Presence or absence of a prefrontal sulcus is linked to reasoning performance during child development

The relationship between structural variability in late-developing association cortices like the lateral prefrontal cortex (LPFC) and the development of higher-order cognitive skills is not well understood. Recent findings show that the morphology of LPFC sulci predicts reasoning performance; this work led to the observation of substantial individual variability in the morphology of one of these sulci, the para-intermediate frontal sulcus (pimfs). Here, we sought to characterize this variability and assess its behavioral significance. To this end, we identified the pimfs in a developmental cohort of 72 participants, ages 6-18. Subsequent analyses revealed that the presence or absence of the ventral component of the pimfs was associated with reasoning, even when controlling for age. This finding shows that the cortex lining the banks of sulci can support the development of complex cognitive abilities and highlights the importance of considering individual differences in local morphology when exploring the neurodevelopmental basis of cognition.

Thinking outside the box: The brain-bilingualism relationship in the light of early neurobiological variability

Bilingualism represents a distinctive way to investigate the interplay between brain and behaviour, and an elegant model to study the role of environmental factors in shaping this relationship. Past neuroimaging research has mainly focused on how bilingualism influences brain structure, and how eventually the brain accommodates a second language. In this paper, we discuss a more recent contribution to the field which views bilingualism as lens to understand brain-behaviour mappings from a different perspective. It has been shown, in contexts not related to bilingualism, that cognitive performance across several domains can be predicted by neuroanatomical variants determined prenatally and largely impervious to postnatal changes. Here, we discuss novel findings indicating that bilingualism modulates the predictive role of these variants on domain-specific cognition. The repercussions of these findings are potentially far-reaching on multiple levels, and highlight the need to shape more complex questions for progress in cognitive neuroscience approaches to bilingualism.

Sulcal pits and patterns in developing human brains

Spatial distribution and specific geometric and topological patterning of early sulcal folds have been hypothesized to be under stronger genetic control and are more associated with optimal organization of cortical functional areas and their white matter connections, compared to later developing sulci. Several previous studies of sulcal pit (putative first sulcal fold) distribution and sulcal pattern analyses using graph structures have provided evidence of the importance of sulcal pits and patterns as remarkable anatomical features closely related to human brain function, suggesting additional insights concerning the anatomical and functional development of the human brain. Recently, early sulcal folding patterns have been observed in healthy fetuses and fetuses with brain abnormalities such as polymicrogyria and agenesis of corpus callosum. Graph-based quantitative sulcal pattern analysis has shown high sensitivity in detecting emerging subtle abnormalities in cerebral cortical growth in early fetal stages that are difficult to detect via qualitative visual assessment or using traditional cortical measures such as gyrification index and curvature. It has proven effective for characterizing genetically influenced early cortical folding development. Future studies will be aimed at better understanding a comprehensive map of spatio-temporal dynamics of fetal cortical folding in a large longitudinal cohort in order to examine individual clinical fetal MRIs and predict postnatal neurodevelopmental outcomes from early fetal life.

Anterior cingulate cortex sulcation and its differential effects on conflict monitoring in bilinguals and monolinguals

The role of the anterior cingulate cortex (ACC) in modulating the effect of bilingual experience on cognitive control has been reported at both functional and structural neural levels. Individual differences in the ACC sulcal patterns have been recently correlated with cognitive control efficiency in monolinguals. We aimed to investigate whether differences of ACC sulcation mediate the effect of bilingualism on cognitive control efficiency. We contrasted the performance of bilinguals and monolinguals during a cognitive control task (i.e., the Flanker Task) using a stratification based on the participants' ACC sulcal features. We found that performance of the two groups was differentially affected by ACC sulcation. Our findings provide the first evidence that early neurodevelopmental mechanisms may modulate the effect of different environmental backgrounds - here, bilingual vs monolingual experience - on cognitive efficiency.

Longitudinal stability of the folding pattern of the anterior cingulate cortex during development

Prenatal processes are likely critical for the differences in cognitive ability and disease risk that unfold in postnatal life. Prenatally established cortical folding patterns are increasingly studied as an adult proxy for earlier development events - under the as yet untested assumption that an individual's folding pattern is developmentally fixed. Here, we provide the first empirical test of this stability assumption using 263 longitudinally-acquired structural MRI brain scans from 75 typically developing individuals spanning ages 7 to 32 years. We focus on the anterior cingulate cortex (ACC) - an intensely studied cortical region that presents two qualitatively distinct and reliably classifiable sulcal patterns with links to postnatal behavior. We show - without exception-that individual ACC sulcal patterns are fixed from childhood to adulthood, at the same time that quantitative anatomical ACC metrics are undergoing profound developmental change. Our findings buttress use of folding typology as a postnatally-stable marker for linking variations in early brain development to later neurocognitive outcomes in ex utero life.

Folding of the anterior cingulate cortex partially explains inhibitory control during childhood: a longitudinal study

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Difficulties in cognitive control are related to several psychiatric conditions.

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Inhibitory control (IC) of children predicts academic and professional successes.

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ACC sulcal patterns at age 5 were related to IC efficiency at age 5 (Stroop scores).

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ACC sulcal patterns at age 5 explained IC efficiency at age 9 (Stroop scores).

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ACC sulcal patterns constrain IC efficiency during childhood.

Difficulties in cognitive control including inhibitory control (IC) are related to the pathophysiology of several psychiatric conditions. In healthy subjects, IC efficiency in childhood is a strong predictor of academic and professional successes later in life. The dorsal anterior cingulate cortex (ACC) is one of the core structures responsible for IC. Although quantitative structural characteristics of the ACC contribute to IC efficiency, the qualitative structural brain characteristics contributing to IC development are less-understood. Using anatomical magnetic resonance imaging, we investigated whether the ACC sulcal pattern at age 5, a stable qualitative characteristic of the brain determined in utero, explains IC at age 9. 18 children performed Stroop tasks at age 5 and age 9. Children with asymmetrical ACC sulcal patterns (n = 7) had better IC efficiency at age 5 and age 9 than children with symmetrical ACC sulcal patterns (n = 11). The ACC sulcal patterns appear to affect specifically IC efficiency given that the ACC sulcal patterns had no effect on verbal working memory. Our study provides the first evidence that the ACC sulcal pattern – a qualitative structural characteristic of the brain not affected by maturation and learning after birth – partially explains IC efficiency during childhood.