DSpace Angular :: Browsing by Author "Moenne Vargas, Cristóbal Matías"

Browsing by Author "Moenne Vargas, Cristóbal Matías"

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Agency improves working memory and accelerates visual and attentional processing
(2020) Loyola-Navarro, R.; Moenne Vargas, Cristóbal Matías; Vergara, R.C.; Hyafil, A.; Aboitiz, Francisco; Maldonado, P.E.
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
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.
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
Biomechanical analysis of expert anesthesiologists and novice residents performing a simulated central venous access procedure
(2021) Villagrán Gutiérrez, Ignacio Andrés; Moenne Vargas, Cristóbal Matías; Aguilera Siviragol, Victoria Ignacia; Garcia, Vicente; Reyes, Jose Tomas; Rodriguez, Sebastian; Miranda Mendoza, Constanza; Altermatt, Fernando; Fuentes López, Eduardo; Delgado Bravo, Mauricio Antonio; Neyem, Andrés
Background Central venous access (CVA) is a frequent procedure taught in medical residencies. However, since CVA is a high-risk procedure requiring a detailed teaching and learning process to ensure trainee proficiency, it is necessary to determine objective differences between the expert’s and the novice’s performance to guide novice practitioners during their training process. This study compares experts’ and novices’ biomechanical variables during a simulated CVA performance. Methods Seven experts and seven novices were part of this study. The participants’ motion data during a CVA simulation procedure was collected using the Vicon Motion System. The procedure was divided into four stages for analysis, and each hand’s speed, acceleration, and jerk were obtained. Also, the procedural time was analyzed. Descriptive analysis and multilevel linear models with random intercept and interaction were used to analyze group, hand, and stage differences. Results There were statistically significant differences between experts and novices regarding time, speed, acceleration, and jerk during a simulated CVA performance. These differences vary significantly by the procedure stage for right-hand acceleration and left-hand jerk. Conclusions Experts take less time to perform the CVA procedure, which is reflected in higher speed, acceleration, and jerk values. This difference varies according to the procedure’s stage, depending on the hand and variable studied, demonstrating that these variables could play an essential role in differentiating between experts and novices, and could be used when designing training strategies.
Corrigendum: The Energy Homeostasis Principle: Neuronal Energy Regulation Drives Local Network Dynamics Generating Behavior
(Frontiers Media SA, 2020) Vergara, Rodrigo C.; Jaramillo-Riveri, Sebastián; Luarte, Alejandro; Moenne Vargas, Cristóbal Matías; Fuentes, Rómulo; Couve C., Andrés; Maldonado, Pedro E.
This article is a correction to: The Energy Homeostasis Principle: Neuronal Energy Regulation Drives Local Network Dynamics Generating Behavior
Cortico-Striatal Oscillations Are Correlated to Motor Activity Levels in Both Physiological and Parkinsonian Conditions
(Frontiers Media SA, 2020) Moenne Vargas, Cristóbal Matías; Astudillo Valenzuela, Carolina; Skovgard, Katrine; Salazar Reyes, Carolina A.; Barrientos, Sebastián A.; García Núñez, Ximena P.; Cenci, M. Angela; Petersson, Per; Fuentes Flores, Rómulo A.
Oscillatory neural activity in the cortico-basal ganglia-thalamocortical (CBGTC) loop is associated with the motor state of a subject, but also with the availability of modulatory neurotransmitters. For example, increased low-frequency oscillations in Parkinson's disease (PD) are related to decreased levels of dopamine and have been proposed as biomarkers to adapt and optimize therapeutic interventions, such as deep brain stimulation. Using neural oscillations as biomarkers require differentiating between changes in oscillatory patterns associated with parkinsonism vs. those related to a subject's motor state. To address this point, we studied the correlation between neural oscillatory activity in the motor cortex and striatum and varying degrees of motor activity under normal and parkinsonian conditions. Using rats with bilateral or unilateral 6-hydroxydopamine lesions as PD models, we correlated the motion index (MI)-a measure based on the physical acceleration of the head of rats-to the local field potential (LFP) oscillatory power in the 1-80 Hz range. In motor cortices and striata, we observed a robust correlation between the motion index and the oscillatory power in two main broad frequency ranges: a low-frequency range [5.0-26.5 Hz] was negatively correlated to motor activity, whereas a high-frequency range [35.0-79.9 Hz] was positively correlated. We observed these correlations in both normal and parkinsonian conditions. In addition to these general changes in broad-band power, we observed a more restricted narrow-band oscillation [25-40 Hz] in dopamine-denervated hemispheres. This oscillation, which seems to be selective to the parkinsonian state, showed a linear frequency dependence on the concurrent motor activity level. We conclude that, independently of the parkinsonian condition, changes in broad-band oscillatory activities of cortico-basal ganglia networks (including changes in the relative power of low- and high-frequency bands) are closely correlated to ongoing motions, most likely reflecting he operations of these neural circuits to control motor activity. Hence, biomarkers based on neural oscillations should focus on specific features, such as narrow frequency bands, to allow differentiation between parkinsonian states and physiological movement-dependent circuit modulation.
Eating contexts determine the efficacy of nutrient warning labels to promote healthy food choices
(Frontiers Media S.A., 2023) Caballero Vivanco, Sara; Moenne Vargas, Cristóbal Matías; Delgado Bravo, Mauricio Antonio; Luarte Rodríguez, Luis Nicolás; Jiménez, Yanireth; Galgani Fuentes, José Eduardo; Perez Leighton, Claudio
Introduction: Unhealthy food choices increase the risk of obesity and its co-morbidities. Nutrition labels are a public health policy that aims to drive individuals toward healthier food choices. Chile has been an example of this policy, where mandatory nutrient warning labels (NWL) identify processed foods high in calories and critical nutrients. Eating contexts influence individual food choices, but whether eating contexts also influence how NWL alter the decision process and selection during food choice is unknown. Methods: In an online mouse-tracking study, participants prompted to health, typical, or unrestricted eating contexts were instructed to choose between pairs of foods in the presence or absence of NWL. Conflict during choices was analyzed using mouse paths and reaction times. Results: NWL increased conflict during unhealthy food choices and reduced conflict during healthy choices in all contexts. However, the probability that NWL reversed an unhealthy choice was 80% in a healthy, 37% in a typical, and 19% in an unrestricted context. A drift-diffusion model analysis showed the effects of NWL on choice were associated with an increased bias toward healthier foods in the healthy and typical but not in the unrestricted context. Discussion: These data suggest that the efficacy of NWL to drive healthy food choices increases in a healthy eating context, whereas NWL are less effective in typical or unrestricted eating contexts.
Effects of the self-perceived sensorimotor demand and immersion during video gaming on visual-attention skills
(Wiley, 2023) Moenne Vargas, Cristóbal Matías; Hernández, Alfredo; Larraguibel, Camila; Lam, Gustavo; Lorca-Ponce, Enrique; Montefusco-Siegmund, Rodrigo; Maldonado, Pedro; Vergara, Rodrigo C.
Playing specific genres of video games (e.g., action video games) has been linked to improvements in cognitive skills mostly related to attentional phenomena. Nonetheless, do video games have features or dimensions in common that impact cognitive improvements beyond the game genre? Here, we argue that the sensorimotor demand-the amount of demand for precise coordination between movement and perception-is a key element in the improvements associated with playing video games. We conducted a two-part study to test this hypothesis: a self-report online gaming instrument development and validation and an in-lab behavioural and electrophysiological study. In the first study, data from 209 participants were used to devise the sensorimotor demand instrument (SMDI). The SMDI was split into three dimensions of video game playing: sensorimotor contingency, immersion and unfocused gaming. Criterion validity related to video gamers' characteristics supported that the SMDI is sensitive to the input device (e.g., keyboard or touchscreens), and the most recent experience gained during gaming sessions while not being sensitive to the game genre. In the second study, data from 20 participants who performed four visual-attentional tasks previously reported in the literature showed that the SMDI's dimensions were associated with behavioural performance measures and the latency and amplitude of event-related potentials (N1, P2 and P3). Despite the challenge of studying the video gamer population, our study remarks on the relevance of sensorimotor demands in the performance of attentional tasks and its potential use as a dimension to characterize the experience of playing video games beyond the game genre.
Electroencefalografía y seguimiento de mirada: Dos técnicas para evaluar la adquisición de la lengua materna en niños pequeños
(Ediciones Universidad Valparaíso, 2022) Jara González, María Cristina; Moenne Vargas, Cristóbal Matías; Peña, Marcela
Los primeros años de vida de los seres humanos son fundacionales para el desarrollo de habilidades cognitivas en etapas posteriores. Una de estas habilidades es la adquisición de la lengua materna, la cual comienza antes del nacimiento. No obstante su importancia, explorar los mecanismos que subyacen a este proceso de adquisición solo con métodos conductuales resulta muy limitado, en parte porque la producción del lenguaje de los infantes no guarda relación con sus competencias perceptuales y sus aprendizajes acerca de su lengua materna. Para investigar en edades tempranas la adquisición del lenguaje resulta útil utilizar técnicas que nos permitan asociar algún tipo de medición con habilidades y aprendizajes lingüísticos. Para tales propósitos, se han utilizado numerosas técnicas, ética y técnicamente apropiadas para niños pequeños, de las cuales destacan la electroencefalografía y el seguimiento de mirada. La electroencefalografía nos permite estudiar los correlatos neurales de las funciones cognitivas relacionadas al aprendizaje del lenguaje mediante el uso de estímulos sonoros y visuales. Por su parte, el seguimiento de mirada persigue el mismo objetivo, pero asociado a la conducta ocular de los infantes. En este artículo revisaremos los aspectos más relevantes a estas técnicas en estudios realizados con infantes a modo de introducir a investigadores que se están iniciando en el uso de este tipo de instrumentos en investigaciones con niños pequeños.
Empirical basis for the development of adaptative interfaces : behavioral and neurophysiological evidences of decision-making and expertise development in a sequencial choice scenario.
(2017) Moenne Vargas, Cristóbal Matías; Mery Quiroz, Domingo; Cosmelli, Diego; Pontificia Universidad Católica de Chile. Escuela de Ingeniería
En el día a día nuestra interacción con interfaces computacionales está llena de situaciones en las cuales pasamos de ser usuarios inexpertos a expertos mediante la repetición de una misma tarea. En muchas de estas interacciones debemos aprender a encontrar una ruta, dentro de una secuencia de decisiones y acciones, la cual nos lleva al resultado buscado. Por ejemplo, cuando retiramos dinero de un cajero automático, las elecciones son presentadas paso a paso y una secuencia específica de acciones debe ser realizada en orden de obtener el resultado deseado. Entonces, a medida que nos hacemos expertos en el uso de estas interfaces, ¿es posible identificar estrategias especificas de búsqueda aprendizaje? De ser así, ¿podemos usar esa información para predecir acciones futuras? Además de comprender mejor los procesos cognitivos que subyacen a la toma de decisiones secuencial, esto podría permitir construir interfaces adaptativas que puedan facilitar la interacción en diferentes momentos de la curva de aprendizaje. Aquí abordamos la pregunta de modelar el comportamiento de toma de decisiones secuencial usando una interfaz visual simple representada por un árbol de decisión binario (por sus siglas en inglés BDT) de cuatro niveles. Registramos datos conductuales de participantes voluntarios mientras tratan de resolver la tarea. Utilizando un enfoque basado en el modelo oculto de Markov, que se capitaliza la estructura jerárquica del comportamiento, luego modelamos el desempeño de los participantes durante la interacción. Nuestros resultados muestran que una partición del espacio del problema en un pequeño grupo de estrategias estereotipadas y relacionadas jerárquicamente pueden capturar potencialmente una serie de comportamientos de b´usqueda. Esto nos permite seguir c´omo los participantes aprendeny desarrollan habilidades en el uso de la interfaz. Más aún, usando una Mezcla de Expertos basadas en las estrategias, somos capaces de predecir el comportamiento de los participantes que aprenden la tarea. Además, usando indicadores conductuales derivados de nuestro modelamiento, somos capaces de capturar la compleja estructura de los procesos de aprendizaje y desarrollo de expertise presente en los registros de Electroencéfalograma (EEG) de los participantes, revelando a nivel cerebral las diferentes etapas del proceso de toma de decisión a través de Potenciales Relacionados a Eventos (pos sus siglas en inglés ERP). Nuestra meta a largo plazo es informar acerca de la construcción de interfaces que puedan establecer una conversación dinámica con sus usuarios, en orden de facilitar la interacción con ellas.
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.
Infants exploit vowels to label objects and actions from continuous audiovisual stimuli
(Nature Research, 2021) Jara González, María Cristina; Moenne Vargas, Cristóbal Matías; Peña, Marcela
Before the 6-months of age, infants succeed to learn words associated with objects and actions when the words are presented isolated or embedded in short utterances. It remains unclear whether such type of learning occurs from fluent audiovisual stimuli, although in natural environments the fluent audiovisual contexts are the default. In 4 experiments, we evaluated if 8-month-old infants could learn word-action and word-object associations from fluent audiovisual streams when the words conveyed either vowel or consonant harmony, two phonological cues that benefit word learning near 6 and 12 months of age, respectively. We found that infants learned both types of words, but only when the words contained vowel harmony. Because object- and action-words have been conceived as rudimentary representations of nouns and verbs, our results suggest that vowels contribute to shape the initial steps of the learning of lexical categories in preverbal infants.
Modeling Search Behaviors during the Acquisition of Expertise in a Sequential Decision-Making Task
(2017) Moenne Vargas, Cristóbal Matías; Vergara, Rodrigo C.; López Hernández, Vladimir; Mery Quiroz, Domingo; Cosmelli, Diego
The Energy Homeostasis Principle: Neuronal Energy Regulation Drives Local Network Dynamics Generating Behavior
(Frontiers, 2019) Vergara, Rodrigo C.; Jaramillo-Riveri, Sebastián; Luarte, Alejandro; Moenne Vargas, Cristóbal Matías; Fuentes, Rómulo; Couve C., Andrés; Maldonado, Pedro E.
A major goal of neuroscience is understanding how neurons arrange themselves into neural networks that result in behavior. Most theoretical and experimental efforts have focused on a top-down approach which seeks to identify neuronal correlates of behaviors. This has been accomplished by effectively mapping specific behaviors to distinct neural patterns, or by creating computational models that produce a desired behavioral outcome. Nonetheless, these approaches have only implicitly considered the fact that neural tissue, like any other physical system, is subjected to several restrictions and boundaries of operations. Here, we proposed a new, bottom-up conceptual paradigm: The Energy Homeostasis Principle, where the balance between energy income, expenditure, and availability are the key parameters in determining the dynamics of neuronal phenomena found from molecular to behavioral levels. Neurons display high energy consumption relative to other cells, with metabolic consumption of the brain representing 20% of the whole-body oxygen uptake, contrasting with this organ representing only 2% of the body weight. Also, neurons have specialized surrounding tissue providing the necessary energy which, in the case of the brain, is provided by astrocytes. Moreover, and unlike other cell types with high energy demands such as muscle cells, neurons have strict aerobic metabolism. These facts indicate that neurons are highly sensitive to energy limitations, with Gibb's free energy dictating the direction of all cellular metabolic processes. From this activity, the largest energy, by far, is expended by action potentials and post-synaptic potentials; therefore, plasticity can be reinterpreted in terms of their energy context. Consequently, neurons, through their synapses, impose energy demands over post-synaptic neurons in a close loop-manner, modulating the dynamics of local circuits. Subsequently, the energy dynamics end up impacting the homeostatic mechanisms of neuronal networks. Furthermore, local energy management also emerges as a neural population property, where most of the energy expenses are triggered by sensory or other modulatory inputs. Local energy management in neurons may be sufficient to explain the emergence of behavior, enabling the assessment of which properties arise in neural circuits and how. Essentially, the proposal of the Energy Homeostasis Principle is also readily testable for simple neuronal networks.
Voluntary self-initiation of the stimuli onset improves working memory and accelerates visual and attentional processing
(Elsevier Ltd, 2022) Loyola-Navarro, R.; Moenne Vargas, Cristóbal Matías; Vergara, Rodrigo C.; Hyafil, Alexandre; Aboitiz, Francisco; Maldonado, Pedro E.
The ability of an organism to voluntarily control the stimuli onset modulates perceptual and attentional functions. Since stimulus encoding is an essential component of working memory (WM), we conjectured that controlling the initiation of the perceptual process would positively modulate WM. To corroborate this proposition, we tested twenty-five healthy subjects in a modified-Sternberg WM task under three stimuli presentation conditions: an automatic presentation of the stimuli, a self-initiated presentation of the stimuli (through a button press), and a self-initiated presentation with random-delay stimuli onset. Concurrently, we recorded the subjects' electroencephalographic signals during WM encoding. We found that the self-initiated condition was associated with better WM accuracy, and earlier latencies of N1, P2 and P3 evoked potential components representing visual, attentional and mental review of the stimuli processes, respectively. Our work demonstrates that self-initiated stimuli enhance WM performance and accelerate early visual and attentional processes deployed during WM encoding. We also found that self-initiated stimuli correlate with an increased attentional state compared to the other two conditions, suggesting a role for temporal stimuli predictability. Our study remarks on the relevance of self-control of the stimuli onset in sensory, attentional and memory updating processing for WM.

Browsing by Author "Moenne Vargas, Cristóbal Matías"

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