: Marcel says that the experience of ownership of actions is given in the specifications for action. He is referring not to a bodily movement but that which precedes it. Is the body involved or are all the changes in the brain? This paper examines the evidence for changes in the spinal cord and muscles that occur with motor imagery, simulation and preparation. There are changes in the alpha motoneurons and in the gamma motoneurons to the muscle spindles. These may (...) be caused by stimulation from the covert efferent arm to the body. To experience the ownership of covert actions in the body requires feedback to the owner as their spatially perspectival source. There is evidence that an ascending pathway from the muscle spindles to the brain carries such feedback. This view of the feedback loop is integrated into the sensorimotor view of the genesis of consciousness of Ellis and Newton. (shrink)

Proprioception has been considered, within neuroscience, in the context of the control of movement. Here we discuss a possible second role for this 'sixth sense', pleasure in and of movement,homologous with the recently described affective touch. We speculate on its evolution and place in human society and suggest that pleasure in movement may depend not on feedback but also on harmony between intention and action. Examples come from expert movers, dancers and sportsmen, and from those without proprioception due to (...) neurological impairment. Finally we suggest that affective proprioception may help bind our sense of agency with our embodied selves at an emotional level. (shrink)

Body feedback is the proprioceptive feedback that denominates the afferent information from position and movement of the body to the central nervous system. It is crucial in experiencing emotions, in forming attitudes and in regulating emotions and behavior. This paper investigates effects of dynamic body feedback on affect and attitudes, focusing on the impact of movement rhythms with smooth vs. sharp reversals as one basic category of movement qualities. It relates those qualities to already explored effects (...) of approach vs. avoidance motor behavior as one basic category of movement shape. Studies 1 and 2 tested the effects of one of two basic movement qualities (smooth vs. sharp rhythms) on affect and cognition. The third study tested those movement qualities in combination with movement shape (approach vs. avoidance motor behavior) and the effects of those combinations on affect and attitudes toward initially valence-free stimuli. Results suggest that movement rhythms influence affect (studies 1 and 2), and attitudes (study 3), and moderate the impact of approach and avoidance motor behavior on attitudes (study 3). Extending static body feedback research with a dynamic account, findings indicate that movement qualities – next to movement shape – play an important role, when movement of the lived body is an independent variable. (shrink)

Proprioception has a crucial role in promoting or hindering motor learning. In particular, an intact position sense strongly correlates with the chances of recovery after stroke. A great majority of neurological patients present both motor dysfunctions and impairments in kinesthesia, but traditional robot and virtual reality training techniques focus either in recovering motor functions or in assessing proprioceptive deficits. An open challenge is to implement effective and reliable tests and training protocols for proprioception that go beyond the mere position (...) sense evaluation and exploit the intrinsic bidirectionality of the kinesthetic sense, which refers to both sense of position and sense of movement. Modulated haptic interaction has a leading role in promoting sensorimotor integration and it is a natural way to enhance volitional effort. Therefore, we designed a preliminary clinical study to test a new proprioception-based motor training technique for augmenting kinesthetic awareness via haptic feedback. The feedback was provided by a robotic manipulandum and the test involved 7 chronic hemiparetic subjects over three weeks. The protocol included evaluation sessions, that consisted of a psychometric estimate of the subject’s kinesthetic sensation, and training sessions, in which the subject executed planar reaching movements in the absence of vision and under a minimally assistive haptic guidance made by sequences of graded force pulses. The bidirectional haptic interaction between the subject and the robot was optimally adapted to each participant in order to achieve a uniform task difficulty over the workspace. All the subjects consistently improved in the perceptual scores as a consequence of training. Moreover, they could minimize the level of haptic guidance in time. Results suggest that the proposed method is effective in enhancing kinesthetic acuity, but the level of impairment may affect the ability of subjects to retain their improvement in time. (shrink)

What is like to live without touch or movement/position sense? The only way to understand the importance of these senses, so familiar we cannot imagine their absence, is to ask someone in that position. Ian Waterman lost them below the neck over forty years ago, though pain and temperature perception and his peripheral movement nerves were unaffected. Without proprioceptive feedback and touch the movement brain was disabled. Completely unable to move, he felt disembodied and frightened. Then, slowly, he (...) taught himself to dress, eat and walk by thinking about each movement and with visual supervision. In Losing Touch, the narrative moves between biography and scientific research, theatre, documentary and zero gravity. The book is the result of nearly 30 years close collaboration between author and subject. (shrink)

Action is a means of acquiring perceptual information about the environment. Turning around, for example, alters your spatial relations to surrounding objects and, hence, which of their properties you visually perceive. Moving your hand over an object’s surface enables you to feel its shape, temperature, and texture. Sniffing and walking around a room enables you to track down the source of an unpleasant smell. Active or passive movements of the body can also generate useful sources of perceptual information (Gibson 1966, (...) 1979). The pattern of optic flow in the retinal image produced by forward locomotion, for example, contains information about the direction in which you are heading, while motion parallax is a “cue” used by the visual system to estimate the relative distances of objects in your field of view. In these uncontroversial ways and others, perception is instrumentally dependent on action. According to an explanatory framework that Susan Hurley (1998) dubs the “Input-Output Picture”, the dependence of perception on action is purely instrumental: "Movement can alter sensory inputs and so result in different perceptions… changes in output are merely a means to changes in input, on which perception depends directly" (1998: 342). -/- The action-based theories of perception, reviewed in this entry, challenge the Input-Output Picture. They maintain that perception can also depend in a noninstrumental or constitutive way on action (or, more generally, on capacities for object-directed motor control). This position has taken many different forms in the history of philosophy and psychology. Most action-based theories of perception in the last 300 years, however, have looked to action in order to explain how vision, in particular, acquires either all or some of its spatial representational content. Accordingly, these are the theories on which we shall focus here. -/- We begin in Section 1 by discussing George Berkeley’s Towards a New Theory of Vision (1709), the historical locus classicus of action-based theories of perception, and one of the most influential texts on vision ever written. Berkeley argues that the basic or “proper” deliverance of vision is not an arrangement of voluminous objects in three-dimensional space, but rather a two-dimensional manifold of light and color. We then turn to a discussion of Lotze, Helmholtz, and the local sign doctrine. The “local signs” were felt cues for the mind to know what sort of spatial content to imbue visual experience with. For Lotze, these cues were “inflowing” kinaesthetic feelings that result from actually moving the eyes, while, for Helmholtz, they were “outflowing” motor commands sent to move the eyes. -/- In Section 2, we discuss sensorimotor contingency theories, which became prominent in the 20thcentury. These views maintain that an ability to predict the sensory consequences of self-initiated actions is necessary for perception. Among the motivations for this family of theories is the problem of visual direction constancy—why do objects appear to be stationary even though the locations on the retina to which they reflect light change with every eye movement?—as well as experiments on adaptation to optical rearrangement devices (ORDs) and sensory substitution. -/- Section 3 examines two other important 20th century theories. According to what we shall call the motor component theory, efference copies generated in the oculomotor system and/or proprioceptive feedback from eye-movements are used together with incoming sensory inputs to determine the spatial attributes of perceived objects. Efferent readiness theories, by contrast, look to the particular ways in which perceptual states prepare the observer to move and act in relation to the environment. The modest readiness theory, as we shall call it, claims that the way an object’s spatial attributes are represented in visual experience can be modulated by one or another form of covert action planning. The bold readiness theory argues for the stronger claim that perception just is covert readiness for action. -/- In Section 4, we move to the disposition theory, most influentially articulated by Gareth Evans (1982, 1985), but more recently defended by Rick Grush (2000, 2007). Evans’ theory is, at its core, very similar to the bold efferent readiness theory. There are some notable differences, though. Evans’ account is more finely articulated in some philosophical respects. It also does not posit a reduction of perception to behavioral dispositions, but rather posits that certain complicated relations between perceptual input and behavioral provide spatial content. Grush proposes a very specific theory that is like Evans’ in that it does not posit a reduction, but unlike Evans’ view, does not put behavioral dispositions and sensory input on an undifferentiated footing. (shrink)

This target article draws together two groups of experimental studies on the control of human movement through peripheral feedback and centrally generated signals of motor commands. First, during natural movement, feedback from muscle, joint, and cutaneous afferents changes; in human subjects these changes have reflex and kinesthetic consequences. Recent psychophysical and microneurographic evidence suggests that joint and even cutaneous afferents may have a proprioceptive role. Second, the role of centrally generated motor commands in the control of normal (...) movements and movements following acute and chronic deafferentation is reviewed. There is increasing evidence that subjects can perceive their motor commands under various conditions, but that this is inadequate for normal movement; deficits in motor performance arise when the reliance on proprioceptive feedback is abolished either experimentally or because of pathology. During natural movement, the CNS appears to have access to functionally useful input from a range of peripheral receptors as well as from internally generated command signals. The unanswered questions that remain suggest a number of avenues for further research. (shrink)

The idea that intentions make the difference between voluntary and non-voluntary behaviors is simple and intuitive. At the same time, we lack an understanding of how voluntary actions actually come about, and the unquestioned appeal to intentions as discrete causes of actions offers little if anything in the way of an answer. We cite evidence suggesting that the origin of actions varies depending on context and effector, and argue that actions emerge from a causal web in the brain, rather than (...) a central origin of intentional action. We argue that this causal web need not be confined to the central nervous system, and that proprioceptive feedback might play a counterintuitive role in the decision process. Finally we argue that the complex and dynamic origins of voluntary action and their interplay with the brain’s propensity to predict the immediate future are better studied using a dynamical systems approach. (shrink)

While robot-assisted arm and hand training after stroke allows for intensive task-oriented practice, it has provided only limited additional benefit over dose-matched physiotherapy up to now. These rehabilitation devices are possibly too supportive during the exercises. Neurophysiological signals might be one way of avoiding slacking and providing robotic support only when the brain is particularly responsive to peripheral input. We tested the feasibility of three-dimensional robotic assistance for reach-to-grasp movements with a multi-joint exoskeleton during motor imagery-related desynchronization of sensorimotor oscillations (...) in the β-band only. We also registered task-related network changes of cortical functional connectivity by electroencephalography via the imaginary part of the coherence function. Healthy subjects and stroke survivors showed similar patterns – but different aptitudes – of controlling the robotic movement. All participants in this pilot study with nine healthy subjects and two stroke patients achieved their maximum performance during the early stages of the task. Robotic control was significantly higher and less variable when proprioceptive feedback was provided in addition to visual feedback, i.e. when the orthosis was actually attached to the subject’s arm during the task. A distributed cortical network of task-related coherent activity in the θ-band showed significant differences between healthy subjects and stroke patients as well as between early and late periods of the task. Brain-robot interfaces may successfully link three-dimensional robotic training to the participants’ efforts and allow for task-oriented practice of activities of daily living with a physiologically controlled multi-joint exoskeleton. Changes of cortical physiology during the task might also help to make subject-specific adjustments of task difficulty and guide adjunct interventions to facilitate motor learning for functional restoration. (shrink)

Reports of phantom limbs amongst aplasics have often been presented as evidence that body image is ‘hard-wired’ in the brain and that neither sensory input nor proprioceptive feedback are essential to its formation. Although attempts have been made to account for these phantoms by other means, these have been on a case by case basis and no satisfactory alternative framework has been proposed. This paper collates the accounts of aplasic phantoms and presents them as compatible with a four-part (...) hypothesis, in which body image is learnt from experience during both pre- and post-natal development, and in which cross-cortical connections and mirror neurons play prominent roles. This model unites several previously disparate theories to offer a viable solution to several longstanding phantom limb mysteries and serves to highlight avenues worthy of further inquiry. (shrink)

It is proposed here that the spinal network of proprioceptive feedback from length and force receptors constitutes the mechanism underlying the coordination of activation thresholds for muscles acting about the same and neighboring joints. For the most part, these circuits come between motoneurons and supraspinal signals, invalidating the idea that the activation thresholds constitute control variables for the motor system.

Many upper limb amputees experience an incessant, post-amputation “phantom limb pain” and report that their missing limbs feel paralyzed in an uncomfortable posture. One hypothesis is that efferent commands no longer generate expected afferent signals, such as proprioceptive feedback from changes in limb configuration, and that the mismatch of motor commands and visual feedback is interpreted as pain. Non-invasive therapeutic techniques for treating phantom limb pain, such as mirror visual feedback (MVF), rely on visualizations of postural (...) changes. Advances in neural interfaces for artificial sensory feedback now make it possible to combine MVF with a high-tech “rubber hand” illusion, in which subjects develop a sense of embodiment with a fake hand when subjected to congruent visual and somatosensory feedback. We discuss clinical benefits that could arise from the confluence of known concepts such as MVF and the rubber hand illusion, and new technologies such as neural interfaces for sensory feedback and highly sensorized robot hand testbeds, such as the “BairClaw” presented here. Our multi-articulating, anthropomorphic robot testbed can be used to study proprioceptive and tactile sensory stimuli during physical finger-object interactions. Conceived for artificial grasp, manipulation, and haptic exploration, the BairClaw could also be used for future studies on the neurorehabilitation of somatosensory disorders due to upper limb impairment or loss. A remote actuation system enables the modular control of tendon-driven hands. The artificial proprioception system enables direct measurement of joint angles and tendon tensions while temperature, vibration, and skin deformation are provided by a multimodal tactile sensor. The provision of multimodal sensory feedback that is spatiotemporally consistent with commanded actions could lead to benefits such as reduced phantom limb pain, and increased prosthesis use due to improved functionality and reduced cognitive burden. (shrink)

Vision is known to improve human postural responses to external perturbations. This study investigates the role of vision for the responses to continuous pseudorandom support surface translations in the body sagittal plane in three visual conditions: with the eyes closed, in stroboscopic illumination and with eyes open in continuous illumination with the room as static visual scene. In the frequency spectrum of the translation stimulus we distinguished on the basis of the response patterns between a low-frequency, mid-frequency, and high-frequency range. (...) With EC, subjects’ mean sway response gain was very low in the LFR. On average it increased with EO/SI and more so with EO/CI. In contrast, the average gain in the MFR decreased from EC to EO/SI and further to EO/CI. In the HFR, all three visual conditions produced, similarly, high gain levels. A single inverted pendulum model controlling center of mass balancing about the ankle joints formally described the EC response as being strongly shaped by a resonance phenomenon arising primarily from the control’s proprioceptive feedback loop. The effect of adding visual information in these simulations lies in a reduction of the resonance, similar as in the experiments. Extending the model to a double inverted pendulum suggested in addition a biomechanical damping effective from trunk sway in the hip joints on the resonance. (shrink)

Postural instability in Parkinson’s disease (PD) is characterized by impaired postural responses to transient perturbations, increased postural sway in stance and difficulty transitioning between tasks. In addition, some studies suggest that loss of dopamine in the basal ganglia due to PD results in difficulty using proprioceptive information for motor control. Here, we quantify the ability of subjects with PD and age-matched control subjects to use and re-weight sensory information for postural control during steady-state conditions of continuous rotations of the (...) stance surface or visual surround. We measure the postural sway of subjects in response to a pseudorandom, surface-tilt stimulus with eyes closed, and in response to a pseudorandom, visual-tilt stimulus. We use a feedback control model of the postural control system to interpret our results, focusing on sensory weighting as a function of stimulus amplitude. We find that subjects with PD can re-weight their dependence upon sensory information in response to changes in surface- or visual-stimulus amplitude. Specifically, subjects with PD behaved like age-matched control subjects by decreasing proprioceptive contribution to stance control with increasing surface-tilt amplitude, and decreasing visual contribution with increasing visual-tilt amplitude. However, subjects with PD do not decrease their reliance on proprioception as much as age-matched controls for small increases in surface-stimulus amplitudes. Levodopa medication did not affect sensory re-weighting behaviors for postural control. The impairment in PD subject’s ability to respond differently to small changes in surface rotation amplitudes is consistent with an increased threshold for perceiving proprioceptive signals, which may result from decreased signal-to-noise in the dopaminergic pathways associated with sensory processing and/or sensory integration. (shrink)

We investigated how motor agency in the voluntary control of body movement influences body awareness. In the Rubber Hand Illusion , synchronous tactile stimulation of a rubber hand and the participant’s hand leads to a feeling of the rubber hand being incorporated in the participant’s own body. One quantifiable behavioural correlate of the illusion is an induced shift in the perceived location of the participant’s hand towards the rubber hand. Previous studies showed that the induced changes in body awareness are (...) local and fragmented: the proprioceptive drift is largely restricted to the stimulated finger. In the present study, we investigated whether active and passive movements, rather than tactile stimulation, would lead to similarly fragmented body awareness. Participants watched a projected image of their hand under three conditions: active finger movement, passive finger movement, and tactile stimulation. Visual feedback was either synchronous or asynchronous with respect to stimulation of the hand. A significant overall RHI, defined as greater drifts following synchronous than asynchronous stimulation, was found in all cases. However, the distribution of the RHI across stimulated and non-stimulated fingers depended on the kind of stimulation. Localised proprioceptive drifts, specific to the stimulated finger, were found for tactile and passive stimulation. Conversely, during active movement of a single digit, the proprioceptive drifts were not localised to that digit, but were spread across the whole hand. Whereas a purely proprioceptive sense of body-ownership is local and fragmented, the motor sense of agency integrates distinct body-parts into a coherent, unified awareness of the body. (shrink)

Impaired hand proprioception can lead to difficulties in performing fine motor tasks, thereby affecting activities of daily living. The majority of children with unilateral cerebral palsy experience proprioceptive deficits, but accurately quantifying these deficits is challenging due to the lack of sensitive measurement methods. Robot-assisted assessments provide a promising alternative, however, there is a need for solutions that specifically target children and their needs. We propose two novel robotics-based assessments to sensitively evaluate active and passive position sense of the (...) index finger metacarpophalangeal joint in children. We then investigate test-retest reliability and discriminant validity of these assessments in uCP and typically developing children, and further use the robotic platform to gain first insights into fundamentals of hand proprioception. Both robotic assessments were performed in two sessions with 1-h break in between. In the passive position sense assessment, participant's finger is passively moved by the robot to a randomly selected position, and she/he needs to indicate the perceived finger position on a tablet screen located directly above the hand, so that the vision of the hand is blocked. Active position sense is assessed by asking participants to accurately move their finger to a target position shown on the tablet screen, without visual feedback of the finger position. Ten children with uCP and 10 age-matched TDC were recruited in this study. Test-retest reliability in both populations was good >0.79). Proprioceptive error was larger for children with uCP than TDC, indicating discriminant validity. The active position sense was more accurate than passive, and the scores were not correlated, underlining the need for targeted assessments to comprehensively evaluate proprioception. There was a significant effect of age on passive position sense in TDC but not uCP, possibly linked to disturbed development of proprioceptive acuity in uCP. Overall, the proposed robot-assisted assessments are reliable, valid and a promising alternative to commonly used clinical methods, which could help gain a better understanding of proprioceptive impairments in uCP, facilitating the design of novel therapies. (shrink)

The present study examined what participants perceive of their hand movements when using a tool. In the experiments different gains for either the x-axis or the y-axis perturbed the relation between hand movements on a digitizer tablet and cursor movements on a display. As a consequence of the perturbation participants drew circles on the display while their covered hand movements followed either vertical or horizontal ellipses on the digitizer tablet. When asked to evaluate their hand movements, participants were extremely uncertain (...) about their trajectories. By varying the amount of visual feedback, findings indicated that the low awareness of one’s own movements originated mainly from an insufficient quality of the humans’ tactile and proprioceptive system or from an insufficient spatial reconstruction of this information in memory. (shrink)

Research suggests that perceptual experience of our movements adapts together with movement control when we are the agents of our actions. Is this agency critical for perceptual and motor adaptation? We had participants view cursor feedback during elbow extension–flexion movements when they actively moved their arm, or had their arm passively moved. We probed adaptation of movement perception by having participants report the reversal point of their unseen movement. We probed adaptation of movement control by having them aim to (...) a target. Perception and control of active movement were influenced by both types of exposure, although adaptation was stronger following active exposure. Furthermore, both types of exposure led to a change in the perception of passive movements. Our findings support the notion that perception and control adapt together, and they suggest that some adaptation is due to recalibrated proprioception that arises independently of active engagement with the environment. (shrink)

According to Gurwitsch, the body is at least at the margin of consciousness. If all components of the field of consciousness were experienced as equally salient, we would indeed not be able to think and behave appropriately. Though the body may become the focus of our conscious field when we are introspectively aware of it, it remains most of the time only at the background of consciousness. However, we may wonder if bodily states do really need to be conscious, even (...) at the margin, or cannot be simply non-conscious. Action control requires permanent proprioceptive and visual feedback about the state and the position of our body parts. Experimental data show that action monitoring operates at a nonconscious level and we may similarly suggest that we have a continuous unconscious access to bodily information. In this chapter, I thus intend to describe the various levels of body representations with the help of Gurwitsch's distinction. I will investigate the properties and the function of each of these levels. (shrink)

The current assessment of behaviors in the inventories to diagnose autism spectrum disorders (ASD) focus on observation and discrete categorizations. Behaviors require movements, yet measurements of physical movements are seldom included. Their inclusion however, could provide an objective characterization of behavior to help unveil interactions between the peripheral and the central nervous systems. Such interactions are critical for the development and maintenance of spontaneous autonomy, self-regulation and voluntary control. At present, current approaches cannot deal with the heterogeneous, dynamic and stochastic (...) nature of development. Accordingly, they leave no avenues for real-time or longitudinal assessments of change in a coping system continuously adapting and developing compensatory mechanisms. We offer a new unifying statistical framework to reveal re-afferent kinesthetic features of the individual with ASD. The new methodology is based on the non-stationary stochastic patterns of minute fluctuations (micro-movements) inherent to our natural actions. Such patterns of behavioral variability provide re-entrant sensory feedback contributing to the autonomous regulation and coordination of the motor output. From an early age, this feedback supports centrally driven volitional control and fluid, flexible transitions between intentional and spontaneous behaviors. We show that in ASD there is a disruption in the maturation of this form of proprioception. Despite this disturbance, each individual has unique adaptive compensatory capabilities that we can unveil and exploit to evoke faster and more accurate decisions. Measuring the kinesthetic re-afference in tandem with stimuli variations we can detect changes in their micro-movements indicative of a more predictive and reliable kinesthetic percept. Our methods address the heterogeneity of ASD with a personalized approach grounded in the inherent sensory-motor abilities that the individual has already developed. (shrink)

In the classical Turing test, participants are challenged to tell whether they are interacting with another human being or with a machine. The way the interaction takes place is not direct, but a distant conversation through computer screen messages. Basic forms of interaction are face-to-face and embodied, context-dependent and based on the detection of reciprocal sensorimotor contingencies. Our idea is that interaction detection requires the integration of proprioceptive and interoceptive patterns with sensorimotor patterns, within quite short time lapses, so (...) that they appear as mutually contingent, as reciprocal. In other words, the experience of interaction takes place when sensorimotor patterns are contingent upon one’s own movements, and vice versa. I react to your movement, you react to mine. When I notice both components, I come to experience an interaction. Therefore, we designed a “minimal” Turing test to investigate how much information is required to detect these reciprocal sensorimotor contingencies. Using a new version of the perceptual crossing paradigm, we tested whether participants resorted to interaction detection to tell apart human from machine agents in repeated encounters with these agents. In two studies, we presented participants with movements of a human agent, either online or offline, and movements of a computerized oscillatory agent in three different blocks. In each block, either auditory or audiovisual feedback was provided along each trial. Analysis of participants’ explicit responses and of the implicit information subsumed in the dynamics of their series will reveal evidence that participants use the reciprocal sensorimotor contingencies within short time windows. For a machine to pass this minimal Turing test, it should be able to generate this sort of reciprocal contingencies. (shrink)

According to behavioural theories deriving from pragmatism, gestalt psychology, existentialism, and ecopsychology, knowledge about the world is gained by intentional action followed by learning. In terms of the neurodynamics described here, if the intending of an act comes to awareness through reafference, it is perceived as a cause. If the consequences of an act come to awareness through proprioception and exteroception, they are perceived as an effect. A sequence of such states of awareness comprises consciousness, which can grow in complexity (...) to include self-awareness. Intentional acts do not require awareness, whereas voluntary acts require self-awareness. Awareness of the action/perception cycle provides the cognitive metaphor of linear causality as an agency. Humans apply this metaphor to objects and events in the world to predict and control them, and to assign social responsibility. Thus, linear causality is the bedrock of technology and social contracts. Complex material systems with distributed non-linear feedback, such as brains and their neural and behavioural activities, cannot be explained by linear causality. They can be said to operate by circular causality without agency. The nature of self-control is described by breaking the circle into a forward limb, the intentional self, and a feedback limb, awareness of the self and its actions. The two limbs are realized through hierarchically stratified kinds of neural activity. Intentional acts are produced by the self-organized microscopic neural activity of cortical and subcortical components in the brain. Awareness supervenes as a macroscopic ordering state, that defers action until the self-organizing microscopic process has reached closure in reflective prediction. Agency, which is removed from the causal hierarchy by the appeal to circularity, re-appears as a metaphor by which events in the world are anthropomorphized, making them appear subject to human control. (shrink)

What are the epistemic bases of the knowledge of the reality of our own body? Proprioception plays a primordial role in body representation and more particularly at the level of body schema. Without proprioception people can feel amputated and the mislocalization of proprioceptive information through the remapping of the Penfield Homonculus induces illusions of phantom limbs, illusions that contradictory visual feedback cannot erase. However, it turns out that it is not as simple as that and that vision also (...) intervenes in body knowledge: vision of one's own body allows deafferented patients to move and phantom limbs to disappear. Finally, the existence of phantom limbs in aplasic patients as well as studies on neonates provide evidence of an innate component of body representation. (shrink)

Observational learning can enhance the acquisition and performance quality of complex motor skills. While an extensive body of research has focused on the benefits of synchronous (i.e., concurrent physical practice) and non-synchronous (i.e., delayed physical practice) observational learning strategies, the question remains as to whether these approaches differentially influence performance outcomes. Accordingly, we investigate the differential outcomes of synchronous and non-synchronous observational training contexts using a novel dance sequence. Using multidimensional cross-recurrence quantification analysis, movement time-series were recorded for novice dancers (...) who either synchronised with (n = 22) or observed and then imitated (n = 20) an expert dancer. Participants performed a 16-count choreographed dance sequence for 20 trials assisted by the expert, followed by one final, unassisted performance trial. Although end-state performance did not significantly differ between synchronous and non-synchronous learners, a significant decline in performance quality from imitation to independent replication was shown for synchronous learners. A non-significant positive trend in performance accuracy was shown for non-synchronous learners. For all participants, better imitative performance across training trials led to better end-state performance, but only for the accuracy (and not timing) of movement reproduction. Collectively, the results suggest that synchronous learners came to rely on a realtime mapping process between visual input from the expert and their own visual and proprioceptive intrinsic feedback, to the detriment of learning. Thus, the act of synchronising alone does not ensure an appropriate training context for advanced sequence learning. (shrink)

Can one be fooled into believing that one intended an action that one in fact did not intend? Past experimental paradigms have demonstrated that participants, when provided with false perceptual feedback about their actions, can be fooled into misperceiving the nature of their intended motor act. However, because veridical proprioceptive/perceptual feedback limits the extent to which participants can be fooled, few studies have been able to answer our question and induce the illusion to intend. In a novel (...) paradigm addressing this question, participants were instructed to move a line on the computer screen by use of a phony brain–computer interface. Line movements were actually controlled by computer program. Demonstrating the illusion to intend, participants reported more intentions to move the line when it moved frequently than when it moved infrequently. Consistent with ideomotor theory, the finding illuminates the intimate liaisons among ideomotor processing, the sense of agency, and action production. (shrink)

Despite the recognized importance of bodily movements in spatial audition, few studies have integrated action-based protocols with spatial hearing in the peripersonal space. Recent work shows that tactile feedback and active exploration allow participants to improve performance in auditory distance perception tasks. However, the role of the different aspects involved in the learning phase, such as voluntary control of movement, proprioceptive cues, and the possibility of self-correcting errors, is still unclear. We study the effect of guided reaching exploration (...) on perceptual learning of auditory distance in peripersonal space. We implemented a pretest-posttest experimental design in which blindfolded participants must reach for a sound source located in this region. They were divided into three groups that were differentiated by the intermediate training phase: Guided, an experimenter guides the participant’s arm to contact the sound source; Active, the participant freely explores the space until contacting the source; and Control, without tactile feedback. The effects of exploration feedback on auditory distance perception in the peripersonal space are heterogeneous. Both the Guided and Active groups change their performance. However, participants in the Guided group tended to overestimate distances more than those in the Active group. The response error of the Guided group corresponds to a generalized calibration criterion over the entire range of reachable distances. Whereas the Active group made different adjustments for proximal and distal positions. The results suggest that guided exploration can induce changes on the boundary of the auditory reachable space. We postulate that aspects of agency such as initiation, control, and monitoring of movement, assume different degrees of involvement in both guided and active tasks, reinforcing a non-binary approach to the question of activity-passivity in perceptual learning and supporting a complex view of the phenomena involved in action-based learning. (shrink)

Traditionally, what we are conscious of in self-consciousness is something non-corporeal. But anti-Cartesian philosophers argue that the self is as much corporeal as it is mental. Because we have the sense of proprioception, a kind of body awareness, we are immediately aware of ourselves as bodies in physical space. In this debate the case histories of patients who have lost their sense of proprioception are clearly relevant. These patients do retain an awareness of themselves as corporeal beings, although they hardly (...) feel their bodies. They can initiate movements, and with the help of visual feedback learn to control them. It is shown that the traditional view of the self as immaterial is not supported by these cases. But the argument against this view has to be amended. It relies too much on bodily sensations, and misses the importance of active self-movement. (shrink)

Mental body-representations are highly plastic and can be modified after brief exposure to unexpected sensory feedback. While the role of vision, touch and proprioception in shaping body-representations has been highlighted by many studies, the auditory influences on mental body-representations remain poorly understood. Changes in body-representations by the manipulation of natural sounds produced when one's body impacts on surfaces have recently been evidenced. But will these changes also occur with non-naturalistic sounds, which provide no information about the impact produced by (...) or on the body? Drawing on the well-documented capacity of dynamic changes in pitch to elicit impressions of motion along the vertical plane and of changes in object size, we asked participants to pull on their right index fingertip with their left hand while they were presented with brief sounds of rising, falling or constant pitches, and in the absence of visual information of their hands. Results show an "auditory Pinocchio" effect, with participants feeling and estimating their finger to be longer after the rising pitch condition. These results provide the first evidence that sounds that are not indicative of veridical movement, such as non-naturalistic sounds, can induce a Pinocchio-like change in body-representation when arbitrarily paired with a bodily action. (shrink)

In the past, researchers have focused mainly on the effects and consequences of self-awareness; however, they have neglected a more basic issue pertaining to the specific mechanisms that initiate and sustain self-perception. The author presents a model of self-awareness that proposes the existence of 3 sources of self-information. First, the social milieu includes early face-to-face interactions, self-relevant feedback, a social comparison mechanism that leads to perspective taking, and audiences. Second, contacts with objects and structures in the physical environment foster (...) self–world differentiation in infants; this environment also contains self-focusing and reflecting stimuli, such as mirrors and video cameras. Third, the self can develop bodily awareness through proprioception and can reflect on itself using imagery and inner speech. Furthermore, self-awareness is mainly mediated by the prefrontal lobes. The author establishes various links among these different neurological, social, ecological, and cognitive elements of the model. (shrink)

Traditionally, what we are conscious of in self-consciousness is something non-corporeal. But anti-Cartesian philosophers argue that the self is as much corporeal as it is mental. Because we have the sense of proprioception, a kind of body awareness, we are immediately aware of ourselves as bodies in physical space. In this debate the case histories of patients who have lost their sense of proprioception are clearly relevant. These patients do retain an awareness of themselves as corporeal beings, although they hardly (...) feel their bodies . They can initiate movements, and with the help of visual feedback learn to control them. It is shown that the traditional view of the self as immaterial is not supported by these cases. But the argument against this view has to be amended. It relies too much on bodily sensations, and misses the importance of active self-movement. (shrink)

Patients with delusions of control are abnormally aware of the sensory consequences of their actions and have difficulty with on-line corrections of movement. As a result they do not feel in control of their movements. At the same time they are strongly aware of the action being intentional. This leads them to believe that their actions are being controlled by an external agent. In contrast, the normal mark of the self in action is that we have very little experience of (...) it. Most of the time we are not aware of the sensory consequences of our actions or of the various subtle corrections that we make during the course of goal-directed actions. We know that we are agents and that we are successfully causing the world to change. But as actors we move through the world like shadows glimpsed only occasional from the corner of an eye. (shrink)

Questions about the relation between mind and world have long occupied philosophers of mind. In _Consciousness in Action_ Susan Hurley invites us to adopt a ninety-degree shift and consider the relation between perception and action. The central theme of the book is an attack on what Hurley dubs the _Input-Output Picture_ of perception and actionthe picture of perceptions as sensory inputs to the cognitive system and intentions as motor outputs from it, with the mind occupying the buffer zone in between. (...) Hurley argues that this picture confuses the personal level of normatively constrained mental contents and the subpersonal level of causal processes sustaining the mind. The notions of perception and action belong to the former, those of input and output to the latter. In place of the Input-Output picture, Hurley proposes a _Two-level _ _Interdependence View_. At the subpersonal level, she points out, there are not only one-way processes from input to output but also a host of feedback loops from output to inputsome internal to the central nervous system, some of wider orbit, involving proprioception, for example, or visual feedback on movement. The system as a whole can be seen as a _dynamical singularity_a tangle of sensorimotor feedback loops centred on the organism but extending out into the world beyond. The processes at this level are the vehicles of perceptions and actions, but, Hurley insists, the two levels cannot be mapped onto each other in a simple way. Changes on the output side may affect the content of perceptions, and changes on the input side may affect that of intentions. Perception and intention are in this way _interdependent_. The point here is not the uncontroversial one that perceptions and intentions can _cause_ changes in each other. That would be compatible with the Input-Output Picture. The dependency, in Hurleys view, is not instrumental, but _constitutive_: the contents of perceptions and intentions are each constituted by processes involving both inputs and outputs.. (shrink)

Deafferented subjects, while lacking proprioceptive awareness of much of their bodies, are nevertheless able to use their bodies in basic action. Sustained visual contact with the body parts of which they are no longer proprioceptively aware enables them to move these parts in a controlled way. This might be taken to straightforwardly show that proprioceptive awareness is inessential to bodily action. I, however, argue that this is not the case. Proprioceptive awareness figures essentially in our self-conscious unity (...) as practical subjects. Recognizing this allows us to better understand the nature of the impairment with which deafferented subjects live. (shrink)

I argue for the possibility of a proprioceptive art in addition to, for example, visual or auditory arts, where aspects of some martial arts will serve as examples of that art form. My argument is inspired by a thought of Ted Shawn’s, one of the pioneers of American modern dance: "Dance is the only art wherein we ourselves are the stuff in which it is made.” In a first step, I point out that in some practices of martial arts (...) (in the paper I will introduce “hyongs” & “katas”), we are, too, the stuff these performances are made of. Second, I show that we, as martial arts practitioners, are not in the first place visual or auditorial observers (as common in painting or music or ballet) but introspective, proprioceptive perceivers of our bodies and their movements. (As a corollary we get that we are, in such a case, necessarily our exclusive audience.) In an third crucial step, I show that the martial arts practices referred to, hyongs & katas, and especially the proprioceptive aspects thereof, can indeed count as art. Thus, proprioceptive art is possible because some practices of some martial arts are actual existing examples of that art form. (shrink)

The ability of using a large variety of tools is important in our daily life. Behind human tool-use abilities lays the brain capacity to incorporate tools into the body representation for action (Body Schema, BS), thought to rely mainly on proprioceptive information. Here we tested whether tool incorporation is possible in absence of proprioception by studying a patient with right upper-limb deafferentation. We adopted a paradigm sensitive to changes of the Body Schema and analysed the kinematics of free-hand movements (...) before and after tool-use, in three sessions over a period of two years. In the first session, before tool-use, the kinematics of the deafferented hand was disrupted. Similarly, the first movements with the tool (a mechanical grabber elongating the arm by ∼40cm) showed an abnormal profile that tended to normalize at the end of the session. Subsequent free-hand movements were also normalised. At session 2, 6 months later, the patient exhibited normal free-hand kinematic profiles, additionally showing changes in grasping kinematics after tool-use, but no sign of tool incorporation. A follow-up two years later, further confirmed the normalized kinematic profile but the absence of tool incorporation. This first description of tool-use in absence of proprioception shows the fundamental role of proprioception in the update of the Body Schema. These results provide an important further step in understanding human motor control and have implications for future development of rehabilitation programs for patients with sensory deficits. (shrink)

Proprioception, a sense of bodily position and movement, is rarely the focus of conscious experience. If we are ordinarily conscious of proprioception, we seem only peripherally so. Thus, evidence that proprioception is present in the periphery of at least some conscious experiences seems to be good evidence that conscious experience is fairly rich. Anosognosia for paralysis is a denial of paralysis of one's limbs, usually in the wake of brain damage from stroke. Because anosognosic patients overlook their paralysis, anosognosia seems (...) be a counter-example to the claim that proprioception exists in the periphery of conscious experience. However, careful consideration of the data shows that anosognosia makes a poor counterexample to a rich theory of consciousness. Thus, we retain reason to believe that proprioception exists in the periphery of conscious experience, and so to conclude that conscious experience is relatively rich. (shrink)

Epistemologists spend a great deal of time thinking about how we should respond to our evidence. They spend far less time thinking about the ways that evidence can be acquired in the first place. This is an oversight. Some ways of acquiring evidence are better than others. Many normative epistemologies struggle to accommodate this fact. In this article I develop one that can and does. I identify a phenomenon – epistemic feedback loops – in which evidence acquisition has gone (...) awry, with the result that even beliefs based on the evidence are irrational. Examples include evidence acquired under the influence of confirmation bias and evidence acquired under the influence of cognitively penetrated experiences caused by implicit bias. I then develop a theoretical framework which enables us to understand why beliefs that are the outputs of epistemic feedback loops are irrational. Finally, I argue that many popular approaches to epistemic normativity may need to be abandoned on the grounds that they cannot comfortably explain feedback loops. The scope of this last claim is broad: it includes almost all contemporary theories of justified/rational belief and of the epistemology of cognitive penetration. (shrink)

Recent research on proprioception reveals that it relies on a systematically distorted model of bodily dimensions. This generates a puzzle about proprioception in action control: action requires accurate bodily parameters. Proprioception is crucial for ordinary action, but if it relies on a systematically distorted body model, then proprioception should contain systematic errors. But we cannot respond by discarding proprioception from motor control, since we know from the severe problems deafferented agents face in acting that ordinary action requires proprioception. The solution (...) is that the possibility of bodily action is provided for by multimodal body representations for action. (shrink)

Proprioception is true perceiving. It and touch form a closely linked mutually dependent yet diverse pair. The puzzle whereby the demands upon the Attention of proprioception are no distraction in instrumental action is resoluble through the fact that the internal active content within an instrumental deed is a harmonious hierarchy. The ‘long‐term body image’ is a causally posited something whose content encompasses body shape, which is a necessary but insufficient condition of proprioception of body shape and posture. It is distinct (...) from the ‘short‐term body image’, which designates the internal content of the proprioceptive perception of the body at any moment. The main philosophical problem consists in assembling a bona fide veridical concept of the long‐term image. Reasons for positing it begin with the common content in the short‐term images over lengthy periods. But they must be supplemented by the fact that bodily sensations do not represent body shape, being already dependent on body‐awareness for both individuation and position. Only through hypothesizing a long‐term image can one make sense of proprioception. Reasons are given for believing the body image is a dispositional psychological phenomenon, it is one and the same when explaining proprioception and sensation‐location, it is an empirical postulate, and even though it falls short of being an a priori necessity, it is as deeply embedded in animal existence as proprioception. (shrink)

In formulating a theory of perception that does justice to the embodied and enactive nature of perceptual experience, proprioception can play a valuable role. Since proprioception is necessarily embodied, and since proprioceptive experience is particularly integrated with one’s bodily actions, it seems clear that proprioception, in addition to, e.g., vision or audition, can provide us with valuable insights into the role of an agent’s corporal skills and capacities in constituting or structuring perceptual experience. However, if we are going to (...) have the opportunity to argue from analogy with proprioception to vision, audition, touch, taste, or smell, then it is necessary to eschew any doubts about the legitimacy of proprioception’s inclusion into the category of perceptual modalities. To this end, in this article, I (1) respond to two arguments that Shaun Gallagher ( 2003 ) presents in “Bodily self-awareness and objectperception” against proprioception’s ability to meet the criteria of object perception, (2) present a diagnosis of Gallagher’s position by locating a misunderstanding in the distinction between proprioceptive information and proprioceptive awareness, and (3) show that treating proprioception as a perceptual modality allows us to account for the interaction of proprioception with the other sensory modalities, to apply the lessons we learn from proprioception to the other sensory modalities, and to account for proprioceptive learning. Finally, (4) I examine Sydney Shoemaker’s ( 1994 ) identification constraint and suggest that a full-fledged notion of object-hood is unnecessary to ground a theory of perception. (shrink)