Browsing by Author "Artigas, Claudio A."

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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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    Multisensory integration in different states of consciousness
    (2022) Artigas, Claudio A.; Rodríguez B., Eugenio; Pontificia Universidad Católica de Chile. Facultad de Medicina
    Nuestro mundo es multisensorial. Distintos mecanismos sensoriales operan para poder captar nuestro mundo y otorgarnos una visión coherente y cohesionada de este. Sin embargo, cómo nuestro cerebro logra unir diversos tipos de información por diversos canales es escasamente comprendido. Para entender estos mecanismos, inducimos somnolencia en las personas mientras veían un estímulo audiovisual. Comparando el estado de alerta y de somnolencia, observamos que había dos frecuencias involucradas, Gamma (30 - 48 Hz) y Alpha (8 - 12 Hz). Gamma se encargaba del procesamiento auditivo mientras que Alpha del procesamiento visual, mientras que ambos se manifestaban en la presentación coordinada del estímulo audiovisual. Esto revela que existe una interacción entre estas frecuencias para generar una percepción cohesionada de un estímulo audiovisual.