Differential neural encoding of sensorimotor and visual body representations.

Sensorimotor processing specifically impacts mental body representations. In particular, deteriorated somatosensory input (as after complete spinal cord injury) increases the relative weight of visual aspects of body parts' representations, leading to aberrancies in how images of body parts are mentally manipulated (e.g. mental rotation). This suggests that a sensorimotor or visual reference frame, respectively, can be relatively dominant in local (hands) versus global (full-body) bodily representations. On this basis, we hypothesized that the recruitment of a specific reference frame could be reflected in the activation of sensorimotor versus visual brain networks. To this aim, we directly compared the brain activity associated with mental rotation of hands versus full-bodies. Mental rotation of hands recruited more strongly the supplementary motor area, premotor cortex, and secondary somatosensory cortex. Conversely, mental rotation of full-bodies determined stronger activity in temporo-occipital regions, including the functionally-localized extrastriate body area. These results support that (1) sensorimotor and visual frames of reference are used to represent the body, (2) two distinct brain networks encode local or global bodily representations, and (3) the extrastriate body area is a multimodal region involved in body processing both at the perceptual and representational level

Parietal/premotor lesions effects on visuomotor cognition in neuro-oncology patients: A multimodal study

Background: Assessing prior to surgery the functionality of brain areas exposed near the tumor requires a multimodal approach that combines the use of neuropsychological testing and fMRI tasks. Paradigms based on motor imagery, which corresponds to the ability to mentally evoke a movement, in the absence of actual action execution, can be used to test sensorimotor areas and the functionality of mental motor representations. Methods: The most commonly used paradigm is the Limb Laterality Recognition Task (LLRT), requiring judgments about whether a limb belongs to the left or right side of the body. The group studied included 38 patients with high-grade (N = 21), low-grade (N = 11) gliomas and meningiomas (N = 6) in areas anterior (N = 21) and posterior (N = 17) to the central sulcus. Patients before surgery underwent neuropsychological assessment and fMRI. They performed the LLRT as an fMRI task. Accuracy, and neuroimaging data were collected and combined in a multimodal study. Structural MRI data analyses were performed by subtracting the overlap of volumes of interest (VOIs) plotted on lesions from the impaired patient group vs the overlap of VOIs from the spared group. The fMRI analyses were performed comparing the impaired patients and spared group. Results: In general, patients were within normal limits on many neuropsychological screening tests. Compared with the control group, 17/38 patients had significantly different performance. The subtraction between the VOIs overlay of the impaired patients' group vs. the VOIs overlay of the spared group revealed that the areas maximally involved by lesions in the impaired patients' group were the right postcentral gyrus, right inferior parietal lobe, right supramarginal gyrus, right precentral gyrus, paracentral lobule, left postcentral gyrus, right superior parietal lobe, left inferior parietal lobe, and left superior and middle frontal gyrus. Analysis of the fMRI data showed which of these areas contributes to a correct LLRT performance. The task (vs. rest) in the group comparison (spared vs. impaired patients) activated a cluster in the left inferior parietal lobe. Conclusion: Underlying the altered performance at LLRT in patients with lesions to the parietal and premotor areas of the right and left hemispheres is a difference in activation of the left inferior parietal lobe. This region is involved in visuomotor processes and those related to motor attention, movement selection, and motor planning

Unisensory and multisensory Self-referential stimulation of the lower limb: An exploratory fMRI study on healthy subjects

Background: The holistic view of the person is the essence of the physiotherapy. Knowledge of approaches that develop the whole person promotes better patient outcomes. Multisensory Selfreferential stimulation, more than a unisensory one, seems to produce a holistic experience of the Self (“Core-Self”). Objectives: (1) To analyze the somatotopic brain activation during unisensory and multisensorial Self-referential stimulus; and (2) to understand if the areas activated by multisensorial Self-referential stimulation are the ones responsible for the “Core-Self.” Methods: An exploratory functional magnetic resonance imaging (fMRI) study was performed with 10 healthy subjects, under the stimulation of the lower limbs with three Self-referential stimuli: unisensory auditory-verbal, unisensory tactile-manual, and multisensory, applying the unisensory stimuli simultaneously. Results: Unisensory stimulation elicits bilateral activations of the temporoparietal junction (TPJ), of the primary somatosensory cortex (S1), of the primary motor cortex (BA4), of the premotor cortex (BA6) and of BA44; multisensory stimulation also elicits activity in TPJ, BA4, and BA6, and when compared with unisensory stimuli, activations were found in: (1) Cortical and subcortical midline structures—BA7 (precuneus), BA9 (medial prefrontal cortex), BA30 (posterior cingulated), superior colliculum and posterior cerebellum; and (2) Posterior lateral cortex—TPJ, posterior BA13 (insula), BA19, and BA37. Bilateral TPJ is the one that showed the biggest activation volume. Conclusion: This specific multisensory stimulation produces a brain activation map in regions that are responsible for multisensory Self-processing and may represent the Core- Self. We recommend the use of this specific multisensory stimulation as a physiotherapy intervention strategy that might promote the Self-reorganization.info:eu-repo/semantics/publishedVersio

Illusory self-identification with an avatar reduces arousal responses to painful stimuli

Looking at one's own body has been shown to induce analgesia. In the present work we investigated whether illusory self-identification with an avatar, as induced experimentally through visuo-tactile stimulation, modulates the response to painful stimuli. In 30 healthy volunteers, a robotic device was used to stroke the participants' back, while they viewed either the body of an avatar, a non-body object (control object), or a body avatar with scrambled body parts (control body). All were visually stimulated in either congruent or incongruent fashion with the participant's body. We collected physiological responses (skin conductance response: SCR) to painful stimuli delivered to the participant's hand and responses to a questionnaire inquiring about self-identification with the avatar. We expected reduced physiological responses to pain during the observation of a body avatar only during synchronous visuo-tactile stroking and no reduction for the control object and the control body. Results showed a reduced SCR to painful stimuli when participants observed the normal body avatar being stroked synchronously that was also associated with largest self-identification ratings recordable already during the pain anticipation. Moreover, a negative correlation between self-identification and SCR was observed, suggesting that a greater degree of self-identification with the avatar was associated with larger decreases in SCR. These results suggest that during states of illusory self-identification with the avatar, the vision of an alien body (anatomically compatible for the vision and congruently stroked for the touch) is effective in modulating physiological responses to painful stimuli. (C) 2014 Elsevier B.V. All rights reserved

Neural substrates of self‐ and external‐preoccupation: A voxel‐based morphometry study

Introduction: Self- and external-preoccupation have been linked to psychopathological states. The neural substrates underlying self- and external-preoccupation remain unclear. In the present study, we aim to provide insight into the information-processing mechanisms associated with self- and external-preoccupation at the structural level. Methods: To investigate the neural substrates of self- and external-preoccupation, we acquired high-resolution T1-weighted structural images and Preoccupation Scale scores from 1,122 young subjects. Associations between regional gray matter volume (rGMV) and Preoccupation Scale subscores for self- and external-preoccupation were estimated using voxel-based morphometry. Results: Significant positive associations between self-preoccupation and rGMV were observed in widespread brain areas such as the bilateral precuneus and posterior cingulate gyri, structures known to be associated with self-triggered self-reference during rest. Significant negative associations between external-preoccupation and rGMV were observed only in the bilateral cerebellum, regions known to be associated with behavioral addiction, sustained attention, and reward system. Conclusion: Our results reveal distinct neural substrates for self- and external-preoccupation at the structural level

The paradigmatic body : embodied simulation, intersubjectivity, the bodily self, and language

In this paper we propose a way in which cognitive neuroscience could provide new insights on three aspects of social cognition: intersubjectivity, the human self, and language. We emphasize the crucial role of the body, conceived as the constitutive source of pre-reflective consciousness of the self and of the other. We provide a critical view of contemporary social cognitive neuroscience, arguing that the brain level of description is a necessary but not sufficient condition for studying intersubjectivity, the human self, and language; which are only properly visible if coupled with a full appreciation of their intertwined relationship with the body. We introduce mirror mechanisms and embodied simulation and discuss their relevance to a new account of intersubjectivity and the human self. In this context, we focus on a specifically human modality of intersubjectivity: language. Aspects of social cognition related to language are discussed in terms of embodiment, while emphasizing the progress and limitations of this approach. We argue that a key aspect of human language consists in its decoupling from its usual denotative role, hence manifesting its power of abstraction. We discuss these features of human language as instantiations of the Greek notion of paradeigma, originally explored by Aristotle to refer to a typical form of rhetorical reasoning and relate it to embodied simulation. Paradigmatic knowledge connects the particular with the particular, moving from the contingent particular situation to an exemplary case. Similarly, embodied simulation is the suspension of the “concrete” application of a process: reuse of motor knowledge in the absence of the movement it realizes is an example of “paradigmatic knowledge.” This new epistemological approach to intersubjectivity generates predictions about the intrinsic functional nature of our social cognitive operations, cutting across, and not subordinated to, a specific ontology of mind

Motor-based bodily self is selectively impaired in eating disorders

BACKGROUND: Body representation disturbances in body schema (i.e. unconscious sensorimotor body representations for action) have been frequently reported in eating disorders. Recently, it has been proposed that body schema relies on adequate functioning of the motor system, which is strongly implicated in discriminating between one’s own and someone else’s body. The present study aimed to investigate the motor-based bodily self in eating disorders and controls, in order to examine the role of the motor system in body representation disturbances at the body schema level. METHODS: Female outpatients diagnosed with eating disorders (N = 15), and healthy controls (N = 18) underwent a hand laterality task, in which their own (self-stimuli) and someone else’s hands (other-stimuli) were displayed at different orientations. Participants had to mentally rotate their own hand in order to provide a laterality judgement. Group differences in motor-based bodily self-recognition—i.e. whether a general advantage occurred when implicitly processing self- vs. other-stimuli − were evaluated, by analyzing response times and accuracy by means of mixed ANOVAs. RESULTS: Patients with eating disorders did not show a temporal advantage when mentally rotating self-stimuli compared to other-stimuli, as opposed to controls (F(1, 31) = 5.6, p = 0.02; eating disorders-other = 1092 ±256 msec, eating disorders-self = 1097±254 msec; healthy controls-other = 1239±233 msec, healthy controls -self = 1192±232 msec). CONCLUSIONS: This study provides initial indication that high-level motor functions might be compromised as part of body schema disturbances in eating disorders. Further larger investigations are required to test motor system abnormalities in the context of body schema disturbance in eating disorders

Flujos informativos, mecanismos y modelos en la síntesis de proteínas

El artículo inicia subrayando la creciente importancia de los diagramas en filosofía de la ciencia, en particular se destaca su capacidad para la evocación heurística, su utilidad para la representación y el cálculo, y su poder de síntesis. A continuación, se presenta la importancia y buena recepción que diagramas de diferentes mecanismos causales en ciencia, han tenido dentro del nuevo mecanicismo lo que contrasta con el rechazo de esta escuela a los enfoques centrados en leyes y modelos. Finalmente se presenta una interpretación de las leyes y de las explicaciones mecanísticas que torna compatibles las ideas de mecanismo y de ley. Se utiliza el mecanismo de la síntesis de proteínas como caso ilustrativoThis paper starts with an emphasis on the increasing importance of diagrams in philosophy of science, highlighting their capacity for heuristic evocation, their usefulness for representation and calculus, and their power of synthesis. Next, we present how diagrams are important and have been well received within the new Mechanistic philosophy of science, which contrasts with this school’s rejection of approaches centered on laws and models. Finally, We propose an interpretation of laws and mechanistic explanations that conciliates the concepts of mechanism and law. The mechanism of protein synthesis is used as an illustrative cas

Role of medial premotor areas in action language processing in relation to motor skills

The literature reports that the supplementary motor area (SMA) and pre-supplementary motor area (pre-SMA) are involved in motor planning and execution, and in motor-related cognitive functions such as motor imagery. However, their specific role in action language processing remains unclear. In the present study, we investigated the impact of repetitive transcranial magnetic stimulation (rTMS) over SMA and pre-SMA during an action semantic analogy task (SAT) in relation with fine motor skills (i.e., manual dexterity) and motor imagery abilities in healthy non-expert adults. The impact of rTMS over SMA (but not pre-SMA) on reaction times (RT) during SAT was correlated with manual dexterity. Specifically, results show that rTMS over SMA modulated RT for those with lower dexterity skills. Our results therefore demonstrate a causal involvement of SMA in action language processing, as well as the existence of inter-individual differences in this involvement. We discuss these findings in light of neurolinguistic theories of language processing

The Phenomenological Origins of Property

This thesis delineates the phenomenological basis of ownership and property. The phenomenological theory of property has three main elements: the minimal self, the relationship between the sense of agency and the sense of ownership, and the psychological phenomenon of associative self-anchoring. The well established neurocognitive concept of the minimal self encapsulates a person’s immediate self-consciousness, and the non-conceptual senses of agency and ownership are two integral constituents of this immediate sensory experience. Notably, this sense of self is typified by a motor intentionality (i.e., the minimal self is primed for goal-directed actions). The motor character of the minimal self primarily manifests itself in the construct of the body schema—a dynamic mental model of the body that functions as an instrument of directed action. A remarkable feature of the body schema is that it expands to incorporate extracorporeal objects that are objectively controlled by the person (e.g., grasping a pen or holding an umbrella). Moreover, this embodiment of extracorporeal objects is accompanied by the phenomenological feeling of ownership towards the embodied objects. In fact, I demonstrate with the aid of empirical evidence from cognitive neuroscience and neuropsychology that the sense of ownership and the sense of agency are inextricably linked, and that the sense of agency modulates (engenders) the sense of ownership. In other words, the mere experience of agency over an object is capable of evoking the sense of ownership—the influence of the sense of agency in eliciting the sense of ownership is moderated by gestalt-like principles of priority, consistency, and exclusivity. In addendum, the non-conceptual sense of ownership is shaped and strengthened by the formation of implicit self-object associations—people psychologically associate themselves with their possessions. Altogether, the motor-intentional nature of the self, the inherent sensory experience of ownership, and the capacity to establish self-object psychological associations make the concept of personal property a natural correlate of mechanisms that lead to the development of self-perception and representation. The phenomenological theory also elucidates the psychological literature on ownership judgments and the vague concept of intellectual property. It is also emphasised that aspects of this property theory are analogous to Hegel’s theory of property. As a result, the phenomenological theory may have implications for Hegelian conceptions of property, and can aid them in determining legitimate property relations—these typically denote a close connection between property and personhood