Brain clocks capture diversity and disparity in aging and dementia.

Brain clocks, which quantify discrepancies between brain age and chronological age, hold promise for understanding brain health and disease. However, the impact of multimodal diversity (geographical, socioeconomic, sociodemographic, sex, neurodegeneration) on the brain age gap (BAG) is unknown. Here, we analyzed datasets from 5,306 participants across 15 countries (7 Latin American countries -LAC, 8 non-LAC). Based on higher-order interactions in brain signals, we developed a BAG deep learning architecture for functional magnetic resonance imaging (fMRI=2,953) and electroencephalography (EEG=2,353). The datasets comprised healthy controls, and individuals with mild cognitive impairment, Alzheimer's disease, and behavioral variant frontotemporal dementia. LAC models evidenced older brain ages (fMRI: MDE=5.60, RMSE=11.91; EEG: MDE=5.34, RMSE=9.82) compared to non-LAC, associated with frontoposterior networks. Structural socioeconomic inequality and other disparity-related factors (pollution, health disparities) were influential predictors of increased brain age gaps, especially in LAC (R2=0.37, F2=0.59, RMSE=6.9). A gradient of increasing BAG from controls to mild cognitive impairment to Alzheimer's disease was found. In LAC, we observed larger BAGs in females in control and Alzheimer's disease groups compared to respective males. Results were not explained by variations in signal quality, demographics, or acquisition methods. Findings provide a quantitative framework capturing the multimodal diversity of accelerated brain aging.

Brain health in diverse settings: How age, demographics and cognition shape brain function.

Diversity in brain health is influenced by individual differences in demographics and cognition. However, most studies on brain health and diseases have typically controlled for these factors rather than explored their potential to predict brain signals. Here, we assessed the role of individual differences in demographics (age, sex, and education; n = 1298) and cognition (n = 725) as predictors of different metrics usually used in case-control studies. These included power spectrum and aperiodic (1/f slope, knee, offset) metrics, as well as complexity (fractal dimension estimation, permutation entropy, Wiener entropy, spectral structure variability) and connectivity (graph-theoretic mutual information, conditional mutual information, organizational information) from the source space resting-state EEG activity in a diverse sample from the global south and north populations. Brain-phenotype models were computed using EEG metrics reflecting local activity (power spectrum and aperiodic components) and brain dynamics and interactions (complexity and graph-theoretic measures). Electrophysiological brain dynamics were modulated by individual differences despite the varied methods of data acquisition and assessments across multiple centers, indicating that results were unlikely to be accounted for by methodological discrepancies. Variations in brain signals were mainly influenced by age and cognition, while education and sex exhibited less importance. Power spectrum activity and graph-theoretic measures were the most sensitive in capturing individual differences. Older age, poorer cognition, and being male were associated with reduced alpha power, whereas older age and less education were associated with reduced network integration and segregation. Findings suggest that basic individual differences impact core metrics of brain function that are used in standard case-control studies. Considering individual variability and diversity in global settings would contribute to a more tailored understanding of brain function.

Neuroanatomical markers of social cognition in neglected adolescents.

Growing up in neglectful households can impact multiple aspects of social cognition. However, research on neglect's effects on social cognition processes and their neuroanatomical correlates during adolescence is scarce. Here, we aimed to comprehensively assess social cognition processes (recognition of basic and contextual emotions, theory of mind, the experience of envy and Schadenfreude and empathy for pain) and their structural brain correlates in adolescents with legal neglect records within family-based care. First, we compared neglected adolescents (n = 27) with control participants (n = 25) on context-sensitive social cognition tasks while controlling for physical and emotional abuse and executive and intellectual functioning. Additionally, we explored the grey matter correlates of these domains through voxel-based morphometry. Compared to controls, neglected adolescents exhibited lower performance in contextual emotional recognition and theory of mind, higher levels of envy and Schadenfreude and diminished empathy. Physical and emotional abuse and executive or intellectual functioning did not explain these effects. Moreover, social cognition scores correlated with brain volumes in regions subserving social cognition and emotional processing. Our results underscore the potential impact of neglect on different aspects of social cognition during adolescence, emphasizing the necessity for preventive and intervention strategies to address these deficits in this population.

Moral Disengagement in Adolescent Offenders: Its Relationship with Antisocial Behavior and Its Presence in Offenders of the Law and School Norms.

This study focuses on understanding the relationship between moral disengagement mechanisms in adolescents who engage in law-breaking activities and those who violate school norms. To do so, we administered the Mechanisms of Moral Disengagement Scale (MMDS), which evaluates moral justification, euphemistic labeling, advantageous comparison, deflection of responsibility, diffusion of responsibility, distortion of consequences, dehumanization, and attribution of blame, to 366 adolescents (60.1% males (n = 220) and 39.9% females (n = 146)). Our results confirmed the hypothesis that law-breaking adolescents presented a higher degree of moral disengagement than those adolescents who violate school norms. Additionally, we found that adolescents who violated school norms displayed significantly higher levels of dehumanization than the controls, and law-breaking adolescents obtained the highest score in this domain. Our findings allow us to suggest that the presence of the dehumanization mechanism in adolescents who violate school norms could be used as an early indicator of the emergence of antisocial behaviors, since this was the only component of moral disengagement that significantly differentiated this group from the controls in the study.

Inducción de estados afectivos a través de imágenes. Segunda validación colombiana del Sistema Internacional de Imágenes Afectivas (IAPS) / Induction of Affective States with Pictures: Second Colombian Validation of the International Affective Pictures System (IAPS)

Resumen El objetivo del presente estudio es validar un segundo grupo de imágenes del Sistema Internacional de Imágenes Afectiva (IAPS) en población colombiana, con el fin de aumentar el banco de imágenes que puedan ser utilizadas en investigaciones en los campos de la emoción, la atención y la memoria, entre otros. Se validaron 240 imágenes pertenecientes a los conjuntos 15, 16, 17 y 18 del IAPS en una muestra de 1.222 personas provenientes de cinco ciudades del país (Bogotá, Medellín, Cali, Barranquilla y Bucaramanga). Para evaluar la respuesta emocional ante las imágenes en las dimensiones de valencia, arousal y dominancia se utilizó el Self-Assessment Manikin (SAM). Los resultados mostraron que las imágenes se distribuyeron de la forma esperada en el espacio afectivo bidimensional compuesto por las dimensiones de valencia y arousal. Se identificó un sesgo emocional positivo en los hombres y un sesgo emocional negativo en las mujeres. Las diferencias entre regiones y estrato socioeconómico se presentaron únicamente en arousal y dominancia, no en valencia. En conjunto, los resultados sugieren que estas imágenes pueden ser utilizadas para inducir estados afectivos en la población colombiana de forma controlada, lo que permite su uso para el estudio científico y experimental de diferentes procesos psicológicos, como la emoción, la motivación y la atención.

Abstract The aim of this study was to validate a second group of images of the International Affective Pictures System (IAPS) in Colombian population, in order to increase the bank of images that can be used in research in the fields of emotion, attention and memory, among others. 240 pictures belonging to sets 15, 16, 17 and 18 of the IAPS were validated in a sample of 1222 participants from five cities in the country (Bogotá, Medellín, Cali, Barranquilla and Bucaramanga). To assess the emotional response to images in the valence, arousal and dominance dimensions, the Self-Assessment Manikin (SAM) was used. The results showed that the pictures were distributed as expected in the two-dimensional affective space composed of the valence and arousal dimensions. A positive emotional bias was identified in men and a negative emotional bias in women. The differences between regions and socioeconomic strata were presented only in arousal and dominance, not in valence. Together, the results suggest that these images can be used to induce affective states in the Colombian population in a controlled manner, which allows their use for the scientific and experimental study of different psychological processes, such as emotion, motivation and attention.