Anouk van der Weiden

Reflecting on the action or its outcome: Behavior representation level modulates high level outcome priming effects on self-agency experiences

Recent research suggests that one can have the feeling of being the cause of an actions outcome, even in the absence of a prior intention to act. That is, experienced self-agency over behavior increases when outcome representations are primed outside of awareness, prior to executing the action and observing the resulting outcome. Based on the notion that behavior can be represented at different levels, we propose that priming outcome representations is more likely to augment self-agency experiences when the primed representation corresponds with a persons behavior representation level. Three experiments, using different priming and self-agency tasks, both measuring and manipulating the level of behavior representation, confirmed this idea. Priming high level outcome representations enhanced experienced self-agency over behavior more strongly when behavior was represented at a higher level, rather than a lower level. Thus, priming effects on self-agency experiences critically depend on behavior representation level.

A Matter of Matching: How Goals and Primes Affect Self-Agency Experiences

The sense of self-agency is a pervasive experience that people infer from their actions and the outcomes they produce. Recent research suggests that self-agency inferences arise from an explicit goal-directed process as well as an implicit outcome-priming process. Three experiments examined potential differences between these 2 processes. Participants had the goal to produce an outcome or were primed with the outcome. Next, they performed an action in an agency-ambiguous situation, followed by an outcome that matched or mismatched the goal or prime, and indicated experienced self-agency over the action-outcome. Results showed that goals reduce self-agency over mismatching outcomes. However, outcome-primes did not affect self-agency over mismatching outcomes but even enhanced self-agency over mismatching proximate outcomes. Goals and outcome-primes equally enhanced self-agency for matches. Our findings provide novel evidence that self-agency experiences result from 2 distinct inferential routes and that goals and primes differentially affect the perception of our own behavior.

When observing gaze shifts of others enhances object desirability.

The present research explored when observing gaze shifts of another person, involving both the observer and a specific object, enhances desirability of the gazed-at object. Specifically, we offer an initial attempt to test the idea that a three-step sequence consisting of direct gaze at the observer, followed by object-directed gaze and then by direct gaze at the observer, cues the desirability of an object to the observer and hence increases the perceived desirability of the gazed-at object. We examined this hypothesis in three experiments by manipulating eye-gaze shifts and including a no-gaze control condition. In line with our prediction, results showed that the dynamic sequence of gaze shifts indeed increases perceived object desirability. These findings provide new evidence that a sequence of gaze behavior involving the observer and an object plays an important role in influencing affective evaluation of objects.

Prime and probability: causal knowledge affects inferential and predictive effects on self-agency experiences.

Experiences of having caused a certain outcome may arise from motor predictions based on action-outcome probabilities and causal inferences based on pre-activated outcome representations. However, when and how both indicators combine to affect such self-agency experiences is still unclear. Based on previous research on prediction and inference effects on self-agency, we propose that their (combined) contribution crucially depends on whether people have knowledge about the causal relation between actions and outcomes that is relevant to subsequent self-agency experiences. Therefore, we manipulated causal knowledge that was either relevant or irrelevant by varying the probability of co-occurrence (50% or 80%) of specific actions and outcomes. Afterwards, we measured self-agency experiences in an action-outcome task where outcomes were primed or not. Results showed that motor prediction only affected self-agency when relevant actions and outcomes were learned to be causally related. Interestingly, however, inference effects also occurred when no relevant causal knowledge was acquired.

Abnormal agency experiences in schizophrenia patients: Examining the role of psychotic symptoms and familial risk

Experiencing self-agency over ones own action outcomes is essential for social functioning. Recent research revealed that patients with schizophrenia do not use implicitly available information about their action-outcomes (i.e., prime-based agency inference) to arrive at self-agency experiences. Here, we examined whether this is related to symptoms and/or familial risk to develop the disease. Fifty-four patients, 54 controls, and 19 unaffected (and unrelated) siblings performed an agency inference task, in which experienced agency was measured over action-outcomes that matched or mismatched outcome-primes that were presented before action performance. The Positive and Negative Syndrome Scale (PANSS) and Comprehensive Assessment of Symptoms and History (CASH) were administered to assess psychopathology. Impairments in prime-based inferences did not differ between patients with symptoms of over- and underattribution. However, patients with agency underattribution symptoms reported significantly lower overall self-agency experiences. Siblings displayed stronger prime-based agency inferences than patients, but weaker prime-based inferences than healthy controls. However, these differences were not statistically significant. Findings suggest that impairments in prime-based agency inferences may be a trait characteristic of schizophrenia. Moreover, this study may stimulate further research on the familial basis and the clinical relevance of impairments in implicit agency inferences.

O2.5. MULTISENSORY INTEGRATION UNDERLYING BODY OWNERSHIP IN SCHIZOPHRENIA AND INDIVIDUALS AT FAMILIAL RISK TO DEVELOP PSYCHOSIS: A STUDY USING THE RUBBER HAND ILLUSION PARADIGM

Abstract Background Patients with schizophrenia suffer from fundamental self-disturbances and have difficulties integrating and distinguishing between the self and others. For example, they experience that bodily boundaries vanish, that body parts are located at the wrong part of the body or that they are not the subject of their own movements. Such experiences are referred to as disturbances in the sense of body ownership. Although these are well-described psychotic symptoms, surprisingly little is known about their etiology and development. Our aim was to replicate a more flexible sense of body ownership in patients, thereby using a well-controlled experimental procedure (with proprioceptive drift and subjective strength of the illusion. Second, we examine whether increased familial risk to develop psychosis (i.e., offspring of patients with schizophrenia), relative to increased familial risk to develop mood disorders or the absence of familial risk, is related to alterations in RHI measures. Methods With a Rubber Hand Illusion (RHI) paradigm, body ownership was assessed in two different cohorts: 1) 54 patients with schizophrenia and 56 age and gender matched controls and 2) 24 children/adolescents with at least one parent with schizophrenia, 33 children/adolescents with at least one parent with bipolar disorder, and 18 age and gender matched controls. In this paradigm, a visible rubber hand and the invisible real hand were stroked either synchronously or asynchronously. Subsequently, proprioceptive drift and subjective RHI were measured. Results All groups showed the rubber hand illusion, i.e., a stronger proprioceptive drift and higher subjective ratings of the RHI after synchronous compared with asynchronous stroking (all p<0.001). The effect of synchronicity on subjective RHI was significantly stronger in patients with schizophrenia as compared with healthy individuals (p=0.03). No significant differences were found between children/adolescents with and without increased familial risk to develop psychosis. Last, in patients the subjective RHI was related to severity of delusions (rho=0.36). Discussion This study confirms alterations in embodied ownership experiences in patients with schizophrenia, but no evidence was found for impairments in children/adolescence with increased familial or clinical risk to develop psychosis. Longitudinal data are needed to reveal whether impairments in body ownership are predictive of psychosis onset, however, our findings provide suggestive evidence that this is not the case. In addition, that group differences were found in multisensory integration processes related to the embodiment, but not proprioceptive drift, implicates different underlying mechanisms. A possible explanation might come from the distinction between bottom-up (i.e., sensory input) and top-down (i.e., cognitive representation of body schema) mechanisms that influence multisensory integration, that is, altered cognitive representations may influence embodiment but not proprioceptive drift.

A matter of you versus me? Experiences of control in a joint go/no-go task

When interacting with others, people represent their own as well as their interaction partners’ actions. Such joint action representation is essential for action coordination, but may also interfere with action control. We investigated how joint action representations affect experienced control over people’s own actions and their interaction partners’ actions. Participants performed a joint go/no-go task, which is commonly used to measure to what extent people represent their own actions in spatial reference to their interaction partner (e.g., as ‘left’ vs. ‘right’). After each second trial, participants indicated experienced control over their own action, their interaction partner’s action, or over action inhibition. Despite this frequent interruption of the go/no-go task, we found strong evidence for the spatial representation of joint actions. However, this joint action representation did not affect experiences of control. Possible explanations and implications of these findings are discussed.