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)
This paper investigates the role of a pre-existing body-model that is an enabling constraint for the incorporation of objects into the body. This body-model is also a basis for the distinction between body extensions (e.g., in the case of tool-use) and incorporation (e.g., in the case of successful prosthesis use). It is argued that, in the case of incorporation, changes in the sense of body-ownership involve a reorganization of the body-model, whereas extension of the body with tools does not involve (...) changes in the sense of body-ownership. (shrink)
The recent distinction between sense of agency and sense of body-ownership has attracted considerable empirical and theoretical interest. The respective contributions of central motor signals and peripheral afferent signals to these two varieties of body experience remain unknown. In the present review, we consider the methodological problems encountered in the empirical study of agency and body-ownership, and we then present a series of experiments that study the interplay between motor and sensory information. In particular, we focus on how multisensory signals (...) interact with body representations to generate the sense of body-ownership, and how the sense of agency modulates the sense of body-ownership. Finally, we consider the respective roles of efferent and afferent signals for the experience of one’s own body and actions, in relation to self-recognition and the recognition of other people’s actions. We suggest that the coherent experience of the body depends on the integration of efferent information with afferent information in action contexts. Overall, whereas afferent signals provide the distinctive content of one’s own body experience, efferent signals seem to structure the experience of one’s own body in an integrative and coherent way. (shrink)
How do we acquire a mental representation of our own face? Recently, synchronous, but not asynchronous, interpersonal multisensory stimulation between one’s own and another person’s face has been used to evoke changes in self-identification. We investigated the conscious experience of these changes with principal component analyses that revealed that while the conscious experience during synchronous IMS focused on resemblance and similarity with the other’s face, during asynchronous IMS it focused on multisensory stimulation. Analyses of the identified common factor structure revealed (...) significant quantitative differences between synchronous and asynchronous IMS on self-identification and perceived similarity with the other’s face. Experiment 2 revealed that participants with lower interoceptive sensitivity experienced stronger enfacement illusion. Overall, self-identification and body-ownership rely on similar basic mechanisms of multisensory integration, but the effects of multisensory input on their experience are qualitatively different, possibly underlying the face’s unique role as a marker of selfhood. (shrink)
Multisensory stimulation has been shown to alter the sense of body-ownership. Given that perceived similarity between one’s own body and those of others is crucial for social cognition, we investigated whether multisensory stimulation can lead participants to experience ownership over a hand of different skin colour. Results from two studies using introspective, behavioural and physiological methods show that, following synchronous visuotactile stimulation, participants can experience body-ownership over hands that seem to belong to a different racial group. Interestingly, a baseline measure (...) of implicit racial bias did not predict whether participants would experience the RHI, but the overall strength of experienced body-ownership seemed to predict the participants’ post-illusion implicit racial bias with those who experienced a stronger RHI showing a lower bias. These findings suggest that multisensory experiences can override strict ingroup/outgroup distinctions based on skin colour and point to a key role for sensory processing in social cognition. (shrink)
Psychology distinguishes between a bodily and a narrative self. Within neuroscience, models of the bodily self are based on exteroceptive sensorimotor processes or on the integration of interoceptive sensations. Recent research has revealed interactions between interoceptive and exteroceptive processing of self-related information, for example that mirror self-observation can improve interoceptive awareness. Using heartbeat perception, we measured the effect on interoceptive awareness of two experimental manipulations, designed to heighten attention to bodily and narrative aspects of the self. Participants gazed at a (...) photograph of their own face or at self-relevant words. In both experimental conditions interoceptive awareness was significantly increased, compared to baseline. Results show that attention to narrative aspects of self, previously regarded as relying on higher-order processes, has an effect similar to self-face stimuli in improving interoceptive awareness. Our findings extend the previously observed interaction between the bodily self and interoception to more abstract amodal representations of the self. (shrink)
The Phenomenal Self (PS) is widely considered to be dependent on body representations, whereas the Narrative Self (NS) is generally thought to rely on abstract cognitive representations. The concept of the Bodily Social Self (BSS) might play an important role in explaining how the high level cognitive self-representations enabling the NS might emerge from the bodily basis of the PS. First, the phenomenal self (PS) and narrative self (NS), are briefly examined. Next, the BSS is defined and its potential for (...) explaining aspects of social cognition is explored. The minimal requirements for a BSS are considered, before reviewing empirical evidence regarding the development of the BSS over the first year of life. Finally, evidence on the involvement of the body in social distinctions between self and other is reviewed to illustrate how the BSS is affected by both the bottom up effects of multisensory stimulation and the top down effects of social identification. (shrink)
This article examines the inflationary view of the body ownership. It reviews a growing body of empirical research on the sense of body ownership that suggests that the deflationary depends on the integration of somatosensory signals. It discusses the results of recent research on out-of-body experiences and shows that the neurocognitive processes involved in the Rubber Hand Illusion are also involved in OBE. It suggests that this experience of bodily ownership may be a critical component of self-specificity.
We become aware of our bodies interoceptively, by processing signals arising from within the body, and exteroceptively, by processing signals arising on or outside the body. Recent research highlights the importance of the interaction of exteroceptive and interoceptive signals in modulating bodily self-consciousness. The current study investigated the effect of social self-focus, manipulated via a video camera that was facing the participants and that was either switched on or off, on interoceptive sensitivity and on tactile perception ). The results indicated (...) a significant effect of self-focus on SSDT performance, but not on interoception. SSDT performance was not moderated by interoceptive sensitivity, although interoceptive sensitivity scores were positively correlated with false alarms, independently of self-focus. Together with previous research, our results suggest that self-focus may exert different effects on body perception depending on its mode . While interoception has been previously shown to be enhanced by private self-focus, the current study failed to find an effect of social self-focus on interoceptive sensitivity, instead demonstrating that social self-focus improves exteroceptive somatosensory processing. (shrink)
The perception of being located within one’s body is an essential feature of everyday self-experience. However, by manipulating exteroceptive input, healthy participants can easily be induced to perceive themselves as being spatially dislocated from their physical bodies. It has previously been suggested that interoception, i.e., the processing of inner physiological signals, contributes to the stability of body representations; however, this relationship has not previously been tested for different dimensions of interoception and bodily self-location. In the present study, using an advanced (...) automatized setup, we systematically manipulated participants’ perspective of their own body as well as the synchrony of visuotactile stimulation. The malleability of bodily self-location was assessed using a questionnaire targeting in-body and out-of-body experiences. Participants also performed a heartbeat discrimination task to assess their interoceptive accuracy, interoceptive sensibility, and interoceptive awareness. Bodily self-location was significantly influenced by perspective, with third-person perspective being associated with stronger out-of-body experiences compared to first-person perspective. Furthermore, there was a significant perspective × stimulation interaction, with subsequent analyses showing that participants reported out-of-body experiences particularly under third-person perspective combined with synchronous visuotactile stimulation. Correlation and regression analyses revealed that meta-cognitive interoceptive awareness was specifically and negatively related to the exteroceptively mediated malleability of body experiences. These results indicate that the perception of the self being located within one’s body relies on the interaction of exteroceptive input and higher-order interoceptive abilities. This has implications for theoretical considerations about the bodily self in health as well as for the understanding of disturbed bodily self-processing in clinical contexts. (shrink)
This article explores Triphiodorus’ use of Cassandra in his brief epic Sack of Troy. An examination of the placing of the prophetess within the poem's plot and a comparison with previous literary attestations demonstrate that Triphiodorus makes extended use of the previously supplementary character. The reader is particularly invited to read Cassandra against the Cassandras of Euripides’ Trojan Women and Quintus Smyrnaeus’ Posthomerica, thus identifying ties with both epic and tragedy. Cassandra's speech alludes to the proem of the epic. At (...) the same time, Cassandra's prophecy constitutes the key for understanding the connection between imagery deployed prior and subsequent to her presence, thus ensuring the thematic congruity of the poem. Triphiodorus’ Cassandra constitutes a doublet of the poet, depicted as imitating his poetic voice and effectively summarizing the entire epic in her speech; entwined in Triphiodorus’ poetic agenda, she also becomes its intradiegetic mouthpiece. (shrink)
Schilbach et al. contrast second-person and third-person approaches to social neuroscience. We discuss relations between second-person and first-person approaches, arguing that they cannot be studied in isolation. Contingency is central for converging first- and second-person approaches. Studies of embodiment show how contingencies scaffold first-person perspective and how the transition from a third- to a second-person perspective fundamentally involves first-person contributions.