Biology subjects

Bunge, S. A.

Publications and source records attributed to Bunge, S. A..

13 recordsLinked to original sources

bioRxiv2025

Advancing High-Resolution 7T Diffusion MRI: Evaluating Phase-Encoding Correction Strategies for Distortion Correction from Basic to Four-Way Acquisitions

PurposeHigh-resolution 7T diffusion MRI (dMRI) is limited by image artifacts that compromise anatomical accuracy. The purpose of this study was to systematically evaluate phase-encoding (PE) acquisition and correction strategies to determine which methods best mitigate geometric distortions and improve data reproducibility. MethodsFive healthy adults were each scanned twice on a 7T MRI scanner (0.9 mm isotropic resolution), using a highly oversampled dMRI protocol with four PE directions (AP, PA, RL, LR). From this dataset, we created and processed eleven time-equivalent, 10-minute acquisitions, ranging from uncorrected single-PE data to comprehensive 4-way PE schemes. These strategies were quantitatively compared on their geometric alignment with T1-weighted images and on the scan-rescan reproducibility of DTI-derived metrics. Results(1) All distortion-corrected schemes significantly improved geometric accuracy over uncorrected data; (2) Strategies correcting with a full set of reversed-PE (2-way) diffusion weighted images (DWIs) outperformed the common approach of using only a single reversed b=0 image; and (3) a 4-way PE acquisition consistently provided the highest image fidelity and reproducibility. The optimized acquisition enabled high-quality reconstruction of both long-range and fine-scale superficial white matter pathways. ConclusionFor high-resolution 7T dMRI, multi-PE acquisition is essential to achieve accurate geometry and stable microstructural estimates (i.e., less residual EPI distortion and better scan-rescan agreement). A 4-way PE scheme provides the most accurate and reproducible results for microstructural and connectivity modeling. Data statementData will be made available in BIDS format upon acceptance of the manuscript. To be updated with DOI.

neuroscience↗

bioRxiv2024

Academic Success and Mental Health: The Paradox of Frontoparietal-Default Mode Network Coupling among Children Facing Poverty

Childhood family income is a powerful predictor of academic achievement and mental health. Here, we ask whether children living in poverty who succeed academically are subsequently protected from, or at risk for, internalizing symptoms. Prior research indicates that children in poverty with better academic performance tend to have higher temporal coupling between the Lateral Frontoparietal Network (LFPN) and Default Mode Network (DMN) than lower-performing children in poverty. An open question is whether higher LFPN-DMN coupling has maladaptive long-term consequences for mental health for this population. In this pre-registered longitudinal study, we analyzed data from 10,829 children (1,931 in poverty) in the ABCD study across four time points (ages 9-13). Higher grades correlated with fewer internalizing symptoms; this association was more pronounced for children below poverty. Longitudinally, LFPN-DMN connectivity correlated positively with internalizing symptoms across both groups and timepoints. Thus, although higher academic performance was associated with better mental health outcomes for all children, the specific pattern of LFPN-DMN connectivity that supports academic resilience among children in poverty may be a risk factor for developing internalizing symptoms. These findings highlight the complex nature of academic resilience in the context of structural inequity. HighlightsO_LIHigh grades linked to fewer internalizing symptoms, especially for kids in poverty. C_LIO_LIHigh LFPN-DMN connectivity predicts higher internalizing symptoms in children. C_LIO_LINeural correlates of academic resilience may predispose children to internalizing. C_LIO_LIChildren below poverty had higher internalizing symptoms. C_LI

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bioRxiv2023

Intensive task-switching training and single-task training differentially affect behavioral and neural manifestations of cognitive control in children

The ability to flexibly switch between tasks develops during childhood. Childrens task-switching performance improves with practice, but the underlying processes remain unclear. We used functional magnetic resonance imaging to examine how nine weeks of task-switching training affect performance and task-related activation and functional connectivity. Children (8-11 years) were assigned to one of three groups: intensive task switching (SW; n = 72), intensive single tasking (SI; n = 74), and passive control (n = 41). While mixing costs decreased in both training groups initially, only the SW group maintained these training-related improvements at the end of training. Activation in dorsolateral prefrontal cortex decreased with training, but again only the SW group maintained these activation decreases at the end of training. Condition-specific connectivity increases with task switching became less pronounced with training, especially in the SI group. Lower costs of task switching along with decreased task-related activations suggest increased processing efficiency in frontoparietal regions with training. Intensive task-switching training was associated with sustained changes, possibly facilitated by a greater mismatch between processing supplies and environmental demands. Our findings suggest that experience-dependent changes with intensive task-switching training do not mirror maturational processes but rather facilitate performance via more efficient task processing.

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bioRxiv2023

Neuroanatomical and functional dissociations between variably present anterior lateral prefrontal sulci

The lateral prefrontal cortex (LPFC) is an evolutionarily expanded region in humans that is critical for numerous complex functions, many of which are largely hominoid-specific. While recent work shows that the presence or absence of specific sulci in anterior LPFC is associated with cognitive performance across age groups, it is unknown whether the presence of these structures relates to individual differences in the functional organization of LPFC. To fill this gap in knowledge, we leveraged multimodal neuroimaging data from 72 young adult humans aged 22-36 and show that dorsal and ventral components of the paraintermediate frontal sulcus (pimfs) present distinct morphological (surface area), architectural (thickness and myelination), and functional (resting-state connectivity networks) properties. We further contextualize the pimfs components within classic and modern cortical parcellations. Taken together, the dorsal and ventral pimfs components mark transitions in anatomy and function in LPFC, across metrics and parcellations. These results emphasize that the pimfs is a critical structure to consider when examining individual differences in the anatomical and functional organization of LPFC and highlight the importance of considering individual anatomy when investigating structural and functional features of the cortex.

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bioRxiv2023

Cognitive relevance of an evolutionarily new and variable prefrontal structure

Identifying structure-function correspondences is a major goal among biologists, cognitive neuroscientists, and brain mappers. Recent studies have identified relationships between performance on cognitive tasks and the presence or absence of small, shallow indentations, or sulci, of the human brain. Building on the previous finding that the presence of one such sulcus in the left anterior lateral prefrontal cortex (aLPFC) was related to reasoning task performance in children and adolescents, we tested whether this relationship extended to a different sample, age group, and reasoning task. As predicted, the presence of this aLPFC sulcus--the ventral para-intermediate frontal sulcus--was also associated with higher reasoning scores in young adults (ages 22-36). These findings have not only direct developmental, but also evolutionary relevance--as recent work shows that the pimfs-v is exceedingly rare in chimpanzees. Thus, the pimfs-v is a novel developmental, cognitive, and evolutionarily relevant feature that should be considered in future studies examining how the complex relationships among multiscale anatomical and functional features of the brain give rise to abstract thought.

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bioRxiv2022

Development of human lateral prefrontal sulcal morphology and its relation to reasoning performance

Previous findings show that the morphology of folds (sulci) of the human cerebral cortex flatten during postnatal development. However, previous studies did not consider the relationship between sulcal morphology and cognitive development in individual participants. Here, we fill this gap in knowledge by leveraging cross-sectional morphological neuroimaging data in the lateral prefrontal cortex (LPFC) from individual human participants (6-36 years old, males and females; N = 108; 3672 sulci), as well as longitudinal morphological and behavioral data from a subset of child and adolescent participants scanned at two timepoints (6-18 years old; N = 44; 2992 sulci). Manually defining thousands of sulci revealed that LPFC sulcal morphology (depth, surface area, gray matter thickness, and local gyrification index) differed between children (6-11 years old)/adolescents (11-18 years old) and young adults (22-36 years old) cross-sectionally, but only cortical thickness showed both cross-sectional differences between children and adolescents and presented longitudinal changes during childhood and adolescence. Furthermore, a data-driven approach relating morphology and cognition identified that longitudinal changes in cortical thickness of four rostral LPFC sulci predicted longitudinal changes in reasoning performance, a higher-level cognitive ability that relies on LPFC. Contrary to previous findings, these results suggest that sulci may flatten either after this time frame or over a longer longitudinal period of time than previously presented. Crucially, these results also suggest that longitudinal changes in the cortex within specific LPFC sulci are behaviorally meaningful--providing targeted structures, and areas of the cortex, for future neuroimaging studies examining the development of cognitive abilities. Significance StatementRecent work has shown that individual differences in neuroanatomical structures (indentations, or sulci) within the lateral prefrontal cortex (LPFC) are behaviorally meaningful during childhood and adolescence. Here, we describe how specific LPFC sulci develop at the level of individual participants for the first time--from both cross-sectional and longitudinal perspectives. Further, we show, also for the first time, that the longitudinal morphological changes in these structures are behaviorally relevant. These findings lay the foundation for a future avenue to precisely study the development of the cortex and highlight the importance of studying the development of sulci in other cortical expanses and charting how these changes relate to the cognitive abilities those areas support at the level of individual participants.

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bioRxiv2022

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. When controlling for age, the presence or absence of the ventral component of the pimfs was associated with reasoning, as was the total surface area of pimfs. These findings show that multiple features of sulci can support the development of complex cognitive abilities and highlight the importance of considering individual differences in local morphology when exploring the neurodevelopmental basis of cognition.

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bioRxiv2021

Sulcal depth in prefrontal cortex: A novel predictor of working memory performance

The neuroanatomical changes that underpin cognitive development is of major interest in neuroscience. Of the many aspects of neuroanatomy to consider, tertiary sulci are particularly appealing as they emerge last in gestation, show a protracted development after birth, and are either human- or hominoid-specific. Thus, they are ideal targets for exploring morphological-cognitive relationships with cognitive skills, such as verbal working memory (WM), that also show protracted development. Yet, the relationship between sulcal morphology and verbal WM is unknown, either in development or more generally. To fill this gap, we adopted a data-driven approach with cross-validation to examine the relationship between sulcal depth in lateral prefrontal cortex (LPFC) and verbal WM in 60 participants ages 6-18. These analyses identified nine left, but not right, LPFC sulci (of which six were tertiary) whose depth predicted verbal WM performance. Most of these sulci are located within and around contours of functionally defined parcellations of LPFC proposed previously. This sulcal depth model out-performed models with age or cortical thickness. Taken together, these findings contribute to building empirical support for a classic theory that tertiary sulci serve as landmarks in association cortices that contribute to aspects of human behavior that show a protracted development.

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bioRxiv2021

Exploring neural correlates of behavioral and academic resilience among children in poverty

Children in poverty must contend with systems that do not meet their needs. We explored what, at a neural level, helps explain childrens resilience in these contexts. Lower coupling between lateral frontoparietal network (LFPN) and default mode network (DMN)--linked, respectively, to externally- and internally-directed thought--has previously been associated with better cognitive performance. However, we recently found the opposite pattern for children in poverty. Here, we probed ecologically-valid assessments of performance. In a pre-registered study, we investigated trajectories of network coupling over ages 9-13 and their relation to school grades and attention problems. We analyzed longitudinal data from ABCD Study (N=8366 children at baseline; 1303 below poverty). The link between cognitive performance and grades was weaker for children in poverty, highlighting the importance of ecologically-valid measures. As predicted, higher LFPN-DMN connectivity was linked to worse grades and attentional problems for children living above poverty, while children below poverty showed opposite tendencies. This interaction between LFPN-DMN connectivity and poverty related to childrens grades two years later; however, it was attenuated when controlling for baseline grades and was not related to attention longitudinally. Together, these findings suggest network connectivity is differentially related to performance in real-world settings for children above and below poverty.

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bioRxiv2020

Cognitive insights from evolutionarily new brain structures in prefrontal cortex

While the disproportionate expansion of lateral prefrontal cortex (LPFC) in humans compared to non-human primates is accepted, the relationship between evolutionarily new LPFC brain structures and uniquely human cognitive skills is largely unknown. Here, we tested the relationship between variability in evolutionarily new LPFC tertiary sulci and reasoning skills in a pediatric cohort. A novel data-driven approach in independent discovery and replication samples revealed that the depth of specific LPFC tertiary sulci predicts individual differences in reasoning skills beyond age. These findings support a classic, yet untested, theory linking the protracted development of tertiary sulci to late-developing cognitive processes. We suggest that deeper LPFC tertiary sulci reflect reduced short-range connections in white matter, which in turn, improve the efficiency of local neural signals underlying cognitive skills such as reasoning that are central to human cognitive development. To expedite discoveries in future neuroanatomical-behavioural studies, we share sulcal definitions with the field.

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bioRxiv2020

What is an adaptive pattern of brain activity for a child? It depends on their environment

Prior research indicates that lower resting-state functional coupling between two brain networks, lateral frontoparietal network (LFPN) and default mode network (DMN), relates to better cognitive test performance. However, most study samples skew towards wealthier individuals--and what is adaptive for one population may not be for another. In a pre-registered study, we analyzed resting-state fMRI from 6839 children ages 9-10 years. For children above poverty, we replicated the prior finding: better cognitive performance correlated with weaker LFPN-DMN coupling. For children in poverty, the slope of the relation was instead positive. This significant interaction related to several features of a childs environment. Future research should investigate the possibility that leveraging internally guided cognition is a mechanism of resilience for children in poverty. In sum, "optimal" brain function depends in part on the external pressures children face, highlighting the need for more diverse samples in research on the human brain and behavior.

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bioRxiv2019

Changes in anterior and posterior hippocampus differentially predict item-space, item-time, and item-item memory improvement

Relational memory requires the hippocampus, but whether distinct hippocampal mechanisms along the anterior-posterior axis are required for different types of relations is debated. We investigated the contribution of structural changes in hippocampal head, body, and tail subregions to the capacity to remember item-space, item-time, and item-item relations. Memory for each relation and volumes of hippocampal subregions were assessed longitudinally in 171 participants across 3 time points (Mage at T1= 9.45 years; Mage at T2= 10.86 years, Mage at T3=12.12 years; comprising 393 behavioral assessments and 362 structural scans). Among older children, volumetric growth in: (a) head and body predicted improvements in item-time memory, (b) head predicted improvements in item-item memory; and (c) right tail predicted improvements in item-space memory. The present research establishes that volumetric changes in hippocampal subregions differentially predict changes in different aspects of relational memory, underscoring a division of labor along the hippocampal anterior-posterior axis.

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bioRxiv2018

The more you know: Investigating why adults get a bigger memory boost from semantic congruency than children

Humans possess the capacity to employ prior knowledge in the service of our ability to remember; thus, memory is oftentimes superior for information that is semantically congruent with our prior knowledge. This congruency benefit grows during development, but little is understood about neurodevelopmental differences that underlie this growth. Here, we sought to explore the brain mechanisms underlying these phenomena. To this end, we examined the neural substrates of semantically congruent vs. incongruent item-context associations in 116 children and 25 young adults who performed encoding and retrieval tasks during functional MRI data collection. Participants encoded item-context pairs by judging whether an item belonged in a scene. Episodic memory was then tested with a source memory task. Consistent with prior work, source memory accuracy improved with age, and was greater for congruent than incongruent pairs; further, this congruency benefit was greater in adults than children. Age-related differences were observed across univariate, functional connectivity, and multivariate analyses, particularly in lateral prefrontal cortex (PFC). In sum, our results revealed two general age differences. First, left ventrolateral/rostrolateral PFC exhibited age-related increases in univariate activity, as well as greater functional connectivity with temporal regions during the processing of congruency. Second, right rostrolateral PFC activation was associated with successfully encoded congruent associations in adults, but not children. Finally, multivariate analyses provided evidence for stronger veridical memory in adults than children in right ventrolateral PFC. These effects in right lateral PFC were significantly correlated with memory performance, implicating them in the process of remembering congruent associations. These results connect brain regions associated with top-down control in the congruency benefit and age-related improvements therein.

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