1,721,946 research outputs found
Transcranial magnetic stimulation reveals two cortical pathways for visual body processing
Full text linkVisual recognition of human bodies is more difficult for upside down than upright presentations. This body inversion effect implies that body perception relies on configural rather than local processing. Although neuroimaging studies indicate that the visual processing of human bodies engages a large fronto-temporo-parietal network, information about the neural underpinnings of configural body processing is meager. Here, we used repetitive transcranial magnetic stimulation (rTMS) to study the causal role of premotor, visual, and parietal areas in configural processing of human bodies. Eighteen participants performed a delayed matching-to-sample task with upright or inverted static body postures. Event-related, dual-pulse rTMS was applied 150 ms after the sample stimulus onset, over left ventral premotor cortex (vPMc), right extrastriate body area (EBA), and right superior parietal lobe (SPL) and, as a control site, over the right primary visual cortex (V1). Interfering stimulation of vPMc significantly reduced accuracy of matching judgments for upright bodies. In contrast, EBA rTMS significantly reduced accuracy for inverted but not for upright bodies. Furthermore, a significant body inversion effect was observed after interfering stimulation of EBA and V1 but not of vPMc and SPL. These results demonstrate an active contribution of the fronto-parietal mirror network to configural processing of bodies and suggest a novel, embodied aspect of visual perception. In contrast, the local processing of the body, possibly based on the form of individual body parts instead of on the whole body unit, appears to depend on EBA. Therefore, we propose two distinct cortical routes for the visual processing of human bodies
Audio-visual feedback improves the BCI performance in the navigational control of a humanoid robot
Full text linkAdvancement in brain computer interfaces (BCI) technology allows people to actively interact in the world through surrogates. Controlling real humanoid robots using BCI as intuitively as we control our body represents a challenge for current research in robotics and neuroscience. In order to successfully interact with the environment the brain integrates multiple sensory cues to form a coherent representation of the world. Cognitive neuroscience studies demonstrate that multisensory integration may imply a gain with respect to a single modality and ultimately improve the overall sensorimotor performance. For example, reactivity to simultaneous visual and auditory stimuli may be higher than to the sum of the same stimuli delivered in isolation or in temporal sequence. Yet, knowledge about whether audio-visual integration may improve the control of a surrogate is meager. To explore this issue, we provided human footstep sounds as audio feedback to BCI users while controlling a humanoid robot. Participants were asked to steer their robot surrogate and perform a pick-and-place task through BCI-SSVEPs. We found that audio-visual synchrony between footsteps sound and actual humanoid's walk reduces the time required for steering the robot. Thus, auditory feedback congruent with the humanoid actions may improve motor decisions of the BCI's user and help in the feeling of control over it. Our results shed light on the possibility to increase robot's control through the combination of multisensory feedback to a BCI user. © 2014 Tidoni, Gergondet, Kheddar and Aglioti
Visually induced analgesia: seeing the body reduces pain
No full textGiven previous reports of strong interactions between vision and somatic senses, we investigated whether vision of the body modulates pain perception. Participants looked into a mirror aligned with their body midline at either the reflection of their own left hand (creating the illusion that they were looking directly at their own right hand) or the reflection of a neutral object. We induced pain using an infrared laser and recorded nociceptive laser-evoked potentials (LEPs). We also collected subjective ratings of pain intensity and unpleasantness. Vision of the body produced clear analgesic effects on both subjective ratings of pain and the N2/P2 complex of LEPs. Similar results were found during direct vision of the hand, without the mirror. Furthermore, these effects were specific to vision of one’s own hand and were absent when viewing another person’s hand. These results demonstrate a novel analgesic effect of non-informative vision of the body
Don't do it! Cortical inhibition and self-attribution during action observation
No full textNumerous studies suggest that both self-generated and observed actions of others activate overlapping neural networks, implying a shared, agent-neutral representation of self and other. Contrary to the shared representation hypothesis, we recently showed that the human motor system is not neutral with respect to the agent of an observed action [Schütz-Bosbach, S., Mancini, B., Aglioti, S. M., & Haggard, P. Self and other in the human motor system. Current Biology, 16, 1830–1834, 2006]. Observation of actions attributed to another agent facilitated the motor system, whereas observation of identical actions linked to the self did not. Here we investigate whether the absence of motor facilitation for observing one’s own actions reflects a specific process of cortical inhibition associated with self-representation. We analyzed the duration of the silent period induced by transcranial magnetic stimulation of the motor cortex in active muscles as an indicator of motor inhibition. We manipulated whether an observed action was attributed to another agent, or to the subjects themselves, using a manipulation of body ownership on the basis of the rubber hand illusion. Observation of actions linked to the self led to longer silent periods than observation of a static hand, but the opposite effect occurred when observing identical actions attributed to another agent. This finding suggests a specific inhibition of the motor system associated with self-representation. Cortical suppression for actions linked to the self might prevent inappropriate perseveration within the motor system
The role of thalamus and basal ganglia in human cognition
No full textCerebral lesions involving the thalamus or the basal ganglia can impair cognitive functions (e.g. language, memory, or attention) that were previously believed to be linked almost exclusively to cortical structures. These impairments are mostly evident when, in addition to nuclear lesions, there is an involvement of the subcortical white matter that includes bundles of fibres for cortico-cortical and cortico-subcortical connections. Based on this result, it has been hypothesized that cognitive deficits after subcortical lesions are due entirely to remote effects on select cortical targets. Thus, the notion of subcortical cognition has been questioned. However, since cortical lesions can have remote effects on their subcortical targets, the notion of cortical cognition can be challenged as well.
The present article deals with the concept of subcortical cognition and reviews lesion studies hinting at a role for thalamus and basal ganglia in complex human behaviour. A proposal is made that the notion of large neural networks with both cortical and subcortical nodes may give a plausible interpretation of cognitive deficits
Don't do it! Cortical inhibition and self-attribution during action observation
No full textNumerous studies suggest that both self-generated and observed actions of others activate overlapping neural networks, implying a shared, agent-neutral representation of self and other. Contrary to the shared representation hypothesis, we recently showed that the human motor system is not neutral with respect to the agent of an observed action [Schütz-Bosbach, S., Mancini, B., Aglioti, S. M., & Haggard, P. Self and other in the human motor system. Current Biology, 16, 1830-1834, 2006]. Observation of actions attributed to another agent facilitated the motor system, whereas observation of identical actions linked to the self did not. Here we investigate whether the absence of motor facilitation for observing one's own actions reflects a specific process of cortical inhibition associated with self-representation. We analyzed the duration of the silent period induced by transcranial magnetic stimulation of the motor cortex in active muscles as an indicator of motor inhibition. We manipulated whether an observed action was attributed to another agent, or to the subjects themselves, using a manipulation of body ownership on the basis of the rubber hand illusion. Observation of actions linked to the self led to longer silent periods than observation of a static hand, but the opposite effect occurred when observing identical actions attributed to another agent. This finding suggests a specific inhibition of the motor system associated with self-representation. Cortical suppression for actions linked to the self might prevent inappropriate perseveration within the motor system. © 2008 Massachusetts Institute of Technology
Review of: Gambetta D., Datacrazia. Politica, cultura algoritmica e conflitti al tempo dei big data, Roma, D Editore, 2018, 360 pp.
No full textRecensione del libro "Datacrazia. Politica, cultura algoritmica e conflitti al tempo dei big data
Sensory and spatial components of somaesthetic deficits following right brain damage
No full textWe instructed patients with right brain damage (RBD) and somatosensory extinction, hemispatial neglect, or both to verbally report light touches delivered to the left hand, to the right hand, or simultaneously to both hands in two experimental situations. In the "anatomic" situation, each hand was in its homonymous hemispace; in the "crossed" one, each hand was held across the corporeal midline, in its heteronymous hemispace. Under both single and the double stimulation conditions, RBD patients detected stimuli delivered to the contralesional hand with lower accuracy in the anatomic than in the crossed position. This result suggests that somaesthetic deficits can be due not only to sensory but also to attentional factors, depending on the spatial position of the hands. Processing of sensory information in primary areas should not be influenced by the hemispatial position of the stimulated body part. These results suggest that somaesthetic deficits may stem not only from damage of primary sensory areas, as classically held, but also from damage of higher-order areas where information about stimuli, body parts, and extrapersonal space is integrated. Finally, the results show that sensory and attentional components of the deficit can be dissociated by using a very simple clinical test
L’Università dei meme: Tra strategie di resistenza digitale e costruzione di comunità affettive
No full textThis article explores how digital culture, and particularly internet memes, has transformed the experience of university life. Through a case study of the Instagram page @Memesunipi, it analyzes how memes function as devices for emotional re-elaboration, enabling students to cope with anxiety, precarity, and academic pressure. Memes are interpreted both as tools of individual catharsis and as catalysts for the creation of affective publics and informal student communities. The study highlights how memetic practices offer alternative narratives to the dominant meritocratic and performative rhetoric of neoliberal academia. By tracing the intersection between platform logics, collective storytelling, and emotional solidarity, the article shows how memes contribute to reconfiguring the boundaries of contemporary student participation and critical agency within the university space
#IOSONOGIORGIA: Genealogia di un meme tra framing e (re)framing
Full text linkThis study delves into the memeification of political discourse, focusing on the “Io Sono Giorgia” meme linked to Italian Prime Minister Giorgia Meloni. Analyzing Meloni’s transformation from a political figure to a meme icon, this research investigates the dynamics of framing and reframing in the digital space, particularly on Instagram. By analyzing empirical data gathered from the hashtags #iosonogiorgia and #iosonogiorgiachallenge, this study employs semantic network analysis to clarify how memes blend humor and pop culture to influence political narratives. The research reveals how strategic interaction with memes can amplify a political figure’s public image and outreach. Meloni’s case demonstrates the profound impact of memes in shaping political communication in the digital era, offering new insights into the role of memes in the hybrid media system. This investigation underscores the power of memes as tools for political engagement and narrative construction in contemporary politics
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