Depressive traits are associated with a reduced effect of choice on implicit sense of agency

Our everyday actions and their subsequent outcomes are accompanied by a feeling of control or agency. This sense of agency (SoA) is dependent on the contribution of both prospective factors (e.g., action choice), and retrospective factors (e.g., outcome valence) with considerable variation in the population. We manipulated freedom of choice and valence of outcome to assess the relationship between implicit SoA and subclinical depressive and psychosis-like traits in a cohort of healthy young adults. Participants (N=150) completed a Libet Clock task, in which they had either a free or forced choice of which of two buttons to press, and received either a positive or negative outcome (cash register or klaxon). Participants were required to judge the time on the clock the tone sounded. We measured outcome binding, the shift in the perceived time of the outcome back in time towards the moment of the action. Participants also completed questionnaires on both depressive and psychosis-like traits. Positive outcomes strongly increased intentional binding. The evidence favoured no effect of freedom of choice on average, but this was influenced by inter-individual differences. Individuals reporting more depressive traits had less of a difference in intentional binding between free and forced choice conditions. The findings show that implicit SoA is sensitive to outcome valence and differs across the subclinical depression continuum.

Sense of agency during and following recovery from anorexia nervosa

The need to feel in control is central to anorexia nervosa (AN). AN patients tend to use dysfunctional behaviour to feel a sense of control. The sense of control in AN has only been studied through self-report. The aim of this study is to investigate an implicit sense of control, the sense of agency (SoA), in AN patients, recovered AN (RAN) patients and HC. We hypothesized that AN patients would exhibit a lower SoA compared to RAN patients and HC. Furthermore, we expected that state-anxiety would negatively predict SoA, and that this would be more prominent in AN patients, as studies have shown that SoA can be influenced by negative emotional states. The SoA was measured with the intentional binding task and state-anxiety levels through a questionnaire. Results showed no differences in SoA between groups. Findings did show that AN patients had significantly higher state anxiety scores compared to RAN patients and HC, and RAN patients had higher state anxiety scores compared to HC. However, state anxiety was not a significant predictor of SoA. We did not find any evidence of differences in SoA between groups. Further studies should focus on specific aspects of the need for control in AN by, for example, by manipulating (un)certainty in these paradigms.

Intentions with actions: The role of intentionality attribution on the vicarious sense of agency in Human–Robot interaction

Sense of Agency (SoA) is the feeling of control over one’s actions and their consequences. In social contexts, people experience a “vicarious” SoA over other humans’ actions; however, the phenomenon disappears when the other agent is a computer. This study aimed to investigate the factors that determine when humans experience vicarious SoA in Human–Robot Interaction (HRI). To this end, in two experiments, we disentangled two potential contributing factors: (1) the possibility of representing the robot’s actions and (2) the adoption of Intentional Stance towards robots. Participants performed an Intentional Binding (IB) task reporting the time of occurrence for self- or robot-generated actions or sensory outcomes. To assess the role of action representation, the robot either performed a physical keypress (Experiment 1) or “acted” by sending a command via Bluetooth (Experiment 2). Before the experiment, attribution of intentionality to the robot was assessed. Results showed that when participants judged the occurrence of the action, vicarious SoA was predicted by the degree of attributed intentionality, but only when the robot’s action was physical. Conversely, digital actions elicited the reversed effect of vicarious IB, suggesting that disembodied actions of robots are perceived as non-intentional. When participants judged the occurrence of the sensory outcome, vicarious SoA emerged only when the causing action was physical. Notably, intentionality attribution predicted vicarious SoA for sensory outcomes independently of the nature of the causing event, physical or digital. In conclusion, both intentionality attribution and action representation play a crucial role for vicarious SoA in HRI.

Intentions with actions: The role of intentionality attribution on the vicarious sense of agency in human-robot interaction

Sense of Agency (SoA) is the feeling of control over one’s actions and their consequences. In social contexts, people experience a “vicarious” SoA over other humans’ actions; however, the phenomenon disappears when the other agent is a computer. The present study aimed to investigate factors that determine when humans experience vicarious SoA in human-robot interaction (HRI). To this end, in two experiments we disentangled two potential contributing factors: (1) the possibility of representing the robot’s actions, and (2) the adoption of Intentional Stance toward robots. Participants performed an Intentional Binding (IB) task reporting the time of occurrence for self- or robot-generated actions or sensory outcomes. To assess the role of action representation, the robot either performed a physical keypress (Experiment 1) or “acted” by sending a command via Bluetooth (Experiment 2). Before the experiment, attribution of intentionality to the robot was assessed. Results showed that when participants judged the occurrence of the action, vicarious SoA was predicted by the degree of attributed intentionality, but only when the robot’s action was physical. Conversely, digital actions elicited reversed effect of vicarious IB, suggesting that disembodied actions of robots are perceived as non-intentional. When participants judged the occurrence of the sensory outcome, vicarious SoA emerged only when the causing action was physical. Notably, intentionality attribution predicted vicarious SoA for sensory outcomes independently of the nature of the causing event, physical or digital. In conclusion, both intentionality attribution and action representation play a crucial role for vicarious SoA in HRI.

Implicit agency is related to gamma power changes in an automatic imitation task

Often we have a feeling that we can control effects in the external world through our actions. The role of action processing associated with this implicit form of agency is still not clear. In this study, we used automatic imitation and electroencephalography to investigate neural oscillations associated with action processing and its possible contribution to implicit agency. Brain activity was recorded while participants performed actions (congruent or incongruent with a displayed finger movement) which subsequently triggered an outcome (a tone). We used a time estimation task to measure intentional binding (an index of implicit agency). We observed a decrease of alpha, beta and gamma power for congruent compared to incongruent actions and increased theta power for incongruent compared to congruent actions. Crucially, participants who showed greater intentional binding for congruent versus incongruent actions also presented greater gamma power differences. Alpha, beta and theta power were modulated by congruency but were unrelated to intentional binding. Our study suggests that an increased implicit agency for facilitated actions is associated with changes in gamma power. Our study also contributes to a characterization of neural oscillations in automatic imitation.

Subclinical depression inhibits the sense of agency at the sensorimotor level

The sense of agency is a feeling that one’s actions affect the outer world, which can be implicitly measured by the intentional binding paradigm. Intentional binding is a temporal illusion in which the time interval of one’s voluntary action and the following effect is perceived as contracted. Although the abnormality of the sense of agency is related to various mental states, it is unclear how depression affects the sense of agency at the sensorimotor level in general. Twenty-four nonclinical participants judged the timing of a keypress and a tone, with or without action-effect association, and reported their depressive symptoms. Replicating the previous studies, in this study, the time prediction of the keypress shifted toward the tone and that of the tone shifted toward the keypress when a tone followed a voluntary keypress. It was found that individuals with more severe depressive symptoms had smaller intentional binding, indicating a decreased sense of agency at the sensorimotor level in subclinical depression. This finding could aid in further understanding the experience of depression at a fundamental level and treating such patients.

Training with Agency-Inspired Feedback from an Instrumented Glove to Improve Functional Grasp Performance

Sensory feedback from wearables can be effective to learn better movement through enhanced information and engagement. Facilitating greater user cognition during movement practice is critical to accelerate gains in motor function during rehabilitation following brain or spinal cord trauma. This preliminary study presents an approach using an instrumented glove to leverage sense of agency, or perception of control, to provide training feedback for functional grasp. Seventeen able-bodied subjects underwent training and testing with a custom-built sensor glove prototype from our laboratory. The glove utilizes onboard force and flex sensors to provide inputs to an artificial neural network that predicts achievement of “secure” grasp. Onboard visual and audio feedback was provided during training with progressively shorter time delay to induce greater agency by intentional binding, or perceived compression in time between an action (grasp) and sensory consequence (feedback). After training, subjects demonstrated a significant reduction (p < 0.05) in movement pathlength and completion time for a functional task involving grasp-move-place of a small object. Future work will include a model-based algorithm to compute secure grasp, virtual reality immersion, and testing with clinical populations.

A Psychophysical Window onto the Subjective Experience of Compulsion

In this perspective, we follow the idea that an integration of cognitive models with sensorimotor theories of compulsion is required to understand the subjective experience of compulsive action. We argue that cognitive biases in obsessive–compulsive disorder may obscure an altered momentary, pre-reflective experience of sensorimotor control, whose detection thus requires an implicit experimental operationalization. We propose that a classic psychophysical test exists that provides this implicit operationalization, i.e., the intentional binding paradigm. We show how intentional binding can pit two ideas against each other that are fundamental to current sensorimotor theories of compulsion, i.e., the idea of excessive conscious monitoring of action, and the idea that patients with obsessive–compulsive disorder compensate for diminished conscious access to “internal states”, including states of the body, by relying on more readily observable proxies. Following these ideas, we develop concrete, testable hypotheses on how intentional binding changes under the assumption of different sensorimotor theories of compulsion. Furthermore, we demonstrate how intentional binding provides a touchstone for predictive coding accounts of obsessive–compulsive disorder. A thorough empirical test of the hypotheses developed in this perspective could help explain the puzzling, disabling phenomenon of compulsion, with implications for the normal subjective experience of human action.

Sense of Agency for Mental Actions: Insights from a Belief-Based Action-Effect Paradigm

A substantial body of research in the past few decades has converged on the idea that the so-called “sense of agency”, the feeling of being in control of our own actions, arises from the integration of multiple sources of information at different levels. In this study, we investigated whether a measurable sense of agency can be detected for mental actions, without the contribution of motor components. We used a fake action-effect paradigm, where participants were led to think that a motor action or a particular thought could trigger a sound. Results showed that the high-level sense of agency, measured through explicit reports, was of comparable strength for motor and mental actions. The ‘intentional binding’ effect, a phenomenon typically associated with the experience of agency, was also observed for both motor and mental actions, with the only exception of short action-effect delays. Furthermore, a consistent relationship between explicit reports of agency and intentional binding was found. Taken together, our results provide novel insights into the specific role of intentional cues in instantiating a sense of agency, even in the absence of motor signals. These results may have important implications for future brain-computer interfaces as well as for the study of pathological disruptions of agency.