Browsing by Author "López Hernández, Vladimir"

Now showing 1 - 20 of 34
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    Analytical and holistic approaches influence the semantic integration: evidence from the N400 effect
    (2019) Aldunate, Nerea; López Hernández, Vladimir; Cornejo Alarcón, Carlos; Moenne Vargas, Cristóbal Matías; Carr, David
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    Attachment style triggers differential neural signature of emotional processing in adolescents
    (2013) Escobar María Josefina; Rivera Rei, Alvaro; Decety, Jean; Huepe Artigas, David; Cardona, Juan Felipe; Canales Johnson, Andrés; Sigman, Mariano; Mikulan, Ezequiel; Helgiu, Elena; López Hernández, Vladimir; Baez, Sandra; Manes, Facundo; Ibáñez, Agustín
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    Attending to the heart is associated with posterior alpha band increase and a reduction in sensitivity to concurrent visual stimuli
    (Society for Psychophysiological Research, 2017) Villena González, Mario; Moenne Vargas, Cristóbal Matías; Lagos, Rodrigo A.; Alliende Correa, Luz María; Billeke, Pablo; Aboitiz, Francisco; López Hernández, Vladimir; Cosmelli, Diego
    Attentional mechanisms have been studied mostly in specific sensory domains, such as auditory, visuospatial, or tactile modalities. In contrast, attention to internal interoceptive visceral targets has only recently begun to be studied, despite its potential importance in emotion, empathy, and self-awareness. Here, we studied the effects of shifting attention to the heart using a cue-target detection paradigm during continuous EEG recordings. Subjects were instructed to count either a series of visual stimuli (visual condition) or their own heartbeats (heart condition). Visual checkerboard stimuli were used as attentional probes throughout the task. Consistent with previous findings, attention modulated the amplitude of the heartbeat-evoked potentials. Directing attention to the heart significantly reduced the visual P1/N1 amplitude evoked by the attentional probe. ERPs locked to the attention-directing cue revealed a novel frontal positivity around 300 ms postcue. Finally, spectral power in the alpha band over parieto-occipital regions was higher while attending to the heart-when compared to the visual task-and correlated with subject's performance in the interoceptive task. These results are consistent with a shared, resource-based attentional mechanism whereby allocating attention to bodily signals can affect early responses to visual stimuli.
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    Auditory processing modulation by visual working memory load
    (2021) Marcenaro Villouta, Bruno; López Hernández, Vladimir; Pontificia Universidad Católica de Chile. Facultad de Medicina
    La modulación descendente de las respuestas sensoriales a estímulos distractores ha sido propuesta como un importante mecanismo por el cual nuestro cerebro puede mantener información relevante en la memoria de trabajo. Trabajos anteriores en memoria de trabajo visual han reportado una modulación de las respuestas neurales a sonidos distractores en diferentes niveles de la vía auditiva central. Se desconoce si este tipo de modulación ocurre a nivel del receptor auditivo. En este trabajo se propuso como hipótesis que las respuestas cocleares a estímulos distractores pueden ser moduladas a través del sistema medial olivococlear por la memoria de trabajo visual. Veintiún sujetos (trece hombres, edad media 25.3 años) con audición normal realizaron una tarea de detección de cambio con distintas condiciones de carga de memoria de trabajo (alta carga: 4 objectos visuales; baja carga: 2 objectos visuales). Los estímulos auditivos fueron distractores y permitieron medir las emisiones otoacústicas producto de distorsión (DPOAE) y potenciales evocados de corteza. Adicionalmente, el reflejo olivococlear medial fue medido usando ruido contralateral. Los resultados mostraron mayor supresión de DPOAEs por ruido contralateral durante el periodo de memoria de trabajo. Estos resultados mostraron que durante el periodo de memoria de trabajo visual hay una modulación del reflejo olivococlear medial, lo que sugiere un posible mecanismo en común para la filtración descendente de respuestas auditivas durante procesos cognitivos.
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    Autonomous sensory meridian response is associated with a larger heartbeat‐evoked potential amplitude without differences in interoceptive awareness
    (2023) Villena González, Mario; Rojas-Thomas, Felipe; Morales-Torres, Ricardo; López Hernández, Vladimir
    Autonomous sensory meridian response (ASMR) describes the experience of a pleasant body sensation accompanied by a feeling of well-being and relaxation in response to specific audiovisual stimuli, such as whispers and personal attention. Previous work suggests a relationship between this experience with the processing of affective and body states; however, no research has explored differences in interoception between people experiencing ASMR and those who do not. We hypothesized that the ASMR experience is based on interoception processing. To test this, we assessed group differences across different dimensions of interoception: Interoceptive sensibility (IS), measured using the multidimensional assessment of interoceptive awareness (MAIA); Interoceptive accuracy score (IAS), measured by calculating performance in a heartbeat counting task (HCT), and the electrophysiological index of interoception, the heartbeat evoked potential (HEP), which was calculated during the HCT and an ASMR tingle reporting task (ASMR-TRT). Our results showed that IS and IAS, dimensions requiring conscious awareness, showed no differences between groups. However, HEP amplitude was larger in the ASMR group in both tasks. We concluded that the ASMR experience is based on an unconscious interoceptive mechanism, reflected by HEP, where exteroceptive social-affective stimuli are integrated to represent a body state of positive affective feelings and relaxation, as has been described for affective touch. The relevance of this finding relies on that interoceptive function, body regulation, and emotional/affective experiences are fundamental for well-being, and the relationship between ASMR and interoception opens the way to future research exploring the causal relationship between them and their potential clinical applications.
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    Behavioral and Electrophysiological Evidence of Enhanced Performance Monitoring in Meditators
    (2017) Andreu, Catherine I.; Moenne Vargas, Cristóbal Matías; López Hernández, Vladimir; Slagter, Heleen A.; Franken, Ingmar H. A.; Cosmelli, Diego
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    Beta Oscillations Distinguish Between Two Forms of Mental Imagery While Gamma and Theta Activity Reflects Auditory Attention
    (2018) Villena González, Mario; Palacios García, Ismael José; Rodríguez B., Eugenio; López Hernández, Vladimir
    Visual sensory processing of external events decreases when attention is internally oriented toward self-generated thoughts and also differences in attenuation have been shown depending on the thought’s modality (visual or auditory thought). The present study aims to assess whether such modulations occurs also in auditory modality. In order to investigate auditory sensory modulations, we compared a passive listening condition with two conditions in which attention was internally oriented as a part of a task; a visual imagery condition and an inner speech condition. EEG signal was recorded from 20 participants while they were exposed to auditory probes during these three conditions. ERP results showed no differences in N1 auditory response comparing the three conditions reflecting maintenance of evoked electrophysiological reactivity for auditory modality. Nonetheless, time-frequency analyses showed that gamma and theta power in frontal regions was higher for passive listening than for internal attentional conditions. Specifically, the reduced amplitude in early gamma and theta band during both inward attention conditions may reflect reduced conscious attention of the current auditory stimulation. Finally, different pattern of beta band activity was observed only during visual imagery which can reflect cross-modal integration between visual and auditory modalities and it can distinguish this form of mental imagery from the inner speech. Taken together, these results showed that attentional suppression mechanisms in auditory modality are different from visual modality during mental imagery processes. Our results about oscillatory activity also confirm the important role of gamma oscillations in auditory processing and the differential neural dynamics underlying the visual and auditory/verbal imagery.
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    Brain signatures of moral sensitivity in adolescents with early social deprivation
    (2014) Escobar, María Josefina; Huepe Artigas, David; Decety, Jean; Sedeño, Lucas; Messow, Marie Kristin; Báez, Sandra; Rivera Rei, Álvaro; Canales Johnson, Andrés; Ibáñez, Agustín; López Hernández, Vladimir
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    Chapter 13 : Origin and evolution of human speech : emergence from a trimodal auditory, visual and vocal network
    (2019) Michon Desbiey, Maëva; López Hernández, Vladimir; Aboitiz, Francisco
    In recent years, there have been important additions to the classical model of speech processing as originally depicted by the Broca–Wernicke model consisting of an anterior, productive region and a posterior, perceptive region, both connected via the arcuate fasciculus. The modern view implies a separation into a dorsal and a ventral pathway conveying different kinds of linguistic information, which parallels the organization of the visual system. Furthermore, this organization is highly conserved in evolution and can be seen as the neural scaffolding from which the speech networks originated. In this chapter we emphasize that the speech networks are embedded in a multimodal system encompassing audio-vocal and visuo-vocal connections, which can be referred to an ancestral audio-visuo-motor pathway present in nonhuman primates. Likewise, we propose a trimodal repertoire for speech processing and acquisition involving auditory, visual and motor representations of the basic elements of speech: phoneme, observation of mouth movements, and articulatory processes. Finally, we discuss this proposal in the context of a scenario for early speech acquisition in infants and in human evolution.
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    Compared to self-immersion, mindful attention reduces salivation and automatic food bias
    (2017) Baquedano, Constanza; Vergara, Rodrigo; López Hernández, Vladimir; Fabar, Catalina; Cosmelli, Diego; Lutz, Antoine
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    Data from brain activity during visual working memory replicates the correlation between contralateral delay activity and memory capacity
    (2020) Villena González, Mario; Rubio Venegas, Iván; López Hernández, Vladimir
    This article provides data from statistical analysis of event-related brain potentials (ERPs) and behavioural performance from 23 participants during a working memory task. Specifically, we used the change detection task from Vogel 2004, using the same timing but a modified size and distance between stimuli. Contralateral delay activity (CDA) was calculated from posterior parieto-occipital electrodes and then it was compared between conditions with different memory load (one, two and four items). Working memory capacity (WMC) was calculated from behavioural data using the formula developed by Pashler (1988). Correlation was performed between WMC and the CDA amplitude difference (from two to four items). The correlation replicates the results from the original paper of Vogel 2004 [1], even though some parameters are different from the original design. (C) 2019 The Author(s). Published by Elsevier Inc.
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    Data of ERPs and spectral alpha power when attention is engaged on visual or verbal/auditory imagery
    (2016) Villena González, Mario; López Hernández, Vladimir; Rodríguez B., Eugenio
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    Do you what I am saying? : electrophysiological dynamics of visual speech processing and the role of orofacial effectors for cross-modal predictions
    (2019) Michon Desbiey, Maëva; López Hernández, Vladimir; Pontificia Universidad Católica de Chile. Escuela de Psicología
    The need of a comprehensive model to account for the neurobiology of language has quite a long history. New empirical data have challenged classical models. A new framework is needed to foster our understanding of brain mechanisms underlying speech perception and production. In this dissertation, we postulate the existence of a trimodal network for speech perception that emphasizes the importance of visual processing of speech related orofacial movements and its representation in motor cortices. In that sense, we hypothesize that auditory (phonemes), visual (visemes) and motor (articulemes) aspects of speech are bonded in a trimodal repertoire. In order to test our hypothesis, we recorded EEG signal while participants were attentively observing different type of linguistic and non-linguistic orofacial movements in two conditions: under normal observation and observation holding a speech effector depressor horizontally between their teeth. ERPs analyses of the signal provide evidence of cross-modal predictions indexed by the N270 and the N400-like components. The amplitude of these components was specifically modulated by the visual salience of visual speech cues; the more salient the more predictable. Interestingly, when orofacial effectors were restricted, the amplitude of N400 was significantly reduced, suggesting that language production system is recruited for predictions. The time-frequency analysis, on the other hand, demonstrated the involvement of motor cortices for visual speech perception. More specifically, a significant difference in the µ-suppression was observed between linguistic and nolinguistic orofacial movements. The power of the µ-suppression was modulated by visual salience but diminished for the more salient visual speech cues when the participants orofacial effectors were blocked. The results reported in this dissertation represent preliminary evidence of the existence of the proposed trimodal network and, in particular, of the articuleme. Undoubtedly, further research using complementary neuroimaging techniques are required to better understand this multimodal interplay during language perception and production.
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    Early detection of intentional harm in the human amygdala
    (2016) Hesse, Eugenia; Mikulan, Ezequiel; Decety, Jean; Sigman, Mariano; García, María Del Carmen; Silva, Walter; Ciraolo, Carlos; Vaucheret, Esteban; Baglivo, Fabricio; López Hernández, Vladimir; Huepe Artigas, David; Manes, Facundo; Tristán, A.; Bekinschtein, Agustín Ibáñez
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    Early influence of affective context on emotion perception : EPN or Early-N400?
    (2018) Aldunate, Nerea; López Hernández, Vladimir; Bosman Vittini, Conrado Arturo
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    Electrophysiological Dynamics of Visual Speech Processing and the Role of Orofacial Effectors for Cross-Modal Predictions
    (2020) Michon Desbiey, Maëva; Boncompte, G.; López Hernández, Vladimir
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    Emotional text messages afect the early processing of emoticons depending on their emotional congruence: evidence from the N170 and EPN event related potentials
    (2024) Aldunate Ruff Nerea Patricia; López Hernández, Vladimir; Rojas Thomas, Felipe Eduardo; Villena González, Mario; Palacios García, Ismael José; Artigas, Claudio A.; Rodríguez B., Eugenio; Bosman, Conrado A.
    Emoticons have been considered pragmatic cues that enhance emotional expressivity during computer-mediated communication. Yet, it is unclear how emoticons are processed in ambiguous text-based communication due to incongruences between the emoticon's emotional valence and its context. In this study, we investigated the electrophysiological correlates of contextual infuence on the early emotional processing of emoticons, during an emotional congruence judgment task. Participants were instructed to judge the congruence between a text message expressing an emotional situation (positive or negative), and a subsequent emoticon expressing positive or negative emotions. We analyzed early event-related potentials elicited by emoticons related to face processing (N170) and emotional salience in visual perception processing (Early Posterior Negativity, EPN). Our results show that accuracy and Reaction Times depend on the interaction between the emotional valence of the context and the emoticon. Negative emoticons elicited a larger N170, suggesting that the emotional information of the emoticon is integrated at the early stages of the perceptual process. During emoticon processing, a valence efect was observed with enhanced EPN amplitudes in occipital areas for emoticons representing negative valences. Moreover, we observed a congruence efect in parieto-temporal sites within the same time-window, with larger amplitudes for the congruent condition. We conclude that, similar to face processing, emoticons are processed diferently according to their emotional content and the context in which they are embedded. A congruent context might enhance the emotional salience of the emoticon (and therefore, its emotional expression) during the early stages of their processing.
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    Empathy and contextual social cognition
    (2014) Melloni, M.; López Hernández, Vladimir; Ibáñez, A.
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    Enhanced response inhibition and reduced midfrontal theta activity in experienced Vipassana meditators
    (Springer Nature Limited, 2019) Andreu, Catherine I.; Palacios García, Ismael José; Moenne Vargas, Cristóbal Matías; López Hernández, Vladimir; Franken, Ingmar; Cosmelli, Diego; Slagter, Heleen
    Response inhibition - the ability to suppress inappropriate thoughts and actions - is a fundamental aspect of cognitive control. Recent research suggests that mental training by meditation may improve cognitive control. Yet, it is still unclear if and how, at the neural level, long-term meditation practice may affect (emotional) response inhibition. The present study aimed to address this outstanding question, and used an emotional Go/Nogo task and electroencephalography (EEG) to examine possible differences in behavioral and electrophysiological indices of response inhibition between Vipassana meditators and an experience-matched active control group (athletes). Behaviorally, meditators made significantly less errors than controls on the emotional Go/Nogo task, independent of the emotional context, while being equally fast. This improvement in response inhibition at the behavioral level was accompanied by a decrease in midfrontal theta activity in Nogo vs. Go trials in the meditators compared to controls. Yet, no changes in ERP indices of response inhibition, as indexed by the amplitude of the N2 and P3 components, were observed. Finally, the meditators subjectively evaluated the emotional pictures lower in valence and arousal. Collectively, these results suggest that meditation may improve response inhibition and control over emotional reactivity.