1,721,049 research outputs found
Neuropsicologia dell'intersoggettività
No full textIl capitolo tratta gli studi sperimentali su soggetti sani, i correlati neurofisiologici e neuroanatomici e le sindromi neuropsicologiche relative alle neuroscienze sociali , con particolare riferimento agli studi sull'empatia e sulla teoria della mente. Presenta inoltre gli strumenti di valutazione neuropsicologica oggi disponibili in lingua italiana e non
Hemispheric metacontrol and cerebral dominance in healthy individuals investigated by means of chimeric faces
No full textCerebral dominance and hemispheric metacontrol were investigated by testing the ability of healthy participants to match chimeric, entire, or half faces presented tachistoscopically. The two hemi-faces compounding chimeric or entire stimuli were presented simultaneously or asynchronously at different exposure times. Participants did not consciously detect chimeric faces for simultaneous presentations lasting up to 40 ms. Interestingly, a 20 ms separation between each half-chimera was sufficient to induce detection of conflicts at a conscious level. Although the presence of chimeric faces was not consciously perceived, performance on chimeric faces was poorer than on entire- and half-faces stimuli, thus indicating an implicit processing of perceptual conflicts. Moreover, the precedence of hemispheric stimulation over-ruled the right hemisphere dominance for face processing, insofar as the hemisphere stimulated last appeared to influence the response. This dynamic reversal of cerebral dominance, however, was not caused by a shift in hemispheric specialization, since the level of performance always reflected the right hemisphere specialization for face recognition. Thus, the dissociation between hemispheric dominance and specialization found in the present study hints at the existence of hemispheric metacontrol in healthy individuals. (c) 2005 Elsevier B.V. All rights reserved
Predictive Action-perception Resonance and Mental Simulation (PARMS)
No full textMounting evidence suggests that even higher order socio-cognitive processes such as mind and intention reading, or action and perception understanding can be mapped onto modal sensorimotor cortices (1). The bodily instantiation of cognitive operations is called ‘embodiment’ and the internal reproduction of others’ mental, perceptuo-motor and emotional states is called ‘simulation’, a process which supposedly enables the interindividual sharing of experiences (2) and that may be linked to the striking functional property of the monkey premotor and parietal neurons (3, 4) activated during both action execution and observation (‘mirror neurons’). Behavioural and neural studies in healthy (5, 6) and brain damaged humans (7-9) indicate that action perception and execution rely upon largely overlapping neural substrates. Moreover, perceptuo-motor codes are tightly associated. Indeed, not only mere action observation strengthens the motor representation of the observed action (10), but also mere motor experience of a given action may improve its visual recognition (11). This inherent functional and anatomic bidirectional link may represent a deceivingly simple mechanism for the striking plastic abilities underlying social learning.
Also quintessential to effective social interactions is the ability to predict and anticipate the actions of other individuals. One crucial but thus far scarcely explored question concerns the role played by the different nodes of the action observation network (AON) in understanding others’ actions and intentions on the basis of predictive coding algorithms (12, 13). We have previously demonstrated that cortico-spinal motor systems are mainly activated when making predictions on upcoming actions (14, 15). Here we plan to expand previous knowledge by investigating: i) the circumstances that induce an observer to represent actions in the future. Single-pulse transcranial magnetic stimulation (spTMS) and fMRI will be used; ii) the causative role played by specific nodes of the AON network in the predictive coding of observed actions as well as of higher-order linguistic action representation. To this aim we will use a) rTMS in healthy subjects to create specific ‘virtual lesions’ and b) state-of-the-art lesion mapping techniques in brain damaged patients; iii) the plastic and dynamic aspects of predictive abilities by testing children while they will learn specific perceptuo-motor skills (e.g. soccer actions) and motorically-visually expert individuals (e.g. elite basketball athletes). Particular attention will be paid to error prediction by testing expert and non-expert healthy subjects and brain damaged patients in observation tasks requiring to make early choices on which action is going to be performed by a model and whether the observed action is performed correctly in time and space. fMRI, spTMS, and psychophysics studies will be carried out.
PARMS may have specific translational implications in different fields: i) robotics: our approach may be fundamentally important for applications aimed at reducing the comparative inability of current robotic systems to cope with the high prediction demands of real world social interactions and at increasing the competence of artificial agents to operate in natural, human-like environments and to produce meaningful behaviours by means of anticipatory simulation; ii) neurorehabilitation of motor deficits following stroke; iii) brain-based training procedures for optimizing sport performance and ultimately helping athletes to achieve excellenc
Racial bias reduces empathic sensorimotor resonance with other-race pain
No full textAlthough social psychology studies suggest that racism often manifests as a lack of empathy [1, 2], i.e., of the ability to share and comprehend others’ feelings and intentions [3–7], evidence for differential empathic reactivity to the pain of same or different race individuals is meager [8, 9]. Using transcranial magnetic stimulation we explored sensorimotor empathic brain responses [10–15], in Black and White individuals who exhibited implicit but not explicit ingroup preference and race-specific autonomic reactivity [16–20]. We found that observing the pain of ingroup models inhibited the onlookers’ corticospinal system as if they were feeling the pain [10–15, 21, 22]. Both Black and White individuals exhibited empathic reactivity also when viewing the pain of stranger, very unfamiliar, violet hand models. By contrast, no vicarious mapping of the pain of individuals culturally marked as outgroup members on the basis of their skin color was found. Importantly, group-specific lack of empathic reactivity was higher in the onlookers who exhibited stronger implicit racial-bias. These results indicate that human beings react empathically to the pain of stranger individuals [3–7]. However, racial-bias and stereotypes may change this reactivity into a group-specific lack of sensorimotor resonance [1–3, 9, 23, 24]
Perturbing and measuring neural activity in the pain resonance network: TMS studies
No full textTranscranial magnetic stimulation (TMS) studies show that watching painful stimuli on another person’s body decreases the excitability of the correspondent corticospinal body part representation in the observers. This observational pain-related inhibition (OPRI) is similar to that found during actual pain perception, suggesting that seeing pain in others triggers pain sensorimotor resonance in the corticospinal system. Using a perturb-and-measure TMS paradigm we provide causal evidence that the primary somatosensory (S1), motor (M1) and premotor (PMc) cortices play distinct critical roles in OPRI. In two experiments, we combined repetitive TMS (1Hz rTMS, to suppress neural activity in selected cortical regions) and single-pulse TMS (spTMS, to assess OPRI) during pain observation.
In keeping with previous studies, a standard OPRI effect was found in a no rTMS condition. The effect was stronger in the subjects who showed greater dispositional empathy (assessed by the Interpersonal Reactivity Index) and provided higher observed-pain scores. OPRI was suppressed and increased by M1 and S1 disruption, respectively and left unaffected by V1 disruption. Importantly, disruption of PMc changed the OPRI into a muscle-specific facilitatory response. Thus, while S1 normal functioning seems to keep under control a potentially excessive embodiment of others’ pain, normal functioning of PMc and M1 exert a same-direction, different strength modulatory effect that allow an optimal tuning of resonant corticospinal mapping of observed pain.
These findings highlight the causative connectivity between PMc-M1-S1 regions and the corticospinal system during embodied pain empathy and suggest that TMS can disclose specific inter-regional neural interactions during social perception
Influenza dello stile cognitivo e della personalità sull'attenzione a sè e agli altri: studio in esperti di Asthanga Yoga.
No full textNel test del Rod and Frame si misurano gli effetti del contesto visivo sulla percezione della verticale visiva soggettiva (VVS) valutando l’errore compiuto nell’allineare un marker visivo, (posto entro una cornice quadrata) alla verticale gravitazionale. Esperti motori in discipline che richiedono grande consapevolezza e controllo del corpo (ad esempio ginnasti) effettuano la stima della VVS senza essere influenzati da indizi ambientali e sono pertanto definiti campo indipendenti (CI). Nel presente studio abbiamo esplorato se una disciplina tesa al controllo del corpo possa essere in grado di alterare la consapevolezza corporea e la sua relazione con stili cognitivi e personologici. Metodi: La CI è stata misurata in un campione di praticanti di Asthanga Yoga (AY) e uno di soggetti senza esperienza in discipline yogiche. Abbiamo raccolto inoltre misure relative all’autotrascendenza, altruismo e consapevolezza corporea per poi analizzarne le relazioni esistenti. Risultati: Il gruppo AY ha mostrato più accuratezza nella stima della VVS e punteggi di autotrascendenza significativamente maggiori che, solo in questo gruppo, correlano negativamente con la strategia utilizzata nel valutare la VVS. Nel gruppo AY abbiamo rilevato che maggiore è l’assiduità e l’abilità nella pratica della disciplina, maggiore è la consapevolezza corporea. La consapevoleza corporea e l’altruismo risultano essere negativamente correlati nel gruppo AY, ma non nel gruppo di controllo. Conclusioni: La pratica assidua di una disciplina che focalizza l’attenzione sul corpo tende ad aumentare l’attenzione su noi stessi, che però potrebbe renderci meno disponibili alle necessità altrui. Inoltre, una maggiore autotrascendenza potrebbe aiutare ad attuare strategie che aumentino l’attenzione ai segnali provenienti dal corpo e consentano di ignorare segnali visivi esterni potenzialmente distraenti
Changes in spatial position of hands modify tactile extinction but not disownership of contralesional hand in two right brain-damaged patients
No full textSomatic misperceptions and misrepresentations, like supernumerary phantom limb and denial of ownership of a given body part, have typically been reported following damage to the right side of the brain. These symptoms typically occur with personal or extrapersonal neglect and extinction of left-sided stimuli, suggesting that all these different symptoms may be linked to the same neural substrate. In the present research, we tested two right brain-damaged (RBD) patients to find out whether changing the position of the hands in space influences tactile extinction and denial of ownership to the same extent. Results showed that manipulation of the spatial position of the hands reduces tactile extinction but leaves denial of ownership of the left hand unaffected. Such a dissociation suggests that delusional misperceptions may be independent from somatic neglect and that representation of hands in space and attribution of ownership are dynamically mapped in at least partly separate neural substrates
Emotional conflict in a model modulates nociceptive processing in an onlooker: a laser-evoked potentials study
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