Is it Mine? Hemispheric Asymmetries in Corporeal Self-recognition
ABSTRACT The aim of this study was to investigate whether the recognition of "self body parts" is independent from the recognition of other people's body parts. If this is the case, the ability to recognize "self body parts" should be selectively impaired after lesion involving specific brain areas. To verify this hypothesis, patients with lesion of the right (right brain-damaged [RBD]) or left (left brain-damaged [LBD]) hemisphere and healthy subjects were submitted to a visual matching-to-sample task in two experiments. In the first experiment, stimuli depicted their own body parts or other people's body parts. In the second experiment, stimuli depicted parts of three categories: objects, bodies, and faces. In both experiments, participants were required to decide which of two vertically aligned images (the upper or the lower one) matched the central target stimulus. The results showed that the task indirectly tapped into bodily self-processing mechanisms, in that both LBD patients and normal subjects performed the task better when they visually matched their own, as compared to others', body parts. In contrast, RBD patients did not show such an advantage for self body parts. Moreover, they were more impaired than LBD patients and normal subjects when visually matching their own body parts, whereas this difference was not evident in performing the task with other people's body parts. RBD patients' performance for the other stimulus categories (face, body, object), although worse than LBD patients' and normal subjects' performance, was comparable across categories. These findings suggest that the right hemisphere may be involved in the recognition of self body parts, through a fronto-parietal network.
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- "It could be that this differential effect of endogenous attention relies on the distinctiveness of the representations of own hands with respect to others' hands (c.f. Frassinetti et al. 2008; Myers and Sowden 2008). Interestingly enough, the socalled self-advantage effect (larger P3 potential for selfrelated stimuli than non-self-related stimuli) whereby self-stimuli receive processing priority (e.g. "
ABSTRACT: High-density electroencephalographic recordings were used to investigate the level of analysis at which attentional expectations modulate the processing of specific stimuli from the same perceptual category but differentiated in terms of a particular non-perceptual feature: body ownership. We used a task in which colour cues predicted whether a picture of a hand stimulus belonged to the participant or to somebody else. Participants were instructed to respond whether the target was a left or a right hand. Results revealed that the ERP pattern depended on stimulus ownership and attention orienting, which influenced the visual processing of own and someone else's hands differentially. Larger amplitude for others' than for own hands was shown at the N1 deflection (at the right hemisphere). Attentional effects were found at the P2 and P3 potentials. The P2 reflected an interaction between stimulus ownership and attentional orienting, due to a larger validity effect for others' hands. At the P3 level, the data showed a significant validity effect only for self-hand stimuli. In sum, our results suggest that (1) differences as a function of stimulus ownership can be detected at early levels of stimulus processing; (2) endogenous attention can be directed to exemplars within the same category, hand stimuli in this case; (3) the effects of attention are modulated by ownership.Experimental Brain Research 05/2015; 233(8). DOI:10.1007/s00221-015-4303-z · 2.04 Impact Factor
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- "It is currently an open question if the performance in egocentric transformations differs when the body of an unknown person or one's own body is presented during a mental rotation task. Neuropsychological and neuroimaging studies (Devue et al., 2007; Frassinetti et al., 2008) revealed a clear distinction between the processing of one's one body and the body of others by showing that the recognition of the own body is independent from that of other person's body. Furthermore, Frassinetti et al. (2008) observed a certain self-advantage, expressed by faster RTs and a higher accuracy in self-related body stimuli. "
ABSTRACT: This experiment investigated the influence of motor expertise on object-based versus egocentric transformations in a chronometric mental rotation task using images of either the own or another person's body as stimulus material. According to the embodied cognition viewpoint, we hypothesized motor-experts to outperform non-motor experts specifically in the egocentric condition because of higher kinesthetic representation and motor simulations compared to object-based transformations. In line with this, we expected that images of the own body are solved faster than another person's body stimuli. Results showed a benefit of motor expertise and representations of another person's body, but only for the object-based transformation task. That is, this other-advantage diminishes in egocentric transformations. Since motor experts did not show any specific expertise in rotational movements, we concluded that using human bodies as stimulus material elicits embodied spatial transformations, which facilitates performance exclusively for egocentric transformations. Regarding stimulus material, the other-advantage ascribed to increased self-awareness-consciousness distracting attention-demanding resources, disappeared in the egocentric condition. This result may be due to the stronger link between the bodily self and motor representations compared to that emerging in object-based transformations.Frontiers in Psychology 06/2014; 5:505. DOI:10.3389/fpsyg.2014.00505 · 2.80 Impact Factor
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- "Several studies have identified brain areas for processing the body (fusiform body area) and body-parts (extrastriate body area) (Downing et al., 2001; Sugiura et al., 2006; Uddin et al., 2006; Devue et al., 2007; Urgesi et al., 2007) and specific networks for self and other body-parts processing (Keenan et al., 2000b, 2001; Sugiura et al., 2006; Frassinetti et al., 2008, 2009, 2010; Hodzic et al., 2009). Frassinetti et al. (2008, 2009) reported a behavioural facilitation (i.e. a self-advantage) when neurologically healthy subjects and left braindamaged patients were presented with stimuli depicting their own compared with someone else's body-parts (hand, foot). Instead, right brain-damaged patients did not show any self-advantage, pointing to a critical role for the right hemisphere in self-processing. "
ABSTRACT: Involvement of fronto-parietal structures within the right hemisphere in bodily self recognition has gained convergent support from behavioural, neuropsychological and neuroimaging studies. Increases in corticospinal excitability via transcranial magnetic stimulation (TMS) also testify to right hemisphere self-related processing. However, evidence for self-dependent modulations of motor excitability is limited to the processing of face-related information that, by definition, conveys someone's identity. Here we tested the hypothesis that vision of one's own hand, as compared with vision of somebody else's hand, would also engage specific self-hand processing in the right hemisphere. Healthy participants were submitted to a classic TMS paradigm to assess changes in corticospinal excitability of the right (Experiment 1) and left (Experiment 2) motor cortex, while viewing pictures of a (contralateral) still hand, which could either be their own (Self) or not (Other). As a control for body selectivity, subjects were also presented with pictures of a hand-related, but non-corporeal object, i.e. a mobile phone, which could similarly be their own or not. Results showed a selective right hemisphere increase in corticospinal excitability with self-hand and self-phone stimuli with respect to Other stimuli. Such a Self vs. Other modulation of primary motor cortex appeared at 600 ms and was maintained at 900 ms, but was not present at earlier timings (100 and 300 ms) and was completely absent following stimulation of the left hemisphere. A similar pattern observed for self-hand and self-phone stimuli suggests that owned hands and objects may undergo similar self-processing, possibly via a different cortical network from that responsible for self-face processing.European Journal of Neuroscience 06/2012; 36(5):2716-21. DOI:10.1111/j.1460-9568.2012.08176.x · 3.18 Impact Factor