The impacts of social determinants of health and cardiometabolic factors on cognitive and functional aging in Colombian underserved populations.

Global initiatives call for further understanding of the impact of inequity on aging across underserved populations. Previous research in low- and middle-income countries (LMICs) presents limitations in assessing combined sources of inequity and outcomes (i.e., cognition and functionality). In this study, we assessed how social determinants of health (SDH), cardiometabolic factors (CMFs), and other medical/social factors predict cognition and functionality in an aging Colombian population. We ran a cross-sectional study that combined theory- (structural equation models) and data-driven (machine learning) approaches in a population-based study (N = 23,694; M = 69.8 years) to assess the best predictors of cognition and functionality. We found that a combination of SDH and CMF accurately predicted cognition and functionality, although SDH was the stronger predictor. Cognition was predicted with the highest accuracy by SDH, followed by demographics, CMF, and other factors. A combination of SDH, age, CMF, and additional physical/psychological factors were the best predictors of functional status. Results highlight the role of inequity in predicting brain health and advancing solutions to reduce the cognitive and functional decline in LMICs.

Neurocognitive factorial structure of executive functions: Evidence from neurotypicals and frontotemporal dementia.

The latent structure of executive functions (EFs) remains controversial. Confirmatory factorial analysis (CFA) has provided support for both multidimensional (assumes EFs to be functionally separable but related components) and bifactor (proposes all components are nested within a common factor) models. However, these CFA models have never been compared in patient samples, nor regarding their neuroanatomical correlates. Here, we systematically contrast both approaches in neurotypicals and in a neurodegenerative lesion model (patients with the behavioral variant frontotemporal dementia, bvFTD), characterized by executive deficits associated with frontal neurodegeneration. First, CFA was used to test the models' fit in a sample of 341 neurotypicals and 29 bvFTD patients based on performance in an executive frontal screening battery which assesses working memory, motor inhibition, verbal inhibition, and abstraction capacity. Second, we compared EFs factor and observed scores between patients and matched controls. Finally, we used voxel-based morphometry (VBM) to compare the grey matter correlates of factor and observed scores. CFA results showed that both models fit the data well. The multidimensional model, however, was more sensitive than the bifactor model and the observed scores to detect EFs impairments in bvFTD patients. VBM results for the multidimensional model revealed common and unique grey matter correlates for EFs components across prefrontal-insular, posterior, and temporal cortices. Regarding the bifactor model, only the common factor was associated with prefrontal-insular hubs. Observed scores presented scant, non-frontal grey matter associations. Converging behavioral and neuroanatomical evidence from healthy populations and a neurodegenerative model of EFs supports an underlying multidimensional structure.

Expression of Olig2, Nestin, NogoA and AQP4 have no impact on overall survival in IDH-wildtype glioblastoma.

Despite many years of research efforts and clinical trials the prognosis of patients diagnosed with glioblastoma remains very poor. The oligodendrocyte transcription factor 2 (Olig2) was identified as a marker for glioma stem cells, which are believed to be responsible for glioma recurrence and therapy resistance. In this retrospective analysis we assessed the prognostic value of oligodendroglial and glioma stem cell markers in 113 IDH-wildtype glioblastomas. Immunohistochemical staining for Olig2, NogoA, AQP4 and Nestin was performed in combination with sequencing of IDH1 and IDH2 as well as promotor methylation analysis of the MGMT gene. Even though differences in overall survival according to Olig2 expression were observed, univariate and multivariate survival analysis did not reveal a firm significant prognostic impact of Olig2, NogoA, AQP4 or Nestin expression. Additionally, no differences in the expression of these markers depending on clinical status, age or gender were found. The established independent prognostic factors age<65, Karnofsky Performance Status> = 70 and methylated MGMT gene promoter were significant in the multivariate analysis. In conclusion expression of oligodendroglial and glioma stem cell markers do not have an independent prognostic effect in IDH-wildtype glioblastoma.

Diagnostic red flags: steroid-treated malignant CNS lymphoma mimicking autoimmune inflammatory demyelination.

The presence of inflammation and demyelination in a central nervous system (CNS) biopsy points towards a limited, yet heterogeneous group of pathologies, of which multiple sclerosis (MS) represents one of the principal considerations. Inflammatory demyelination has also been reported in patients with clinically suspected primary central nervous system lymphoma (PCNSL), especially when steroids had been administered prior to biopsy acquisition. The histopathological changes induced by corticosteroid treatment can range from mild reduction to complete disappearance of lymphoma cells. It has been proposed that in the absence of neoplastic B cells, these biopsies are indistinguishable from MS, yet despite the clinical relevance, no histological studies have specifically compared the two entities. In this work, we analyzed CNS biopsies from eight patients with inflammatory demyelination in whom PCNSL was later histologically confirmed, and compared them with nine well defined early active multiple sclerosis lesions. In the patients with steroid-treated PCNSL (ST-PCNSL) the interval between first and second biopsy ranged from 3 to 32 weeks; all of the patients had received corticosteroids before the first, but not the second biopsy. ST-PCNSL patients were older than MS patients (mean age: ST-PCNSL: 62 ± 4 years, MS: 30 ± 2 years), and histological analysis revealed numerous apoptoses, patchy and incomplete rather than confluent and complete demyelination and a fuzzy lesion edge. The loss of Luxol fast blue histochemistry was more profound than that of myelin proteins in immunohistochemistry, and T cell infiltration in ST-PCNSL exceeded that in MS by around fivefold (P = 0.005). Our data indicate that in the presence of extensive inflammation and incomplete, inhomogeneous demyelination, the neuropathologist should refrain from primarily considering autoimmune inflammatory demyelination and, even in the absence of lymphoma cells, instigate close clinical follow-up of the patient to detect recurrent lymphoma.

Funciones ejecutivas entre músicos y no músicos: un metaanálisis / Executive functions between musicians and non-musicians: a metanalysis

Resumen Se ha sugerido que la práctica profesional de un instrumento musical esta relacionada con mejores puntajes en tareas de funciones ejecutivas. Con el fin de examinar sistemáticamente esta hipótesis se realizó un metaanálisis para identificar el efecto de la interpretación de un instrumento en las funciones ejecutivas, así como las variables que podrían moderar dicho efecto. El metaanálisis incluyó estudios empíricos que: (1) compararon los puntajes en medidas de funciones ejecutivas entre músicos y no músicos; (2) reportaron las medias y desviaciones estándar; (3) el grupo de comparación no recibió entrenamiento musical; y (4) los participantes no presentaron discapacidad motora o cognitiva. Se identificó que los músicos, en comparación con los no músicos, muestran mejores puntajes en tareas de funciones ejecutivas (d = .712). Los resultados apoyan la hipótesis de que la práctica de un instrumento musical está relacionada con mejores puntuaciones en tareas de funciones ejecutivas.

Abstract Nowadays, it is widely accepted that experience can modify multiple aspects of the functioning and structure of the brain; however, there is still a long way to go to understand the mechanisms behind these modifications. In order to understand the relationship between experience and brain plasticity, models and paradigms have been adapted from cognitive neurosciences; one of them has been music training. In the last decades, this paradigm has strengthened because it allows us to understand the structural and functional modifications produced by training. It has been demonstrated that musicians compared to non-musicians present larger sizes of specific brain regions, in particular, the prefrontal cortex, which is associated with a better performance in executive functions tasks. In addition, long-term neurophysiological changes have been identified in people who play an instrument. A relationship between playing an instrument and better performance in executive functions has been identified. However, the evidence of this effect is contradictory. Executive functions are a series of general control processes that help regulate thinking and behavior. Some research indicates that learning an instrument is associated with better performance in working memory, but not regarding tasks related to inhibitory control and cognitive flexibility. However, other studies have revealed significant differences between musicians and non-musicians, both in working memory and tasks of cognitive flexibility as well as in inhibitory control. It is possible that the contradictory results are due to the methodological diversity through which this topic has been addressed, since some studies have carried out experimental and quasi-experimental designs, and others have developed correlational approaches. In addition, different theoretical models have been used to evaluate executive functions. For this study, we work with the theoretical model of Miyake et al. (2000), which is a solid theoretical-empirical proposal about three clearly differentiable executive functions: inhibitory control, cognitive flexibility, and working memory. A meta-analysis was performed with the purpose of identifying the effect of playing an instrument on executive functions as well as identifying the moderator variables. By doing this, we wanted to clarify the problem in question and the controversial results; therefore, empirical studies comparing musicians against non-musicians were included. The comparison group should not have been exposed to musical training, the participants should not present motor or cognitive disabilities, and finally, studies should report means and standard deviations for the scores on executive functions tasks. We included papers published between January 2000 and July 2017. The moderator variables studied were: age in months at the time of evaluation, age at which training began, and total years of training. The coding strategy allowed us to identify a total of 42 294 articles. The titles and abstracts were analyzed and those that did not meet the inclusion criteria were eliminated. This procedure allowed the detection of 24 articles for future analysis, and 12 out of them were finally selected. These 12 articles contributed to 60 effect sizes and 513 participants. The results showed that musicians have a better performance in executive functions tasks when they are compared to non-musicians, d = .712, n = 60, IC95% = (.57; .85), p < .0001. Additionally, the analysis of moderating variables revealed that the practice of an instrument equally benefits all executive functions, and the most important benefit occurs in older adults and children. Results support the hypothesis that the high level of difficulty involved with learning to play an instrument can influence a better performance in executive functions tasks. Our study points out the need of designing research that allows the scientific community to investigate the effect of prolonged musical training over time.

Working memory capacity in a go/no-go task: age differences in interference, processing speed, and attentional control.

We tested the limits of working-memory capacity (WMC) of young adults, old adults, and children with a memory-updating task. The task consisted of mentally shifting spatial positions within a grid according to arrows, their color signaling either only go (control) or go/no-go conditions. The interference model (IM) of Oberauer and Kliegl (2006) was simultaneously fitted to the data of all groups. In addition to the 3 main model parameters (feature overlap, noise, and processing rate), we estimated the time for switching between go and no-go steps as a new model parameter. In this study, we examined the IM parameters across the life span. The IM parameter estimates show that (a) conditions were not different in interference by feature overlap and interference by confusion; (b) switching costs time; (c) young adults and children were less susceptible than old adults to interference due to feature overlap; (d) noise was highest for children, followed by old and young adults; (e) old adults differed from children and young adults in lower processing rate; and (f) children and old adults had a larger switch cost between go steps and no-go steps. Thus, the results of this study indicated that across age, the IM parameters contribute distinctively for explaining the limits of WMC.

Modelos de variables latentes, modelación cognitiva y memoria de trabajo: un punto de encuentro

Los modelos de variables latentes y los modelos cognitivos formales comparten algunos aspectos de su objeto de estudio, varios aspectos filosóficos y parte de su metodología. A pesar de ello, existe poca comunicación entre sus teorías y hallazgos. Con el objetivo de resaltar similitudes y diferencias entre ambos enfoques en este estudio se implementó y evaluó un modelo formal que propone la interferencia entre representaciones como el mecanismo que limita la capacidad de memoria de trabajo (i.e., el modelo de interferencia de Oberauer & Kliegl, 2006). Además, se incorporó una manipulación experimental que tuvo como objetivo evaluar el papel de la inhibición en respuestas inminentes y el desplazamiento de la atención entre tareas en el contexto del modelo de interferencia. A partir de estos hallazgos se expusieron algunas conexiones que podrían facilitar el acercamiento entre los modelos cognitivos formales y los modelos psicométricos basados en la teoría de la variable latente.

Latent variable models and formal cognitive models share some elements of their object of study, various philosophical aspects, and some parts of their methodology. Nevertheless, little communication exists between their theories and findings. In order to highlight similarities and differences, this study implemented and tested a formal model proposing that interference among representations is a mechanism limiting working memory capacity (i.e., the interference model of Oberauer & Kliegl, 2006). Furthermore, the study incorporated an experimental manipulation to evaluate the role of the inhibition in prepotent responses and task switching in the interference model framework. These findings were used to expose some connections that could facilitate a rapprochement between formal cognitive models and psychometric models based on the latent variable theory.