Biology subjects

Hernandez-Cabrera, J. A.

Publications and source records attributed to Hernandez-Cabrera, J. A..

4 recordsLinked to original sources

bioRxiv2021

Genome-wide association analyses of individual differences in quantitatively assessed reading- and language-related skills in up to 34,000 people

The use of spoken and written language is a capacity that is unique to humans. Individual differences in reading- and language-related skills are influenced by genetic variation, with twin-based heritability estimates of 30-80%, depending on the trait. The relevant genetic architecture is complex, heterogeneous, and multifactorial, and yet to be investigated with well-powered studies. Here, we present a multicohort genome-wide association study (GWAS) of five traits assessed individually using psychometric measures: word reading, nonword reading, spelling, phoneme awareness, and nonword repetition, with total sample sizes ranging from 13,633 to 33,959 participants aged 5-26 years (12,411 to 27,180 for those with European ancestry, defined by principal component analyses). We identified a genome-wide significant association with word reading (rs11208009, p=1.098 x 10-8) independent of known loci associated with intelligence or educational attainment. All five reading-/language-related traits had robust SNP-heritability estimates (0.13-0.26), and genetic correlations between them were modest to high. Using genomic structural equation modelling, we found evidence for a shared genetic factor explaining the majority of variation in word and nonword reading, spelling, and phoneme awareness, which only partially overlapped with genetic variation contributing to nonword repetition, intelligence and educational attainment. A multivariate GWAS was performed to jointly analyse word and nonword reading, spelling, and phoneme awareness, maximizing power for follow-up investigation. Genetic correlation analysis of multivariate GWAS results with neuroimaging traits identified association with cortical surface area of the banks of the left superior temporal sulcus, a brain region with known links to processing of spoken and written language. Analysis of evolutionary annotations on the lineage that led to modern humans showed enriched heritability in regions depleted of Neanderthal variants. Together, these results provide new avenues for deciphering the biological underpinnings of these uniquely human traits.

genomics↗

bioRxiv2020

Cortical surface alterations in cingulate and frontal regulatory areas underlies insensitive mothering

This study focuses on severe insensitive or neglectful mothering, the most prevalent type of child maltreatment, to examine cortical surface feature alterations underlying maternal functioning and their impact on mother-child interactive bonding. High-resolution 3D volumetric images were obtained on 24 neglectful (NM) and 21 non-neglectful control (CM) mothers. Using surface-based morphometry, we compared differences in cortical thickness and surface area. Mothers completed alexithymia and cortical integrity measures and participated with their children in a play task (Emotional Availability Scale). We found cortical thinning for NM in the right rostral middle frontal gyrus and the right anterior/medial cingulate cortex, and also increased surface area in the right occipital lingual and fusiform areas and the caudal middle frontal area. Mediation analyses showed that cognitive integrity and alexithymia mediated, respectively, the positive and negative effect of the rostral middle frontal gyrus on Emotional Availability. The findings suggest cortical thinning in the rostral frontal area underlying high-order regulatory functioning as being critical for poor maternal self-awareness of emotions and the organization of coordinated actions during mother-child interactive bonding.

neuroscience↗

bioRxiv2020

Linguistic input drives brain network configuration during language comprehension.

Assessing the synchrony and interplay between distributed neural regions is critical to understanding how language is processed. Here, we investigated possible neuro-functional links between form and meaning during sentence comprehension combining a classical whole-brain approach, which characterizes patterns of brain activation resulting from our experimental manipulation, and a novel multivariate network-based approach, which uses graph-theory measures to unravel the architectural configuration of the language system. Capitalizing on the Spanish gender agreement system, we experimentally manipulated formal and conceptual factors: whether the noun-adjective grammatical gender relationship was congruent or not and whether the noun gender type was semantically informative or strictly formal. Left inferior and middle frontal gyri, as well as left MTG/STG emerged as critical areas for the computation of grammatical relations. We demonstrate how the interface between formal and conceptual features depends on the synergic articulation of brain areas divided in three subnetworks that extend beyond the classical left-lateralized perisylvian language circuit. Critically, we isolated a subregion of the left angular gyrus showing a significant interaction between gender congruency and gender type. The functional interplay between the angular gyrus and left perisylvian language-specific circuit proves crucial for constructing coherent and meaningful messages. Importantly, using graph theory we show that this complex system is functionally malleable: the role each node plays within the network changes depending on the available linguistic cues. Significance StatementNeural networks can be described as graphs comprising distributed and interconnected nodes. These nodes share functional properties but also differ in terms of functional specialization and the number of interconnections mediating the efficient transfer of information. Previous work has shown functional connectivity differences based on graph-theory properties between typical and atypical samples. However, here we have used concepts from graph theory to characterize connectivity during language processing using task-related fMRI. This approach allowed us to demonstrate how linguistic input drives brain network configuration during language comprehension. This is the first evidence of functional flexibility in language networks: the communicative capacity of each hub changes depending on whether the linguistic input grants access to meaning or is purely formal.

neuroscience↗

bioRxiv2019

Neglectful maternal caregiving involves altered brain plasticity in empathy-related areas

The maternal brain undergoes functional and structural adaptations to sensitive caregiving that are critical for ensuring infant wellbeing. This study investigates brain structural alterations in neglectful caregiving and their impact on mother-child interactive behavior. High-resolution 3D volumetric images were obtained on 25 neglectful (NM) and 23 non-neglectful control (CM) mothers. Using Voxel-Based Morphometry, we compared gray and white matter volume (GMV/WMV) between the two groups. Mothers also completed an empathy scale and participated with their children in a standardized play task (Emotional Availability Scale, EA). NM, as compared to CM, showed GMV reductions in right insula, anterior/middle cingulate, and right inferior frontal gyrus (IFG), as well as WMV reductions in bilateral frontal regions. A GMV increase was observed in the right fusiform and cerebellum. Regression analyses showed a negative effect of fusiform GMV and a positive effect of right frontal WMV on EA Mediation analyses showed the mediating role of emotional empathy in the positive effect of insula and IFG, and the negative effect of cerebellum on EA. Neglectful mothering involves an altered plasticity in emotional empathy-related areas and in frontal areas associated with poor mother-child interactive bonding, indicating how critical the structural changes in these areas are for infant wellbeing.

neuroscience↗