Browsing by Author "Lin, Zikai"

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    Delay discounting and alcohol consumption correlate with dorsal anterior insula activation during choice in non‐treatment‐seeking heavy drinkers
    (Wiley, 2022) Halcomb, Meredith; Dzemidzic, Mario; Shen, Yitong I.; Lin, Zikai; Butcher, Tarah J.; Yoder, Karmen K.; Oberlin, Brandon; Radiology and Imaging Sciences, School of Medicine
    Background The anterior insular cortex (AIC), a prominent salience network node, integrates interoceptive information and emotional states into decision-making. While AIC activation during delay discounting (DD) in alcohol use disorder (AUD) has been previously reported, the associations between AIC activation, impulsive choice, alcohol consumption, and connectivity remain unknown. We therefore tested AIC brain responses during DD in heavy drinkers and their association with DD performance, alcohol drinking, and task-based connectivity. Methods Twenty-nine heavy drinkers (12 females; 31.5±6.1 years; 40.8±23.4 drinks/week) completed a DD task during functional MRI. Regions activated during delay discounting decision-making were tested for correlations with DD behavior and alcohol drinking. Psychophysiological interaction (PPI) models assessed task-dependent functional connectivity (FC) of activation during choice. Results DD choice activated bilateral anterior insular cortex, anterior cingulate cortex, and left precentral gyrus. Right dorsal (d) AIC activation during choice negatively correlated with discounting of delayed rewards and alcohol consumption. PPI analysis revealed FC of right dAIC to both anterior and posterior cingulate cortex (PCC)—key nodes in the midline default mode network. Conclusions Greater dAIC involvement in intertemporal choice may confer more adaptive behavior (lower impulsivity and alcohol consumption). Moreover, salience network processes governing discounting may require midline default mode (precuneus/PCC) recruitment. These findings support a key adaptive role for right dAIC in decision-making involving future rewards and risky drinking.
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    Longitudinal white-matter abnormalities in sports-related concussion: A diffusion MRI study
    (Wolters Kluwer, 2020-08) Wu, Yu-Chien; Harezlak, Jaroslaw; Elsaid, Nahla M. H.; Lin, Zikai; Wen, Qiuting; Mustafi, Sourajit M.; Riggen, Larry D.; Koch, Kevin M.; Nencka, Andrew S.; Meier, Timothy B.; Mayer, Andrew R.; Wang, Yang; Giza, Christopher C.; DiFiori, John P.; Guskiewicz, Kevin M.; Mihalik, Jason P.; LaConte, Stephen M.; Duma, Stefan M.; Broglio, Steven P.; Saykin, Andrew J.; McCrea, Michael A.; McAllister, Thomas W.; Radiology and Imaging Sciences, School of Medicine
    Objective To study longitudinal recovery trajectories of white matter after sports-related concussion (SRC) by performing diffusion tensor imaging (DTI) on collegiate athletes who sustained SRC. Methods Collegiate athletes (n = 219, 82 concussed athletes, 68 contact-sport controls, and 69 non–contact-sport controls) were included from the Concussion Assessment, Research and Education Consortium. The participants completed clinical assessments and DTI at 4 time points: 24 to 48 hours after injury, asymptomatic state, 7 days after return-to-play, and 6 months after injury. Tract-based spatial statistics was used to investigate group differences in DTI metrics and to identify white-matter areas with persistent abnormalities. Generalized linear mixed models were used to study longitudinal changes and associations between outcome measures and DTI metrics. Cox proportional hazards model was used to study effects of white-matter abnormalities on recovery time. Results In the white matter of concussed athletes, DTI-derived mean diffusivity was significantly higher than in the controls at 24 to 48 hours after injury and beyond the point when the concussed athletes became asymptomatic. While the extent of affected white matter decreased over time, part of the corpus callosum had persistent group differences across all the time points. Furthermore, greater elevation of mean diffusivity at acute concussion was associated with worse clinical outcome measures (i.e., Brief Symptom Inventory scores and symptom severity scores) and prolonged recovery time. No significant differences in DTI metrics were observed between the contact-sport and non–contact-sport controls. Conclusions Changes in white matter were evident after SRC at 6 months after injury but were not observed in contact-sport exposure. Furthermore, the persistent white-matter abnormalities were associated with clinical outcomes and delayed recovery time
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    Semiparametric Estimation of Task-Based Dynamic Functional Connectivity on the Population Level
    (Frontiers, 2019-06-21) Kudela, Maria A.; Dzemidzic, Mario; Oberlin, Brandon G.; Lin, Zikai; Goñi, Joaquín; Kareken, David A.; Harezlak, Jaroslaw; Neurology, IU School of Medicine
    Dynamic functional connectivity (dFC) estimates time-dependent associations between pairs of brain region time series as typically acquired during functional MRI. dFC changes are most commonly quantified by pairwise correlation coefficients between the time series within a sliding window. Here, we applied a recently developed bootstrap-based technique (Kudela et al., 2017) to robustly estimate subject-level dFC and its confidence intervals in a task-based fMRI study (24 subjects who tasted their most frequently consumed beer and Gatorade as an appetitive control). We then combined information across subjects and scans utilizing semiparametric mixed models to obtain a group-level dFC estimate for each pair of brain regions, flavor, and the difference between flavors. The proposed approach relies on the estimated group-level dFC accounting for complex correlation structures of the fMRI data, multiple repeated observations per subject, experimental design, and subject-specific variability. It also provides condition-specific dFC and confidence intervals for the whole brain at the group level. As a summary dFC metric, we used the proportion of time when the estimated associations were either significantly positive or negative. For both flavors, our fully-data driven approach yielded regional associations that reflected known, biologically meaningful brain organization as shown in prior work, as well as closely resembled resting state networks (RSNs). Specifically, beer flavor-potentiated associations were detected between several reward-related regions, including the right ventral striatum (VST), lateral orbitofrontal cortex, and ventral anterior insular cortex (vAIC). The enhancement of right VST-vAIC association by a taste of beer independently validated the main activation-based finding (Oberlin et al., 2016). Most notably, our novel dFC methodology uncovered numerous associations undetected by the traditional static FC analysis. The data-driven, novel dFC methodology presented here can be used for a wide range of task-based fMRI designs to estimate the dFC at multiple levels-group-, individual-, and task-specific, utilizing a combination of well-established statistical methods.