1,142 research outputs found
On KPSS with GARCH errors
In this paper we discuss the finite sample behavior of the KPSS test in the presence of conditionally heteroskedastic errors. We confirm that under stationary GARCH errors the asymptotics of the KPSS remains valid. However, in finite samples we observe a slight size distortion and a power distortion. Interestingly, IGARCH errors do not seem to affect the size of the test, however they may often cause a substantial loss of power.asymptotic and finite sample properties
A comparison between tests for changes in the adjustment coefficients in cointegrated systems
In this paper we examine several approaches to detecting changes in the adjustment coefficients in cointegrated VARs. We adopt recursive and rolling techniques as mis-specification tests for the detection of non-constancy and the estimation of the breakpoints. We find that inspection of the recursive eigenvalues is not useful to detect a break in the adjustment coefficients, whilst recursive estimation of the coefficients can only indicate non-constancy, but not the exact breakpoint. Rolling estimation is found to perform better in detecting non-constancy in the parameters and their true value after the breakpoint. However, it only detects a region where the break is likely to occur. To overcome the drawbacks of these techniques, we use an OLS-based sequential test. To assess its performance, we derive its critical values for different sample sizes. Monte Carlo evidence shows that the test has reasonably good power even in moderately sized samples and that it can be used as a graphical device, as it shows a kink at the breakpoint. As a benchmark we use the Kalman filter, of which we analyse the performance on the same data generating processes (DGP)
My child is an anarchist, a feminist, a communist
Veronica Barassi explores digital parenthood and the everyday construction of children’s digital profiles. She argues that children’s data flows are not only connected to questions about identity and privacy, but to new questions about ‘digital citizenship’. Veronica is an anthropologist in the Department of Media and Communications at Goldsmiths University. She is one of the founders of the Goldsmiths Media Ethnography Group and principal investigator on the ‘Social Movements and Media Technologies: Present Challenges and Future Developments’ ESRC Seminar series
Commentary: Cerebellar atrophy and its contribution to cognition in frontotemporal dementias
Chen et al. (2018) provide unprecedented evidence of syndrome-specific changes in cerebellar gray matter integrity (mainly in lobules VI, Crus I and Crus II) across three frontotemporal dementia (FTD) subtypes, alongside specific associations with attentional, visuospatial, mnesic, and language-motor deficits. Moreover, results survived covariation with each group's distinctive atrophy pattern. These outcomes illuminate the critical role of the cerebellum in non-motor processes, while highlighting the relevance of distributed network approaches to cognitive (dys)function.Although the cerebellum has been implicated in higher-order domains (Roca et al., 2013; García et al., 2017; Sokolov et al., 2017), including executive functions, language, interoception, and social cognition, these results may prove surprising to many clinical neuroscientists. Indeed, the cerebellum remains notably underexplored within neurocognitive assessments of dementia, where it is still largely conceived as a specifically motoric region and is thus often excluded from imaging analyses seeking to map brain-behavior associations. Similarly, except for research on ataxia, systematic assessments of regional, and network-level alterations involving the cerebellum are wanting in the field. This counterproductive neglect, we believe, stems from a dissociation between dementia studies and current neurocognitive theories (Ibáñez and García, 2018).Fertile ground could be gained by anchoring neurodegeneration research on the embodied cognition approach, which has revealed multidimensional links between action-related circuits and higher-order functions. The cerebellum, as a core hub in these cortical-subcortical networks, would play an important, enactive role in several cognitive processes. While lesion and agenesia studies suggest that this role may not be causal, cerebellar circuits have been directly implicated in embodied domains (Koziol et al., 2012; Birba et al., 2017; García et al., 2017; Cervetto et al., 2018). Beyond the field's traditional focus on canonical atrophy patterns and selected cognitive skills, emerging evidence suggests that diffuse neurocognitive dysfunctions are partially overlapped across dementias. The profuse interconnectedness, functional richness, and transdiagnostic vulnerability of the cerebellum render it a key target to examine embodied cognitive deficits in FTD and other conditions.Accordingly, embodied theories of the cerebellum could become critical tools to foster relevant translational developments. First, they underscore the need to systematically report cerebellar involvement in diverse neurocognitive deficits. Also, they provide a profitable platform to track intercognitive phenomena?enactive synergies among varied psychobiological (dys)functions?from a network-based perspective (Koziol et al., 2012; Ibanez et al., 2014, 2018; García and Ibáñez, 2016; Birba et al., 2017; García et al., 2017; Cervetto et al., 2018; Ibáñez and García, 2018). Moreover, they promote a reinterpretation of symptoms from an action-grounded neurocognitive rationale (Krakauer et al., 2017). These milestones could have direct clinical implications, as the lack of proper theoretical frameworks can lead to neglecting, downplaying, or delaying the report of cerebellar disturbances across pathologies. We call for novel studies integrating embodied, intercognitive, network-based conceptualizations of the cerebellum to foster translational breakthroughs in dementia research.Fil: Ibáñez Barassi, Agustín Mariano. Universidad Adolfo Ibañez; Chile. Universidad Autónoma del Caribe; Colombia. Australian Research Council; Australia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva y Traslacional. Fundación Ineco Rosario Sede del Incyt | Instituto de Neurología Cognitiva. Instituto de Neurociencia Cognitiva y Traslacional. Fundación Ineco Rosario Sede del Incyt | Fundación Favaloro. Instituto de Neurociencia Cognitiva y Traslacional. Fundación Ineco Rosario Sede del Incyt; ArgentinaFil: García, Adolfo Martín. Universidad Nacional de Cuyo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva y Traslacional. Fundación Ineco Rosario Sede del Incyt | Instituto de Neurología Cognitiva. Instituto de Neurociencia Cognitiva y Traslacional. Fundación Ineco Rosario Sede del Incyt | Fundación Favaloro. Instituto de Neurociencia Cognitiva y Traslacional. Fundación Ineco Rosario Sede del Incyt; Argentin
Interactivity in the education of the engineering of the chemical reactions. An innovative proposal
Este artículo presenta la realización de una experiencia interactiva en la enseñanza de la Ingeniería de Reactores en la carrera de Ingeniería Química en la Universidad Nacional del Comahue, Argentina. Se basa en la utilización de Textos Interactivos, herramienta construida sobre la estructura del software 'Mathematica'. Específicamente, el texto que se propone en el trabajo corresponde a la enseñanza de Mecanismos de Reacción Química, presentándose los resultados obtenidos sobre la base de consideraciones pedagógicas. Sobre esta base, el uso de textos interactivos como herramienta en la enseñanza superior es enfáticamente recomendado.The student, nowadays, demands new pedagogic approaches, which implies a major use of the educational technology. The computer programs of modeling and calculation are available for the academic context. In this article it appears to an interactive text on Mechanisms of Chemical Reaction, developed with the software Mathematica (Wolfram, 1996), and the results of the evaluation that were obtained on having applied the above mentioned text. The pupils showed a major level of motivation in the development of the task with the alternative methodology that with the traditional class, and this motivation linked to the use of the software
Increased moral condemnation of accidental harm in institutionalized adolescents
Social deprivation, as faced by children in institutional rearing, involves socio-cognitive deficits that may persist into adolescence. In particular, two relevant domains which prove sensitive to pre-adult neurodevelopment are theory of mind (ToM) and moral judgment (a complex skill which partially depend upon ToM). However, no study has assessed moral evaluation in adolescents with a history of institutional care, let alone its relationship with ToM skills. The present study aims to bridge this gap, focusing on moral evaluation of harmful actions in institutionalized adolescents (IAs). Relative to adolescents raised with their biological families, IAs exhibited less willingness to exculpate protagonists for accidental harms, suggesting an under-reliance on information about a person’s (innocent) intentions. Moreover, such abnormalities in IAs were associated with ToM impairments. Taken together, our findings extend previous findings of delayed ToM under social deprivation, further showing that the development of moral cognition is also vulnerable to the impact of institutionalization. These results could pave the way for novel research on the role of institutional rearing in ToM and moral development during adolescence.Fil: Baez, Sandra. Universidad de los Andes; ColombiaFil: Herrera, Eduar. Universidad Icesi; ColombiaFil: García, Adolfo Martín. Universidad Nacional de Cuyo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva y Traslacional. Fundación Ineco Rosario Sede del Incyt | Instituto de Neurología Cognitiva. Instituto de Neurociencia Cognitiva y Traslacional. Fundación Ineco Rosario Sede del Incyt | Fundación Favaloro. Instituto de Neurociencia Cognitiva y Traslacional. Fundación Ineco Rosario Sede del Incyt; ArgentinaFil: Huepe, David. Universidad Adolfo Ibañez; ChileFil: Santamaría-García, Hernando. Pontificia Universidad Javeriana; Colombia. Hospital Universitario San Ignacio; ColombiaFil: Ibáñez Barassi, Agustín Mariano. Universidad Autónoma del Caribe; Colombia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva y Traslacional. Fundación Ineco Rosario Sede del Incyt | Instituto de Neurología Cognitiva. Instituto de Neurociencia Cognitiva y Traslacional. Fundación Ineco Rosario Sede del Incyt | Fundación Favaloro. Instituto de Neurociencia Cognitiva y Traslacional. Fundación Ineco Rosario Sede del Incyt; Argentina. Universidad Adolfo Ibañez; Chile. Centre of Excellence in Cognition and its Disorders; Australi
Word reading and translation in bilinguals: the impact of formal and informal translation expertise
Studies on bilingual word reading and translation have examined the effects of lexical variables (e.g., concreteness, cognate status) by comparing groups of non-translators with varying levels of L2 proficiency. However, little attention has been paid to another relevant factor: translation expertise (TI). To explore this issue, we administered word reading and translation tasks to two groups of non-translators possessing different levels of informal TI (Experiment 1), and to three groups of bilinguals possessing different levels of translation training (Experiment 2). Reaction-time recordings showed that in all groups reading was faster than translation and unaffected by concreteness and cognate effects. Conversely, in both experiments, all groups translated concrete and cognate words faster than abstract and non-cognate words, respectively. Notably, an advantage of backward over forward translation was observed only for low-proficiency non-translators (in Experiment 1). Also, in Experiment 2, the modifications induced by translation expertise were more marked in the early than in the late stages of training and practice. The results suggest that TI contributes to modulating inter-equivalent connections in bilingual memory.Fil: García, Adolfo Martín. Universidad Nacional de Córdoba; Argentina. Universidad Diego Portales; Chile. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva. Fundación Favaloro. Instituto de Neurociencia Cognitiva; ArgentinaFil: Ibáñez Barassi, Agustín Mariano. Universidad Diego Portales; Chile. Universidad Autónoma del Caribe; Colombia. Australian Research Council; Australia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva. Fundación Favaloro. Instituto de Neurociencia Cognitiva; ArgentinaFil: Huepe, David. Universidad Diego Portales; ChileFil: Houck, Alexander L.. University of Tennessee; Estados UnidosFil: Michon, Maeva. Universidad Diego Portales; ChileFil: Gelormini Lezama, Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva. Fundación Favaloro. Instituto de Neurociencia Cognitiva; ArgentinaFil: Chadha, Sumeer. Universidad Diego Portales; ChileFil: Rivera Rei, Álvaro. Universidad Diego Portales; Chil
Detaching from the negative by reappraisal: the role of right superior frontal gyrus (BA9/32)
The ability to reappraise the emotional impact of events is related to long-term mental health. Self-focused reappraisal (REAPPself), i.e., reducing the personal relevance of the negative events, has been previously associated with neural activity in regions near right medial prefrontal cortex, but rarely investigated among brain-damaged individuals. Thus, we aimed to examine the REAPPself ability of brain-damaged patients and healthy controls considering structural atrophies and gray matter intensities, respectively. Twenty patients with well-defined cortex lesions due to an acquired circumscribed tumor or cyst and 23 healthy controls performed a REAPPself task, in which they had to either observe negative stimuli or decrease emotional responding by REAPPself. Next, they rated the impact of negative arousal and valence. REAPPself ability scores were calculated by subtracting the negative picture ratings after applying REAPPself from the ratings of the observing condition. The scores of the patients were included in a voxel-based lesion-symptom mapping (VLSM) analysis to identify deficit related areas (ROI). Then, a ROI group-wise comparison was performed. Additionally, a whole-brain voxel-based-morphometry (VBM) analysis was run, in which healthy participant's REAPPself ability scores were correlated with gray matter intensities. Results showed that (1) regions in the right superior frontal gyrus (SFG), comprising the right dorsolateral prefrontal cortex (BA9) and the right dorsal anterior cingulate cortex (BA32), were associated with patient's impaired down-regulation of arousal, (2) a lesion in the depicted ROI occasioned significant REAPPself impairments, (3) REAPPself ability of controls was linked with increased gray matter intensities in the ROI regions. Our findings show for the first time that the neural integrity and the structural volume of right SFG regions (BA9/32) might be indispensable for REAPPself. Implications for neurofeedback research are discussed.Fil: Falquez, Rosalux. University of Heidelberg; AlemaniaFil: Couto, Juan Blas Marcos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva. Fundación Favaloro. Instituto de Neurociencia Cognitiva; ArgentinaFil: Ibáñez Barassi, Agustín Mariano. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva. Fundación Favaloro. Instituto de Neurociencia Cognitiva; ArgentinaFil: Freitag, Martin T.. German Cancer Research Center; AlemaniaFil: Berger, Moritz. German Cancer Research Center; AlemaniaFil: Arens, Elisabeth A.. University of Heidelberg; AlemaniaFil: Lang, Simone. University of Heidelberg; AlemaniaFil: Barnow, Sven. University of Heidelberg; Alemani
Aportes neurocientíficos sobre interocepción cardíaca, emociones y redes insulares
El estudio de la Ínsula de Reil, ha cobrado un reciente interés por la que fuera un área cerebral poco mencionada en la neurociencia cognitiva moderna. Sucesivas revisiones de trabajos de campos diversos como estudios clínicos, modelos experimentales, y neuroimágenes, han revelado la participación de la ínsula en múltiples tareas cognitivas, afectivas y perceptuales. Un posible marco teórico integrador de estos variados procesos, es la interocepción o censado del estado homeostático y visceral. El procesamiento insular y su comunicación a áreas homólogas motrices como la corteza cingulada anterior (CCA), desencadenaría y regularía comportamientos que entrañan un contenido afectivo-emocional esencial para el mantenimiento de la consciencia corporal a nivel individual. En este artículo, se analiza evidencia que involucra a la interocepción y al procesamiento insular integrativo en el surgimiento de estados emocionales conscientes haciendo especial énfasis en el papel de los estudios de lesiones y el uso de técnicas de conectividad funcional en resonancia magnética funcional (RMf). Además, se revisa la conceptualización de la interocepción cardíaca, su estudio a través de la evaluación de pacientes con patología cerebral vascular isquémica y patología cardíaca en el marco de los de las interacciones corazón-cerebro, nuevo campo de estudio de las neurociencias.The insula of Reil has recently became an interesting research topic, in despite of its few mention in modern cognitive neuroscience. Several studies in different areas like clinical reports, experimental models and neuroimaging have revealed the role of the insula in cognitive, emotional and visceral perception tasks. In this article, we revise different studies in patients with stroke and cardiac disease regarding cardiac interoception. Particularly, it has been suggested that the insular processing through its connections with the anterior cingulate cortex is required for the representation of the visceral state of the body and critical for the emerging of emotional awareness. Furthermore, evidence from different methodologies such as lesion studies and functional connectivity analysis of magnetic resonance imaging support those hypotheses. We conclude that the understanding of this new field of research in neuroscience, the heart-brain relationships, would highly benefit from the study of insular integration and the arise of conscious emotional states while make emphasis on the convergent use of lesion and functional neuroimaging approaches as a powerful research strategy.Fil: García Cordero, Indira. Instituto de Neurología Cognitiva. Laboratorio de Psicología Experimental y Neurociencia; Argentina. Universidad Favaloro; ArgentinaFil: Couto, Juan Blas Marcos. Instituto de Neurología Cognitiva. Laboratorio de Psicología Experimental y Neurociencia; Argentina. Universidad Favaloro. Facultad de Medicina. Instituto de Neurociencias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ibanez Barassi, Agustín Mariano. Instituto de Neurología Cognitiva. Laboratorio de Psicología Experimental y Neurociencia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Diego Portales; Chil
Action semantics at the bottom of the brain: Insights from dysplastic cerebellar gangliocytoma
Recent embodied cognition research shows that access to action verbs in shallow-processing tasks becomes selectively compromised upon atrophy of the cerebellum, a critical motor region. Here we assessed whether cerebellar damage also disturbs explicit semantic processing of action pictures and its integration with ongoing motor responses. We evaluated a cognitively preserved 33-year-old man with severe dysplastic cerebellar gangliocytoma (Lhermitte-Duclos disease), encompassing most of the right cerebellum and the posterior part of the left cerebellum. The patient and eight healthy controls completed two semantic association tasks (involving pictures of objects and actions, respectively) that required motor responses. Accuracy results via Crawford's modified t-tests revealed that the patient was selectively impaired in action association. Moreover, reaction-time analysis through Crawford's Revised Standardized Difference Test showed that, while processing of action concepts involved slower manual responses in controls, no such effect was observed in the patient, suggesting that motor-semantic integration dynamics may be compromised following cerebellar damage. Notably, a Bayesian Test for a Deficit allowing for Covariates revealed that these patterns remained after covarying for executive performance, indicating that they were not secondary to extra-linguistic impairments. Taken together, our results extend incipient findings on the embodied functions of the cerebellum, offering unprecedented evidence of its crucial role in processing non-verbal action meanings and integrating them with concomitant movements. These findings illuminate the relatively unexplored semantic functions of this region while calling for extensions of motor cognition models.Fil: Cervetto Manciameli, Sabrina Fabiana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva. Fundación Favaloro. Instituto de Neurociencia Cognitiva; Argentina. Universidad de la República; UruguayFil: Abrevaya, Sofia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva. Fundación Favaloro. Instituto de Neurociencia Cognitiva; ArgentinaFil: Martorell Caro, Miguel Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva. Fundación Favaloro. Instituto de Neurociencia Cognitiva; ArgentinaFil: Kozono, Giselle. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva. Fundación Favaloro. Instituto de Neurociencia Cognitiva; ArgentinaFil: Muñoz, Edinson. Universidad de Santiago de Chile; ChileFil: Ferrari, Jesica. Instituto de Neurología Cognitiva; ArgentinaFil: Sedeño, Lucas. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva. Fundación Favaloro. Instituto de Neurociencia Cognitiva; ArgentinaFil: Ibáñez Barassi, Agustín Mariano. Australian Research Council; Australia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva. Fundación Favaloro. Instituto de Neurociencia Cognitiva; Argentina. Universidad Autónoma del Caribe; Colombia. Universidad Adolfo Ibañez; ChileFil: García, Adolfo Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Neurociencia Cognitiva. Fundación Favaloro. Instituto de Neurociencia Cognitiva; Argentina. Universidad Nacional de Cuyo; Argentin
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