Artículos Gobierno

Permanent URI for this collection

http://repositorio.udd.cl/handle/11447/158

Browse

Now showing 1 - 20 of 221

Patients recovering from COVID‑19 who presented with anosmia during their acute episode have behavioral, functional, and structural brain alterations
(2024) Kausel, Leonie; Figueroa-Vargas, Alejandra; Zamorano, Francisco; Stecher, Ximena; Carvajal-Paredes, Patricio; Márquez-Rodríguez, Víctor; Martínez-Molina, María Paz; Román, Claudio; Soto-Fernández, Patricio; Valdebenito-Oyarzo, Gabriela; Manterola, Carla; Uribe-San-Martín, Reinaldo; Silva, Claudio; Henríquez-Ch., Rodrigo; Aboitiz, Francisco; Polania, Rafael; Guevara, Pamela; Munoz Venturelli, Paula; Soto-Icaza, Patricia; Billeke, Pablo
Patients recovering from COVID-19 commonly exhibit cognitive and brain alterations, yet the specific neuropathological mechanisms and risk factors underlying these alterations remain elusive. Given the significant global incidence of COVID-19, identifying factors that can distinguish individuals at risk of developing brain alterations is crucial for prioritizing follow-up care. Here, we report findings from a sample of patients consisting of 73 adults with a mild to moderate SARS-CoV-2 infection without signs of respiratory failure and 27 with infections attributed to other agents and no history of COVID-19. The participants underwent cognitive screening, a decision-making task, and MRI evaluations. We assessed for the presence of anosmia and the requirement for hospitalization. Groups did not differ in age or cognitive performance. Patients who presented with anosmia exhibited more impulsive alternative changes after a shift in probabilities (r = - 0.26, p = 0.001), while patients who required hospitalization showed more perseverative choices (r = 0.25, p = 0.003). Anosmia correlated with brain measures, including decreased functional activity during the decision-making task, thinning of cortical thickness in parietal regions, and loss of white matter integrity. Hence, anosmia could be a factor to be considered when identifying at-risk populations for follow-up.
Estrategias y recomendaciones para enfrentar la enfermedad por virus respiratorio sincicial el año 2024
(2024) Paris, Enrique; Daza Narbona, Paula; Tapia, Lorena; Díaz, Juan Pablo; Cruces Romero, Pablo; Castillo, Andrés; González, Cecilia; Endeiza, María Luz; Jofré, Leonor; Castro, Fabiola; Zamorano, Alejandra; Rodríguez, Jaime; Acevedo, Johanna; Santa Cruz, Teresita; González, Jaime; Escárate, Raúl; Moreno, Juan Pablo; Cisternas, Paula
Durante el invierno de 2023, Chile enfrentó una compleja situación relacionada con al virus respiratorio sincicial (VRS). Después de experimentar una disminución en la circulación del VRS durante los años de la pandemia de SARS-CoV-2, se observó un brote tardío en la primavera de 2022 y un inicio anticipado del brote en 2023, con un aumento significativo en el número de casos graves. La poca efectividad en la planificación estratégica y comunicación de riesgo contribuyeron a la complejidad de la situación. Para evitar lo anterior el próximo invierno, se sugieren medidas como vigilancia activa, unificación de definiciones para infecciones respiratorias agudas, identificación de variantes del VRS, educación pública sobre contagios y preparación anticipada respecto a camas hospitalarias y personal de salud. Se destaca la importancia de la inmunización y colaboración intersectorial para adquirir nuevas alternativas preventivas como también la necesidad de una comunicación temprana sobre la importancia de la inmunización e identificación de grupos de alto riesgo, mejora en capaci taciones del personal médico y planificación estratégica del Ministerio de Salud buscando un enfoque proactivo y colaborativo para abordar la compleja situación del VRS en futuros inviernos. El Comité Asesor en Vacunas y Estrategias de Inmunización de Chile ya realizó un análisis y recomendación sobre una nueva alternativa de prevención. Este grupo de trabajo apoyará cualquier decisión del Ministerio de Salud en políticas públicas que intenten un cambio en el paradigma del control de esta enfermedad por la salud de los niños/as de nuestro país.
Overcoming Health Inequities: Spatial Analysis of Seroprevalence and Vaccination Against COVID-19 in Chile
(2024) Muriel Ramírez-Santana , Juan Hormazábal, Luis Canales, Pablo Vial, and Ximena Aguilera; Correa, Juan; Núñez Franz, Loreto; Apablaza, Mauricio; Rubilar, Paola; Vial Cox, María Cecilia; Cortes, Lina Jimena; Hormazabal, Juan; Canales, Luis; Vial, Pablo; Aguilera, Ximena
Background: In unequal economies, the spread of the ﬁrst waves of the COVID-19 was usually associated withlow socioeconomic status of individuals and their families. Chile exempliﬁed this. By mid-2020, Chile had one ofthe highest SARS-CoV-2 infection rates in the world predominantly in poorer areas. A year later, the countrylaunched a universal vaccination campaign based on the national strategy of immunization established in1975. By 2022, Chile presented one of the highest COVID-19 vaccination coverages globally, reaching 94.3%of the population with the primary scheme by the end of 2022.Objective: This study analyzes the spatial distribution of SARS-CoV-2 seroprevalence at the beginning of the pan-demic (2020) compared with the seroprevalence after 2 years of ongoing epidemic and COVID-19 vaccinationcampaigns (2022).Methods: Two population-based random samples of individuals aged 7 years and older from two Chilean citieswere studied. Utilizing an enzyme-linked immunosorbent assay test, IgG antibodies were measured in serum of1061 participants in 2020, and 853 in 2022.Results: Using the Global Moran’s Index, the seroprevalence distribution pattern for the year 2020 showed clus-tering in the two cities. Conversely, seroprevalence and vaccinations were homogeneously distributed in 2022.These results show the success of the vaccination campaign in Chile, not only in coverage but also because itwidely reached all individuals.Conclusions: The uptake of this preventive measure is high, regardless of the social and economic factors,achieving broad population immunity. The extensive deployment of the primary health care network contrib-uted to reducing health inequities and promoting to universal health access.
Quantitative evaluation of a theoretical-conceptual model based on affective and socio-behavioral dimensions to explain the academic performance of mathematics students
(2024) Marín-Álvarez, Felipe; Flores-Prado, Luis; Figueroa, Oriana; Polo Rodrigo, Pablo; Varela, Jorge; Muñoz Reyes, José Antonio
Objective: There is evidence that suggests that affective dimensions, personality traits, as well as students’ cooperative interpersonal interactions, are an important element in the students learning process. In this work we propose a theoretical model, based on evidence, that shows the direct and indirect relationships between these factors and academic performance in mathematics courses, in undergraduate and school students. Methods: To understand the type of relationships between these variables, the PANAS psychometric test of positive and negative affect, the BIG FIVE personality test and the economic decision game DUPLES GAME were applied. The study sample was 130 students between 17 and 22 years of age from undergraduate and school (M ± SD = 20.1 ± 3.99). Results: From a path analysis, statistically significant relationships were found, for example, a direct relationship between neuroticism and positive affect, which in turn is related to academic performance. We also found a direct relationship between neuroticism and negative affect, extraversion and positive affect. This allows us to propose that some of the independent variables of the model directly and indirectly influence the academic performance of students in the subject of mathematics. Conclusion: Positive affect and negative affect directly affect academic performance in mathematics, neuroticism has a direct impact on negative affect and extraversion direct impact on positive affect. Consequently, there are direct and indirect relationships between personality traits and affective dimensions, which affect the academic performance of mathematics students.
Social isolation consequences: lessons from COVID-19 pandemic in a context of dynamic lock-down in Chile
(2024) Patrono, Alessandra; Renzetti, Stefano; Guerini, Cristian; Macgowan, Mark; Moncada, Stefanny M.; Placidi, Donatella; Memo, Maurizio; Lucchini, Roberto G.
Background Chile did not adopt general and unifed lockdowns for the whole nation but organized itself with dynamic and sometimes irregular lockdowns. These dynamics and consequences of social isolation could be generalized to other contexts of isolation such as those afecting minorities such as immigrants, prisoners, refugees. Methods In this study, we investigated the physical and mental health symptoms associated with lifestyle changes due to lockdown among university students in Chile. We examined psychopathological variations in relation to mental health problems in a healthy young population. Our goal was to develop interventions to address these new psychosocial problems in potentially comparable post-pandemic contexts. From May 10th 2021 to June 2th 2021, 420 University students took part in an anonymous survey asking for information on habits and symptoms that emerged during the lockdown in response to the COVID-19 pandemic. Three health outcomes were assessed: digestive disorders; headache; fear of COVID-19. Covariates including conditions and lifestyle during the pandemic, SARS-CoV-2 infections in the family, fnancial situation and productivity were considered in the analysis. Results Participants experienced headache and fear of COVID-19 quite frequently during the lockdown period. More than half of the sample also experienced social isolation. Female gender, sleep quality, memory difculties, and a change in eating habits resulted associated with an increased risk of health outcomes such as headaches and digestive disorders. Conclusions The results of this study ft within an original pandemic context: The results of this study can help identify needs and promote solutions applicable to diferent contexts. Future interventions should focus on the promotion and implementation of healthy habits focused on sleep hygiene, psychoeducation on the use of mobile devices and gender medicine with the support of healthcare organizations and University
Más allá de la ley. La virginidad en la genealogía del liberalismo
(2024) Martínez Rivas, Rafael
Los estudios foucaultianos sobre la gubernamentalidad neoliberal han prestado mucha atención a la tercera parte de Las confesiones de la carne, en la que Foucault traza la arqueología del “hombre de deseo” y del sujeto jurídico. Sin embargo, la literatura ha tendido a prestar poca atención a la segunda parte del libro, dedicada al estudio de la virginidad. Es esta parte la que este trabajo pretende estudiar, reconstruyendo críticamente los argumentos de Foucault y mostrando el lugar que la virginidad cristiana ocupa en la genealogía del sujeto moderno y de la gubernamentalidad liberal. Por último, el trabajo pretende mostrar que la virginidad cristiana primitiva, tal y como la presentan Brown y Foucault, puede definirse como lo que este último denominó una “contraconducta”.
Chimera states and information transfer in interacting populations of map-based neurons
(2024) Márquez-Rodríguez, V. J.; Tucci, K.; Cosenza, M. G.
We investigate the synchronization behavior and the emergence of chimera states in a system of two interacting populations of maps possessing chaotic neural-like dynamics. We characterize four collective states on the space of coupling parameters of the system: complete synchronization, generalized synchronization, chimera states, and incoherence. We quantify the information exchange between the two neuron populations in chimera states. We have found a well-defined direction of the flow of information in chimera states, from the desynchronized population to the synchronized one. The incoherent population functions as a driver of the coherent neuron population in a chimera state. This feature is independent of the population sizes or population partitions. Our results yield insight into the communication mechanisms arising in brain processes such as unihemispheric sleep and epileptic seizures that have been associated to chimera states.
The political business cycle of tax reforms
(2024) Rossel, Lucia; Huysmans, Martijn; Ferwerda, Joras
A political business cycle (PBC), with governments adjusting and timing economic policy for electoral gains, has long been hypothesized. A lack of data has so far limited testing of this phenomenon for government policies as opposed to fiscal outcomes such as tax revenue or government deficit, especially at the national level. We use new monthly data on tax reform announcements for a set of 22 democracies, 1988–2014, to test the PBC hypothesis for taxation. In addition to the traditional electoral strategy formulation of the PBC, we also put forward and test a capacity version of the PBC. We find evidence for the capacity version but not the traditional version of the PBC: tax reforms are less likely to be announced before elections and more likely after elections, independently of whether they are increases or decreases. Our evidence suggests that while a PBC exists, it may be less driven by strategic electioneering and more innocuous than previously assumed.
Vaccine effectiveness in reducing COVID-19-related hospitalization after a risk-age-based mass vaccination program in a Chilean municipality: A comparison of observational study designs
(2024) Urquidi, Cinthya; Sepúlveda-Peñaloza, Alejandro; Valenzuela, María T.; Ponce, Alexander; Menares, Verónica; Cortes, Claudia P.; Benítez, Rosana; Santelices, Emilio; Anfossi, Renato; Moller, Andrea; Santolaya, María E.
Background: Case–control studies involving test-negative (TN) and syndrome-negative (SN) controls are reliable for evaluating influenza and rotavirus vaccine effectiveness (VE) during a random vaccination process. However, there is no empirical evidence regarding the impact in real-world mass vaccination campaigns against SARS-CoV-2 using TN and SN controls. Objective: To compare in the same population the effectiveness of SARS-CoV-2 vaccination on COVID-19-related hospitalization rates across a cohort design, TN and SN designs. Method: We conducted an unmatched population-based cohort, TN and SN case–control designs linking data from four data sources (public primary healthcare system, hospitalization registers, epidemiological surveillance systems and the national immunization program) in a Chilean municipality (Rancagua) between March 1, 2021 and August 31, 2021. The outcome was COVID-19-related hospitalization. To ensure sufficient sample size in the unexposed group, completion of follow-up in the cohort design, and sufficient time between vaccination and hospitalization in the case–control design, VE was estimated comparing 8-week periods for each individual. Results: Among the 191,505 individuals registered in the primary healthcare system of Rancagua in Chile on March 1, 2021; 116,453 met the cohort study’s inclusion criteria. Of the 9,471 hospitalizations registered during the study period in the same place, 526 were COVID-19 cases, 108 were TN controls, and 1,628 were SN controls. For any vaccine product, the age- and sex-adjusted vaccine effectiveness comparing fully and nonvaccinated individuals was 67.2 (55.7–76.3) in the cohort design, whereas it was 67.8 (44.1–81.4) and 77.9 (70.2–83.8) in the TN and SN control designs, respectively. Conclusion: The VE of a COVID-19 vaccination program based on age and risk groups tended to differ across the three observational study designs. The SN case-control design may be an efficient option for evaluating COVID- 19 VE in real-world settings.
Impact of urban facilities spatial inequality on sustainable travel mode
(2024) Urrutia-Mosquera, Jorge; Flórez-Calderón, Luz; Cortés, Yasna; Troncoso, Rodrigo; Lufin, Marcelo
With the implementation of sustainable development objectives in developing countries, urban planning, land use regulation, and urban mobility policies are expected to help reduce inequalities in access to urban facilities. Urban transport policies are also expected to encourage travel by non-motorised modes and public transport. These are considered to be the sustainable modes of urban transport. In this paper, we investigate how inequality of urban facilities impacts trips made by sustainable modes in the city of Santiago de Chile. We use aPoisson regression model and its geographical extension, the geographically weighted Poisson regression model (GWPR). The results suggest that the inequality of urban facilities impacts trips made by sustainable modes. The variables with the highest relevance are the spatial distribution of mixed land use, the spatial distribution of urban services related to transport infrastructure, primary and secondary education, as well as the spatial distribution of demographic variables related to people’s life cycle.
The parietal cortex has a causal role in ambiguity computations in humans
(2024) Valdebenito-Oyarzo, Gabriela; Martínez-Molina, María Paz; Soto-Icaza, Patricia; Zamorano, Francisco; Figueroa-Vargas, Alejandra; Larraín-Valenzuela, Josefina; Stecher, Ximena; Salinas, César; Bastin, Julien; Valero-Cabré, Antoni; Polania, Rafael; Billeke, Pablo
Humans often face the challenge of making decisions between ambiguous options. The level of ambiguity in decision-making has been linked to activity in the parietal cortex, but its exact computational role remains elusive. To test the hypothesis that the parietal cortex plays a causal role in computing ambiguous probabilities, we conducted consecutive fMRI and TMS-EEG studies. We found that participants assigned unknown probabilities to objective probabilities, elevating the uncertainty of their decisions. Parietal cortex activity correlated with the objective degree of ambiguity and with a process that underestimates the uncertainty during decision-making. Conversely, the midcingulate cortex (MCC) encodes prediction errors and increases its connectivity with the parietal cortex during outcome processing. Disruption of the parietal activity increased the uncertainty evaluation of the options, decreasing cingulate cortex oscillations during outcome evaluation and lateral frontal oscillations related to value ambiguous probability. These results provide evidence for a causal role of the parietal cortex in computing uncertainty during ambiguous decisions made by humans.
Analysis of the Assessment of Vocal Performance Samples of Students of Acting from a Social Behavioral Perspective
(2024) Fernandez-Fresard, Gala; Flores Prado, Luis; Duarte, Maria; Muñoz Reyes, José Antonio; Polo Rodrigo, Pablo
The present study proposes an innovative analysis of the assessment of vocal performance samples (VPSs) from a social–behavioral perspective. The study’s main purpose was to analyze the cooperative tendency of teacher–student interaction to estimate the impact of cooperation on the formative nature of VPSs’ assessment experience. The latter was held in two different contexts based on the teachers’ perception: as an evaluator and as a spectator. The formative nature was judged through the students’ learning achievement and measured by their grades and their perceptual valuing of the assessment results provided by the teachers. The experiment was conducted at a Chilean university with twenty-two teachers and fourteen students of acting. The results indicate that no significant differences were observed in the control group (students assessed under the traditional system) between teachers who did not exhibit cooperative tendencies and those who did. However, in the experimental group (students assessed using a social–behavioral perspective system), teachers who did not exhibit cooperative tendencies were valued significantly lower than those who did. It was concluded that the presence of cooperative components in the teacher–student interaction contributes to determining the formative nature of the assessment experience in terms of how the students perceive it. The following is true as long as the structure of this experience promotes a collaborative interaction between teachers and students. This type of formative assessment can improve the assessment experience by fostering a teacher–student interaction that allows the co-construction of the theatrical phenomenon, which could potentially positively impact students’ vocal expressiveness.
Estimating multinomial logit models with endogenous variables: Control function versus two adapted approaches
(2024) Grange, Louis de; González, Felipe; Marechal, Matthieu; Troncoso, Rodrigo
It is shown that the control function (CF) method’s estimates of the modal constants in a multinomial logit model (MNL) with endogenous explanatory variables are biased. This has not previously been reported in the literature, and has consequences in demand analysis, transportation policy design and project evaluation. Two adaptations of existing approaches are proposed as alternatives to CF for deriving estimators of parameters in MNL models with endogenous explanatory variables that evidence good consistency properties. The first approach is based on moment conditions while the second one combines parameters obtained in two consecutive estimation stages. Both approaches employ instrumental variables. These two adapted approaches are implemented using simulated data from a transport mode choice problem. The results are compared with those obtained using the classic control-function method, typically used by practitioners for estimating transport demand models with endogenous variables and making quantitative evaluations of transport policies and projects. All three approaches generate similar estimates for the parameters of the explanatory variables, but the two proposed adaptations produce considerably more accurate estimates of the modal constants. This greater accuracy has potentially significant consequences for multinomial logit models’ predictive ability and estimates of marginal effects, elasticities and the social benefits of projects based on con sumer surplus calculations.
Translating the behaviour change technique taxonomy version 1 into Spanish: Methodology and validation
(2024) Castro, Oscar; Fajardo, Gabriela; Johnston, Marie; Laroze, Denise; Leiva-Pinto, Eduardo; Figueroa, Oriana; Corker, Elizabeth; Chacón-Candia, Jeanette A.; Duarte, Giuliano
Background: Precise and unequivocal specification of intervention content is key to facilitating the accumulation and implementation of knowledge. The Behaviour Change Technique Taxonomy v1 (BCTTv1) is the most widely used classification of behaviour change techniques (BCTs), providing a shared, standardized vocabulary to identify the active ingredients of behavioural interventions. However, the BCTTv1 is only available in English and this hampers its broad use and adoption. The aim of the present article is to report the process of translation of the BCTTv1 into Spanish. Methods: A bilingual team led the translation of the BCTTv1, involving seven iterative steps: (i) establish a Committee, (ii) forward translation from English to Spanish, (iii) back translation from Spanish to English, (iv) comparison of original BCTTv1 and back translation, (v) opportunistic comparison against an independent BCTTv1 translation, (vi) empirical testing, and (vii) final Committee review. Results: Changes as a result of the translation process included relabelling BCTs, amending definitions, and fixing conceptual and grammatical inconsistencies, yielding the final version. Very satisfactory inter-coder reliability in BCT identification was observed as part of the empirical testing (i.e., prevalence and bias-adjusted kappa scores > 0.8). Conclusions: This work provides the Spanish-speaking population with a rigorous and validated BCTTv1 translation which can be used in both research and practice to provide a greater level of intervention detail for evidence synthesis, comparison, and replication of behaviour change interventions. The translation process described here may prove helpful to guide future translation efforts in behavioural science and beyond.
Lateral prefrontal theta oscillations causally drive a computational mechanism underlying conflict expectation and adaptation
(2024) Martínez-Molina, María Paz; Valdebenito-Oyarzo, Gabriela; Soto-Icaza, Patricia; Zamorano, Francisco; Figueroa-Vargas, Alejandra; Carvajal-Paredes, Patricio; Stecher, Ximena; Salinas, César; Valero-Cabré, Antoni; Polania, Rafael; Billeke, Pablo
Adapting our behavior to environmental demands relies on our capacity to perceive and manage potential conflicts within our surroundings. While evidence implicates the involvement of the lateral prefrontal cortex and theta oscillations in detecting conflict stimuli, their causal role in conflict expectation remains elusive. Consequently, the exact computations and neural mechanisms underlying these cognitive processes still need to be determined. We employed an integrative approach involving cognitive computational modeling, fMRI, TMS, and EEG to establish a causal link between oscillatory brain function, its neurocomputational role, and the resulting conflict processing and adaptation behavior. Our results reveal a computational process underlying conflict expectation, which correlates with BOLD-fMRI and theta activity in the superior frontal gyrus (SFG). Modulation of theta activity via rhythmic TMS applied over the SFG induces endogenous theta activity, which in turn enhances computations associated with conflict expectation. These findings provide evidence for the causal involvement of SFG theta activity in learning and allocating cognitive resources to address forthcoming conflict stimuli. Similar content being viewe
Dominance hierarchy regulates social behavior during spatial movement
(2024) Lara-Vasquez, Ariel; Espinosa, Nelson; Morales, Cristian; Moran, Constanza; Billeke, Pablo; Gallagher, Joseph; Strohl, Joshua J.; Huerta, Patricio T.; Fuentealba, Pablo
Rodents establish dominance hierarchy as a social ranking system in which one subject acts as dominant over all the other subordinate individuals. Dominance hierarchy regulates food access and mating opportunities, but little is known about its significance in other social behaviors, for instance during collective navigation for foraging or migration. Here, we implemented a simplified goal-directed spatial task in mice, in which animals navigated individually or collectively with their littermates foraging for food. We compared between conditions and found that the social condition exerts significant influence on individual displacement patterns, even when efficient navigation rules leading to reward had been previously learned. Thus, movement patterns and consequent task performance were strongly dependent on contingent social interactions arising during collective displacement, yet their influence on individual behavior was determined by dominance hierarchy. Dominant animals did not behave as leaders during collective displacement; conversely, they were most sensitive to the social environment adjusting their performance accordingly. Social ranking in turn was associated with specific spontaneous neural activity patterns in the prefrontal cortex and hippocampus, with dominant mice showing higher firing rates, larger ripple oscillations, and stronger neuronal entrainment by ripples than subordinate animals. Moreover, dominant animals selectively increased their cortical spiking activity during collective movement, while subordinate mice did not modify their firing rates, consistent with dominant animals being more sensitive to the social context. These results suggest that dominance hierarchy influences behavioral performance during contingent social interactions, likely supported by the coordinated activity in the hippocampal-prefrontal circuit.
The effect of a cognitive training therapy based on stimulation of brain oscillations in patients with mild cognitive impairment in a Chilean sample: study protocol for a phase IIb, 2 × 3 mixed factorial, double‑blind randomised controlled trial
(2024) Figueroa‑Vargas, Alejandra; Góngora, Begoña; Alonso, María Francisca; Ortega, Alonso; Soto‑Fernández, Patricio; Z‑Rivera, Lucía; Ramírez, Sebastián; González, Francisca; Muñoz Venturelli, Paula; Billeke, Pablo
Background The ageing population has increased the prevalence of disabling and high-cost diseases, such as dementia and mild cognitive impairment (MCI). The latter can be considered a prodromal phase of some dementias and a critical stage for interventions to postpone the impairment of functionality. Working memory (WM) is a pivotal cognitive function, representing the fundamental element of executive functions. This project proposes an intervention protocol to enhance WM in these users, combining cognitive training with transcranial electrical stimulation of alternating current (tACS). This technique has been suggested to enhance the neuronal plasticity needed for cognitive processes involving oscillatory patterns. WM stands to benefit significantly from this approach, given its well-defined electrophysiological oscillations. Therefore, tACS could potentially boost WM in patients with neurodegenerative diseases. Methods This study is a phase IIb randomised, double-blind clinical trial with a 3-month follow-up period. The study participants will be 62 participants diagnosed with MCI, aged over 60, from Valparaíso, Chile. Participants will receive an intervention combining twelve cognitive training sessions with tACS. Participants will receive either tACS or placebo stimulation in eight out of twelve training sessions. Sessions will occur twice weekly over 6 weeks. The primary outcomes will be electroencephalographic measurements through the prefrontal theta oscillatory activity, while the secondary effects will be cognitive assessments of WM. The participants will be evaluated before, immediately after, and 3 months after the end of the intervention. Discussion The outcomes of this trial will add empirical evidence about the benefits and feasibility of an intervention that combines cognitive training with non-invasive brain stimulation. The objective is to contribute tools for optimal cognitive treatment in patients with MCI. To enhance WM capacity, postpone the impairment of functionality, and obtain a better quality of life.
Patients recovering from COVID-19 who presented with anosmia during their acute episode have behavioral, functional, and structural brain alterations
(2024) Kausel, Leonie; Figueroa-Vargas, Alejandra; Zamorano, Francisco; Stecher, Ximena; Aspé-Sánchez, Mauricio; Carvajal-Paredes, Patricio; Márquez-Rodríguez, Víctor; Martínez-Molina, María Paz; Román, Claudio; Soto-Fernández, Patricio; Valdebenito-Oyarzo, Gabriela; Manterola, Carla; Uribe-San-Martín, Reinaldo; Silva, Claudio; Henríquez-Ch, Rodrigo; Aboitiz, Francisco; Polania, Rafael; Guevara, Pamela; Muñoz-Venturelli, Paula; Soto-Icaza, Patricia; Billeke, Pablo
Patients recovering from COVID-19 commonly exhibit cognitive and brain alterations, yet the specific neuropathological mechanisms and risk factors underlying these alterations remain elusive. Given the significant global incidence of COVID-19, identifying factors that can distinguish individuals at risk of developing brain alterations is crucial for prioritizing follow-up care. Here, we report findings from a sample of patients consisting of 73 adults with a mild to moderate SARS-CoV-2 infection without signs of respiratory failure and 27 with infections attributed to other agents and no history of COVID-19. The participants underwent cognitive screening, a decision-making task, and MRI evaluations. We assessed for the presence of anosmia and the requirement for hospitalization. Groups did not differ in age or cognitive performance. Patients who presented with anosmia exhibited more impulsive alternative changes after a shift in probabilities (r = − 0.26, p = 0.001), while patients who required hospitalization showed more perseverative choices (r = 0.25, p = 0.003). Anosmia correlated with brain measures, including decreased functional activity during the decision-making task, thinning of cortical thickness in parietal regions, and loss of white matter integrity. Hence, anosmia could be a factor to be considered when identifying at-risk populations for follow-up
Spanish version of Multidimensional Mentalizing Questionnaire (MMQ): Translation, adaptation and psychometric properties in a Chilean population
(2024) Aldunate, Nerea; López-Silva, Pablo; Brotfeld, Cristian; Guerra, Ernesto; Kronmüller, Edmundo
This paper presents the first translation and adaptation of the Multidimensional Mentalizing Questionnaire (MMQ) into Spanish for a native Spanish-speaking sample in Chile. The study examines the psychometric properties and internal consistency of the translated MMQ. The instrument undergoes modifications based on a confirmatory factor analysis of the original structure, resulting in the elimination of items with cross-loadings and improvement in model fit. The modified scale is then analyzed, demonstrating strong psychometric properties. Convergent evidence is assessed by correlating MMQ subscales with the Interpersonal Reactivity Index (IRI) and Empathy Quotient (EQ), while divergent evidence is assessed by correlating aggressive traits using the Buss-Perry Aggression Questionnaire (BPAQ). The study also explores gender differences and age. Results reveal positive correlations between good mentalizing and empathy, particularly cognitive empathy, supporting the significance of positive mentalization in empathy. Negative mentalization is associated with difficulties in perspective-taking and social skills, as well as aggressive traits. Gender differences in mentalizing capacities are observed, and negative aspects of mentalization decrease with age. The availability of the Spanish translation of the MMQ, the first self-reporting scale measuring mentalization adapted to Chilean population, contributes to research aiming to understand its relationship with other psychological phenomena in different cultural context and facilitating clinical interventions with different population groups. We therefore encourage further investigation into cultural, gender and age differences in mentalization.
A mathematical model of semantic access in lexical and semantic decisions
(2024) Chaigneau, Sergio E.; Marchant, Nicolás; Canessa, Enrique; Aldunate, Nerea
In this work, we use a mathematical model of the property listing task dynamics and test its ability to predict processing time in semantic and lexical decision tasks. The study aims at exploring the temporal dynamics of semantic access in these tasks and showing that the mathematical model captures essential aspects of semantic access, beyond the original task for which it was developed. In two studies using the semantic and lexical decision tasks, we used the mathematical model’s coefficients to predict reaction times. Results showed that the model was able to predict processing time in both tasks, accounting for an independent portion of the total variance, relative to variance predicted by traditional psycholinguistic variables (i.e., frequency, familiarity, concreteness imageability). Overall, this study provides evidence of the mathematical model’s validity and generality, and offers insights regarding the characterization of concrete and abstract words.

Browse

Recent Submissions