Disturbances of self-other distinction after stimulation of the extrastriate body area in the human brain
ABSTRACT In a recent experiment with functional magnetic-resonance imaging, we found that brain activity in the extrastriate body area (EBA) distinguished between observed self- and other-generated movements, being significantly higher during observation of someone else's movement. Here, we investigated further the role of EBA in self-other distinctions using low-frequency repetitive transcranial magnetic stimulation (rTMS). As compared with rTMS applied over a control site, rTMS applied over the EBA increased reaction times, without affecting accuracy, for the detection of other-generated movements. Performance on a control motion-direction detection task was unaffected. These findings provide additional evidence for the role of the EBA in processing information necessary for identifying ourselves as agents of self-generated movements.
- SourceAvailable from: Sébastien Hétu
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- "led researchers to investigate its possible role in self-other discrimination. For instance, David et al.  showed that low frequency rTMS on the EBA decreased the subjects' performance on self-other discrimination task. Similar results were found by disrupting the functioning of the inferior parietal lobule  or the superior parietal lobule . "
ABSTRACT: Empathy is a multi-dimensional concept allowing humans to understand the emotions of others and respond adaptively from a social perspective. This mental process, essential to social interactions, has attracted the attention of many scholars from different fields of study but the blooming interest for empathy in cognitive neurosciences has rekindled this interest. This paper reviews the growing literature stemming from studies using brain stimulation techniques that have investigated directly or indirectly the different components of empathy, including resonance, self-other discrimination, and mentalizing. Some studies have also ventured toward the modulation of this complex process and toward the investigation of different components in populations that show reduced empathic skills. We argue that brain stimulation techniques have the potential to make a unique contribution to the field of empathy research with their exclusive capacity, compared to other brain imaging techniques, to modulate the neural systems involved in the distinct components of this process. Provided the development of innovative ecological paradigms that will put people in actual social interactions as well as comprehensive and adaptive models that can integrate research from different domains, the ultimate goal of this research domain is to devise protocols that can modulate empathy in people with developmental, neurological and psychiatric disorders.Brain Stimulation 03/2012; 5(2):95-102. DOI:10.1016/j.brs.2012.03.005 · 5.43 Impact Factor
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- "Ten years ago, a visual area located in the human occipito-temporal cortex was shown to respond selectively to body parts (extrastriate body area, EBA, ). More recently, the same area was proposed to perform a " sorting of body part images by identity " , either by itself    , or as part of a right hemisphere network  , thus adding to the rich neuroanatomical data on agency attribution     . "
ABSTRACT: You are queuing at the bus stop, and notice that someone suddenly turns her walk into a run: typically, you assume that she wants to catch the bus and may want to tell the driver to wait. Faced with a sudden speed change, rather than considering it bizarre or unnatural, observers attach a meaning to it, and act consequently. In a social context, speed of a movement often bears as much significance as its form, and can be adapted to vehicle precise meanings. This pragmatic rule facilitates decoding of non-verbal messages from other individuals, but may not necessarily apply when observing one's own movements, for which intentions should be informative enough. Hence, the range of motion speeds labeled as 'natural' could be broader for other people's actions compared to one's own. We explored this possibility through a task in which human observers decided whether speed of a gesture had been artificially modified. A virtual hand was presented, which - unbeknownst to participants - moved according to the kinematics of either the observer, or another individual. Although a self/other distinction was never required, participants applied different criteria when dealing with self compared to other people's gestures, suggesting that the brain implicitly extracts identity information before any overt judgment is produced. Interestingly, observers were reluctant to labeling movements of another individual as artificial, in keeping with the hypothesis that large variations in movements' speed can vehicle social messages, and therefore are not regarded a priori as unnatural.Neuroscience Letters 07/2011; 498(1):6-9. DOI:10.1016/j.neulet.2011.04.032 · 2.06 Impact Factor
- "In another study by the same group, observers had to discriminate between visual feedbacks congruent and incongruent with their own movements. rTMS applied over the left EBA increased the reaction time of the discrimination without affecting its accuracy, suggesting that EBA plays some role in monitoring the sensory consequences of one's own movements and thus may participate in the sense of agency and the self/other distinction (David et al. 2008). Yet other cortical regions, such as the insula, are probably more important than EBA for the sense of agency and the sense of body ownership, both of which are probably essential for self-consciousness. "
Article: The body in the brain[Show abstract] [Hide abstract]
ABSTRACT: Corporeal awareness is a difficult concept which refers to perception, knowledge and evaluation of one's own body as well as of other bodies. We discuss here some controversies regarding the significance of the concepts of body schema and body image, as variously entertained by different authors, for the understanding of corporeal awareness, and consider some newly proposed alternatives. We describe some recent discoveries of cortical areas specialized for the processing of bodily forms and bodily actions, as revealed by neuroimaging, neurophysiological, and lesion studies. We further describe new empirical and theoretical evidence for the importance of interoception, in addition to exteroception and proprioception, for corporeal awareness, and discuss how itch, a typical interoceptive input, has been wrongly excluded from the classic concept of the proprioceptive-tactile body schema. Finally, we consider the role of the insular cortex as the terminal cortical station of interoception and other bodily signals, along with Craig's proposal that the human insular cortex sets our species apart from other species by supporting consciousness of the body and the self. We conclude that corporeal awareness depends on the spatiotemporally distributed activity of many bodies in the brain, none of which is isomorphic with the actual body.Experimental Brain Research 09/2009; 200(1):25-35. DOI:10.1007/s00221-009-1970-7 · 2.17 Impact Factor