1,721,080 research outputs found
Tongue motor cortex: The back door of the reward system
Full text linkIn paragraph 3.5 of their article, the authors provide some information about the nonmotor properties of tongue motor cortex. As a complement to the interesting work of Bono et al. (2022), in this commentary we focus on this aspect by addressing the link of the tongue motor cortex to the reward system, and its relevance for emotion processing, social cognition and psychopathology via connections of tongue motor area with other brain structures
Mu rhythm and corticospinal excitability capture two different frames of motor resonance: A TMS–EEG co-registration study
Full text linkHumans are equipped with an extraordinary ability to understand and imitate actions by mapping the observed movement onto their own cortical motor system. Long-established lines of research have identified two correlates of this motor resonance following action observation: the mu rhythm event-related desynchronization (mu-ERD) recorded through electroencephalography (EEG) and the facilitation of motor evoked potentials (MEPs) induced by transcranial magnetic stimulation (TMS) of the primary motor cortex (M1). Yet, whether mu-ERD and MEP facilitation reflect unique or distinct mechanisms is not conclusive, as prior work did not combine simultaneous TMS-EEG recording with a trial-by-trial analysis of the two markers. To address this issue, here, we used TMS-EEG co-registration while participants observed and executed finger movements. EEG was continuously recorded while single-pulse TMS was administered over the left M1 and MEPs were recorded from the right hand. We found stronger motor cortex recruitment during action execution and observation as shown by mu-ERD. MEPs instead were larger overall during action execution and showed a facilitation specific to the muscles involved in the observed movements. Interestingly, when analyzing these two parameters using a trial-by-trial statistical approach, we did not find any relationship between mu-ERD and MEPs within the action observation condition. Our findings support the notion that EEG and TMS indices of motor resonance reflect distinct neural mechanisms
Kinaesthetic imagery and tool-specific modulation of corticospinal representations in expert tennis players
No full textNeural Correlates and Molecular Mechanisms of Memory and Learning
Full text linkMemory and learning are essential cognitive processes that enable us to obtain, retain, and recall information. These factors are crucial for survival, adaptation, and creativity. However, the neural and molecular mechanisms that underlie these cognitive functions are not fully elucidated. For decades, researchers have been fascinated by the neurobiological and molecular basis of acquiring, storing, and retrieving information. Recent neuroimaging technologies have provided valuable insights into underlying neuroanatomical brain circuits. The amygdala, hippocampus, and prefrontal cortex (PFC) are pivotal for shaping memory and facilitating learning. The amygdala, recognized for its significance in emotional processing, interacts with downstream structures such as the hypothalamus and brainstem regions, influencing the expression of emotionally charged responses. The inhibitory mechanisms within the amygdala, including specific divisions and nuclei, contribute to memory modulation. The hippocampus, which is essential for spatial navigation and contextual memory, forms direct projections with the infralimbic cortex in the PFC and the basolateral amygdala. Distinct subregions of the hippocampus have been implicated in various human behavioral features, highlighting their multifaceted roles in cognitive processes
Representación cerebral de la empatía y de los procesos intergrupales
No full textLas últimas dos décadas han sido testigos del crecimiento en la comprensión de los mecanismos cerebrales que subyacen a la empatía, es decir, la capacidad de compartir y comprender los estados internos de los demás. En este capítulo revisamos la investigación en neurociencia social y afectiva, destacando los componentes cognitivos y afectivos de la empatía, que implican no solo la activación de redes cerebrales que apoyan la comprensión cognitiva de los estados mentales de los demás, sino también redes afectivas y sensoriomotoras que son responsables del carácter compartido de esos estados. Todo ello, a su vez, sugiere que nuestra capacidad de empatizar con los demás se basa en aspectos afectivos y redes sensoriomotoras para sentir y mover el cuerpo. La empatía también es sensible al contexto y se ve afectada por las diferencias individuales y el sesgo intergrupal. Existe una mayor respuesta empática del cerebro hacia los individuos que pertenecen al propio grupo social que hacia los individuos que pertenecen a otros grupos. Los investigadores han comenzado a examinar las influencias socioculturales sobre el sesgo intragrupal en las respuestas neuronales empáticas, así como las posibles intervenciones para reducirlo. Estos hallazgos tienen implicaciones importantes para comprender el favoritismo intragrupal en el comportamiento social y para mejorar la comunicación intergrupal
Racial Bias Reduces Empathic Sensorimotor Resonance with Other-Race Pain
No full textAlthough social psychology studies suggest that racism often manifests itself as a lack of empathy [1, 2], i.e., 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]
Sense of agency predicts severity of moral judgments
Full text linkSense of Agency (SoA) refers to the awareness of being the agent of our own actions. A key feature of SoA relies on the perceived temporal compression between our own actions and their sensory consequences, a phenomenon known as “Intentional Binding.” Prior studies have linked SoA to the sense of responsibility for our own actions. However, it is unclear whether SoA predicts the way we judge the actions of others – including judgments of morally wrong actions like harming others. To address this issue, we ran an on-line pilot experiment where participants underwent two different tasks designed to tap into SoA and moral cognition. SoA was measured using the Intentional Binding task which allowed us to obtain both implicit (Intentional Binding) and explicit (Agency Rating) measures of SoA. Moral cognition was assessed by asking the same participants to evaluate videoclips where an agent could deliberately or inadvertently cause suffering to a victim (Intentional vs. Accidental Harm) compared with Neutral scenarios. Results showed a significant relation between both implicit and explicit measures of SoA and moral evaluation of the Accidental Harm scenarios, with stronger SoA predicting stricter moral judgments. These findings suggest that our capacity to feel in control of our actions predicts the way we judge others’ actions, with stronger feelings of responsibility over our own actions predicting the severity of our moral evaluations of other actions. This was particularly true in ambiguous scenarios characterized by an incongruency between an apparently innocent intention and a negative action outcome
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
Neuroanatomical substrates of action perception and understanding: an anatomic likelihood estimation meta-analysis of lesion-symptom mapping studies in brain injured patients.
Full text linkSeveral neurophysiologic and neuroimaging studies suggested that motor and perceptual systems are tightly linked along a continuum rather than providing segregated mechanisms supporting different functions. Using correlational approaches, these studies demonstrated that action observation activates not only visual but also motor brain regions. On the other hand, brain stimulation and brain lesion evidence allows tackling the critical question of whether our action representations are necessary to perceive and understand others’ actions. In particular, recent neuropsychological studies have shown that patients with temporal, parietal and frontal lesions exhibit a number of possible deficits in the visual perception and the understanding of others’ actions. The specific anatomical substrates of such neuropsychological deficits however are still a matter of debate. Here we review the existing literature on this issue and perform an anatomic likelihood estimation meta-analysis of studies using lesion-symptom mapping methods on the causal relation between brain lesions and non-linguistic action perception and understanding deficits. The meta-analysis encompassed data from 361 patients tested in 11 studies and identified regions in the inferior frontal cortex, the inferior parietal cortex and the middle/superior temporal cortex, whose damage is consistently associated with poor performance in action perception and understanding tasks across studies. Interestingly, these areas correspond to the three nodes of the action observation network that are strongly activated in response to visual action perception in neuroimaging research and that have been targeted in previous brain stimulation studies. Thus, brain lesion mapping research provides converging causal evidence that premotor, parietal and temporal regions play a crucial role in action recognition and understanding
Gradual enhancement of corticomotor excitability during cortico-cortical paired associative stimulation
Full text linkCortico-cortical paired associative stimulation (ccPAS) is an effective transcranial magnetic stimulation (TMS) method for inducing associative plasticity between interconnected brain areas in humans. Prior ccPAS studies have focused on protocol’s aftereffects. Here, we investigated physiological changes induced “online” during ccPAS administration. We tested 109 participants receiving ccPAS over left ventral premotor cortex (PMv) and primary motor cortex (M1) using a standard procedure (90 paired-pulses with 8-ms interstimulus interval, repeated at 0.1 Hz frequency). On each paired-pulse, we recorded a motor-evoked potential (MEP) to continuously trace the emergence of corticomotor changes. Participant receiving forward-ccPAS (on each pair, a first TMS pulse was administered over PMv, second over M1, i.e., PMv-to-M1) showed a gradual and linear increase in MEP size that did not reach a plateau at the end of the protocol and was greater in participants with low motor threshold. Participants receiving reverse-ccPAS (i.e., M1-to-PMv) showed a trend toward inhibition. Our study highlights the facilitatory and inhibitory modulations that occur during ccPAS administration and suggest that online MEP monitoring could provide insights into the malleability of the motor system and protocol’s effectiveness. Our findings open interesting prospects about ccPAS potential optimization in experimental and clinical settings
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