Orthodox neurocognitive accounts of the bodily sense of agency suggest that the experience of agency arises when action-effects are anticipated accurately. In this paper, I argue that while successful anticipation is crucial for the sense of agency, the role of unsuccessful prediction has been neglected, and that inefficacy and uncertainty are no less central to the sense of agency. I will argue that this is reflected in the phenomenology of agency, which can be characterized both as the experience of efficacy (...) and effort. Specifically, the “sense of efficacy” refers to the perceptual experience of an action unfolding as anticipated. The “sense of effort”, in contrast, arises when an action has an uncertain trajectory, feels difficult, and demands the exertion of control. In this case, actions do not unfold as anticipated and require continuing adaptation if they are to be efficacious. I propose that, taken individually, the experience of efficacy and effort are insufficient for the sense of agency and that these experiences can even disrupt the sense of agency when they occur in isolation from each other. I further argue that a fully-fledged sense of agency depends on the temporally extensive process of prediction error-cancelation. This way, a comparator account can accommodate both the role of accurate prediction and prediction error and thus efficacy and effort. (shrink)

A radical interpretation of the predictive coding approach suggests that the mind is “seamless” – that is, that cancellation of error signals can propagate smoothly from highest to lowest levels of the control hierarchy, dissolving a distinction between belief and perception. Delusions of alien control provide a test case. Close examination suggests that while they are evidence of predictive coding within the cortex, they are not evidence for the seamless interpretation.

Motor imagery provides a direct insight into action representations. The aim of the present study was to investigate the level of impairment of action monitoring in schizophrenia by evaluating the performance of schizophrenic patients on mental rotation tasks. We raised the following questions: Are schizophrenic patients impaired in motor imagery both at the explicit and at the implicit level? Are body parts more difficult for them to mentally rotate than objects? Is there any link between the performance and the hallucinating (...) symptom profile? The schizophrenic patients displayed the same pattern of performance as the control subjects . More particularly, schizophrenic patients’ reaction time varied as a function of the angular disparity of the stimuli. On the other hand, they were significantly slower and less accurate. Interestingly, patients suffering from hallucinations made significantly more errors than non-hallucinatory patients. We discussed these latter results in terms of deficit of the forward model. We emphasized the necessity to distinguish different levels of action, more or less impaired in schizophrenia. (shrink)

Imbalanced plasticity of neural networks in the brain is proposed to underlie deficits in the integration of efferent and afferent processes in schizophrenia. These deficits affect the priming of the behavior implementing systems by prior knowledge, and thus impair both controlled regulation and automatic activation of mental and motor processes. The sense of self as a distinct entity can consequently be undermined. In predominantly reality-distorting patients, hypo-plasticity of neural connectivity may cause the emergence of highly focused but inflexible patterns of (...) activation in their representation and response systems. This may lead to dominance of prepotent patterns of activity in these systems and a relative inability of higher control systems to bias lower level activity towards congruence with the ongoing cognitive and motor context. By contrast, predominantly disorganized patients are characterized by hyper-plastic connectivity. This leads to a weakening of prepotent response tendencies but also, as in reality-distorting patients, to less effective top-down contextual constraining. (shrink)