Biology subjects

Nee, D. E.

Publications and source records attributed to Nee, D. E..

6 recordsLinked to original sources

bioRxiv2025

Precision fMRI reveals densely interdigitated network patches with conserved motifs in the lateral prefrontal cortex

Dominant models of human lateral prefrontal cortex (LPFC) organization emphasize broad domain-general zones and smooth functional gradients. However, these models rely heavily on group-averaged neuroimaging, which can obscure fine-scale cortical features - especially in highly inter-individually variable regions like the LPFC. To address this limitation, we collected a new precision fMRI dataset from 10 individuals, each with approximately 2 hours of resting-state and 6 hours of task data. We mapped individual-specific LPFC networks using resting-state fMRI and tested network-level functional preferences using task fMRI. We found that individual LPFC organization differed markedly from group-averaged estimates. Individual maps showed more fragmented and interdigitated networks - especially in anterior LPFC - including novel conserved motifs present across individuals. Task fMRI revealed that distinct but adjacent networks support domain-specific processes (i.e., language, social cognition, episodic projection) versus domain-general control. Sharp functional boundaries were visible at the individual level that could not be observed in group data. These findings uncover previously hidden organizational principles in the LPFC and offer a framework for understanding how the LPFC supports flexible, complex cognition through a finely organized architecture.

neuroscience↗

bioRxiv2025

Evidence for abstract codes in parietal cortex guiding prospective working memory

The recent past helps us predict and prepare for the near future. Such preparation relies on working memory (WM) which actively maintains and manipulates information providing a temporal bridge. Numerous studies have shown that recently presented visual stimuli can be decoded from fMRI signals in visual cortex (VC) and the intra-parietal sulcus (IPS) suggesting that these areas sustain the recent past. Yet, in many cases, concrete, sensory signals of past information must be transformed into the abstract codes to guide future cognition. However, this process remains poorly understood. Here, human participants used WM to maintain a separate spatial location in each hemifield wherein locations were embedded in a learned spatial sequence. On each trial, participants made a sequence-match decision to a probe and then updated their WM with the probe. The same abstract sequence guided judgments in each hemifield, allowing the separate detection of concrete spatial locations (hemifield-specific) and abstract sequence positions (hemifield-general), and also tracking of representations of the past (last location/position) and future (next location/position). Consistent with previous reports, concrete past locations held in WM could be decoded from VC and IPS. Moreover, in anticipation of the probe, representations shifted from past to future locations in both areas. Critically, we observed abstract coding of future sequence positions in the IPS whose magnitude related to speeded performance. These data suggest that the IPS sustains abstract codes to facilitate future preparation and reveal a transformation of the sensory past into abstract codes guiding future behavior. Significant StatementTo act efficiently, we must use the recent past to prepare for what comes next. For this purpose, working memory (WM) is critical. Although substantial research has shown that WM retains recently presented sensory information, preparation for the future involves abstraction wherein shared meaning is aggregated while superfluous sensory details are discarded. The mechanisms underlying this process remain unclear. Analyzing functional MRI signals in the intraparietal sulcus (IPS), we found that distinct sensory states with shared predictive meaning were initially maintained in a sensory-like fashion, but over time, became aggregated indicative of abstraction. Abstraction was associated with behavioral efficiency highlighting its role in preparation. These findings reveal neural mechanisms supporting the transformation from past to future in WM.

neuroscience↗

bioRxiv2020

Integrative frontal-parietal dynamics supporting cognitive control

Coordinating among the demands of the external environment and internal plans requires cognitive control supported by a fronto-parietal control network (FPCN). Evidence suggests that multiple control systems span the FPCN whose operations are poorly understood. Previously (Nee and DEsposito, 2016; 2017), we detailed frontal dynamics that support control processing, but left open their role in broader cortical function. Here, I show that the FPCN consists of an external/present-oriented to internal/future-oriented cortical gradient extending outwardly from sensory-motor cortices. Areas at the ends of this gradient act in a segregative manner, exciting areas at the same level, but suppressing areas at different levels. By contrast, areas in the middle of the gradient excite areas at all levels, promoting integration of control processing. Individual differences in integrative dynamics predict higher-level cognitive ability and amenability to neuromodulation. These data suggest that an intermediary zone within the FPCN underlies integrative processing that supports cognitive control. Impact StatementThis study shows that intermediary areas within the FPCN are critical for integrating control processing, cognitive ability, and amenability to neuromodulation.

neuroscience↗

bioRxiv2019

Brain Abnormalities Associated with Self-Injurious Thoughts and Behaviors: A Meta-Analysis of Neuroimaging Studies

Self-injurious thoughts and behaviors (SITBs) have long been believed to result in part from brain abnormalities. This meta-analysis aims to evaluate whether the extant literature justifies any definitive conclusions about whether and how SITBs may be associated with aberrant findings. Sixty studies published through June 1st, 2017 that compared individuals with and without SITBs were included, resulting in 734 coordinates. A pooled meta-analysis assessing for general risk for SITBs indicated a lack of convergence on structural abnormalities. Functional abnormalities in the precuneus/posterior cingulate cortex (PCC), temporal-parietal junction, and rostral-lateral prefrontal cortex were significant using multi-level kernel density analysis but nonsignificant using activation-likelihood estimation. Separate analyses for types of SITBs suggested that deliberate self-harm might be associated with abnormalities in the precuneus/PCC. Some moderator effects were detected. Overall, the meta-analytic evidence was not robust. More studies are needed to reach definitive conclusions about whether SITBs are associated with brain abnormalities.

neuroscience↗

bioRxiv2018

Correspondence: fMRI replicability depends upon sufficient individual-level data

The replicability of findings drawn from functional magnetic resonance imaging (fMRI) data have increasingly been called into question. Concerns have been raised that historically, sample sizes have been insufficient to produce adequate power, leading to unreliable results. Recently, Turner and colleagues demonstrated that even with large sample sizes, the replicability of fMRI can be worryingly low. However, their datasets featured low amounts of data at the individual-level. Here, I demonstrate that replicability depends critically on sufficient individual-level sampling. I show that fMRI can have strong replicability even at modest sample sizes when individuals are adequately sampled, but that inadequate individual-level sampling leads to poor replicability. These data indicate that fMRI replicability cannot be judged solely on sample size, and that adequate sampling at the individual-level is a critical design consideration.

neuroscience↗

bioRxiv2017

Causal Evidence for Lateral Prefrontal Cortex Dynamics Supporting Cognitive Control

The lateral prefrontal cortex (LPFC) is essential for higher-level cognition, but how interactions among LPFC areas support cognitive control has remained elusive. In previous work, dynamic causal modeling (DCM) of fMRI data revealed that demands on cognitive control elicited a convergence of influences towards mid LPFC. We proposed that these findings reflect the integration of abstract, rostral and concrete, caudal influences to inform context-appropriate action. Here, we provide a causal test of this model using continuous theta-burst transcranial magnetic stimulation (cTBS). cTBS was applied to caudal, mid, or rostral LPFC, as well as a control site in counterbalanced sessions. In most cases, behavioral modulations resulting from cTBS could be predicted based upon the direction of influences within the previously estimated DCM. However, inconsistent with our DCM, we found that cTBS to caudal LPFC impaired cognitive control processes presumed to involve rostral LPFC. Revising the original DCM with a pathway from caudal LPFC to rostral LPFC significantly improved the fitted DCM and accounted for the observed behavioral findings. These data provide causal evidence for LPFC dynamics supporting cognitive control and demonstrate the utility of combining DCM with causal manipulations to create, test, and refine models of cognition.

neuroscience↗