Implicit signatures of voluntary action reduce with repeated motor practice.

The sense of controlling one's actions and their consequences is a critical aspect of successful motor activity. While motor performance typically improves with learning, it is unclear whether, how, and why higher order aspects of motor cognition are also affected. Here, we used an implicit measure of sense of agency-the 'intentional binding' effect-as participants learned to make a skilled action involving precise control of thumb adduction. These actions were predictably followed by a tone (the outcome). At pre-test, we showed the perceived time of the tone was shifted towards the thumb action, compared to a control condition in which tones occurred without actions. Next, a relevant training group learned to refine the direction of the thumb movement, while an irrelevant training group was trained on another movement. Manipulation checks demonstrated that, as expected, the relevant training group improved performance of the trained movement, while the irrelevant training group did not. Critically, while both groups still showed binding of the tone towards the thumb action at post-test, the relevant training group showed less binding than the irrelevant training group. Given the link between intentional binding and volitional control of action, we suggest our result demonstrates subjective agency over the outcome of a skilled action decreases as practice makes the skilled action more fluent. We suggest that this reduction in sense of agency over movement outcomes is consistent with the decreasing cognitive engagement, or automatization, that occurs during skill learning.

Actions of a shaken heart: Interoception interacts with action processing.

In the present study, we investigated the modulatory influence of the unconscious, bodily arousal on motor-related embodied information. Specifically, we examined how the interoceptive prediction error interacts with the event-related potentials linked to action-effect processing. Participants were asked to perform a task with self-initiated or externally-triggered sounds while receiving synchronous or false auditory cardiac feedback. The results found that interaction of interoceptive manipulation and action-effect processing modulates the frontal subcomponent of the P3 response. During the synchronous cardiac feedback, the P3 response to self-initiated tones was enhanced. During the false cardiac feedback, the frontal cortical response was reversed. N1 and P2 components were affected by the interoceptive manipulation, but not by the interaction of interoception and action processing. These findings provide experimental support for the theoretical accounts of the interaction between interoception and action processing within a framework of predictive coding, manifested particularly in the higher stages of action processing.

Inferior parietal lobule involved in representation of "what" in a delayed-action Libet task.

Intentional motor action is typically characterized by the decision about the timing, and the selection of the action variant, known as the "what" component. We compared free action selection with instructed action, where the movement type was externally cued, in order to investigate the action selection and action representation in a Libet's task. Temporal and spatial locus of these processes was examined using the combination of high-density electroencephalography, topographic analysis of variance, and source reconstruction. Instructed action, engaging representation of the response movement, was associated with distinct negativity at the parietal and centro-parietal channels starting around 750 ms before the movement, which has a source particularly in the bilateral inferior parietal lobule. This suggests that in delayed-action tasks, the process of action representation in the inferior parietal lobule may play an important part in the larger parieto-frontal activity responsible for movement selection.

Sensory attenuation of action outcomes of varying amplitude and valence.

Stimuli caused by self-initiated actions are perceived as less intense than those caused externally; this effect is called sensory attenuation (SA). In two experiments, we aimed to assess the impact of the amplitude of outcomes and its affective valence on SA and explicit ratings of sense of agency. This allowed us to test the predictions of the available SA frameworks and better understand the link between SA, affect, and agency. The results indicated that SA can be reversed, and such sensory amplification is driven by low-amplitude and positive-valence outcomes. We also show that intentional action influences the perceived valence of outcomes, and that modulations of explicit sense of agency are divergent from those of SA. Our study shows that valence influences the processing of the amplitude of intentional action outcomes and suggests that none of the currently available frameworks give full justice to SA's variability.

Learning from informative losses boosts the sense of agency.

Sense of agency, the feeling of having control over one's actions, is modulated by whether one's choices lead to desired or undesired outcomes. Learning similarly depends on outcome values from previous experience. In the current study, we evaluate a possible link between the sense of agency and learning, by investigating how intentional binding, an implicit measure of agency, changes during a probabilistic learning task. In two experiments, we show increased intentional binding in trials that follow losses, compared with trials that follow wins. Experiment 1 demonstrated that this post-error agency boost (PEAB) effect is rule-specific, as it did not occur if the trial following an error involved different action-outcome contingencies. Furthermore, PEAB was not modulated by the type of outcome presentation (monetary vs. affective). Experiment 2 showed that the PEAB effect can also occur when the current action involves a forced (as opposed to free) choice, but only when the previous, loss-provoking action was chosen freely. Thus, PEAB occurs when current actions are informed by outcomes of one's own previous action choices. Electroencephalography (EEG) data linked these effects to two event-related potential components, namely, the Feedback Related Negativity and the P300. Taken together, these results support the notion that PEAB reflects an adaptive property of human sense of agency, facilitating effective learning about the action-outcome structure of a specific task, to optimise future performance. By clarifying the conditions for enhancing the sense of agency through learning, this work adds to our understanding of human learning and agency.

Unexpected action outcomes produce enhanced temporal binding but diminished judgement of agency.

Sense of agency (SoA) is the feeling of being the author of given actions and their effects. Recent works have investigated the cue integration approach to agency, according to which different predictive and inferential cues form SoA. In the current research we focus on how two such cues, i.e. accuracy of sensorimotor prediction and prior causal belief, influence SoA measured by temporal binding (TB) and questionnaires. Our results show that whereas learnt action effects produce normal TB and explicit agency, unexpected oddball effects produce enhanced TB but diminished explicit agency. Increased binding was modulated by temporal prediction, but not by identity prediction. A few interpretations of the results are given, including cue integration and pre-activation mechanisms. The research casts new light on the mechanisms and dynamics of TB and adds to the evidence for discrepancies between SoA measures.

Schizophrenia as a disorder of embodied self. / Schizofrenia jako zaburzenie "ja" ucielesnionego.

Theories of schizophrenia propose numerous mechanisms underlying development of this disorder, yet the account including satisfactory etiological explanation is still lacking. Current trend is to indicate core, basic factors which may further give rise to whole diversity of symptoms. Experimental data and patients' reports show that such key factor may be selfexperience disturbed on a basic, pre-reflective level, which can then lead to many higher-order symptoms. In this article we review and analyze these data, as well as the most influential cognitive theories focusing on mechanisms influencing the clinical picture of schizophrenia and giving rise to the anomalous experience of embodied self. These approaches pay attention to different, but complementary aspects of experience, such as body schema and body image, sense of ownership and sense of agency, or hyperreflexivity and diminished self-affection. Predictive coding approach is also introduced - the theory which, by appealing to the disturbance in a process of neural prediction, complements previous accounts and links various cognitive functions by means of single common predictive mechanism. Although very broad in its possible meanings, the self appears to be a concept of high explanatory value, grasping in the single framework many schizophrenic symptoms - these observable on neural, low-level of information processing, as well as on the level of phenomenology of subjective experience. Such approach appears to be valuable and useful for both research and practice.