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Browsing by Author "Billeke, Pablo"

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A multifactorial approach of nutritional, intellectual, brain development, cardiovascular risk, socio-economic, demographic and educational variables affecting the scholastic achievement in Chilean students: An eight- year follow-up study
(2019) Ivanovic, Daniza M.; Almagià, Atilio F.; Arancibia, Violeta C.; Ibaceta, Camila V.; Arias, Vanessa F.; Rojas, Tatiana; Flores, Ofelia C.; Villagrán, Francisca S.; Tapia, Liliana U.; Acevedo, Javiera A .; Morales, Gladys I.; Martínez, Víctor C.; Larraín, Cristián G.; Silva, Claudio F.A.; Valenzuela, Rodrigo B.; Barrera, Cynthia R.; Billeke, Pablo; Zamorano, Francisco M.; Orellana, Yasna Z.
The aim of this study was to quantitate the relative impact of nutritional, intellectual, brain development, cardiovascular risk, socio-economic, demographic and educational variables on the results of the 2009 Quality Education Measurement System (SIMCE) tests of language and mathematics for scholastic achievement (SA) applying a multifactorial approach, in school-age children of the 2010 5th elementary school grade (5ESG) and of the 1st grade of high school (1HSG). The purposes were: i) to test the hypothesis that intellectual ability, the level of SA of the educational establishments in the 2009 SIMCE tests, sex, parental schooling levels, and head circumference-for-age Z-score are the most relevant parameters associated with 2009 SIMCE outcomes; ii) to determine the predictive ability of the 2009 SIMCE results in determining the 2013 SIMCE outcomes for the 2010 5ESG cohort (when they graduated from elementary school, 8th grade) and for determining the 2013 University Selection Test (PSU) outcomes for the 2010 1HSG group (for university admission, when they graduated from high school, 4th grade); iii) to determine the association between the 2009 SIMCE results with the 2017 PSU outcomes for the 2010 5ESG group (for university admission, when they graduated from high school, 4th grade). A representative, proportional and stratified sample of 33 schools of the Metropolitan Region of Chile was randomly chosen. In these schools, 1,353 school-age children of both sexes, of the 2010 5ESG (n = 682; mean age = 10.8 years, SD = 0.6) and of the 2010 1HSG (n = 671; mean age = 14.8 years, SD = 0.6) participated. In both grades and tests, the findings confirm the hypotheses formulated. 2009 SIMCE outcomes were positively and significantly associated with 2013 SIMCE and with 2017 PSU and, with 2013 PSU outcomes in school-age children from 2010 5ESG and 1HSG, respectively. These findings may be useful for educational and health planning in Chile and countries in a comparable stage of development.
Anatomical dissociation of intracerebral signals for reward and punishment prediction errors in humans
(2021) Gueguen, Maëlle C. M.; Lopez-Persem, Alizée; Billeke, Pablo; Lachaux, Jean-Philippe; Rheims, Sylvain; Kahane, Philippe; Minotti, Lorella; David, Olivier; Pessiglione, Mathias; Bastin, Julien
Whether maximizing rewards and minimizing punishments rely on distinct brain systems remains debated, given inconsistent results coming from human neuroimaging and animal electrophysiology studies. Bridging the gap across techniques, we recorded intracerebral activity from twenty participants while they performed an instrumental learning task. We found that both reward and punishment prediction errors (PE), estimated from computational modeling of choice behavior, correlate positively with broadband gamma activity (BGA) in several brain regions. In all cases, BGA scaled positively with the outcome (reward or punishment versus nothing) and negatively with the expectation (predictability of reward or punishment). However, reward PE were better signaled in some regions (such as the ventromedial prefrontal and lateral orbitofrontal cortex), and punishment PE in other regions (such as the anterior insula and dorsolateral prefrontal cortex). These regions might therefore belong to brain systems that differentially contribute to the repetition of rewarded choices and the avoidance of punished choices.
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.
Attending to the heart is associated with posterior alpha band increase and a reduction in sensitivity to concurrent visual stimuli.
(2017) Villena-González, M.; Moënne-Loccoz, C.; Lagos, R.; Alliende, Luz M.; Billeke, Pablo; Aboitiz, Francisco; López, V.; Cosmelli, D.
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.
Beta oscillations precede joint attention and correlate with mentalization in typical development and autism
(Elsevier Ltd., 2019) Soto-Icaza, Patricia; Vargas, Lorena; Aboitiz, Francisco; Billeke, Pablo
A precursor of adult social functioning is joint attention (JA), which is the capacity to share attention on an object with another person. JA precedes the development of the capacity to attribute mental states to others (i.e., mentalization or theory of mind). The neural mechanisms involved in the development of mentalization are not fully understood. Electroencephalographic recordings were made of children while they watched stimuli on a screen and their interaction with the experimenter was assessed. We tested whether neuronal activity preceding JA correlates with mentalization in typically developing (TD) children and whether this activity is impaired in children with autistic spectrum disorder (ASD) who evidence deficits in JA and mentalization skills. Both groups exhibited JA behavior with comparable frequency. TD children displayed a higher amplitude of negative central (Nc) event-related potential preceding JA behavior (∼500 msec after stimuli presentation), than did the ASD group. Previous to JA behavior, TD children demonstrated beta oscillatory activity in the temporoparietal region, while ASD children did not show an increase in beta activity. In both groups, the beta power correlated with mentalization, suggesting that this specific neuronal mechanism is involved in mentalization, which used during social interaction.
Brain state-dependent recruitment of high-frequency oscillations in the human hippocampus
(01/09/2017) Billeke, Pablo; Ossandón, Tomás; Stockle, Marcelo; Perrone-Bertolotti, Marcela; Kahane, Philippe; Lachaux, Jean-Philippe; Fuentealba, Pablo
Ripples are high-frequency bouts of coordinated hippocampal activity believed to be crucial for information transfer and memory formation. We used intracortical macro electrodes to record neural activity in the human hippocampus of awake subjects undergoing surgical treatment for refractory epilepsy and distinguished two populations of ripple episodes based on their frequency spectrum. The phase-coupling of one population, slow ripples (90-110 Hz), to cortical delta oscillations was differentially modulated by cognitive task; whereas the second population, fast ripples (130-170 Hz), was not seemingly correlated to local neural activity. Furthermore, as cognitive tasks changed, the ongoing coordination of neural activity associated to slow ripples progressively augmented along the parahippocampal axis. Thus, during resting states, slow ripples were coordinated in restricted hippocampal territories; whereas during active states, such as attentionally-demanding tasks, high frequency activity emerged across the hippocampus and parehippocampal cortex, that was synchronized with slow ripples, consistent with ripples supporting information transfer and coupling anatomically distant regions. Hence, our results provide further evidence of neural diversity in hippocampal high-frequency oscillations and their association to cognitive processing in humans. (C) 2017 Elsevier Ltd. All rights reserved.
Brain structural parameters correlate with University Selection Test outcomes in Chilean high school graduates
(2022) Ivanovic, Daniza; Zamorano, Francisco; Soto-Icaza, Patricia; Rojas, Tatiana; Larraín, Cristián; Silva F., Claudio; Almagià, Atilio; Bustamante, Claudia; Arancibia, Violeta; Villagrán, Francisca; Valenzuela, Rodrigo; Barrera, Cynthia; Billeke, Pablo
How well students learn and perform in academic contexts is a focus of interest for the students, their families, and the entire educational system. Although evidence has shown that several neurobiological factors are involved in scholastic achievement (SA), specific brain measures associated with academic outcomes and whether such associations are independent of other factors remain unclear. This study attempts to identify the relationship between brain structural parameters, and the Chilean national University Selection Test (PSU) results in high school graduates within a multidimensional approach that considers socio-economic, intellectual, nutritional, and demographic variables. To this end, the brain morphology of a sample of 102 students who took the PSU test was estimated using Magnetic Resonance Imaging. Anthropometric parameters, intellectual ability (IA), and socioeconomic status (SES) were also measured. The results revealed that, independently of sex, IA, gray matter volume, right inferior frontal gyrus thickness, and SES were significantly associated with SA. These findings highlight the role of nutrition, health, and socioeconomic variables in academic success
Country-level gender inequality is associated with structural differences in the brains of women and men
(2023) Zugman, André; Alliende, Luz María; Medel, Vicente; Bethlehem, Richard A.I.; Seidlitz, Jakob; Ringlein, Grace; Arango, Celso; Arnatkevičiūtė, Aurina; Asmal, Laila; Bellgrove, Mark; Benegal, Vivek; Bernardo, Miquel; Billeke, Pablo; Bosch-Bayard, Jorge; Bressan, Rodrigo; Busatto, Geraldo F.; Castro, Mariana N.; Chaim-Avancini, Tiffany; Compte, Albert; Costanzi, Monise; Czepielewsk, Leticia; Dazzan, Paola; Fuente-Sandoval, Camilo de la; Forti, Marta Di; Díaz-Caneja, Covadonga M.; Díaz-Zuluaga, Ana María; Ples, Stefan Du; Duran, Fabio L. S.; Fittipaldi, Sol; Fornito, Alex; Freimer, Nelson B.; Gadelha, Ary; Gama, Clarissa S.; Garani, Ranjini; Garcia-Rizo, Clemente; Gonzalez Campo, Cecilia; Gonzalez-Valderrama, Alfonso; Guinjoan, Salvador; Holla, Bharath; Undurraga, Juan
Gender inequality across the world has been associated with a higher risk to mental health problems and lower academic achievement in women compared to men. We also know that the brain is shaped by nurturing and adverse socio-environmental experiences. Therefore, unequal exposure to harsher conditions for women compared to men in gender-unequal countries might be reflected in differences in their brain structure, and this could be the neural mechanism partly explaining women's worse outcomes in gender-unequal countries. We examined this through a random-effects meta-analysis on cortical thickness and surface area differences between adult healthy men and women, including a meta-regression in which country-level gender inequality acted as an explanatory variable for the observed differences. A total of 139 samples from 29 different countries, totaling 7,876 MRI scans, were included. Thickness of the right hemisphere, and particularly the right caudal anterior cingulate, right medial orbitofrontal, and left lateral occipital cortex, presented no differences or even thicker regional cortices in women compared to men in gender-equal countries, reversing to thinner cortices in countries with greater gender inequality. These results point to the potentially hazardous effect of gender inequality on women's brains and provide initial evidence for neuroscience-informed policies for gender equality.
Development of social skills in children: neural and behavioral evidence for the elaboration of cognitive models
(2015) Soto-Icaza, Patricia; Aboitiz, Francisco; Billeke, Pablo
Social skills refer to a wide group of abilities that allow us to interact and communicate with others. Children learn how to solve social situations by predicting and understanding other’s behaviors. The way in which humans learn to interact successfully with others encompasses a complex interaction between neural, behavioral, and environmental elements. These have a role in the accomplishment of positive developmental outcomes, including peer acceptance, academic achievement, and mental health. All these social abilities depend on widespread brain networks that are recently being studied by neuroscience. In this paper, we will first review the studies on this topic, aiming to clarify the behavioral and neural mechanisms related to the acquisition of social skills during infancy and their appearance in time. Second, we will briefly describe how developmental diseases like Autism Spectrum Disorders (ASD) can inform about the neurobiological mechanisms of social skills. We finally sketch a general framework for the elaboration of cognitive models in order to facilitate the comprehension of human social development.
Differences in cortical processing of facial emotions in broader autism phenotype
(2022) Soto-Icaza, Patricia; Beffara-Bret, Brice; Vargas, Lorena; Aboitiz, Francisco; Billeke, Pablo
Autism Spectrum Disorder (ASD) is a heterogeneous condition that affects face perception. Evidence shows that there are differences in face perception associated with the processing of low spatial frequency (LSF) and high spatial frequency (HSF) of visual stimuli between non-symptomatic relatives of individuals with autism (broader autism phenotype, BAP) and typically developing individuals. However, the neural mechanisms involved in these differences are not fully understood. Here we tested whether face-sensitive event related potentials could serve as neuronal markers of differential spatial frequency processing, and whether these potentials could differentiate non-symptomatic parents of children with autism (pASD) from parents of typically developing children (pTD). To this end, we performed electroencephalographic recordings of both groups of parents while they had to recognize emotions of face pictures composed of the same or different emotions (happiness or anger) presented in different spatial frequencies. We found no significant differences in the accuracy between groups but lower amplitude modulation in the Late Positive Potential activity in pASD. Source analysis showed a difference in the right posterior part of the superior temporal region that correlated with ASD symptomatology of the child. These results reveal differences in brain processing of recognition of facial emotion in BAP that could be a precursor of ASD.
Docosahexaenoic acid levels in erythrocytes and their association with the University Selection Test Outcomes in Chile
(2018) Valenzuela, Rodrigo; Barrera, Cynthia; Orellana, Yasna; Almagià, Atilio; Arancibia, Violeta; Larraín, Cristian; Silva, Claudio; Billeke, Pablo; Zamorano, Francisco; Martínez, Víctor; Valenzuela, Alfonso; Ivanovic, Daniza
The aim of this study was to quantitate the relative impact of DHA and AA levels in erythrocytes, anthropometric parameters and socio-economic status of school-age children, of both genders, graduated from high school in Chile, on the scholastic achievement in the University Selection Test (Prueba de Selección Universitaria, PSU) both language scholastic achievement (LSA) and mathematics scholastic achievement (MSA). A representative sample of 671 school-age young graduated from high school in 2013, 550 and 548 of them took the PSU for LSA and MSA, respectively. Only school-age young with high (n=91) and low (n=69) SA in both tests were considered. A total of 122 school-age children agreed to participate in the study and were divided as follows: Group 1: high PSU outcome (n=70; males n=48) and Group 2: low PSU outcome (n=52; males n=23). Data were analyzed by means of SAS software. Independently of gender, DHA, socio-economic status and head circumference-for-age Z-score were the most relevant parameters explaining both LSA (R2=0.650; p<0.0001) and MSA outcomes (R2=0.700; p<0.0001). These results can be useful for nutrition, health and education planning, in order to protect children starting from an early age and thus increase their school outcomes.
Explicit and implicit markers of fairness preeminence in criminal judges
(2021) Santamaría‐García, Hernando; Martínez Cotrina, Jorge; FlorezTorres, Nicolás; Buitrago, Carlos; Aponte‐Canencio, Diego Mauricio; Caicedo, Juan Carlos; Billeke, Pablo; Gantiva, Carlos; Baez, Sandra
Achieving justice could be considered a complex social decision-making scenario. Despite the relevance of social decisions for legal contexts, these processes have still not been explored for individuals who work as criminal judges dispensing justice. To bridge the gap, we used a complex social decision-making task (Ultimatum game) and tracked a heart rate variability measurement: the square root of the mean squared differences of successive NN intervals (RMSSD) at their baseline (as an implicit measurement that tracks emotion regulation behavior) for criminal judges (n = 24) and a control group (n = 27). Our results revealed that, compared to controls, judges were slower and rejected a bigger proportion of unfair offers. Moreover, the rate of rejections and the reaction times were predicted by higher RMSSD scores for the judges. This study provides evidence about the impact of legal background and expertise in complex social decision-making. Our results contribute to understanding how expertise can shape criminal judges’ social behaviors and pave the way for promising new research into the cognitive and physiological factors associated with social decision-making.
Fluctuating Minds: Spontaneous Psychophysical Variability during Mind-Wandering
(2016) Henríquez, Rodrigo A.; Chica, Ana B.; Billeke, Pablo; Bartolomeo, Paolo
Mind-wandering is the occasional distraction we experience while performing a cognitive task. It arises without any external precedent, varies over time, and interferes with the processing of sensory information. Here, we asked whether the transition from the on-task state to mind-wandering is a gradual process or an abrupt event. We developed a new experimental approach, based on the continuous, online assessment of individual psychophysical performance. Probe questions were asked whenever response times (RTs) exceeded 2 standard deviations from the participant’s average RT. Results showed that mind-wandering reports were generally preceded by slower RTs, as compared to trials preceding on-task reports. Mind-wandering episodes could be reliably predicted from the response time difference between the last and the second-to-last trials. Thus, mind-wandering reports follow an abrupt increase in behavioral variability, lasting between 2.5 and 10 seconds
Frontoparietal connectivity correlates with working memory performance in multiple sclerosis
(2020) Figueroa-Vargas, Alejandra; Cárcamo, Claudia; Henríquez-Ch, Rodrigo; Zamorano, Francisco; Ciampi, Ethel; Uribe-San-Martin, Reinaldo; Vásquez, Macarena; Aboitiz, Francisco; Billeke, Pablo
Working Memory (WM) impairment is the most common cognitive deficit of patients with Multiple Sclerosis (MS). However, evidence of its neurobiological mechanisms is scarce. Here we recorded electroencephalographic activity of twenty patients with relapsing-remitting MS and minimal cognitive deficit, and 20 healthy control (HC) subjects while they solved a WM task. In spite of similar performance, the HC group demonstrated both a correlation between temporoparietal theta activity and memory load, and a correlation between medial frontal theta activity and successful memory performances. MS patients did not show theses correlations leading significant differences between groups. Moreover, cortical connectivity analyses using granger causality and phase-amplitude coupling between theta and gamma revealed that HC group, but not MS group, presented a load-modulated progression of the frontal-to-parietal connectivity. This connectivity correlated with working memory capacity in MS groups. This early alterations in the oscillatory dynamics underlaying working memory could be useful for plan therapeutic interventions.
Functional Cortical Network in Alpha Band Correlates with Social Bargaining
(2014) Billeke, Pablo; Zamorano, Francisco; Chavez, Mario; Cosmelli, Diego; Aboitiz, Francisco
Solving demanding tasks requires fast and flexible coordination among different brain areas. Everyday examples of this are the social dilemmas in which goals tend to clash, requiring one to weigh alternative courses of action in limited time. In spite of this fact, there are few studies that directly address the dynamics of flexible brain network integration during social interaction. To study the preceding, we carried out EEG recordings while subjects played a repeated version of the Ultimatum Game in both human (social) and computer (non-social) conditions. We found phase synchrony (inter-site-phaseclustering) modulation in alpha band that was specific to the human condition and independent of power modulation. The strength and patterns of the inter-site-phaseclustering of the cortical networks were also modulated, and these modulations were mainly in frontal and parietal regions. Moreover, changes in the individuals’ alpha network structure correlated with the risk of the offers made only in social conditions. This correlation was independent of changes in power and inter-site-phase-clustering strength. Our results indicate that, when subjects believe they are participating in a social interaction, a specific modulation of functional cortical networks in alpha band takes place, suggesting that phase synchrony of alpha oscillations could serve as a mechanism by which different brain areas flexibly interact in order to adapt ongoing behavior in socially demanding contexts
Functional Dizziness as a Spatial Cognitive Dysfunction
(2024) Breinbauer, Hayo; Stecher, Ximena; Zamorano, Francisco; Billeke, Pablo; Arévalo, Camilo; Villarroel, Karen; Lavin, Claudio; Faúndez, Felipe; Garrido, Rosario; Alarcón, Kevin; Delano, Paul
(1) Background: Persistent postural-perceptual dizziness (PPPD) is a common chronic dizziness disorder with an unclear pathophysiology. It is hypothesized that PPPD may involve disrupted spatial cognition processes as a core feature. (2) Methods: A cohort of 19 PPPD patients underwent psycho-cognitive testing, including assessments for anxiety, depression, memory, attention, planning, and executive functions, with an emphasis on spatial navigation via a virtual Morris water maze. These patients were compared with 12 healthy controls and 20 individuals with other vestibular disorders but without PPPD. Vestibular function was evaluated using video head impulse testing and vestibular evoked myogenic potentials, while brain magnetic resonance imaging was used to exclude confounding pathology. (3) Results: PPPD patients demonstrated unique impairments in allocentric spatial navigation (as evidenced by the virtual Morris water maze) and in other high-demand visuospatial cognitive tasks that involve executive functions and planning, such as the Towers of London and Trail Making B tests. A factor analysis highlighted spatial navigation and advanced visuospatial functions as being central to PPPD, with a strong correlation to symptom severity. (4) Conclusions: PPPD may broadly impair higher cognitive functions, especially in spatial cognition. We discuss a disruption in the creation of enriched cognitive spatial maps as a possible pathophysiology for PPPD
Human Anterior Insula Encodes Performance Feedback and Relays Prediction Error to the Medial Prefrontal Cortex
(2020) Billeke, Pablo; Ossandon, Tomas; Perrone-Bertolotti, Marcela; Kahane, Philippe; Bastin, Julien; Jerbi, Karim; Lachaux, Jean-Philippe; Fuentealba, Pablo
Adaptive behavior requires the comparison of outcome predictions with actual outcomes (e.g., performance feedback). This process of performance monitoring is computed by a distributed brain network comprising the medial prefrontal cortex (mPFC) and the anterior insular cortex (AIC). Despite being consistently co-activated during different tasks, the precise neuronal computations of each region and their interactions remain elusive. In order to assess the neural mechanism by which the AIC processes performance feedback, we recorded AIC electrophysiological activity in humans. We found that the AIC beta oscillations amplitude is modulated by the probability of performance feedback valence (positive or negative) given the context (task and condition difficulty). Furthermore, the valence of feedback was encoded by delta waves phase-modulating the power of beta oscillations. Finally, connectivity and causal analysis showed that beta oscillations relay feedback information signals to the mPFC. These results reveal that structured oscillatory activity in the anterior insula encodes performance feedback information, thus coordinating brain circuits related to reward-based learning.
Human reciprocity: behavioural components and neurocognitive signatures discriminating outcomes and intentions in trust-repayment behaviour – and some evolutionary considerations
(Universidad del Desarrollo. Facultad de Gobierno, 2020-09) Aspé Sánchez, Mauricio; Billeke, Pablo; Rodríguez-Sickert, Carlos
Oxytocin (OXT) and arginine-vasopressin (AVP) are two phylogenetically conserved neuropeptides that have been implicated in a wide range of social behaviors. Although a large body of research, ranging from rodents to humans, has reported on the effects of OXT and AVP administration on affiliative and trust behaviors, and has highlighted the genetic contributions of OXT and AVP receptor polymorphisms to both social behaviors and to diseases related to social deficits, the consequences of peptide administration on psychiatric symptoms, and the impact of receptor polymorphisms on receptor function, are still unclear. Despite the exciting advances that these reports have brought to social neuroscience, they remain preliminary and suffer from the problems that are inherent to monogenetic linkage and association studies. As an alternative, some studies are using polygenic approaches, and consider the contributions of other genes and pathways, including those involving DA, 5-HT, and reelin, in addition to OXT and AVP; a handful of report are also using genome-wide association studies. This review summarizes findings on the associations between OXT and AVP receptor polymorphism, social behavior, and psychiatric diseases. In addition, we discuss reports on the interactions of OXT and AVP receptor genes and genes involved in other pathways (like those of dopamine, serotonin, and reelin), as well as research that has shed some light on the impact of gene polymorphisms on the volume, connectivity, and activation of specific neural structures, differential receptor expression, and plasma levels of the OXT and AVP peptides. We hope that this effort will be helpful for understanding the studies performed so far, and for encouraging the inclusion of other candidate genes not explored to date.
Impact of anthropometric nutritional parameters on the university selection test in Chile: A multifactorial approach
(Elsevier Inc., 2019-01) Ivanovic, Daniza; Valenzuela, Rodrigo; Almagia, Atilio; Barrera, Cynthia; Arancibia, Violeta; Larraín, Cristian; Silva, Claudio; Billeke, Pablo; Zamorano, Francisco; Villagrán, Francisca; Orellana, Yasna; Martínez, Víctor
Objectives Scholastic achievement (SA) is a multifactorial problem that depends on factors related to the child, the child's family, and the educational system. The aim of this study was to quantify the relative impact of significant variables at the beginning of high school during 2010 (first grade of high school [1 HSG]) on 2013 university selection test (Prueba de Seleccion Universitaria [PSU]) outcomes, both in language scholastic achievement (LSA) and mathematics scholastic achievement (MSA), when students graduated from high school (4 HSG). This was done at the time of university admission with a multicausal approach. The purpose was to confirm the hypothesis that the level of educational establishment SA, intellectual ability, sex, parental schooling levels, and head circumference for age Z-score at the onset of high school are the most relevant parameters associated with 2013 PSU outcomes, both in LSA and MSA. Methods A representative, proportional, and stratified sample of 671 children of both sexes who enrolled in 1 HSG in 2010 (mean age: 14.8 ± 0.6 y) participated in the study. Nutritional, intellectual, brain developmental, cardiovascular risk, socio-to-economic, demographic, and educational variables were quantitated. SA was assessed at 4 HSG with the 2013 PSU tests. Data were analyzed with SAS software. Results Educational establishment SA, intellectual ability, maternal schooling, and age Z-score were the most relevant parameters to explain LSA (R2 = 0.493; P < 0.0001) and MSA variance in addition to sex (male), but only in MSA (R2 = 0.600; P < 0.0001). Conclusions These findings confirm the hypothesis and can be useful to support nutritional, health, and educational planning.
Intra-individual response variability assessed by ex-Gaussian analysis may be a new endophenotype for attention-deficit/hyperactivity disorder
(2015) Henríquez-Henríquez, Marcela Patricia; Billeke, Pablo; Henríquez, Hugo; Zamorano, Francisco Javier; Rothhammer, Francisco; Aboitiz, Francisco
Intra-individual variability of response times (RTisv) is considered as potential endophenotype for attentional deficit/hyperactivity disorder (ADHD). Traditional methods for estimating RTisv lose information regarding response times (RTs) distribution along the task, with eventual effects on statistical power. Ex-Gaussian analysis captures the dynamic nature of RTisv, estimating normal and exponential components for RT distribution, with specific phenomenological correlates. Here, we applied ex-Gaussian analysis to explore whether intra-individual variability of RTs agrees with criteria proposed by Gottesman and Gould for endophenotypes. Specifically, we evaluated if normal and/or exponential components of RTs may (a) present the stair-like distribution expected for endophenotypes (ADHD > siblings > typically developing children (TD) without familiar history of ADHD) and (b) represent a phenotypic correlate for previously described genetic risk variants. This is a pilot study including 55 subjects (20 ADHD-discordant sibling-pairs and 15 TD children), all aged between 8 and 13 years. Participants resolved a visual Go/Nogo with 10% Nogo probability. Ex-Gaussian distributions were fitted to individual RT data and compared among the three samples. In order to test whether intra-individual variability may represent a correlate for previously described genetic risk variants, VNTRs at DRD4 and SLC6A3 were identified in all sibling-pairs following standard protocols. Groups were compared adjusting independent general linear models for the exponential and normal components from the ex-Gaussian analysis. Identified trends were confirmed by the non-parametric Jonckheere-Terpstra test. Stair-like distributions were observed for μ (p = 0.036) and σ (p = 0.009). An additional "DRD4-genotype" × "clinical status" interaction was present for τ (p = 0.014) reflecting a possible severity factor. Thus, normal and exponential RTisv components are suitable as ADHD endophenotypes.

Browsing by Author "Billeke, Pablo"

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