Browsing by Author "Zamorano, Francisco"
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Publication A real-time fMRI neurofeedback system for the clinical alleviation of depression with a subject-independent classification of brain states: A proof of principle study(2022) Pereira, Jaime A.; Ray, Andreas; Rana, Mohit; Silva, Claudio; Salinas, César; Zamorano, Francisco; Irani, Martín; Opazo, Patricia; Sitaram, Ranganatha; Ruíz, SergioMost clinical neurofeedback studies based on functional magnetic resonance imaging use the patient's own neural activity as feedback. The objective of this study was to create a subject-independent brain state classifier as part of a real-time fMRI neurofeedback (rt-fMRI NF) system that can guide patients with depression in achieving a healthy brain state, and then to examine subsequent clinical changes. In a first step, a brain classifier based on a support vector machine (SVM) was trained from the neural information of happy autobiographical imagery and motor imagery blocks received from a healthy female participant during an MRI session. In the second step, 7 right-handed female patients with mild or moderate depressive symptoms were trained to match their own neural activity with the neural activity corresponding to the “happiness emotional brain state” of the healthy participant. The training (4 training sessions over 2 weeks) was carried out using the rt-fMRI NF system guided by the brain-state classifier we had created. Thus, the informative voxels previously obtained in the first step, using SVM classification and Effect Mapping, were used to classify the Blood-Oxygen-Level Dependent (BOLD) activity of the patients and converted into real-time visual feedback during the neurofeedback training runs. Improvements in the classifier accuracy toward the end of the training were observed in all the patients [Session 4–1 Median = 6.563%; Range = 4.10–27.34; Wilcoxon Test (0), 2-tailed p = 0.031]. Clinical improvement also was observed in a blind standardized clinical evaluation [HDRS CE2-1 Median = 7; Range 2 to 15; Wilcoxon Test (0), 2-tailed p = 0.016], and in self-report assessments [BDI-II CE2-1 Median = 8; Range 1–15; Wilcoxon Test (0), 2-tailed p = 0.031]. In addition, the clinical improvement was still present 10 days after the intervention [BDI-II CE3-2_Median = 0; Range −1 to 2; Wilcoxon Test (0), 2-tailed p = 0.50/ HDRS CE3-2 Median = 0; Range −1 to 2; Wilcoxon Test (0), 2-tailed p = 0.625]. Although the number of participants needs to be increased and a control group included to confirm these findings, the results suggest a novel option for neural modulation and clinical alleviation in depression using noninvasive stimulation technologies.Item A subject-independent pattern-based Brain-Computer Interface(2015) Ray, Andreas M.; Sitaram, Ranganatha; Rana, Mohit; Pasqualotto, Emanuele; Buyukturkoglu, Korhan; Guan, Cuntai; Ang, Kai-Keng; Tejos, Cristián; Zamorano, Francisco; Aboitiz, Francisco; Birbaumer, Niels; Ruiz, SergioWhile earlier Brain-Computer Interface (BCI) studies have mostly focused on modulating specific brain regions or signals, new developments in pattern classification of brain states are enabling real-time decoding and modulation of an entire functional network. The present study proposes a new method for real-time pattern classification and neurofeedback of brain states from electroencephalographic (EEG) signals. It involves the creation of a fused classification model based on the method of Common Spatial Patterns (CSPs) from data of several healthy individuals. The subject-independent model is then used to classify EEG data in real-time and provide feedback to new individuals. In a series of offline experiments involving training and testing of the classifier with individual data from 27 healthy subjects, a mean classification accuracy of 75.30% was achieved, demonstrating that the classification system at hand can reliably decode two types of imagery used in our experiments, i.e., happy emotional imagery and motor imagery. In a subsequent experiment it is shown that the classifier can be used to provide neurofeedback to new subjects, and that these subjects learn to "match" their brain pattern to that of the fused classification model in a few days of neurofeedback training. This finding can have important implications for future studies on neurofeedback and its clinical applications on neuropsychiatric disorders.Item 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, PabloHow 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 successItem Design of an eOSCE for the Chilean Healthcare Context(2022) Zamorano, Francisco; Reyes, Mauricio; Espinoza, Germán; Reyes, Edison-PabloObjective Structured Clinical Examination (OSCE) is the standard to assess and train clinical skills in healthcare students. However, conducting an OSCE demands expensive resources such as time, qualified personnel, and adequate facilities. The aim to provide more cost-effective examinations has promoted the emergence of electronic versions of OSCEs (eOSCEs). However, existing eOSCEs available in the market do not adequately adapt to diverse local contexts. For a Spanish-speaking country such as Chile, implementing foreign eOSCEs requires to adjust the examination to unfamiliar terminology, archetypes, and procedures, thus hindering the quality of the assessment. This article reports on the design of Ch-eOSCE, an eOSCE tailored for the Chilean local context and culture. Ch-eOSCE is comprised of a mobile application and a back-end system. A prototype of the application was developed and tested with three healthcare experts to gather their perception of usability and coherence, yielding an overall evaluation of 4.5 in a scale range of 5. The preliminary results reveal that Ch-eOSCE has the potential to become a viable solution for a context-specific eOSCE for the Chilean healthcare context.Item 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, DanizaThe 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.Item From imitation to meaning: circuit plasticity and the acquisition of a conventionalized semantics(2014) García, Ricardo R.; Zamorano, Francisco; Aboitiz, FranciscoThe capacity for language is arguably the most remarkable innovation of the human brain. A relatively recent interpretation prescribes that part of the language-related circuits were co-opted from circuitry involved in hand control—the mirror neuron system (MNS), involved both in the perception and in the execution of voluntary grasping actions. A less radical view is that in early humans, communication was opportunistic and multimodal, using signs, vocalizations or whatever means available to transmit social information. However, one point that is not yet clear under either perspective is how learned communication acquired a semantic property thereby allowing us to name objects and eventually describe our surrounding environment. Here we suggest a scenario involving both manual gestures and learned vocalizations that led to the development of a primitive form of conventionalized reference. This proposal is based on comparative evidence gathered from other species and on neurolinguistic evidence in humans, which points to a crucial role for vocal learning in the early development of language. Firstly, the capacity to direct the attention of others to a common object may have been crucial for developing a consensual referential system. Pointing, which is a ritualized grasping gesture, may have been crucial to this end. Vocalizations also served to generate joint attention among conversants, especially when combined with gaze direction. Another contributing element was the development of pantomimic actions resembling events or animals. In conjunction with this mimicry, the development of plastic neural circuits that support complex, learned vocalizations was probably a significant factor in the evolution of conventionalized semantics in our species. Thus, vocal imitations of sounds, as in onomatopoeias (words whose sound resembles their meaning), are possibly supported by mirror system circuits, and may have been relevant in the acquisition of early meanings.Item 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, PabloWorking 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.Item Functional Cortical Network in Alpha Band Correlates with Social Bargaining(2014) Billeke, Pablo; Zamorano, Francisco; Chavez, Mario; Cosmelli, Diego; Aboitiz, FranciscoSolving 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 contextsPublication 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 PPPDItem 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, VíctorObjectives 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.Item Irrelevant stimulus processing in ADHD: catecholamine dynamics and attentional networks(2014) Aboitiz, Francisco; Ossandón, Tomás; Zamorano, Francisco; Palma, Bárbara; Carrasco, XimenaA cardinal symptom of attention deficit and hyperactivity disorder (ADHD) is a general distractibility where children and adults shift their attentional focus to stimuli that are irrelevant to the ongoing behavior. This has been attributed to a deficit in dopaminergic signaling in cortico-striatal networks that regulate goal-directed behavior. Furthermore, recent imaging evidence points to an impairment of large scale, antagonistic brain networks that normally contribute to attentional engagement and disengagement, such as the task-positive networks and the default mode network (DMN). Related networks are the ventral attentional network (VAN) involved in attentional shifting, and the salience network (SN) related to task expectancy. Here we discuss the tonic–phasic dynamics of catecholaminergic signaling in the brain, and attempt to provide a link between this and the activities of the large-scale cortical networks that regulate behavior. More specifically, we propose that a disbalance of tonic catecholamine levels during task performance produces an emphasis of phasic signaling and increased excitability of the VAN, yielding distractibility symptoms. Likewise, immaturity of the SN may relate to abnormal tonic signaling and an incapacity to build up a proper executive system during task performance. We discuss different lines of evidence including pharmacology, brain imaging and electrophysiology, that are consistent with our proposal. Finally, restoring the pharmacodynamics of catecholaminergic signaling seems crucial to alleviate ADHD symptoms; however, the possibility is open to explore cognitive rehabilitation strategies to top-down modulate network dynamics compensating the pharmacological deficits.Item 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, PabloAttention 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.Publication 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, PabloAdapting 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 vieweItem Lateral Prefrontal Theta Oscillations Reflect Proactive Cognitive Control Impairment in Males With Attention Deficit Hyperactivity Disorder(2020-06) Zamorano, Francisco; Kausel, Leonie; Albornoz, Carlos; Lavin, Claudio; Figueroa-Vargas, Alejandra; Stecher, Ximena; Aragón-Caqueo, Diego; Carrasco, Ximena; Aboitiz, Francisco; Billeke, Pablottention Deficit Hyperactivity Disorder (ADHD) is a common neuropsychiatric disorder in which children present prefrontal cortex (PFC) related functions deficit. Proactive cognitive control is a process that anticipates the requirement of cognitive control and crucially depends on the maturity of the PFC. Since this process is important to ADHD symptomatology, we here test the hypothesis that children with ADHD have proactive cognitive control impairments and that these impairments are reflected in the PFC oscillatory activity. We recorded EEG signals from 29 male children with ADHD and 25 typically developing (TD) male children while they performed a Go-Nogo task, where the likelihood of a Nogo stimulus increased while a sequence of consecutive Go stimuli elapsed. TD children showed proactive cognitive control by increasing their reaction time (RT) concerning the number of preceding Go stimuli, whereas children with ADHD did not. This adaptation was related to modulations in both P3a potential and lateral prefrontal theta oscillation for TD children. Children with ADHD as a group did not demonstrate either P3a or theta modulation. But, individual variation in theta activity was correlated with the ADHD symptomatology. The results depict a neurobiological mechanism of proactive cognitive control impairments in children with ADHD.Item Morphometric analysis program: Detection of epileptic foci in young children using an adult normative database: Initial experience(2021) Stecher, Ximena; Schonstedt, Valeria; Manterola, Carla; Velásquez, Álvaro; Zamorano, Francisco; Carreño, Fernando; Castillo, MauricioObjective: To report our initial experience using an adult-template MAP in drugresistant focal epilepsy in five children with apparently normal MRI. Methods: Patients selected were highly suspicious of harboring focal structural lesions and had negative brain MRI studies. MAP was performed using a locally obtained adult database as a template. Results were reviewed by two neuroradiologists. Pertinence of MAP-positive areas was confirmed by the focal epileptic hypothesis or by pathology when possible (J Neuroradiol, 39, 2012, 87). Visual analysis was performed using Mango Software. MRI studies were reanalyzed at the workstation with knowledge of the clinical suspicion to confirm or discard the possibility of FCD. Results: Five patients aged 19-48 months were studied, all with initial 3T MRI studies interpreted as normal. All had focal epileptic hypothesis with coherence of clinical seizure characterization and electroencephalographic findings. In two patients, histology showed type 1 FCD. Due to the age of our subjects, the junction map always highlighted the subcortical white matter in relationship to maturity differences. FCD was identified as asymmetric U-shaped highlighted regions in the junction map. Significance: FCD is the most frequent pathology reported in pediatric epilepsy surgery series (Epileptic Disord, 18, 2016, 240). Significant number of FCDs may be overlooked on MRIs, reducing the odds of seizure freedom after surgery (Epilepsy Res, 89, 2010, 310). MAP is an image postprocessing method for enhanced visualization of FCD; however, when using an adult template in developing brains, normal subcortical regions may be highlighted as pathological. Creating a pediatric template is difficult, due to the need for general anesthesia to acquire the MRI database. Here, we were able to show that MAP identified FCDs as asymmetric “U-” shaped highlighted regions in the junction maps of all five patients, which may indicate that obtaining childhood databases for this purpose may not be necessary and that adult ones suffice for diagnosis of FCD.Item Neural Dynamics of Improved Bimodal Attention and Working Memory in Musically Trained Children(2020-10) Kausel, Leonie; Zamorano, Francisco; Billeke, Pablo; Sutherland, Mary E.; Larraín-Valenzuela, Josefina; Stecher, Ximena; Schlaug, Gottfried; Aboitiz, FranciscoAttention and working memory (WM) are core components of executive functions, and they can be enhanced by training. One activity that has shown to improve executive functions is musical training, but the brain networks underlying these improvements are not well known. We aimed to identify, using functional MRI (fMRI), these networks in children who regularly learn and play a musical instrument. Girls and boys aged 10-13 with and without musical training completed an attention and WM task while their brain activity was measured with fMRI. Participants were presented with a pair of bimodal stimuli (auditory and visual) and were asked to pay attention only to the auditory, only to the visual, or to both at the same time. The stimuli were afterward tested with a memory task in order to confirm attention allocation. Both groups had higher accuracy on items that they were instructed to attend, but musicians had an overall better performance on both memory tasks across attention conditions. In line with this, musicians showed higher activation than controls in cognitive control regions such as the fronto-parietal control network during all encoding phases. In addition, facilitated encoding of auditory stimuli in musicians was positively correlated with years of training and higher activity in the left inferior frontal gyrus and the left supramarginal gyrus, structures that support the phonological loop. Taken together, our results elucidate the neural dynamics that underlie improved bimodal attention and WM of musically trained children and contribute new knowledge to this model of brain plasticity.Item Neural progenitors, patterning and ecology in neocortical origins(01/11/2013) Aboitiz, Francisco; Zamorano, FranciscoThe anatomical organization of the mammalian neocortex stands out among vertebrates for its laminar and columnar arrangement, featuring vertically oriented, excitatory pyramidal neurons. The evolutionary origin of this structure is discussed here in relation to the brain organization of other amniotes, i.e., the sauropsids (reptiles and birds). Specifically, we address the developmental modifications that had to take place to generate the neocortex, and to what extent these modifications were shared by other amniote lineages or can be considered unique to mammals. In this article, we propose a hypothesis that combines the control of proliferation in neural progenitor pools with the specification of regional morphogenetic gradients, yielding different anatomical results by virtue of the differential modulation of these processes in each lineage. Thus, there is a highly conserved genetic and developmental battery that becomes modulated in different directions according to specific selective pressures. In the case of early mammals, ecological conditions like nocturnal habits and reproductive strategies are considered to have played a key role in the selection of the particular brain patterning mechanisms that led to the origin of the neocortexItem Paradoxical Expectation: Oscillatory Brain Activity Reveals Social Interaction Impairment in Schizophrenia(2015) Billeke, Pablo; Armijo, Alejandra; Castillo, Daniel; López, Tamara; Zamorano, Francisco; Cosmelli, Diego; Aboitiz, FranciscoBackground People with schizophrenia show social impairments that are related to functional outcomes. We tested the hypothesis that social interaction impairments in people with schizophrenia are related to alterations in the predictions of others’ behavior and explored their underlying neurobiological mechanisms. Methods Electroencephalography was performed in 20 patients with schizophrenia and 25 well-matched control subjects. Participants played as proposers in the repeated version of the Ultimatum Game believing that they were playing with another human or with a computer. The power of oscillatory brain activity was obtained by means of the wavelet transform. We performed a trial-by-trial correlation between the oscillatory activity and the risk of the offer. Results Control subjects adapted their offers when playing with computers and tended to maintain their offers when playing with humans, as such revealing learning and bargaining strategies, respectively. People with schizophrenia presented the opposite pattern of behavior in both games. During the anticipation of others’ responses, the power of alpha oscillations correlated with the risk of the offers made, in a different way in both games. Patients with schizophrenia presented a greater correlation in computer games than in human games; control subjects showed the opposite pattern. The alpha activity correlated with positive symptoms. Conclusions Our results reveal an alteration in social interaction in patients with schizophrenia that is related to oscillatory brain activity, suggesting maladjustment of expectation when patients face social and nonsocial agents. This alteration is related to psychotic symptoms and could guide further therapies for improving social functioning in patients with schizophrenia.Publication 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, PabloPatients 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-upItem Someone has to give in: theta oscillations correlate with adaptive behavior in social bargaining(2014) Billeke, Pablo; Zamorano, Francisco; López, Tamara; Rodriguez, Carlos; Cosmelli, Diego; Aboitiz, Francisco