Proprioceptive acuity is of great significance in basic research exploring a possible neural mechanism of fine motor control and in neurorehabilitation practice promoting motor function recovery of limb-disabled people. Moreover, body representation relies on the integration of multiple somatic sensations, including proprioception that is mainly generated in muscles and tendons of human joints. This study aimed to examine two hypotheses: First, different extension positions of wrist joint have different proprioceptive acuities, which might indicate different body representations of wrist joint in (...) the brain. Second, repetitive peripheral magnetic stimulation applied peripherally to the forearm radial nerve and extensors could change proprioceptive acuity at the wrist joint. Thirty-five healthy participants were recruited then randomly divided into the real stimulation group and the sham stimulation group. The participants’ non-dominant side wrist joint position sense was tested at six extension positions within the physiological joint motion range both before stimulation and after stimulation. Results showed that proprioceptive bias among six extension positions could be divided into lower-extension position and higher-extension position. One session rPMS could influence proprioceptive bias in lower-extension position but not in higher-extension position. However, proprioceptive precision was not influenced. To conclude, proprioceptive bias may vary between different wrist extension positions due to different hand postures being related to changes in body representation, and different functions relating to proprioceptive bias and proprioceptive precision may underlie two aspects of body representation. (shrink)

Advances in artificial intelligence, as well as its increased presence in everyday life, have brought the emergence of many new phenomena, including an intriguing appearance of what seems to be a variant of body dysmorphic disorder, coined “Snapchat dysmorphia”. Body dysmorphic disorder is a DSM-5 psychiatric disorder defined as a preoccupation with one or more perceived defects or flaws in physical appearance that are not observable or appear slight to others. Snapchat dysmorphia is fueled by automated selfie filters that reflect (...) unrealistic sociocultural standard. In this paper, we discuss how body dysmorphic disorder and related body image distortions could arise, using the conceptual resources provided by the active inference framework. We suggest that these disorders involve dysfunctional self-modelling which entails maladaptive internalization of sociocultural preferences during adolescent identity formation. Identity formation is hereby described as cycles of interpersonal active inference that arbitrate between identity exploration and commitment. We propose that impaired self-modelling is unable to reduce interpersonal uncertainty during identity exploration, which, over time, degenerates into uncontrollable epistemic habits that isolate the body image from corrective sensory evidence. In light of these insights, we subsequently explore some of the consequences of image-centered social media platforms on the identity formation process. We conclude that heightened interpersonal uncertainty in this novel context could precipitate the onset of body dysmorphic disorder and related body image distortions, particularly when selfie filters are involved. (shrink)

Advances in artificial intelligence, as well as its increased presence in everyday life, have brought the emergence of many new phenomena, including an intriguing appearance of what seems to be a variant of body dysmorphic disorder, coined “Snapchat dysmorphia”. Body dysmorphic disorder is a DSM-5 psychiatric disorder defined as a preoccupation with one or more perceived defects or flaws in physical appearance that are not observable or appear slight to others. Snapchat dysmorphia is fueled by automated selfie filters that reflect (...) unrealistic sociocultural standard. In this paper, we discuss how body dysmorphic disorder and related body image distortions could arise, using the conceptual resources provided by the active inference framework. We suggest that these disorders involve dysfunctional self-modelling which entails maladaptive internalization of sociocultural preferences during adolescent identity formation. Identity formation is hereby described as cycles of interpersonal active inference that arbitrate between identity exploration and commitment. We propose that impaired self-modelling is unable to reduce interpersonal uncertainty during identity exploration, which, over time, degenerates into uncontrollable epistemic habits that isolate the body image from corrective sensory evidence. In light of these insights, we subsequently explore some of the consequences of image-centered social media platforms on the identity formation process. We conclude that heightened interpersonal uncertainty in this novel context could precipitate the onset of body dysmorphic disorder and related body image distortions, particularly when selfie filters are involved. (shrink)

Recent research has drawn attention to the prevalence of self-reported autism within online communities of involuntary celibates (incels). These studies suggest that some individuals with autism may be particularly vulnerable to the impact of incel forums and the hopelessness they generate. However, a more precise description of the experiential connection between inceldom, self-reported autism, and hopelessness has remained unarticulated. Therefore, this article combines empirical studies on the incel community with phenomenological and embodiment approaches to autism, hopelessness, and online affectivity. We (...) analyze three interrelated aspects of online interactions in incel communities – worldview, bodily self-relation, and mutual dismissals – and examine how these elements contribute to the consolidation of the loss of significant life possibilities. By investigating the potential negative influence of specific online environments on affective dispositions, our approach contributes to the debate on current challenges to “situate” phenomenological psychopathology. (shrink)

Bodily awareness seems to present the body as a topologically connected whole, composed of many parts. In consequence, the source of topological and mereological content of bodily awareness comes into question. In particular, it may be asked whether (a) such content is provided by the bodily sense, i.e., sensory mechanisms which, like proprioception, presents the body “from the inside,” or (b) it is a product of “exteroceptive” elements of bodily awareness, which represents the body “from the outside” in a similar (...) way to that of other physical objects. This paper argues that while passive touch and proprioception are unlikely to present the body as a topological and a mereological whole, such content is likely to be provided by kinesthesis. In consequence, it is plausible that holistic topological and mereological bodily content is present in virtue of certain mechanisms of bodily sense. (shrink)

Body image and body schema refer to two different yet closely related systems. Whereas BI can be defined as a system of perceptions, attitudes, and beliefs pertaining to one's own body, BS is a system of sensory-motor capacities that functions without awareness or the necessity of perceptual monitoring. Studies have demonstrated that applying the concepts of BI and BS enables us to conceptualize complex pathological phenomena such as anorexia, schizophrenia, and depersonalization. Likewise, it has further been argued that these concepts (...) play a crucial role in our ability to grasp our bodily experiences in the socio-cultural world according to various factors, such as gender, social class, and ethnicity. Referring to the insights of Frantz Fanon, the author of Black Skin, White Masks, this paper suggests that under certain conditions the BI can take over and reshape the BS. Based on an examination of Fanon’s writings, the paper suggests that not only the BI can truly remold the BS but that the gaze of the other can directly influence the BI. (shrink)