of motor control, with reference to how aging affects the weighting process of predictive and sensory signals for efficient sensorimotor integration.

An investigation of the experience of control through the sense of agency in people with obsessive-compulsive disorder: a review and meta-analysis

The construct of sense of agency (SoA) has proven useful for understanding mechanisms underlying obsessive-compulsive disorder (OCD) phenomenology, especially in explaining the apparent dissociation in OCD between actual and perceived control over one's actions. Paradoxically, people with OCD appear to experience both diminished SoA (feeling unable to control their actions) and inflated SoA (having "magical" control over events). The present review investigated the extent to which the SoA is distorted in OCD, in terms of both implicit (ie, inferred from correlates and outcomes of voluntary actions) and explicit (ie, subjective judgment of one's control over an outcome) measures of SoA. Our search resulted in 15 studies that met the criteria for inclusion in a meta-analysis, where we also examined the potential moderating effects of the type of measure (explicit versus implicit) and of the actual control participants had over the outcome. We found that participants with OCD or with high levels of OCD symptoms show lower implicit measures of SoA and at the same time tend to overestimate their control in situations where they do not actually have it. Together, these findings support the hypothesized dissociation in OCD between actual and perceived control over one's actions.

Choice effects on temporal binding of action and outcomes: Examining the role of outcome focus and measures of time interval estimation

The ability to make one's own choices is vital to the experience of intentional behavior. Such agency experiences are reflected in the perceptual compression of time between actions and resulting outcomes. Whereas some studies show that choice limitations weaken temporal binding, other studies do not find such an effect. Reviewing the literature, we noted two potential factors that may moderate choice limitation effects on temporal binding: (a) the extent to which individuals represent their actions in terms of the consequences they produce; and (b) the response mode of the time interval estimation measurement where participants report numbers or use a slider to indicate time intervals. Testing these conceptual and methodological factors in two separate experiments yielded clear effects of choice limitation on temporal binding but no clear moderator role of the two factors. Interestingly, overall analyses showed that the choice limitation effect gradually vanishes over time.

Intentional binding for noninvasive BCI control

Objective. Noninvasive brain-computer interfaces (BCIs) allow to interact with the external environment by naturally bypassing the musculoskeletal system. Making BCIs efficient and accurate is paramount to improve the reliability of real-life and clinical applications, from open-loop device control to closed-loop neurorehabilitation.Approach. By promoting sense of agency and embodiment, realistic setups including multimodal channels of communication, such as eye-gaze, and robotic prostheses aim to improve BCI performance. However, how the mental imagery command should be integrated in those hybrid systems so as to ensure the best interaction is still poorly understood. To address this question, we performed a hybrid EEG-based BCI training involving healthy volunteers enrolled in a reach-and-grasp action operated by a robotic arm.Main results. Showed that the hand grasping motor imagery timing significantly affects the BCI accuracy evolution as well as the spatiotemporal brain dynamics. Larger accuracy improvement was obtained when motor imagery is performed just after the robot reaching, as compared to before or during the movement. The proximity with the subsequent robot grasping favored intentional binding, led to stronger motor-related brain activity, and primed the ability of sensorimotor areas to integrate information from regions implicated in higher-order cognitive functions.Significance. Taken together, these findings provided fresh evidence about the effects of intentional binding on human behavior and cortical network dynamics that can be exploited to design a new generation of efficient brain-machine interfaces.

Obedience induces agentic shifts by increasing the perceived time between own action and results

The concept of 'agentic shift,' introduced by Stanley Milgram, suggests that obedience reduces the sense of agency. In a recent study simulating the seminal work of Milgram, Caspar et al., 2016 examined this idea in a financial harm context. They demonstrated that, compared to situations of voluntary decision-making, coercion increases the perceived time between action and outcomes-suggested as a marker of diminished agency. Importantly, in this study, participants were agent and victim (relying on a reciprocal relationship) and first experienced free choices, followed by forced choices. This diverts from Milgram's original study, where participants were no victims but only agents who were forced to harm. The current study replicates and extends findings from the 2016 study by Caspar et al. in an online meeting setting, where participants served only as agents-similar to the original Milgram studies-while controlling the order of free and forced choice blocks. Substantiating earlier findings, forced choices reduced temporal binding (increased time interval estimations) compared to free choices independent of the order. We briefly discuss the importance of replications of coercion effects on the sense of agency, particularly in online decision-making settings.

Explicit and implicit sense of agency in depersonalisation experiences

The sense of agency, the feeling of controlling one's bodily actions and the world is altered in Depersonalisation (DP), a condition that makes people feel detached from one's self and body. To investigate the link between depersonalisation and both implicit and explicit sense of agency, an online study was conducted using the influential Intentional Binding paradigm in a sample of non-clinical DP participants. The results did not reveal significant differences between individuals with low and high occurrences of DP experiences on the implicit and explicit sense of agency. However, participants with high occurrences of DP experiences showed a more time-sensitive explicit sense of agency and greater temporal distortions for short intervals in the absence of self-initiated motion. These results suggest that there is a discrepancy between implicit and explicit sense of agency in people with high levels of depersonalisation. Altogether, these findings call for further investigations of the key role of time perception on altered sense of self and agency in both non-clinical and clinical populations, to disentangle the mechanisms associated with the explicit and implicit sense of agency.

Enhancing Agency in Posttraumatic Stress Disorder Therapies Through Sensorimotor Technologies

Posttraumatic stress disorder (PTSD) is a significant public health concern, with only a third of patients recovering within a year of treatment. While PTSD often disrupts the sense of body ownership and sense of agency (SA), attention to the SA in trauma has been lacking. This perspective paper explores the loss of the SA in PTSD and its relevance in the development of symptoms. Trauma is viewed as a breakdown of the SA, related to a freeze response, with peritraumatic dissociation increasing the risk of PTSD. Drawing from embodied cognition, we propose an enactive perspective of PTSD, suggesting therapies that restore the SA through direct engagement with the body and environment. We discuss the potential of agency-based therapies and innovative technologies such as gesture sonification, which translates body movements into sounds to enhance the SA. Gesture sonification offers a screen-free, noninvasive approach that could complement existing trauma-focused therapies. We emphasize the need for interdisciplinary collaboration and clinical research to further explore these approaches in preventing and treating PTSD.

Self-ownership, not self-production, modulates bias and agency over a synthesised voice

Voices are fundamentally social stimuli, and their importance to the self may be underpinned by how far they can be used to express the self and achieve communicative goals. This paper examines how self-bias and agency over a synthesised voice is altered when that voice is used to represent the self in social interaction. To enable participants to use a new voice, a novel two-player game was created, in which participants communicated online using a text-to-speech (TTS) synthesised voice. We then measured self-bias and sense of agency attributed to this synthesised voice, comparing participants who had used their new voice to interact with another person (n = 44) to a control group of participants (n = 44) who had been only briefly exposed to the voices. We predicted that the new, synthesised self-voice would be more perceptually prioritised after it had been self-produced. Further, that participants' sense of agency over the voice would be increased, if they had experienced self-producing the voice, relative to those who only owned it. Contrary to the hypothesis, the results indicated that both experimental participants and control participants similarly prioritised the new synthesised voice and experienced a similar degree of agency over it, relative to voices owned by others. Critically then, being able to produce the new voice in a social interaction did not modulate bias towards it nor participant's sense of agency over it. These results suggest that merely having ownership over a new voice may be sufficient to generate a perceptual bias and a sense of agency over it.

Temporal binding and sense of agency in major depression

Background

Alterations in the experience of controlling oneself and one's environment are of high relevance to understanding the psychopathology of depression. This study investigated the relationship between Temporal Binding for action-event sequences, sense of agency, self-efficacy and symptom severity in Major Depressive Disorder.

Method

We employed the Sense of Agency Scale (SoAS) and the General Self-Efficacy Scale (GSE) to assess explicit Sense of Agency and self-efficacy in a group of 42 persons diagnosed with Major Depressive Disorder (MDD) [20 identifying as female, 19 as male; mean age 37.8 years (± 13.3)] and 40 control persons without a psychiatric diagnosis (CG) [22 identifying as female, 20 as male; mean age 38.0 years ( ± 13.3)]. Depressive symptom severity was measured using the BDI-II. We additionally performed a temporal binding paradigm as a potential correlate to Sense of Agency. Participants partook in a time estimation task judging three intervals (250ms, 450ms, 650ms) while either observing or causing stimulus presentations. The underestimation of intervals following intentional actions causing stimulus presentations (compared to merely observing the stimulus presentation) is interpreted as temporal binding.

Results

SoAS scores demonstrated an inverse correlation with depressive symptoms (CG: p=.032, R2=.113; MDD: p<.001, R2=.260) and a positive correlation with GSE scores (CG: p<.001, R2=.379; MDD: p<.001, R2=.254). We found distinct differences in temporal binding between healthy participants and the Major Depressive Disorder group without significant correlation between temporal binding and the SoAS or GSE scores. The data suggest group differences in time estimation particular pertaining to time intervals involving intentional action and increasingly complex multisensory stimuli.

Discussion

We investigated parameters of subjective control, namely Sense of Agency and Self Efficacy. Here, we were able to reveal their inverse relationship with depressive symptoms in patients with major depressive disorder, highlighting a profound experience of loss of control with increasing symptom load. Deficits in experiencing control, particularly involving intentional motor actions (and more complex multisensory stimuli), appear to be more pronounced in Major Depressive Disorder, involving not only negative self-efficacy expectations but also an altered Sense of Agency and temporal binding. Temporal binding and SoAS scores did not correlate, adding to the growing evidence that the two measures may not be directly related. We propose that future research be directed at this contiguous relationship between Sense of Agency and Self Efficacy in Major Depressive Disorder.

You do you: susceptibility of temporal binding to self-relevance

The self-prioritization effect suggests that self-relevant information has a processing advantage over information that is not directly associated with the self. In consequence, reaction times are faster and accuracy rates higher when reacting to self-associated stimuli rather than to other-related stimuli (Sui et al., Journal of Experimental Psychology: Human Perception and Performance 38:1105-1117, 2012). This spurs the assumption that self-associated action-effects should also be perceived earlier than other-related outcomes. One way to measure this is temporal binding. Previous research indeed showed that the perceived temporal interval between actions and self-associated outcomes was reduced compared to friend- and other-associated outcomes. However, the employed method (interval estimations) and several experimental design choices make it impossible to discern whether the perceived shortening of the interval between a keypress and a self-relevant outcome is due to a perceptual shift of the action or of the action-effect or both. Thus, we conducted four experiments to assess whether temporal binding can indeed be modulated by self-relevance and if so where this perceptual bias is located. The results did not support stronger temporal binding for self- vs other-related action-effects. We discuss these results against the backdrop of the attentional basis of self-prioritization and propose directions for future research.

The sense of agency in near and far space

The sense of agency is the ability to recognize that we are the actors of our actions and their consequences. We explored whether and how spatial cues may modulate the agency experience by manipulating the ecological validity of the experimental setup (real-space or computer-based setup) and the distance of the action-outcome (near or far). We tested 58 healthy adults collecting explicit agency judgments and the perceived time interval between movements and outcomes (to quantify the intentional binding phenomenon, an implicit index of agency). Participants show greater implicit agency for voluntary actions when there is a temporal and spatial action-outcome contingency. Conversely, participants reported similar explicit agency for outcomes appearing in the near and far space. Notably, these effects were independent of the ecological validity of the setting. These results suggest that spatial proximity, realistic or illusory, is essential for feeling implicitly responsible for the consequences of our actions.

When time does not matter: cultures differ in their use of temporal cues to infer agency over action effects

Sense of agency (SoA) is the sense of having control over one's own actions and through them events in the outside world. Sometimes temporal cues, that is temporal contiguity between action and effect, or temporal expectation regarding the occurrence of the effect are used to infer whether one has agency over an effect. This has mainly been investigated in Western cultures. However, Western and Eastern cultures differ in their time concepts and thus their usage of temporal cues may also differ. We investigated whether Western and Eastern cultures (Austrian vs. Mongolian students) use temporal cues differently. Participants performed adaption blocks in which actions were followed by immediate (immediate effect group) or by delayed (delayed effect group) effects. In subsequent test blocks the action-effect delay was varied and participants' SoA over the effect was assessed. In Austrian students, the immediate effect group experienced more SoA for short action-effect delays, whereas the reverse was true for the delayed effect group. Thus, temporal expectation rather than temporal contiguity is used as predominant agency cue. In Mongolian students, SoA did not significantly differ between different action-effect delays in both groups, indicating that Mongolian students hardly rely on temporal cues. In conclusion, due to linear time concepts in Western cultures, the timing of an effect may be an important agency cue in Austrian students. However, due to cyclical time concepts in some Eastern cultures, it may be a less important agency cue in Mongolian students. Thus, the use of temporal agency cues is culture-dependent.

Numerosity estimation of virtual humans as a digital-robotic marker for hallucinations in Parkinson's disease

Hallucinations are frequent non-motor symptoms in Parkinson's disease (PD) associated with dementia and higher mortality. Despite their high clinical relevance, current assessments of hallucinations are based on verbal self-reports and interviews that are limited by important biases. Here, we used virtual reality (VR), robotics, and digital online technology to quantify presence hallucination (vivid sensations that another person is nearby when no one is actually present and can neither be seen nor heard) in laboratory and home-based settings. We establish that elevated numerosity estimation of virtual human agents in VR is a digital marker for experimentally induced presence hallucinations in healthy participants, as confirmed across several control conditions and analyses. We translated the digital marker (numerosity estimation) to an online procedure that 170 PD patients carried out remotely at their homes, revealing that PD patients with disease-related presence hallucinations (but not control PD patients) showed higher numerosity estimation. Numerosity estimation enables quantitative monitoring of hallucinations, is an easy-to-use unobtrusive online method, reaching people far away from medical centers, translating neuroscientific findings using robotics and VR, to patients' homes without specific equipment or trained staff.

Intentional binding - Is it just causal binding? A replication study of Suzuki et al. (2019)

Intentional actions produce a temporal compression between the action and its outcome, known as intentional binding. However, Suzuki et al. (2019) recently showed that temporal compression can be observed without intentional actions. However, their results show a clear regression to the mean, which might have confounded the estimates of temporal intervals. To control these effects, we presented temporal intervals block-wise. Indeed, we found systematically greater compression for active than passive trials, in contrast to Suzuki et al. (2019). In our second experiment, our goal was to conceptually replicate the previous study. However, we were unable to reproduce their results and instead found more pronounced temporal compression in active trials compared to passive ones. In a subsequent attempt at a direct replication, we did not observe the same findings as the original study. Our findings reinforce the theory that intentions rather than causality cause temporal binding. During the preparation of this work, the authors used ChatGPT in order to improve the readability of the paper. After using this tool/service, the authors reviewed and edited the content as needed and take full responsibility for the content of the publication.

Eye did this! Sense of agency in eye movements

This study investigates the sense of agency (SoA) for saccades with implicit and explicit agency measures. In two eye tracking experiments, participants moved their eyes towards on-screen stimuli that subsequently changed color. Participants then either reproduced the temporal interval between saccade and color-change (Experiment 1) or reported the time points of these events with an auditory Libet clock (Experiment 2) to measure temporal binding effects as implicit indices of SoA. Participants were either made to believe to exert control over the color change or not (agency manipulation). Explicit ratings indicated that the manipulation of causal beliefs and hence agency was successful. However, temporal binding was only evident for caused effects, and only when a sufficiently sensitive procedure was used (auditory Libet clock). This suggests a feebler connection between temporal binding and SoA than previously proposed. The results also provide evidence for a relatively fast acquisition of sense of agency for previously never experienced types of action-effect associations. This indicates that the underlying processes of action control may be rooted in more intricate and adaptable cognitive models than previously thought. Oculomotor SoA as addressed in the present study presumably represents an important cognitive foundation of gaze-based social interaction (social sense of agency) or gaze-based human-machine interaction scenarios. PUBLIC SIGNIFICANCE STATEMENT: In this study, sense of agency for eye movements in the non-social domain is investigated in detail, using both explicit and implicit measures. Therefore, it offers novel and specific insights into comprehending sense of agency concerning effects induced by eye movements, as well as broader insights into agency pertaining to entirely newly acquired types of action-effect associations. Oculomotor sense of agency presumably represents an important cognitive foundation of gaze-based social interaction (social agency) or gaze-based human-machine interaction scenarios. Due to peculiarities of the oculomotor domain such as the varying degree of volitional control, eye movements could provide new information regarding more general theories of sense of agency in future research.

A spatial-attentional mechanism underlies action-related distortions of time judgment

Temporal binding has been understood as an illusion in timing judgment. When an action triggers an outcome (e.g. a sound) after a brief delay, the action is reported to occur later than if the outcome does not occur, and the outcome is reported to occur earlier than a similar outcome not caused by an action. We show here that an attention mechanism underlies the seeming illusion of timing judgment. In one method, participants watch a rotating clock hand and report event times by noting the clock hand position when the event occurs. We find that visual spatial attention is critically involved in shaping event time reports made in this way. This occurs because action and outcome events result in shifts of attention around the clock rim, thereby biasing the perceived location of the clock hand. Using a probe detection task to measure attention, we show a difference in the distribution of visual spatial attention between a single-event condition (sound only or action only) and a two-event agency condition (action plus sound). Participants accordingly report the timing of the same event (the sound or the action) differently in the two conditions: spatial attentional shifts masquerading as temporal binding. Furthermore, computational modeling based on the attention measure can reproduce the temporal binding effect. Studies that use time judgment as an implicit marker of voluntary agency should first discount the artefactual changes in event timing reports that actually reflect differences in spatial attention. The study also has important implications for related results in mental chronometry obtained with the clock-like method since Wundt, as attention may well be a critical confounding factor in the interpretation of these studies.

Evaluating the Bayesian causal inference model of intentional binding through computational modeling

Intentional binding refers to the subjective compression of the time interval between an action and its consequence. While intentional binding has been widely used as a proxy for the sense of agency, its underlying mechanism has been largely veiled. Bayesian causal inference (BCI) has gained attention as a potential explanation, but currently lacks sufficient empirical support. Thus, this study implemented various computational models to describe the possible mechanisms of intentional binding, fitted them to individual observed data, and quantitatively evaluated their performance. The BCI models successfully isolated the parameters that potentially contributed to intentional binding (i.e., causal belief and temporal prediction) and generally better explained an observer's time estimation than traditional models such as maximum likelihood estimation. The estimated parameter values suggested that the time compression resulted from an expectation that the actions would immediately cause sensory outcomes. Furthermore, I investigated the algorithm that realized this BCI and found probability-matching to be a plausible candidate; people might heuristically reconstruct event timing depending on causal uncertainty rather than optimally integrating causal and temporal posteriors. The evidence demonstrated the utility of computational modeling to investigate how humans infer the causal and temporal structures of events and individual differences in that process.

Libet's legacy: A primer to the neuroscience of volition

The neuroscience of volition is an emerging subfield of the brain sciences, with hundreds of papers on the role of consciousness in action formation published each year. This makes the state-of-the-art in the discipline poorly accessible to newcomers and difficult to follow even for experts in the field. Here we provide a comprehensive summary of research in this field since its inception that will be useful to both groups. We also discuss important ideas that have received little coverage in the literature so far. We systematically reviewed a set of 2220 publications, with detailed consideration of almost 500 of the most relevant papers. We provide a thorough introduction to the seminal work of Benjamin Libet from the 1960s to 1980s. We also discuss common criticisms of Libet's method, including temporal introspection, the interpretation of the assumed physiological correlates of volition, and various conceptual issues. We conclude with recent advances and potential future directions in the field, highlighting modern methodological approaches to volition, as well as important recent findings.

Sense of agency in joint action: a critical review of we-agency

The sense of agency refers to the experience of control over voluntary actions and their effects. There is growing interest in the notion of we-agency, whereby individual sense of agency is supplanted by a collective agentic experience. The existence of this unique agentic state would have profound implications for human responsibility, and, as such, warrants further scrutiny. In this paper, we review the concept of we-agency and examine whether evidence supports it. We argue that this concept entails multiplying hypothetical agentic states associated with joint action, thus ending up with an entangled phenomenology that appears somewhat speculative when weighted against the available evidence. In light of this, we suggest that the concept of we-agency should be abandoned in favor of a more parsimonious framework for the sense of agency in joint action.

Neural correlates of an illusionary sense of agency caused by virtual reality

Sense of agency (SoA) is the sensation that self-actions lead to ensuing perceptual consequences. The prospective mechanism emphasizes that SoA arises from motor prediction and its comparison with actual action outcomes, while the reconstructive mechanism stresses that SoA emerges from retrospective causal processing about the action outcomes. Consistent with the prospective mechanism, motor planning regions were identified by neuroimaging studies using the temporal binding (TB) effect, a behavioral measure often linked to implicit SoA. Yet, TB also occurs during passive observation of another's action, lending support to the reconstructive mechanism, but its neural correlates remain unexplored. Here, we employed virtual reality (VR) to modulate such observation-based SoA and examined it with functional magnetic resonance imaging (fMRI). After manipulating an avatar hand in VR, participants passively observed an avatar's "action" and showed a significant increase in TB. The binding effect was associated with the right angular gyrus and inferior parietal lobule, which are critical nodes for inferential and agency processing. These results suggest that the experience of controlling an avatar may potentiate inferential processing within the right inferior parietal cortex and give rise to the illusionary SoA without voluntary action.

Action-outcome delays modulate the temporal expansion of intended outcomes

The phenomenon of intentional binding pertains to the perceived connection between a voluntary action and its anticipated result. When an individual intends an outcome, it appears to subjectively extend in time due to a pre-activation of the intended result, particularly evident at shorter action-outcome delays. However, there is a concern that the operationalisation of intention might have led to a mixed interpretation of the outcome expansion attributed to the pre-activation of intention, given the sensitivity of time perception and intentional binding to external cues that could accelerate the realisation of expectations. To investigate the expansion dynamics of an intended outcome, we employed a modified version of the temporal bisection task in two experiments. Experiment 1 considered the action-outcome delay as a within-subject factor, while experiment 2 treated it as a between-subject factor. The results revealed that the temporal expansion of an intended outcome was only evident under the longer action-outcome delay condition. We attribute this observation to working memory demands and attentional allocation due to temporal relevancy and not due to pre-activation. The discrepancy in effects across studies is explained by operationalising different components of the intentional binding effect, guided by the cue integration theory. Moreover, we discussed speculative ideas regarding the involvement of specific intentions based on the proximal intent distal intent (PIDI) theory and whether causality plays a role in temporal binding. Our study contributes to the understanding of how intention influences time perception and sheds light on how various methodological factors, cues, and delays can impact the dynamics of temporal expansion associated with an intended outcome.

I am not the cause of this pain: An experimental study of the cognitive processes underlying causal attribution in the unpredictable situation whether negative outcomes

OBJECTIVES

Pain causal attribution is the attribution of pain causes to self or others, which may depend on one's choice of actions. The study aimed to examine how the cognitive processes of pain causal attribution as one aspect of the sense of agency change in healthy individuals based on free or forced choice, using a temporal binding (TB) experimental task.

METHODS

Participants pressed keys (action) in a combined TB task, with one key having a high probability of delivering pain (with tone). In fact, only the bias between the free-choice and the forced choice conditions was manipulated. Participants estimated the time between their action and tone, with shorter intervals indicating internal attribution.

RESULTS

Interval estimation was significantly longer in the forced-choice condition than in the free-choice condition when a pain stimulus was delivered.

CONCLUSIONS

Explicit complaints of pain being caused by others may be represented in implicit cognitive processes.

Sense of agency and its disturbances: A systematic review targeting the intentional binding effect in neuropsychiatric disorders

Sense of agency (SoA) indicates a person's ability to perceive her/his own motor acts as actually being her/his and, through them, to exert control over the course of external events. Disruptions in SoA may profoundly affect the individual's functioning, as observed in several neuropsychiatric disorders. This is the first article to systematically review studies that investigated intentional binding (IB), a quantitative proxy for SoA measurement, in neurological and psychiatric patients. Eligible were studies of IB involving patients with neurological and/or psychiatric disorders. We included 15 studies involving 692 individuals. Risk of bias was low throughout studies. Abnormally increased action-outcome binding was found in schizophrenia and in patients with Parkinson's disease taking dopaminergic medications or reporting impulsive-compulsive behaviors. A decreased IB effect was observed in Tourette's disorder and functional movement disorders, whereas increased action-outcome binding was found in patients with the cortico-basal syndrome. The extent of IB deviation from healthy control values correlated with the severity of symptoms in several disorders. Inconsistent effects were found for autism spectrum disorders, anorexia nervosa, and borderline personality disorder. Findings pave the way for treatments specifically targeting SoA in neuropsychiatric disorders where IB is altered.

Action-effect knowledge transfers to similar effect stimuli

The ability to anticipate the sensory consequences of our actions (i.e., action-effects) is known to be important for intentional action initiation and control. Learned action-effects can select the responses that previously have been associated with them. What has been largely unexplored is how learned action-effect associations can aid action selection for effects that have not previously associated with an action but are similar to learned effects. In two studies, we aimed to show that when presented new, unknown action-effects, participants select the responses that have previously been associated with similar action-effects. In the first study (n = 27), action-effect similarity was operationalized via stimuli belonging to the same or different categories as the previously learned action-effects. In the second study (n = 31), action-effect similarity was realized via stimuli that require comparable motor responses in real life. Participants first learned that specific responses are followed by specific visual effect stimuli. In the test phase, learned effect stimuli, new but similar effect stimuli and new but dissimilar effect stimuli were presented ahead of the response. The findings revealed that both learned effect stimuli and new similar effect stimuli affected response times, whereas new dissimilar effects did not. When a learned or a new similar effect was followed by a learned response, compared to an unlearned response, the responses were faster. We interpret these findings in terms of action-effect learning. The action-effect once bound to an action is used to select an action if a similar effect for which no action has been learned yet is presented. However, it is noteworthy that, due to our design, other explanations for the found transfer are conceivable. We address these limitations in the General Discussion.

Using Virtual Objects With Hand-Tracking: The Effects of Visual Congruence and Mid-Air Haptics on Sense of Agency

Virtual reality expands the possibilities of human action. With hand-tracking technology, we can directly interact with these environments without the need for a mediating controller. Much previous research has looked at the user-avatar relationship. Here we explore the avatar-object relationship by manipulating the visual congruence and haptic feedback of the virtual object of interaction. We examine the effect of these variables on the sense of agency (SoA), which refers to the feeling of control over our actions and their effects. This psychological variable is highly relevant to user experience and is attracting increased interest in the field. Our results showed that implicit SoA was not significantly affected by visual congruence and haptics. However, both of these manipulations significantly affected explicit SoA, which was strengthened by the presence of mid-air haptics and was weakened by the presence of visual incongruence. We propose an explanation of these findings that draws on the cue integration theory of SoA. We also discuss the implications of these findings for HCI research and design.