Natalia Trujillo-Orrego

Tracking the Cognitive, Social, and Neuroanatomical Profile in Early Neurodegeneration: Type III Cockayne Syndrome

Cockayne syndrome (CS) is an autosomal recessive disease associated with premature aging, progressive multiorgan degeneration, and nervous system abnormalities including cerebral and cerebellar atrophy, brain calcifications, and white matter abnormalities. Although several clinical descriptions of CS patients have reported developmental delay and cognitive impairment with relative preservation of social skills, no previous studies have carried out a comprehensive neuropsychological and social cognition assessment. Furthermore, no previous research in individuals with CS has examined the relationship between brain atrophy and performance on neuropsychological and social cognition tests. This study describes the case of an atypical late-onset type III CS patient who exceeds the mean life expectancy of individuals with this pathology. The patient and a group of healthy controls underwent a comprehensive assessment that included multiple neuropsychological and social cognition (emotion recognition, theory of mind, and empathy) tasks. In addition, we compared the pattern of atrophy in the patient to controls and to its concordance with ERCC8 gene expression in a healthy brain. The results showed memory, language, and executive deficits that contrast with the relative preservation of social cognition skills. The cognitive profile of the patient was consistent with his pattern of global cerebral and cerebellar loss of gray matter volume (frontal structures, bilateral cerebellum, basal ganglia, temporal lobe, and occipito-temporal/occipito-parietal regions), which in turn was anatomically consistent with the ERCC8 gene expression level in a healthy donor’s brain. The study of exceptional cases, such as the one described here, is fundamental to elucidating the processes that affect the brain in premature aging diseases, and such studies provide an important source of information for understanding the problems associated with normal and pathological aging.

Potential cognitive endophenotypes in multigenerational families: segregating ADHD from a genetic isolate

Endophenotypes are neurobiological markers cosegregating and associated with illness. These biomarkers represent a promising strategy to dissect ADHD biological causes. This study was aimed at contrasting the genetics of neuropsychological tasks for intelligence, attention, memory, visual-motor skills, and executive function in children from multigenerational and extended pedigrees that cluster ADHD in a genetic isolate. In a sample of 288 children and adolescents, 194 (67.4%) ADHD affected and 94 (32.6%) unaffected, a battery of neuropsychological tests was utilized to assess the association between genetic transmission and the ADHD phenotype. We found significant differences between affected and unaffected children in the WISC block design, PIQ and FSIQ, continuous vigilance, and visual-motor skills, and these variables exhibited a significant heritability. Given the association between these neuropsychological variables and ADHD, and also the high genetic component underlying their transmission in the studied pedigrees, we suggest that these variables be considered as potential cognitive endophenotypes suitable as quantitative trait loci (QTLs) in future studies of linkage and association.

Evaluating Empathy in Colombian Ex-Combatants: Examination of the Internal Structure of the Interpersonal Reactivity Index (IRI) in Spanish.

The Republic of Colombia has a long-standing history of internal armed conflict, further complicated by the ideological assumptions underlying their war. In recent years, its government designed the Program for Reincorporation to Civilian Life (Programa para la Reincorporación a la Vida Civil, PRVC), aiming demobilization of thousands of insurgents who were involved in guerilla and paramilitary forces. One PRVC goal involves the psychological characterization of its reincorporated members, aiming the informed design of effective and efficacious interventions to improve their adjustment. We are interested in the examination of empathy in this population. Empathy refers to the ability to predict, understand, and experience other’s feelings. Empathy appears to have an effect on level of aggressive behavior. The Interpersonal Reactivity Index (IRI; Davis, 1980, 1983) is a well-established 28-item self-report tool for the assessment of empathy, including 4 scales: Perspective Taking, Fantasy, Empathic Concern, and Personal Distress. Versions in Spanish were validated in Spain and Chile, but no norms for Colombians exist. We examined the factorial structure of the IRI in a sample of 548 (83.4% males) members of the PRVC. Ten items with low factor loadings were eliminated following a series of confirmatory factor analyses (CFA). The final 4-factor model (Model 2) reached an acceptable fit (e.g., CFI = .898). A second-order CFA demonstrated that empathic concern correlated too high with a common “empathy” latent factor. With these results at hand, our 18-item IRI version in Spanish achieved a factorial structure comparable to that previously validated for Spanish speakers from other countries.

Detecting atypical functioning of emotional processing in Colombian ex-combatants

The reincorporation process of Colombian ex-combatants is hindered by their chronic exposure to violence, which affects their Emotional Processing (EP). Characterizing their EP will contribute to their reinsertion. The objective of this work is to define an EEG-based brain connectivity approach to identify differences in EP between Colombian ex-combatants and individuals who were not directly exposed to the armed conflict. The proposed approach involves defining the Regions of Interest (ROI) and selecting one of five commonly used brain connectivity metrics: Correlation, Cross-Correlation, Coherence, Imaginary part of Coherency, and Phase-Lag Index. Significant differences were found in the positive valence stimuli in the Beta frequency band. These results support the previously reported trend in the literature regarding the difficulties ex-combatants have to process emotional information with positive valence.