DSpace Repository :: Browsing by Author "López, Vladimir"

Browsing by Author "López, Vladimir"

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Another in need enhances prosociality and modulates frontal theta oscillations in young adults
(2023) Lavín, Claudio; Soto-Icaza, Patricia; López, Vladimir; Billeke, Pablo
Introduction: Decision-making is a process that can be strongly affected by social factors. Evidence has shown how people deviate from traditional rationalchoice predictions under different levels of social interactions. The emergence of prosocial decision-making, defined as any action that is addressed to benefit another individual even at the expense of personal benefits, has been reported as an example of such social influence. Furthermore, brain evidence has shown the involvement of structures such as the prefrontal cortex, anterior insula, and midcingulate cortex during decision settings in which a decision maker interacts with others under physical pain or distress or while being observed by others. Methods: Using a slightly modified version of the dictator game and EEG recordings, we tested the hypothesis that the inclusion of another person into the decision setting increases prosocial decisions in young adults and that this increase is higher when the other person is associated with others in need. At the brain level, we hypothesized that the increase in prosocial decisions correlates with frontal theta activity. Results and Discussion: The results showed that including another person in the decision, setting increased prosocial behavior only when this presence was associated with someone in need. This effect was associated with an increase in frontocentral theta-oscillatory activity. These results suggest that the presence of someone in need enhances empathy concerns and norm compliance, raising the participants’ prosocial decision-making.
Emotional text messages affect the early processing of emoticons depending on their emotional congruence: evidence from the N170 and EPN event related potentials
(2024) Aldunate, Nerea; López, Vladimir; Rojas‑Thomas, Felipe; Villena‑González, Mario; Palacios, Ismael; Artigas, Claudio; Rodríguez, 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 influence 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 effect was observed with enhanced EPN amplitudes in occipital areas for emoticons representing negative valences. Moreover, we observed a congruence effect 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 differently 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.
Lateral prefrontal activity as a compensatory strategy for deficits of cortical processing in Attention Deficit Hyperactivity Disorder
(2017) Zamorano, Francisco; Aboitiz, Francisco; Carrasco, Ximena; López, Vladimir; Hurtado, José M.; Stecher, Ximena; Larraín, Josefina; Kausel, Leonie; Billeke, Pablo
Attention Deficit Hyperactivity Disorder (ADHD) is the most common neuropsychiatric disorder in childhood and is characterized by a delay of cortical maturation in frontal regions. In order to investigate interference control, which is a key function of frontal areas, a functional MRI study was conducted on 17 ADHD boys and 17 typically developing (TD) boys, while solving the multi source interference task (MSIT). This task consists of two conditions, a "congruent condition" and an "incongruent condition". The latter requires to inhibit information that interferes with task-relevant stimuli. Behavioral results showed that ADHD subjects committed more errors than TD children. In addition, TD children presented a larger MSIT effect -a greater difference in reaction times between the incongruent and the congruent conditions- than ADHD children. Associated to the MSIT effect, neuroimaging results showed a significant enhancement in the activation of the right lateral prefrontal cortex (rlPFC) in ADHD than in TD subjects. Finally, ADHD subjects presented greater functional connectivity between rlPFC and bilateral orbitofrontal cortex than the TD group. This difference in connectivity correlated with worse performance in both groups. Our results could reflect a compensatory strategy of ADHD children resulting from their effort to maintain an adequate performance during MSIT.
Temporal Constraints of Behavioral Inhibition: Relevance of Inter-stimulus Interval in a Go-Nogo Task
(2014) Zamorano, Francisco; Billeke, Pablo; Hurtado, José M.; López, Vladimir; Carrasco, Ximena; Ossandón, Tomás; Aboitiz, Francisco
The capacity to inhibit prepotent and automatic responses is crucial for proper cognitive and social development, and inhibitory impairments have been considered to be key for some neuropsychiatric conditions. One of the most used paradigms to analyze inhibitory processes is the Go-Nogo task (GNG). This task has been widely used in psychophysical and cognitive EEG studies, and more recently in paradigms using fMRI. However, a technical limitation is that the time resolution of fMRI is poorer than that of the EEG technique. In order to compensate for these temporal constraints, it has become common practice in the fMRI field to use longer inter-stimulus intervals (ISI) than those used in EEG protocols. Despite the noticeable temporal differences between these two techniques, it is currently assumed that both approaches assess similar inhibitory processes. We performed an EEG study using a GNG task with both short ISI (fast-condition, FC, as in EEG protocols) and long ISI (slow-condition, SC, as in fMRI protocols). We found that in the FC there was a stronger Nogo-N2 effect than in the SC. Moreover, in the FC, but not in the SC, the number of preceding Go trials correlated positively with the Nogo-P3 amplitude and with the Go trial reaction time; and negatively with commission errors. In addition, we found significant topographical differences for the Go-P3 elicited in FC and SC, which is interpreted in terms of different neurotransmitter dynamics. Taken together, our results provide evidence that frequency of stimulus presentation in the GNG task strongly modulates the behavioral response and the evoked EEG activity. Therefore, it is likely that short-ISI EEG protocols and long-ISI fMRI protocols do not assess equivalent inhibitory processes
Us versus them mentality in football fans: Significant social defeat engages the mentalization network and disengages cognitive control areas [version 1; peer review: awaiting peer review]
(2023) Zamorano, Francisco; Patricio Carvajal-Paredes; Soto-Icaza, Patricia; Stecher, Ximena; Salinas, César; Muñoz Reyes, José Antonio; López, Vladimir; Méndez, Waldemar; Barrera, Joel; Aragón-Caqueo, Gonzalo; Billeke, Pablo; Carvajal Paredes, Francisco
Background: Social affiliation is one of the building blocks that shapes cultures and communities. This motivation contributes to the development of social bonding among individuals within a group, enjoying rights, assuming obligations, and strengthening its identity. Evidence has shown that social affiliation has inspired different social phenomena, such as wars, political movements, social struggles, among others, based on two human motivations: the ingroup love and the outgroup hate. One contemporary group to study as a proxy of social affiliation, and ingroup and outgroup motivations is the sports competition. However, this affiliation model has been poorly considered in social neuroscience research. This research aimed to shed light on the neurobiological networks that are related to social affiliation in football fans of two of the most popular Chilean football teams. Methods: To this end, 43 male fans of two football rival teams watched videos of winning and losing goals of their favorite team while their brain activity was measured with functional magnetic resonance imaging (fMRI). Results: The results showed that while the activation of the reward system was observed in fans when their team scores goals against the rival, both the activation of the mentalization network and the inhibition of the dorsal anterior cingulate cortex were associated with the emotional correlates of defeat in football fans. Conclusions: Taking these findings together could contribute to a deeper understanding of social affiliation, and more importantly, of extreme affiliation phenomena, and fanaticism.
Us versus them mentality in football fans: Significant social defeat engages the mentalization network and disengages cognitive control areas [version 1; peer review: awaiting peer review]
(2022) Zamorano, Francisco; Carvajal-Paredes, Patricio; Soto-Icaza, Patricia; Stecher, Ximena; Salinas, César; Muñuz-Reyes, José Antonio; López, Vladimir; Méndez, Valdemar; Barrera, Joel; Aragón-Caqueo, Gonzalo; Billeke, Pablo
Background: Social affiliation is one of the building blocks that shapes cultures and communities. This motivation contributes to the development of social bonding among individuals within a group, enjoying rights, assuming obligations, and strengthening its identity. Evidence has shown that social affiliation has inspired different social phenomena, such as wars, political movements, social struggles, among others, based on two human motivations: the ingroup love and the outgroup hate. One contemporary group to study as a proxy of social affiliation, and ingroup and outgroup motivations is the sports competition. However, this affiliation model has been poorly considered in social neuroscience research. This research aimed to shed light on the neurobiological networks that are related to social affiliation in football fans of two of the most popular Chilean football teams. Methods: To this end, 43 male fans of two football rival teams watched videos of winning and losing goals of their favorite team while their brain activity was measured with functional magnetic resonance imaging (fMRI). Results: The results showed that while the activation of the reward system was observed in fans when their team scores goals against the rival, both the activation of the mentalization network and the inhibition of the dorsal anterior cingulate cortex were associated with the emotional correlates of defeat in football fans. Conclusions: Taking these findings together could contribute to a deeper understanding of social affiliation, and more importantly, of extreme affiliation phenomena, and fanaticism

Browsing by Author "López, Vladimir"

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