Reliability and validity of composite scores from the NIH Toolbox Cognition Battery in adults

A phase I trial of accelerated intermittent theta burst rTMS for amnestic MCI

BACKGROUND

Emerging evidence suggests that repetitive transcranial magnetic stimulation (rTMS) enhances cognition in mild cognitive impairment (MCI). Accelerated intermittent theta burst stimulation (iTBS) rTMS protocols are promising as they substantially reduce burden by shortening the treatment course, but the safety, feasibility, and acceptability of iTBS have not been established in MCI.

METHODS

24 older adults with amnestic MCI (aMCI) due to possible Alzheimer's disease enrolled in a phase I trial of open-label accelerated iTBS to the left dorsolateral prefrontal cortex (8 stimulation sessions of 600 pulses of iTBS/day for 3 days). Participants rated common side effects during and after each session and retrospectively (at post-treatment and 4-week follow-up). They completed brain MRI (for safety assessments and electric field modeling), neuropsychiatric evaluations, and neuropsychological testing before and after treatment; a subset of measures was administered at follow-up.

RESULTS

Retention was high (95%) and there were no adverse neuroradiological, neuropsychiatric, or neurocognitive effects of treatment. Participants reported high acceptability, minimal side effects, and low desire to quit despite some rating the treatment as tiring. Electric field modeling data suggest that all participants received safe and therapeutic cortical stimulation intensities. We observed a significant, large effect size (d=0.98) improvement in fluid cognition using the NIH Toolbox Cognition Battery from pre-treatment to post-treatment.

CONCLUSIONS

Our findings support the safety, feasibility, and acceptability of accelerated iTBS in aMCI. In addition, we provide evidence of target engagement in the form of improved cognition following treatment. These promising results directly inform future trials aimed at optimizing treatment parameters.

TRIAL REGISTRATION NUMBER

NCT04503096.

Functionality of arousal-regulating brain circuitry at rest predicts human cognitive abilities

Arousal state is regulated by subcortical neuromodulatory nuclei, such as locus coeruleus, which send wide-reaching projections to cortex. Whether higher-order cortical regions have the capacity to recruit neuromodulatory systems to aid cognition is unclear. Here, we hypothesized that select cortical regions activate the arousal system, which, in turn, modulates large-scale brain activity, creating a functional circuit predicting cognitive ability. We utilized the Human Connectome Project 7T functional magnetic resonance imaging dataset (n = 149), acquired at rest with simultaneous eye tracking, along with extensive cognitive assessment for each subject. First, we discovered select frontoparietal cortical regions that drive large-scale spontaneous brain activity specifically via engaging the arousal system. Second, we show that the functionality of the arousal circuit driven by bilateral posterior cingulate cortex (associated with the default mode network) predicts subjects' cognitive abilities. This suggests that a cortical region that is typically associated with self-referential processing supports cognition by regulating the arousal system.

Disparities in Metabolic Syndrome and Neurocognitive Function Among Older Hispanics/Latinos with Human Immunodeficiency Virus

Neurocognitive impairment and metabolic syndrome (MetS) are prevalent in persons with HIV (PWH). We examined disparities in HIV-associated neurocognitive function between Hispanic and non-Hispanic White older PWH, and the role of MetS in explaining these disparities. Participants included 116 community-dwelling PWH aged 50-75 years enrolled in a cohort study in southern California [58 Hispanic (53% Spanish speaking) and 58 age-comparable non-Hispanic White; overall group: age: M = 57.9, standard deviation (SD) = 5.7; education (years): M = 13, SD = 3.4; 83% male, 58% AIDS, 94% on antiretroviral therapy]. Global neurocognition was derived from T-scores adjusted for demographics (age, education, sex, ethnicity, language) on a battery of 10 cognitive tests. MetS was ascertained via standard criteria that considered central obesity, and fasting elevated triglycerides, low high-density lipoprotein cholesterol and elevated glucose, or medical treatment for these conditions. Covariates examined included sociodemographic, psychiatric, substance use and HIV disease characteristics. Compared with non-Hispanic Whites, Hispanics showed worse global neurocognitive function (Cohen's d = 0.56, p < 0.05) and had higher rates of MetS (38% vs. 56%, p < 0.05). A stepwise regression model including ethnicity and significant covariates showed Hispanic ethnicity was the sole significant predictor of worse global neurocognition (B = -3.82, SE = 1.27, p < 0.01). A model also including MetS showed that both Hispanic ethnicity (B = -3.39, SE = 1.31, p = 0.01) and MetS (B = -2.73, SE = 1.31, p = 0.04) were independently associated with worse neurocognition. In conclusion, findings indicate that increased MetS is associated with worse neurocognitive function in both Hispanic and non-Hispanic White older PWH, but does not explain neurocognitive disparities. MetS remains an important target for intervention efforts to ameliorate neurocognitive dysfunction among diverse older PWH.

Interpreting reliable change on the Spanish-language NIH toolbox cognition battery

This study applied a reliable change methodology to the test-retest data from the Spanish-language NIH Toolbox Cognition Battery (NIHTB-CB) normative sample. Participants included Spanish-speaking adults (n = 48; 54.2% women, 100% Latinx) evaluated twice within one to two weeks on the Spanish-language NIHTB-CB, consisting of two crystallized and five fluid cognitive tests. Test-retest means, standard deviations, and intraclass correlations were used to calculate upper and lower bounds of 70, 80, and 90% confidence intervals (CIs) around change scores, with these bounds used as cutoffs for inferring reliable change. Cutoffs were calculated for raw scores, age-adjusted standard scores (SS; M = 100, SD = 15), and demographic-adjusted T-scores (T; M = 50, SD = 10), adjusting for age, gender, and education. Test-retest change scores on the Spanish-language NIHTB-CB exceeding the following cutoffs indicate reliable change based on an 80% CI (i.e., values exceeding these cutoffs indicate greater decline or greater improvement than 90% of the sample): Dimensional Change Card Sort (SS ≥ 15/T ≥ 11), Flanker (SS ≥ 13/T ≥ 10), List Sorting (SS ≥ 13/T ≥ 9), Picture Sequence Memory (SS ≥ 14/T ≥ 9), Pattern Comparison (SS ≥ 14/T ≥ 10), Picture Vocabulary (SS ≥ 8/T ≥ 6), Oral Reading (SS ≥ 7/T ≥ 5), Fluid Cognition Composite (SS ≥ 12/T ≥ 9), Crystallized Cognition Composite (SS ≥ 6/T ≥ 5), and Total Cognition Composite (SS ≥ 8/T ≥ 7). These cutoffs are one of few resources to interpret cognitive change at retest among Spanish-speaking patients and participants.

Associations of Brain Entropy Estimated by Resting State fMRI With Physiological Indices, Body Mass Index, and Cognition

BACKGROUND

In recent years, resting-state fMRI (rsfMRI)-based brain entropy (BEN) has gained increasing interest as a tool to characterize brain activity. While previous studies indicate that BEN is correlated with cognition, it remains unclear whether BEN is influenced by other factors that typically affect brain activity measured by fMRI.

PURPOSE

To investigate the relationship between BEN and physiological indices, including respiratory rate (RR), heart rate (HR), systolic blood pressure (s-BP), and body mass index (BMI), and to investigate whether and to what extent the relationship between BEN and cognition is influenced by physiological variables.

STUDY TYPE

Retrospective.

SUBJECTS

One thousand two hundred six healthy subjects (mean age: 28.83 ± 3.69 years; 550 male) with rsfMRI datasets selected from the Human Connectome Project (HCP).

FIELD STRENGTH/SEQUENCE

Multiband echo planar imaging (EPI) sequence at 3.0 Tesla.

ASSESSMENT

Neurocognitive, physical health (RR, HR, s-BP, BMI), and rsfMRI data were retrieved from the HCP datasets. Neurocognition was measured through the total cognition composite (TCC) score provided by HCP. BEN maps were calculated from rsfMRI data.

STATISTICAL TESTS

Multiple regression models, pheight-family wise error (FWE) < 0.05 and pcluster-FWE < 0.05 were considered statistically significant.

RESULTS

BEN was negatively associated with RR (T-thresholds ranging from 4.75 to 4.8; r-threshold = |0.15|) and positively associated with s-BP and BMI (T-thresholds ranging from 4.75 to 4.8; r-threshold = |0.15|) in areas overlapping with the default mode network. After controlling the physiological effects, BEN still showed regional associations with TCC, including negative associations (T-thresholds = 3.09; r-threshold = |0.1|) in the fronto-parietal cortex and positive associations (T-thresholds = 3.09; r-threshold = |0.1|) in the sensorimotor system (motor network and the limbic system).

DATA CONCLUSIONS

RR negatively affects rsfMRI-derived BEN, while s-BP and BMI positively affect BEN. The positive associations between BEN and cognition in the motor network and the limbic system might indicate a facilitation of information processing in the sensorimotor system.

EVIDENCE LEVEL

3 TECHNICAL EFFICACY: Stage 3.

Utility of the NIH Toolbox Cognition Battery in middle to older aged adults with longstanding type 1 diabetes: The DCCT/EDIC study

Objective: Adults with type 1 diabetes (T1D) face an increased risk for cognitive decline and dementia. Diabetes-related and vascular risk factors have been linked to cognitive decline using detailed neuropsychological testing; however, it is unclear if cognitive screening batteries can detect cognitive changes associated with aging in T1D. Method: 1,049 participants with T1D (median age 59 years; range 43-74) from the Diabetes Control and Complications Trial (DCCT), and the follow-up Epidemiology of Diabetes Interventions and Complications (EDIC) study, completed the NIH Toolbox Cognition Battery (NIHTB-C) and Montreal Cognitive Assessment (MoCA). Neuropsychological assessments, depression, glycated hemoglobin levels (HbA1c), severe hypoglycemia, T1D complications, and vascular risk factors were assessed repeatedly over 32 years to determine associations with current NIHTB-C performance. Available cognitive data was clinically adjudicated to determine cognitive impairment status. Results: NIHTB-C scores had moderate associations (r = 0.36-0.53) with concurrently administered neuropsychological tests. In multivariate models, prior severe hypoglycemic episodes, depression symptoms, nephropathy, lower BMI, and higher HbA1c and LDL cholesterol were associated with poorer NIHTB-C Fluid Cognition Composite scores. The NIHTB-C adequately detected adjudicated cognitive impairment (Area Under the Curve = 0.86; optimal cut score ≤90). The MoCA performed similarly (Area Under the Curve = 0.83; optimal cut score ≤25). Conclusions: The NIHTB-C is sensitive to the cognitive effects of diabetes-related and vascular risk factors, correlated with neuropsychological testing, and accurately detects adjudicated cognitive impairment. These data support its use as a screening test in middle to older aged adults with T1D to determine if referral for detailed neuropsychological assessment is needed.

Estimating the prevalence of Non-Verbal Learning Disability (NVLD) from the ABCD sample

Non-Verbal Learning Disability (NVLD) is a neurodevelopmental disorder characterized by deficits in processing visuospatial information but with age-appropriate verbal skills. This cognitive profile has been hypothesized to be associated with atypical white matter, but at the present there is a lack of evidence for this hypothesis. Currently, the condition is not characterized within the main diagnostic systems, in part because no clear set of criteria for characterizing the disorder exists. This report is the first attempt to estimate NVLD prevalence, using two sets of diagnostic criteria, in a large sample of over 11,000 children who were selected without regards to problems of specific nature, either psychological, neurological, physical and/or social. Furthermore, it examined the association between the profile of cognitive abilities and aspects of whole-brain white matter measures in children with and without symptoms associated with NVLD. Participants were drawn from the Adolescent Brain Cognitive Development (ABCD) study, a 10-year longitudinal study of 11,876 children in the U.S. The data used in the present study were drawn from the initial testing point at which the children were 9-10 years old. Prevalence of NVLD based on two distinct sets of criteria, correlations between the measures used to create the criteria, correlations between criteria measures and measures of white matter integrity. The cognitive criteria included measures of visuospatial processing, reading, intelligence and social skills. By varying the cut-offs applied to social skills in conjunction with visuo-spatial difficulties, spared reading skills and intelligence scores, we calculated prevalence for two NVLD groups. White matter characteristics were measures of volume, fractional anisotropy and mean diffusivity. Based on the criteria used, the estimated prevalence of NVLD varied from 1 to 8%. Furthermore, children with NVLD showed a dissociation between measures of visuo-spatial processing not observed in non-NVLD children. At the neurological level, findings provide preliminary evidence of associations between the cognitive profile of NVLD and abnormalities in white matters tracts. The present study documents that exists, within this large non-selected sample, a proportion of youth who show evidence of NVLD. Given those results, it appears essential to establish the best diagnostic criteria, to improve the treatment options and quality of life for children with this disorder.

Predictability of intelligence and age from structural connectomes

In this study, structural images of 1048 healthy subjects from the Human Connectome Project Young Adult study and 94 from ADNI-3 study were processed by an in-house tractography pipeline and analyzed together with pre-processed data of the same subjects from braingraph.org. Whole brain structural connectome features were used to build a simple correlation-based regression machine learning model to predict intelligence and age of healthy subjects. Our results showed that different forms of intelligence as well as age are predictable to a certain degree from diffusion tensor imaging detecting anatomical fiber tracts in the living human brain. Though we did not identify significant differences in the prediction capability for the investigated features depending on the imaging feature extraction method, we did find that crystallized intelligence was consistently better predictable than fluid intelligence from structural connectivity data through all datasets. Our findings suggest a practical and scalable processing and analysis framework to explore broader research topics employing brain MR imaging.

The effects of insufficient sleep and adequate sleep on cognitive function in healthy adults

STUDY OBJECTIVES

Although sleep affects a range of waking behaviors, the majority of studies have focused on sleep loss with relatively little attention on sustained periods of adequate sleep. The goal of this study was to use an experimental design to examine the effect of both of these sleep patterns on cognitive performance in healthy adults.

METHODS

This study used a randomized crossover design. Participants who regularly slept 7-9 hours/night completed two 6-week intervention conditions, adequate sleep (maintenance of habitual bed/wake times) and insufficient sleep (reduction in sleep of 1.5 hours relative to adequate sleep), separated by a 2-6weeks (median=43days) washout period. Cognitive functioning was evaluated at baseline and endpoint of each intervention using the NIH Toolbox Cognition Battery. General linear models contrasted scores following each condition to the baseline of the first condition; the baseline of the second condition was included to evaluate practice effects.

RESULTS

Sixty-five participants (age 35.9 ± 4.9years, 89% women, 52% non-White race/ethnicity) completed study procedures. There was improvement in performance on the List Sorting Working Memory task after the adequate sleep condition that exceeded practice effects. Cognitive performance after insufficient sleep did not reach the level expected with practice and did not differ from baseline. A similar pattern was found on the Flanker Inhibitory Control and Attention task.

CONCLUSIONS

These findings contribute to our understanding of the complex interplay between sleep and cognition and demonstrate that consistent, stable sleep of at least 7 hours/night improves working memory and response inhibition in healthy adults.

CLINICAL TRIAL REGISTRATION

The manuscript reports on data from two clinical trials: Impact of Sleep Restriction on Performance in Adults (URL: https://clinicaltrials.gov/ct2/show/NCT02960776, ID Number: NCT02960776) and Impact of Sleep Restriction in Women (URL: https://clinicaltrials.gov/ct2/show/NCT02835261, ID Number: NCT02835261).

Longitudinal changes in diffusion tensor imaging in hemodialysis patients

INTRODUCTION

Hemodialysis patients have increased white matter and gray matter pathology in the brain relative to controls based on MRI. Diffusion tensor imaging is useful in detecting differences between hemodialysis and controls but has not identified the expected longitudinal decline in hemodialysis patients. In this study we implemented specialized post-processing techniques to reduce noise to detect longitudinal changes in diffusion tensor imaging parameters and evaluated for any association with changes in cognition.

METHODS

We collected anatomical and diffusion MRIs as well as cognitive testing from in-center hemodialysis patients at baseline and 1 year later. Gray matter thickness, white matter volume, and white matter diffusion tensor imaging parameters were measured to identify longitudinal changes. We analyzed the diffusion tensor imaging parameters by averaging the whole white matter and using a pothole analysis. Eighteen hemodialysis patients were included in the longitudinal analysis and 15 controls were used for the pothole analysis. We used the NIH Toolbox Cognition Battery to assess cognitive performance over the same time frame.

FINDINGS

Over the course of a year on hemodialysis, we found a decrease in white matter fractional anisotropy across the entire white matter (p < 0.01), and an increase in the number of white matter fractional anisotropy voxels below pothole threshold (p = 0.03). We did not find any relationship between changes in whole brain structural parameters and cognitive performance.

DISCUSSION

By employing noise reducing techniques, we were able to detect longitudinal changes in diffusion tensor imaging parameters in hemodialysis patients. The fractional anisotropy declines over the year indicate significant decreases in white matter health. However, we did not find that declines in fractional anisotropy was associated with declines in cognitive performance.

Functionality of arousal-regulating brain circuitry at rest predicts human cognitive abilities

Arousal state is regulated by subcortical neuromodulatory nuclei, such as locus coeruleus, which send wide-reaching projections to cortex. Whether higher-order cortical regions have the capacity to recruit neuromodulatory systems to aid cognition is unclear. Here, we hypothesized that select cortical regions activate the arousal system, which in turn modulates large-scale brain activity, creating a functional circuit predicting cognitive ability. We utilized the Human Connectome Project 7T functional magnetic resonance imaging dataset (N=149), acquired at rest with simultaneous eye tracking, along with extensive cognitive assessment for each subject. First, we discovered select frontoparietal cortical regions that drive large-scale spontaneous brain activity specifically via engaging the arousal system. Second, we show that the functionality of the arousal circuit driven by bilateral posterior cingulate cortex (associated with the default mode network) predicts subjects' cognitive abilities. This suggests that a cortical region that is typically associated with self-referential processing supports cognition by regulating the arousal system.

Hippocampal functional connectivity mediates the association between cardiorespiratory fitness and cognitive function in healthy young adults

OBJECTIVE

Higher cardiorespiratory fitness (CRF) induces neuroprotective effects in the hippocampus, a key brain region for memory and learning. We investigated the association between CRF and functional connectivity (FC) of the hippocampus in healthy young adults. We also examined the association between hippocampal FC and neurocognitive function. Lastly, we tested whether hippocampal FC mediates the association between 2-Min Walk Test (2MWT) and neurocognitive function.

METHODS

913 young adults (28.7 ± 3.7 years) from the Human Connectome Project were included in the analyses. The 2MWT performance result was used as a proxy for cardiovascular endurance. Fluid and crystalized composite neurocognitive scores were used to assess cognition. Resting-state functional MRI data were processed to measure hippocampal FC. Linear regression was used to examine the association between 2MWT, hippocampal FC, and neurocognitive outcomes after controlling for age, sex, years of education, body mass index, systolic blood pressure, and gait speed.

RESULTS

Better 2MWT performance was associated with greater FC between the anterior hippocampus and right posterior cingulate and left middle temporal gyrus. No associations between 2MWT and posterior hippocampal FC, whole hippocampal FC, and caudate FC (control region) were observed. Greater anterior hippocampal FC was associated with better crystalized cognition scores. Lastly, greater FC between the anterior hippocampus and right posterior cingulate mediated the association between better 2MWT scores and higher crystalized cognition scores.

CONCLUSIONS

Anterior hippocampal FC may be one underlying neurophysiological mechanism that promotes the association between 2MWT performance and crystalized composite cognitive function in healthy young adults.

Health literacy mediates the association between cognition and healthcare provider interactions among gay and bisexual men with HIV disease

Introduction: Gay and bisexual men (GBM) account for the highest rates of incident infection with HIV in the U.S., and experience social, systemic barriers to accessing and engaging in healthcare services. Interacting with healthcare providers can be a complex process for some GBM with HIV disease. The current study examined the contributions of cognition and health literacy to perceived interactions with healthcare providers among GBM with HIV disease. Methods: The sample included 100 adults with HIV disease (ages 24-75) who identified as GBM. All participants completed the Dealing with Health Professionals subscale of the Beliefs Related to Medication Adherence survey, as well as the Cogstate neuropsychological battery, self-report measures of cognitive symptoms, and well-validated measures of health literacy. Results: Worse performance-based cognition and subjective cognitive symptoms were both associated with perceived difficulties dealing with healthcare providers, but these associations were fully mediated by lower health literacy. Conclusion: Health literacy may play a role in the association between poorer cognitive functioning and difficulties navigating healthcare interactions among GBM with HIV disease. Further studies are needed to determine whether cognitive approaches to enhancing the access, understanding, and use of health information in GBM with HIV disease improves healthcare interactions and outcomes.

Development and Validation of a Vocabulary Measure in the Mobile Toolbox

OBJECTIVE

We describe the development of a new computer adaptive vocabulary test, Mobile Toolbox (MTB) Word Meaning, and validity evidence from 3 studies.

METHOD

Word Meaning was designed to be a multiple-choice synonym test optimized for self-administration on a personal smartphone. The items were first calibrated online in a sample of 7,525 participants to create the computer-adaptive test algorithm for the Word Meaning measure within the MTB app. In Study 1, 92 participants self-administered Word Meaning on study-provided smartphones in the lab and were administered external measures by trained examiners. In Study 2, 1,021 participants completed the external measures in the lab and Word Meaning was self-administered remotely on their personal smartphones. In Study 3, 141 participants self-administered Word Meaning remotely twice with a 2-week delay on personal iPhones.

RESULTS

The final bank included 1363 items. Internal consistency was adequate to good across samples (ρxx = 0.78 to 0.81, p < .001). Test-retest reliability was good (ICC = 0.65, p < .001), and the mean theta score was not significantly different upon the second administration. Correlations were moderate to large with measures of similar constructs (ρ = 0.67-0.75, p < .001) and non-significant with measures of dissimilar constructs. Scores demonstrated small to moderate correlations with age (ρ = 0.35 to 0.45, p < .001) and education (ρ = 0.26, p < .001).

CONCLUSION

The MTB Word Meaning measure demonstrated evidence of reliability and validity in three samples. Further validation studies in clinical samples are necessary.

Test-Retest Reliability and Reliable Change on the NIH Toolbox Cognition Battery

OBJECTIVE

Researchers and practitioners can detect cognitive improvement or decline within a single examinee by applying a reliable change methodology. This study examined reliable change through test-retest data from the English-language National Institutes of Health Toolbox Cognition Battery (NIHTB-CB) normative sample.

METHOD

Participants included adults (n = 138; age: M ± SD = 54.8 ± 20.0, range: 18-85; 51.4% men; 68.1% White) who completed test-retest assessments about a week apart on five fluid cognition tests, providing raw scores, age-adjusted standard scores (SS), and demographic-adjusted T-scores (T).

RESULTS

The Fluid Cognition Composite (SS: ICC = 0.87; T-score: ICC = 0.84) and the five fluid cognition tests had good test-retest reliability (SS: ICC range = 0.66-0.85; T-score: ICC range = 0.64-0.86). The lower and upper bounds of 70%, 80%, and 90% confidence intervals (CIs) were calculated around change scores, which serve as cutoffs for determining reliable change. Using T-scores, 90% CI, and adjustment for practice effects, 32.3% declined on one or more tests, 9.7% declined on two or more tests, 36.6% improved on one or more tests, and 5.4% improved on two or more tests.

CONCLUSIONS

It was common for participants to show reliable change on at least one test score, but not two or more test scores. Per an 80% CI, test-retest difference scores beyond these cutoffs would indicate reliable change: Dimensional Change Card Sort (SS ≥ 14/T ≥ 10), Flanker (SS ≥ 12/T ≥ 8), List Sorting (SS ≥ 14/T ≥ 10), Picture Sequence Memory (SS ≥ 19/T ≥ 13), Pattern Comparison (SS ≥ 11/T ≥ 8), and Fluid Cognition Composite (SS ≥ 10/T ≥ 7). The reliable change cutoffs could be applied in research or practice to detect within-person change in fluid cognition at the individual level.

Performance Validity Testing on the NIH Toolbox Cognition Battery: Base Rates of Failed Embedded Validity Indicators in the Adult Normative Sample

OBJECTIVE

The goal of this study was to determine the base rates of failing proposed embedded validity indicators (EVIs) for the National Institutes of Health Toolbox Cognition Battery (NIHTB-CB) in the normative sample.

METHOD

Participants included adults in the NIHTB-CB normative sample with data to calculate age-adjusted standard scores (n = 855; ages: M(SD) = 46.9(17.3), range: 18-85; 65.0% women; education: M(SD) = 14.1(2.5) years) or demographically adjusted T-scores (n = 803; ages: M(SD) = 47.3(17.3), range: 18-85; 65.3% women; education: M(SD) = 14.2(2.5) years) for all tests. The NIHTB-CB includes two tests of crystallized cognition and five tests of fluid cognition. Individual norm-referenced test performances were categorized as falling above or below liberal and conservative cutoffs based on proposed univariate EVIs. The number of univariate EVI failures was summed to compute multivariable EVIs. EVI failure rates above 10% were considered high false-positive rates, indicating specificity < .90. Using chi-square analyses, the frequencies of EVI failures were compared based on gender, race/ethnicity, education, and crystallized composite.

RESULTS

The multivariable EVIs had predominantly low false-positive rates in the normative sample. EVI failure rates were most common among participants with low crystallized composites. Using age-adjusted standard scores, EVI failure rates varied by education, race/ethnicity, and estimated premorbid intelligence. These differences were mostly eliminated when using demographically adjusted T-scores.

CONCLUSIONS

Multivariable EVIs requiring ≥ 4 failures using liberal cutoffs or ≥ 3 failures using conservative cutoffs had acceptable false-positive rates (i.e., < 10%) using both age-adjusted standard scores and demographically adjusted T-scores. These multivariable EVIs could be applied to large data sets with NIHTB-CB data to screen for potentially invalid test performances.

Associations between physical exercise type, fluid intelligence, executive function, and processing speed in the oldest-old (85 +)

BACKGROUND

While much is known about the effects of physical exercise in adult humans, literature on the oldest-old (≥ 85 years old) is sparse. The present study explored the relationship between self-reported engagement in physical exercise and cognition in the oldest-old.

METHODS

The sample included 184 cognitively healthy participants (98 females, MoCA mean score = 24.81) aged 85 to 99 years old (mean = 88.49 years). Participants completed the Community Healthy Activities Model Program for Seniors (CHAMPS) questionnaire and a cognitive battery including NIH-TB, Coding, Symbol Search, Letter Fluency, and Stroop task. Three groups of participants - sedentary (n = 58; MoCA mean score = 24; 36 females; mean age = 89.03), cardio (n = 60; MoCA mean score = 25.08; 29 females; mean age = 88.62), and cardio + strength training (n = 66; MoCA mean score = 25.28; 33 females; mean age = 87.91) - were derived from responses on CHAMPS.

RESULTS

Analyses controlled for years of education, NIH-TB Crystallized Composite, and metabolic equivalent of tasks. The cardio + strength training group had the highest cognitive performances overall and scored significantly better on Coding (p < 0.001) and Symbol Search (p < 0.05) compared to the sedentary group. The cardio + strength training group scored significantly better on Symbol Search, Letter Fluency, and Stroop Color-Word compared to the cardio group (p < 0.05).

CONCLUSIONS

Our findings suggest self-reported exercise in the oldest-old is linked to better performance on cognitive measures of processing speed and executive functioning, and that there may be a synergistic effect of combining aerobic and resistance training on cognition.

How brain structure-function decoupling supports individual cognition and its molecular mechanism

Functional signals emerge from the structural network, supporting multiple cognitive processes through underlying molecular mechanism. The link between human brain structure and function is region-specific and hierarchical across the neocortex. However, the relationship between hierarchical structure-function decoupling and the manifestation of individual behavior and cognition, along with the significance of the functional systems involved, and the specific molecular mechanism underlying structure-function decoupling remain incompletely characterized. Here, we used the structural-decoupling index (SDI) to quantify the dependency of functional signals on the structural connectome using a significantly larger cohort of healthy subjects. Canonical correlation analysis (CCA) was utilized to assess the general multivariate correlation pattern between region-specific SDIs across the whole brain and multiple cognitive traits. Then, we predicted five composite cognitive scores resulting from multivariate analysis using SDIs in primary networks, association networks, and all networks, respectively. Finally, we explored the molecular mechanism related to SDI by investigating its genetic factors and relationship with neurotransmitter receptors/transporters. We demonstrated that structure-function decoupling is hierarchical across the neocortex, spanning from primary networks to association networks. We revealed better performance in cognition prediction is achieved by using high-level hierarchical SDIs, with varying significance of different brain regions in predicting cognitive processes. We found that the SDIs were associated with the gene expression level of several receptor-related terms, and we also found the spatial distributions of four receptors/transporters significantly correlated with SDIs, namely D2, NET, MOR, and mGluR5, which play an important role in the flexibility of neuronal function. Collectively, our findings corroborate the association between hierarchical macroscale structure-function decoupling and individual cognition and provide implications for comprehending the molecular mechanism of structure-function decoupling. PRACTITIONER POINTS: Structure-function decoupling is hierarchical across the neocortex, spanning from primary networks to association networks. High-level hierarchical structure-function decoupling contributes much more than low-level decoupling to individual cognition. Structure-function decoupling could be regulated by genes associated with pivotal receptors that are crucial for neuronal function flexibility.

Minimal Detectable Change for the ImPACT Subtests at Baseline

OBJECTIVE

To establish the minimal detectable change (MDC) of the subtests that comprise the composite scores from remotely administered Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) baselines.

METHOD

Remote ImPACT baseline data from 172 (male = 45, female = 127) National Collegiate Athletic Association Division I student-athletes from the 2020 and 2021 athletic preseasons were used to calculate the MDC at the 95%, 90%, and 80% confidence intervals (CIs) for all subtest scores used to generate the four core composite scores and the impulse control composite.

RESULTS

The MDCs for the verbal memory subtests at the 95% CI were 10.31 for word memory percent correct, 4.68 for symbol match total correct hidden, and 18.25 for three letters percentage correct. Visual memory subtest MDCs were 19.03 for design memory total percent correct and 4.90 for XO total correct memory. Visual motor speed subtest MDCs were 18.89 for XO total correct interference and 5.40 for three letters average counted correctly. Reaction time (RT) MDCs were 0.12 for XO average correct, 0.95 for symbol match average correct RT, and 0.28 for color match average correct. Impulse control MDCs were 5.97 for XO total incorrect and 1.15 for color match total commissions. One-way repeated measures MANOVA, repeated measures ANOVAs, and Wilcoxon signed-ranks test all suggested no significant difference between any subtests across two remote ImPACT baselines.

CONCLUSIONS

The ImPACT subtest scores did not significantly change between athletic seasons. Our study suggests the subtests be evaluated in conjunction with the composite scores to provide additional metrics for clinical interpretation.

Toward Personalized Cognitive Training in Older Adults: A Pilot Investigation of the Effects of Baseline Performance and Age on Cognitive Training Outcomes

BACKGROUND

Cognitive training holds potential as a non-pharmacological intervention to decrease cognitive symptoms associated with Alzheimer's disease (AD), but more research is needed to understand individual differences that may predict maximal training benefits.

OBJECTIVE

We conducted a pilot study using a six-month training regimen in healthy aging adults with no cognitive decline. We investigated the effects of baseline performance and age on training and transfer improvements.

METHODS

Out of 43 participants aged 65-84 years, 31 successfully completed cognitive training (BrainHQ) in one of three cognitive domains: processing speed (N = 13), inhibitory control (N = 9), or episodic memory (N = 9). We used standardized assessments to measure baseline performance and transfer effects.

RESULTS

All 31 participants improved on the cognitive training regimen and age was positively associated with training improvement (p = 0.039). The processing speed group improved significantly across many near- and far-transfer tasks. In the inhibitory control group, individuals with lower baseline performance improved more on inhibitory control and cognitive flexibility tasks. In the episodic memory group, older individuals improved most on a memory task while younger individuals improved most on an executive function far-transfer task.

CONCLUSIONS

Individual differences are predictive of cognitive training gains, and the impact of individual differences on training improvements is specific to the domain of training. We provide initial insight regarding how non-pharmacological interventions can be optimized to combat the onset of cognitive decline in older adults. With future research this work can inform the design of effective cognitive interventions for delaying cognitive decline in preclinical AD.

Emotional health and its association with neurocognition in Hispanic and non-Hispanic White people with HIV

OBJECTIVE

Emotional functioning is linked to HIV-associated neurocognitive impairment, yet research on this association among diverse people with HIV (PWH) is scant. We examined emotional health and its association with neurocognition in Hispanic and White PWH.

METHODS

Participants included 107 Hispanic (41% primarily Spanish-speakers; 80% Mexican heritage/origin) and 216 White PWH (Overall age: M = 53.62, SD = 12.19; 86% male; 63% AIDS; 92% on antiretroviral therapy). Emotional health was assessed via the National Institute of Health Toolbox (NIHTB)-Emotion Battery, which yields T-scores for three factor-based summary scores (negative affect, social satisfaction, and psychological well-being) and 13 individual component scales. Neurocognition was measured via demographically adjusted fluid cognition T-scores from the NIHTB-cognition battery.

RESULTS

27%-39% of the sample had problematic socioemotional summary scores. Hispanic PWH showed less loneliness, better social satisfaction, higher meaning and purpose, and better psychological well-being than Whites (ps <.05). Within Hispanics, Spanish-speakers showed better meaning and purpose, higher psychological well-being summary score, less anger hostility, but greater fear affect than English speakers. Only in Whites, worse negative affect (fear affect, perceived stress, and sadness) was associated with worse neurocognition (p <.05); and in both groups, worse social satisfaction (emotional support, friendship, and perceived rejection) was linked with worse neurocognition (p <.05).

CONCLUSION

Adverse emotional health is common among PWH, with subgroups of Hispanics showing relative strengths in some domains. Aspects of emotional health differentially relate to neurocogntition among PWH and cross-culturally. Understanding these varying associations is an important step towards the development of culturally relevant interventions that promote neurocognitive health among Hispanic PWH.

Investigating the effects of age and prior military service on fluid and crystallized cognitive functions using virtual morris water maze (vMWM) and NIH Toolbox tasks

Much of current knowledge of aging involves war veterans and research about age-related cognitive changes in veterans involves generalized or single function tests or health or neurological disorders. The current study examined military service within the context of comparisons of young and old humans involving generally healthy individuals to address normal age-associated cognitive changes. Adult participants included 11 young females (8 non-veterans; 3 veterans; 21-31 years), 5 young males (non-veterans, 21-24 years), 9 older females (non-veterans, 62-80 years), and 21 older males (11 non-veterans; 10 veterans; 60-86 years). They were tested in virtual Morris water maze (vMWM) tasks, which were designed to test spatial learning, cognitive flexibility and working memory, similar to rodent studies, and were validated by correlations with specific NIH Toolbox (NIH-TB) Cognitive Battery or Wechsler Memory Scale (WMS) Logical Memory I and II tests. Significant age-related deficits were seen on multiple vMWM tasks and NIH-TB fluid cognition tasks. Among older males, vMWM tasks appeared to be more sensitive, based on finding statistical differences, to prior military service than NIH Toolbox tasks. Compared with male non-veterans of comparable age and younger, older male veterans exhibited significant deficits in spatial learning, cognitive flexibility, and working memory on vMWM tasks. Our findings support continued development and characterization of vMWM tasks that are comparable between rodents and humans for translating aging interventions between species, and provide impetus for larger investigations examining the extent to which prior military service can serve as a "hidden" variable in normal biological declines of cognitive functions.

Brain white matter microstructural changes in chemotherapy-treated older long-term breast cancer survivors

PURPOSE

To assess white matter microstructural changes in older long-term breast cancer survivors 5-15 years post-chemotherapy treatment.

METHODS

Breast cancer survivors aged 65 years or older who underwent chemotherapy (C+) and who did not undergo chemotherapy (C-) and age- and sex-matched healthy controls (HC) were enrolled at time point 1 (TP1) and followed for 2 years for time point 2 (TP2). All participants underwent brain MRI with diffusion tensor images and neuropsychological (NP) testing with the NIH Toolbox Cognition Battery. Tract-based spatial statistics (TBSS) analysis was performed on the diffusion tensor images to assess white matter microstructural changes with the fractional anisotropy (FA) parameter.

RESULTS

There were significant longitudinal alterations in FA within the C+ group over time. The C+ group showed diminished FA in the body and genu of corpus callosum, anterior corona radiate, and external capsule on both the whole brain and region of interest (ROI) based analyses after p < 0.05 family-wise error (FWE) correction. However, there were no significant group differences between the groups at TP1. Additionally, at TP1, a positive correlation (R = 0.58, p = 0.04) was observed between the FA value of the anterior corona radiata and the crystallized composite score in the C+ group.

CONCLUSIONS

Brain white matter microstructural alterations may be the underlying neural correlates of cognitive changes in older breast cancer survivors who had chemotherapy treatment years ago.

Test-retest reliability and predictive utility of a macroscale principal functional connectivity gradient

Mapping individual differences in brain function has been hampered by poor reliability as well as limited interpretability. Leveraging patterns of brain-wide functional connectivity (FC) offers some promise in this endeavor. In particular, a macroscale principal FC gradient that recapitulates a hierarchical organization spanning molecular, cellular, and circuit level features along a sensory-to-association cortical axis has emerged as both a parsimonious and interpretable measure of individual differences in behavior. However, the measurement reliabilities of this FC gradient have not been fully evaluated. Here, we assess the reliabilities of both global and regional principal FC gradient measures using test-retest data from the young adult Human Connectome Project (HCP-YA) and the Dunedin Study. Analyses revealed that the reliabilities of principal FC gradient measures were (1) consistently higher than those for traditional edge-wise FC measures, (2) higher for FC measures derived from general FC (GFC) in comparison with resting-state FC, and (3) higher for longer scan lengths. We additionally examined the relative utility of these principal FC gradient measures in predicting cognition and aging in both datasets as well as the HCP-aging dataset. These analyses revealed that regional FC gradient measures and global gradient range were significantly associated with aging in all three datasets, and moderately associated with cognition in the HCP-YA and Dunedin Study datasets, reflecting contractions and expansions of the cortical hierarchy, respectively. Collectively, these results demonstrate that measures of the principal FC gradient, especially derived using GFC, effectively capture a reliable feature of the human brain subject to interpretable and biologically meaningful individual variation, offering some advantages over traditional edge-wise FC measures in the search for brain-behavior associations.

Evidence for a Compensatory Relationship between Left- and Right-Lateralized Brain Networks

The two hemispheres of the human brain are functionally asymmetric. At the network level, the language network exhibits left-hemisphere lateralization. While this asymmetry is widely replicated, the extent to which other functional networks demonstrate lateralization remains a subject of Investigation. Additionally, it is unknown how the lateralization of one functional network may affect the lateralization of other networks within individuals. We quantified lateralization for each of 17 networks by computing the relative surface area on the left and right cerebral hemispheres. After examining the ecological, convergent, and external validity and test-retest reliability of this surface area-based measure of lateralization, we addressed two hypotheses across multiple datasets (Human Connectome Project = 553, Human Connectome Project-Development = 343, Natural Scenes Dataset = 8). First, we hypothesized that networks associated with language, visuospatial attention, and executive control would show the greatest lateralization. Second, we hypothesized that relationships between lateralized networks would follow a dependent relationship such that greater left-lateralization of a network would be associated with greater right-lateralization of a different network within individuals, and that this pattern would be systematic across individuals. A language network was among the three networks identified as being significantly left-lateralized, and attention and executive control networks were among the five networks identified as being significantly right-lateralized. Next, correlation matrices, an exploratory factor analysis, and confirmatory factor analyses were used to test the second hypothesis and examine the organization of lateralized networks. We found general support for a dependent relationship between highly left- and right-lateralized networks, meaning that across subjects, greater left lateralization of a given network (such as a language network) was linked to greater right lateralization of another network (such as a ventral attention/salience network) and vice versa. These results further our understanding of brain organization at the macro-scale network level in individuals, carrying specific relevance for neurodevelopmental conditions characterized by disruptions in lateralization such as autism and schizophrenia.

Memory for social media images following traumatic brain injury

PRIMARY OBJECTIVE

An emerging body of research examines the role of computer-mediated communication in supporting social connection in persons with traumatic brain injury (TBI). We examine the cognitive impacts of engaging with images posted to social media for persons with moderate-severe TBI.

RESEARCH DESIGN

Prior work shows that after viewing social media posts, adults have better memory for posts when they generate a comment about the post. We examined if persons with TBI experience a memory benefit for commented-upon social media images similar to non-injured comparison participants.

METHODS AND PROCEDURES

53 persons with moderate-to-severe TBI and 52 non-injured comparison participants viewed arrays of real social media images and were prompted to comment on some of them. After a brief delay, a surprise two-alternative forced choice recognition memory test measured memory for these images.

MAIN OUTCOMES AND RESULTS

Persons with TBI remembered social media images at above-chance levels and experienced a commenting-related memory boost much like non-injured comparison participants.

CONCLUSIONS

These findings add to a growing literature on the potential benefits of social media use in individuals with TBI and point to the benefits of active engagement for memory in social media contexts in TBI.

Patterns of Social Determinants of Health and Child Mental Health, Cognition, and Physical Health

Importance

Social determinants of health (SDOH) influence child health. However, most previous studies have used individual, small-set, or cherry-picked SDOH variables without examining unbiased computed SDOH patterns from high-dimensional SDOH factors to investigate associations with child mental health, cognition, and physical health.

Objective

To identify SDOH patterns and estimate their associations with children's mental, cognitive, and physical developmental outcomes.

Design, Setting, and Participants

This population-based cohort study included children aged 9 to 10 years at baseline and their caregivers enrolled in the Adolescent Brain Cognitive Development (ABCD) Study between 2016 and 2021. The ABCD Study includes 21 sites across 17 states.

Exposures

Eighty-four neighborhood-level, geocoded variables spanning 7 domains of SDOH, including bias, education, physical and health infrastructure, natural environment, socioeconomic status, social context, and crime and drugs, were studied. Hierarchical agglomerative clustering was used to identify SDOH patterns.

Main Outcomes and Measures

Associations of SDOH and child mental health (internalizing and externalizing behaviors) and suicidal behaviors, cognitive function (performance, reading skills), and physical health (body mass index, exercise, sleep disorder) were estimated using mixed-effects linear and logistic regression models.

Results

Among 10 504 children (baseline median [SD] age, 9.9 [0.6] years; 5510 boys [52.5%] and 4994 girls [47.5%]; 229 Asian [2.2%], 1468 Black [14.0%], 2128 Hispanic [20.3%], 5565 White [53.0%], and 1108 multiracial [10.5%]), 4 SDOH patterns were identified: pattern 1, affluence (4078 children [38.8%]); pattern 2, high-stigma environment (2661 children [25.3%]); pattern 3, high socioeconomic deprivation (2653 children [25.3%]); and pattern 4, high crime and drug sales, low education, and high population density (1112 children [10.6%]). The SDOH patterns were distinctly associated with child health outcomes. Children exposed to socioeconomic deprivation (SDOH pattern 3) showed the worst health profiles, manifesting more internalizing (β = 0.75; 95% CI, 0.14-1.37) and externalizing (β = 1.43; 95% CI, 0.83-2.02) mental health problems, lower cognitive performance, and adverse physical health.

Conclusions

This study shows that an unbiased quantitative analysis of multidimensional SDOH can permit the determination of how SDOH patterns are associated with child developmental outcomes. Children exposed to socioeconomic deprivation showed the worst outcomes relative to other SDOH categories. These findings suggest the need to determine whether improvement in socioeconomic conditions can enhance child developmental outcomes.

Supporting physical activity for mobility in older adults with mobility limitations (SuPA Mobility): study protocol for a randomized controlled trial

BACKGROUND

Limited mobility in older adults consistently predicts both morbidity and mortality. As individuals age, the rates of mobility disability increase from 1.0% in people aged 15-24 to 20.6% in adults over 65 years of age. Physical activity can effectively improve mobility in older adults, yet many older adults do not engage in sufficient physical activity. Evidence shows that increasing physical activity by 50 min of moderate intensity physical activity in sedentary older adults with mobility limitations can improve mobility and reduce the incidence of mobility disability. To maximize the healthy life span of older adults, it is necessary to find effective and efficient interventions that can be delivered widely to prevent mobility limitations, increase physical activity participation, and improve quality of life in older adults. We propose a randomized controlled trial to assess the effect of a physical activity health coaching intervention on mobility in older adults with mobility limitations.

METHODS

This randomized controlled trial among 290 (145 per group) community-dwelling older adults with mobility limitations, aged 70-89 years old, will compare the effect of a physical activity health coaching intervention versus a general healthy aging education program on mobility, as assessed with the Short Physical Performance Battery. The physical activity health coaching intervention will be delivered by exercise individuals who are trained in Brief Action Planning. The coaches will use evidence-based behavior change techniques including goal-setting, action planning, self-monitoring, and feedback to improve participation in physical activity by a known dose of 50 min per week. There will be a total of 9 health coaching or education sessions delivered over 26 weeks with a subsequent 26-week follow-up period, wherein both groups will receive the same duration and frequency of study visits and activities.

DISCUSSION

The consequences of limited mobility pose a significant burden on the quality of life of older adults. Our trial is novel in that it investigates implementing a dose of physical activity that is known to improve mobility in older adults utilizing a health coaching intervention.

TRIAL REGISTRATION

ClinicalTrials.gov Protocol Registration System: NCT05978336; registered on 28 July 2023.

Effects of exercise on cancer-related cognitive impairment in breast cancer survivors: a scoping review

BACKGROUND

Cancer-related cognitive impairment (CRCI) is one of the major long-term concerns reported by breast cancer survivors after overcoming the disease. The present study undertakes a scoping review of relevant research publications to explore the effect of increasing physical activity (PA) levels or the use of exercise (EX)-based programs on CRCI in female breast cancer survivors; who have completed neo/adjuvant chemotherapy treatment and are awaiting or receiving hormonal therapy.

METHODS

An electronic search of Pubmed, Embase, Scopus, WOS, and Cochrane databases has been conducted to identify published literature from January 2000 to December 2021.

RESULTS

Of 1129 articles, twenty met the inclusion criteria. The majority of the included observational studies (90%) reported cross-sectional design; meanwhile, 72% of experimental research reported randomized controlled trials (RCTs) or randomized crossover trials. 15 neuropsychological batteries and tests, and 5 self-reported validated questionnaires were employed. Only 27% of the included articles used a combination of the previously mentioned methods. The recorder of moderate-vigorous PA (MVPA), defined as more than 3 METs, or represented as average daily minutes spent (≥ 1952 counts/min) was the most analyzed variable in cross-sectional studies, and EX programs based on aerobic training (AT) were the most proposed by RCTs.

CONCLUSIONS

The exploratory approach of this review demonstrates modest but increasingly promising evidence regarding exercise's potential to improve brain health among breast cancer survivors although these findings highlight the importance of addressing methodological heterogeneity in the same direction with the view of using exercise within the clinic area.

Time-efficient, high-resistance inspiratory muscle strength training increases cerebrovascular reactivity in midlife and older adults

Aging is associated with increased risk for cognitive decline and dementia due in part to increases in systolic blood pressure (SBP) and cerebrovascular dysfunction. High-resistance inspiratory muscle strength training (IMST) is a time-efficient, intensive respiratory training protocol (30 resisted inspirations/day) that lowers SBP and improves peripheral vascular function in midlife/older adults with above-normal SBP. However, whether, and by what mechanisms, IMST can improve cerebrovascular function is unknown. We hypothesized that IMST would increase cerebrovascular reactivity to hypercapnia (CVR to CO2), which would coincide with changes to the plasma milieu that improve brain endothelial cell function and enhance cognitive performance (NIH Toolbox). We conducted a 6-wk double-blind, randomized, controlled clinical trial investigating high-resistance IMST [75% maximal inspiratory pressure (PImax); 6×/wk; 4 females, 5 males] vs. low-resistance sham training (15% PImax; 6×/wk; 2 females, 5 males) in midlife/older adults (age 50-79 yr) with initial above-normal SBP. Human brain endothelial cells (HBECs) were exposed to participant plasma and assessed for acetylcholine-stimulated nitric oxide (NO) production. CVR to CO2 increased after high-resistance IMST (pre: 1.38 ± 0.66 cm/s/mmHg; post: 2.31 ± 1.02 cm/s/mmHg, P = 0.020). Acetylcholine-stimulated NO production increased in HBECs exposed to plasma from after vs. before the IMST intervention [pre: 1.49 ± 0.33; post: 1.73 ± 0.35 arbitrary units (AU); P < 0.001]. Episodic memory increased modestly after the IMST intervention (pre: 95 ± 13; post: 103 ± 17 AU; P = 0.045). Cerebrovascular and cognitive function were unchanged in the sham control group. High-resistance IMST may be a promising strategy to improve cerebrovascular and cognitive function in midlife/older adults with above-normal SBP, a population at risk for future cognitive decline and dementia.NEW & NOTEWORTHY Midlife/older adults with above-normal blood pressure are at increased risk of developing cognitive decline and dementia. Our findings suggest that high-resistance inspiratory muscle strength training (IMST), a novel, time-efficient (5-10 min/day) form of physical training, may increase cerebrovascular reactivity to CO2 and episodic memory in midlife/older adults with initial above-normal blood pressure.

Plasma proteomics show altered inflammatory and mitochondrial proteins in patients with neurologic symptoms of post-acute sequelae of SARS-CoV-2 infection

Persistent symptoms of COVID-19 survivors constitute long COVID syndrome, also called post-acute sequelae of SARS-CoV-2 infection (PASC). Neurologic manifestations of PASC (Neuro-PASC) are particularly debilitating, long lasting, and poorly understood. To gain insight into the pathogenesis of PASC, we leveraged a well-characterized group of Neuro-PASC (NP) patients seen at our Neuro-COVID-19 clinic who had mild acute COVID-19 and never required hospitalization to investigate their plasma proteome. Using the SomaLogic platform, SomaScan, the plasma concentration of >7000 proteins was measured from 92 unvaccinated individuals, including 48 NP patients, 20 COVID-19 convalescents (CC) without lingering symptoms, and 24 unexposed healthy controls (HC) to interrogate underlying pathobiology and potential biomarkers of PASC. We analyzed the plasma proteome based on post-COVID-19 status, neurologic and non-neurologic symptoms, as well as subjective and objective standardized tests for changes in quality-of-life (QoL) and cognition associated with Neuro-PASC. The plasma proteome of NP patients differed from CC and HC subjects more substantially than post-COVID-19 groups (NP and CC combined) differed from HC. Proteomic differences in NP patients 3-9 months following acute COVID-19 showed alterations in inflammatory proteins and pathways relative to CC and HC subjects. Proteomic associations with Neuro-PASC symptoms of brain fog and fatigue included changes in markers of DNA repair, oxidative stress, and neutrophil degranulation. Furthermore, we discovered a correlation between NP patients lower subjective impression of recovery to pre-COVID-19 baseline with an increase in the concentration of the oxidative phosphorylation protein COX7A1, which was also associated with neurologic symptoms and fatigue, as well as impairment in QoL and cognitive dysfunction. Finally, we identified other oxidative phosphorylation-associated proteins correlating with central nervous system symptoms. Our results suggest ongoing inflammatory changes and mitochondrial involvement in Neuro-PASC and pave the way for biomarker validation for use in monitoring and development of therapeutic intervention for this debilitating condition.

Prenatal alcohol exposure and cognition at midlife: Evidence of fluid cognition deficits in two cohorts

BACKGROUND

Prenatal alcohol exposure (PAE) impacts cognition in childhood and early adulthood. Here we evaluate the cognitive abilities of middle-aged adults with and without a history of PAE.

METHODS

Participants (N = 200) were recruited from longitudinal cohorts in the Atlanta and Seattle metropolitan areas and completed measures comprising the National Institutes of Health Toolbox's Fluid Cognition Composite.

RESULTS

We found that individuals with PAE had lower Fluid Cognition Summary scores and lower Dimensional Change Card Sort and Flanker task subtest scores than non-PAE controls, after accounting for both potentially confounding demographic variables using propensity scores and the effects of study site. When we evaluated the effects of PAE with and without dysmorphic physical features, we found that middle-aged adults in both groups had lower fluid cognition scores than non-PAE controls. However, only the presence of PAE with dysmorphic features was associated with lower performance on the Dimensional Change Card Sort Test and Flanker tasks.

CONCLUSION

While all participants with PAE had lower fluid cognition, those with PAE and dysmorphic features also exhibited specific deficits in their performance on measures of inhibition, attention, and cognitive flexibility. Thus, PAE is associated with ongoing cognitive deficits in middle adulthood, which can be observed most clearly among individuals with dysmorphic features.

Executive Function and Processing Speed in Children Living with Sickle Cell Anemia

Executive function and processing speed difficulties are observed in children living with sickle cell anemia (SCA). The influence of processing speed on executive function is not well understood. We recruited 59 children living with SCA and 24 matched controls aged 8-18 years between 2010 and 2016 from clinics in the UK. Children completed tests in processing speed and cognitive flexibility, subdomains of executive function. MRI scans were conducted within one year of testing; oxygen saturation was obtained on the day of testing. Hemoglobin levels were obtained from medical records. Caregivers completed the executive function questionnaire. Hierarchical linear regressions found that hemoglobin, oxygen saturation, age, infarct status, and processing speed were not independent predictors for any model. However, for all cognitive flexibility tests, there was a significant interaction between infarct status and processing speed; children without silent cerebral infarction (SCI) with faster processing speed had better cognitive flexibility. Our findings indicate that, when interpreting executive function difficulties, it is important to account for the relationship between SCI status and processing speed. More research is needed to elucidate the mechanisms, but clinically, including executive function testing as part of clinic visits by embedding psychologists within the healthcare team would appear to be a critical step.

Relation of resting brain signal variability to cognitive and socioemotional measures in an adult lifespan sample

Temporal variability of the fMRI-derived blood-oxygen-level-dependent (BOLD) signal during cognitive tasks shows important associations with individual differences in age and performance. Less is known about relations between spontaneous BOLD variability measured at rest and relatively stable cognitive measures, such as IQ or socioemotional function. Here, we examined associations among resting BOLD variability, cognitive/socioemotional scores from the NIH Toolbox and optimal time of day for alertness (chronotype) in a sample of 157 adults from 20 to 86 years of age. To investigate individual differences in these associations independently of age, we regressed age out from both behavioral and BOLD variability scores. We hypothesized that greater BOLD variability would be related to higher fluid cognition scores, more positive scores on socioemotional scales and a morningness chronotype. Consistent with this idea, we found positive correlations between resting BOLD variability, positive socioemotional scores (e.g. self-efficacy) and morning chronotype, as well as negative correlations between variability and negative emotional scores (e.g. loneliness). Unexpectedly, we found negative correlations between BOLD variability and fluid cognition. These results suggest that greater resting brain signal variability facilitates optimal socioemotional function and characterizes those with morning-type circadian rhythms, but individuals with greater fluid cognition may be more likely to show less temporal variability in spontaneous measures of BOLD activity.

Three-month Practice Effect of the National Institutes of Health Toolbox Cognition Battery in Young Healthy Adults

The National Institutes of Health Toolbox-Cognition Battery (NIHTB-CB) is a tablet-based cognitive assessment intended for individuals with neurological diseases of all ages. NIHTB-CB practice effects (PEs), however, need clarification if this measure is used to track longitudinal change. We explored the test-retest PEs on NIHTB-CB performance at 3 months in young healthy adults (n = 22). We examined corrected T-scores normalized for demographic factors and calculated PEs using Cohen's d. There were significant PEs for all NIHTB-CB composite scores and on 4/7 subtests. This work suggests the need to further assess NIHTB-CB PEs as this may affect the interpretation of study results incorporating this battery.

Dose-Response of Creatine Supplementation on Cognitive Function in Healthy Young Adults

To determine if creatine (Cr) supplementation could influence cognitive performance and whether any changes were related to changes in prefrontal cortex (PFC) activation during such cognitive tasks, thirty (M = 11, F = 19) participants were evenly randomized to receive supplementation with Cr (CR10:10 g/day or CR20:20 g/day) or a placebo (PLA:10 g/day) for 6 weeks. Participants completed a cognitive test battery (processing speed, episodic memory, and attention) on two separate occasions prior to and following supplementation. Functional near-infrared spectroscopy (fNIRS) was used to measure PFC oxyhemoglobin (O2Hb) during the cognitive evaluation. A two-way repeated measures ANOVA was used to determine the differences between the groups and the timepoints for the cognitive performance scores and PFC O2Hb. In addition, a one-way ANOVA of % change was used to determine pre- and post-differences between the groups. Creatine (independent of dosage) had no significant effect on the measures of cognitive performance. There was a trend for decreased relative PFC O2Hb in the CR10 group versus the PLA group in the processing speed test (p = 0.06). Overall, six weeks of Cr supplementation at a moderate or high dose does not improve cognitive performance or change PFC activation in young adults.

Metabolic syndrome and adiposity: Risk factors for decreased myelin in cognitively healthy adults

Metabolic syndrome (MetS) is a cluster of conditions that affects ∼25% of the global population, including excess adiposity, hyperglycemia, dyslipidemia, and elevated blood pressure. MetS is one of major risk factors not only for chronic diseases, but also for dementia and cognitive dysfunction, although the underlying mechanisms remain poorly understood. White matter is of particular interest in the context of MetS due to the metabolic vulnerability of myelin maintenance, and the accumulating evidence for the importance of the white matter in the pathophysiology of dementia. Therefore, we investigated the associations of MetS risk score and adiposity (combined body mass index and waist circumference) with myelin water fraction measured with myelin water imaging. In 90 cognitively and neurologically healthy adults (20-79 years), we found that both high MetS risk score and adiposity were correlated with lower myelin water fraction in late-myelinating prefrontal and associative fibers, controlling for age, sex, race, ethnicity, education and income. Our findings call for randomized clinical trials to establish causality between MetS, adiposity, and myelin content, and to explore the potential of weight loss and visceral adiposity reduction as means to support maintenance of myelin integrity throughout adulthood, which could open new avenues for prevention or treatment of cognitive decline and dementia.

Different patterns of intrinsic functional connectivity at the default mode and attentional networks predict crystalized and fluid abilities in childhood

Crystallized abilities are skills used to solve problems based on experience, while fluid abilities are linked to reasoning without evoke prior knowledge. To what extent crystallized and fluid abilities involve dissociated or overlapping neural systems is debatable. Due to often deployed small sample sizes or different study settings in prior work, the neural basis of crystallized and fluid abilities in childhood remains largely unknown. Here we analyzed within and between network connectivity patterns from resting-state functional MRI of 2707 children between 9 and 10 years from the ABCD study. We hypothesized that differences in functional connectivity at the default mode network (DMN), ventral, and dorsal attentional networks (VAN, DAN) explain differences in fluid and crystallized abilities. We found that stronger between-network connectivity of the DMN and VAN, DMN and DAN, and VAN and DAN predicted crystallized abilities. Within-network connectivity of the DAN predicted both crystallized and fluid abilities. Our findings reveal that crystallized abilities rely on the functional coupling between attentional networks and the DMN, whereas fluid abilities are associated with a focal connectivity configuration at the DAN. Our study provides new evidence into the neural basis of child intelligence and calls for future comparative research in adulthood during neuropsychiatric diseases.

Accelerated epigenetic aging in older adults with HIV disease: associations with serostatus, HIV clinical factors, and health literacy

The prevalence of older persons with HIV (PWH) disease has increased considerably in the last 20 years, but our understanding of biological factors of aging and their clinical correlates among PWH remains limited. Study participants were 149 persons aged 50 and older, including 107 PWH and 42 seronegatives. All participants completed a blood draw, research medical evaluation, structured psychiatric interview, neurocognitive assessment, questionnaires, and measures of health literacy. Four epigenetic clocks were generated from stored blood samples using standardized laboratory methods. In regression models adjusting for sex and smoking status, PWH had significantly higher epigenetic aging acceleration values than seronegatives on all four indicators. Within the PWH sample, higher levels of epigenetic aging acceleration were moderately associated with lower current CD4 count, AIDS diagnoses, higher scores on the Veterans Aging Cohort Study Index, and lower telomere values. Higher epigenetic aging acceleration indices were also associated with lower health literacy among PWH. PWH experience accelerated aging as measured by a series of epigenetic clocks, which may be linked to immune compromise and risk of all-cause mortality. Health literacy may be a modifiable target for mitigating the risk of accelerated aging among older PWH.

Silent cerebral infarction during immune TTP remission: prevalence, predictors, and impact on cognition

Immune thrombotic thrombocytopenic purpura (iTTP) survivors have increased risk of cardiovascular disease, including strokes, and report persistent cognitive difficulties during remission. We conducted this prospective study involving iTTP survivors during clinical remission to determine the prevalence of silent cerebral infarction (SCI), defined as magnetic resonance imaging (MRI) evidence of brain infarction without corresponding overt neurodeficits. We also tested the hypothesis that SCI is associated with cognitive impairment, assessed using the National Institutes of Health ToolBox Cognition Battery. For cognitive assessments, we used fully corrected T scores adjusted for age, sex, race, and education. Based on the diagnostic and statistical manual 5 criteria, we defined mild and major cognitive impairment as T scores with a 1 or 2 standard deviation (SD) and >2 SD below the mean on at least 1 test, respectively. Forty-two patients were enrolled, with 36 completing MRIs. SCI was present in 50% of the patients (18), of which 8 (44.4%) had prior overt stroke including during acute iTTP. Patients with SCI had higher rates of cognitive impairment (66.7% vs 27.7%; P = .026), including major cognitive impairment (50% vs 5.6%; P = .010). In separate logistic regression models, SCI was associated with any (mild or major) cognitive impairment (odds ratio [OR] 10.5 [95% confidence interval (95% CI), 1.45-76.63]; P = .020) and major cognitive impairment (OR 7.98 [95% CI, 1.11-57.27]; P = .039) after adjusting for history of stroke and Beck depression inventory scores. MRI evidence of brain infarction is common in iTTP survivors; the strong association of SCI with impaired cognition suggests that these silent infarcts are neither silent nor innocuous.

Comparison of Various Metrics of Repetitive Head Impact Exposure And Their Associations With Neurocognition in Collegiate-Aged Athletes

OBJECTIVE

Characterize the levels of various metrics of repetitive head impacts (RHI) in contact (CS) and non-contact (NCS) sport athletes and determine the extent to which they are associated with fluid cognition.

METHODS

Collegiate-aged athletes (n = 176) completed semi-structured interviews about participation in contact sport. RHI was operationalized based on current sport (CS/NCS), the cumulative number of years of participation, age at first exposure (AFE), and based on recently proposed traumatic encephalopathy syndrome (TES) categories. The NIH Toolbox Cognition Battery assessed fluid cognition. General linear models compared RHI metrics between CS and NCS athletes and tested associations of RHI measures with fluid cognition.

RESULTS

CS athletes had more years of RHI exposure, higher rates of "extensive" exposure based on TES criteria, and were more likely to have AFE before age 12 relative to NCS (ps < .001). A subset of NCS athletes, however, reported prior RHI at levels categorized as being "extensive" based on TES criteria (5%), while a larger minority had AFE before 12 (34%). No adverse associations of RHI and fluid cognition were observed (ps > .05). Across all RHI metrics, more or earlier RHI was associated with better episodic memory (ps ≤ .05). Secondary analyses showed this effect was driven by women.

CONCLUSIONS

Current results find no evidence that RHI in collegiate-aged athletes is associated with worse neurocognition. Although there was extensive overlap among RHI measures, results demonstrate that categorizing athletes based on their current sport undercounts the lifetime RHI exposure in many NCS athletes.

Neurologic Manifestations of Long COVID Differ Based on Acute COVID-19 Severity

OBJECTIVE

To characterize neurologic manifestations in post-hospitalization Neuro-PASC (PNP) and non-hospitalized Neuro-PASC (NNP) patients.

METHODS

Prospective study of the first 100 consecutive PNP and 500 NNP patients evaluated at a Neuro-COVID-19 clinic between 5/2020 and 8/2021.

RESULTS

PNP were older than NNP patients (mean 53.9 vs 44.9 y; p < 0.0001) with a higher prevalence of pre-existing comorbidities. An average 6.8 months from onset, the main neurologic symptoms were "brain fog" (81.2%), headache (70.3%), and dizziness (49.5%) with only anosmia, dysgeusia and myalgias being more frequent in the NNP compared to the PNP group (59 vs 39%, 57.6 vs 39% and 50.4 vs 33%, all p < 0.003). Moreover, 85.8% of patients experienced fatigue. PNP more frequently had an abnormal neurologic exam than NNP patients (62.2 vs 37%, p < 0.0001). Both groups had impaired quality of life in cognitive, fatigue, sleep, anxiety, and depression domains. PNP patients performed worse on processing speed, attention, and working memory tasks than NNP patients (T-score 41.5 vs 55, 42.5 vs 47 and 45.5 vs 49, all p < 0.001) and a US normative population. NNP patients had lower results in attention task only. Subjective impression of cognitive ability correlated with cognitive test results in NNP but not in PNP patients.

INTERPRETATION

PNP and NNP patients both experience persistent neurologic symptoms affecting their quality of life. However, they harbor significant differences in demographics, comorbidities, neurologic symptoms and findings, as well as pattern of cognitive dysfunction. Such differences suggest distinct etiologies of Neuro-PASC in these populations warranting targeted interventions. ANN NEUROL 2023;94:146-159.

Validity of the NIH toolbox cognitive battery in a healthy oldest-old 85+ sample

OBJECTIVE

To evaluate the construct validity of the NIH Toolbox Cognitive Battery (NIH TB-CB) in the healthy oldest-old (85+ years old).

METHOD

Our sample from the McKnight Brain Aging Registry consists of 179 individuals, 85 to 99 years of age, screened for memory, neurological, and psychiatric disorders. Using previous research methods on a sample of 85 + y/o adults, we conducted confirmatory factor analyses on models of NIH TB-CB and same domain standard neuropsychological measures. We hypothesized the five-factor model (Reading, Vocabulary, Memory, Working Memory, and Executive/Speed) would have the best fit, consistent with younger populations. We assessed confirmatory and discriminant validity. We also evaluated demographic and computer use predictors of NIH TB-CB composite scores.

RESULTS

Findings suggest the six-factor model (Vocabulary, Reading, Memory, Working Memory, Executive, and Speed) had a better fit than alternative models. NIH TB-CB tests had good convergent and discriminant validity, though tests in the executive functioning domain had high inter-correlations with other cognitive domains. Computer use was strongly associated with higher NIH TB-CB overall and fluid cognition composite scores.

CONCLUSION

The NIH TB-CB is a valid assessment for the oldest-old samples, with relatively weak validity in the domain of executive functioning. Computer use's impact on composite scores could be due to the executive demands of learning to use a tablet. Strong relationships of executive function with other cognitive domains could be due to cognitive dedifferentiation. Overall, the NIH TB-CB could be useful for testing cognition in the oldest-old and the impact of aging on cognition in older populations.

Cognitive Training Improves Joint Stiffness Regulation and Function in ACLR Patients Compared to Healthy Controls

As cognitive function is critical for muscle coordination, cognitive training may also improve neuromuscular control strategy and knee function following an anterior cruciate ligament reconstruction (ACLR). The purpose of this case-control study was to examine the effects of cognitive training on joint stiffness regulation in response to negative visual stimuli and knee function following ACLR. A total of 20 ACLR patients and 20 healthy controls received four weeks of online cognitive training. Executive function, joint stiffness in response to emotionally evocative visual stimuli (neutral, fearful, knee injury related), and knee function outcomes before and after the intervention were compared. Both groups improved executive function following the intervention (p = 0.005). The ACLR group had greater mid-range stiffness in response to fearful (p = 0.024) and injury-related pictures (p = 0.017) than neutral contents before the intervention, while no post-intervention stiffness differences were observed among picture types. The ACLR group showed better single-legged hop for distance after cognitive training (p = 0.047), while the healthy group demonstrated no improvement. Cognitive training enhanced executive function, which may reduce joint stiffness dysregulation in response to emotionally arousing images and improve knee function in ACLR patients, presumably by facilitating neural processing necessary for neuromuscular control.

Intensive assessment of executive functions derived from performance in cognitive training games

Traditional neuropsychological tests accurately describe the current cognitive state but fall short to characterize cognitive change over multiple short time periods. We present an innovative approach to remote monitoring of executive functions on a monthly basis, which leverages the performance indicators from self-administered computerized cognitive training games (NUP-EXE). We evaluated the measurement properties of NUP-EXE in N = 56 individuals (59% women, 60-80 years) at increased risk of Alzheimer's disease (APOE-ϵ4 carriers with subjective cognitive decline) who completed a 12-month multimodal intervention for preventing cognitive decline. NUP-EXE presented good psychometric properties and greater sensitivity to change than traditional tests. Improvements in NUP-EXE correlated with improvements in functionality and were affected by participants' age and gender. This novel data collection methodology is expected to allow a more accurate characterization of an individual's response to a cognitive decline preventive intervention and to inform development of outcome measures for a new generation of intervention trials.

Graph-matching distance between individuals' functional connectomes varies with relatedness, age, and cognitive score

Functional connectomes (FCs), represented by networks or graphs that summarize coactivation patterns between pairs of brain regions, have been related at a population level to age, sex, cognitive/behavioral scores, life experience, genetics, and disease/disorders. However, quantifying FC differences between individuals also provides a rich source of information with which to map to differences in those individuals' biology, experience, genetics or behavior. In this study, graph matching is used to create a novel inter-individual FC metric, called swap distance, that quantifies the distance between pairs of individuals' partial FCs, with a smaller swap distance indicating the individuals have more similar FC. We apply graph matching to align FCs between individuals from the the Human Connectome ProjectN = 997 and find that swap distance (i) increases with increasing familial distance, (ii) increases with subjects' ages, (iii) is smaller for pairs of females compared to pairs of males, and (iv) is larger for females with lower cognitive scores compared to females with larger cognitive scores. Regions that contributed most to individuals' swap distances were in higher-order networks, that is, default-mode and fronto-parietal, that underlie executive function and memory. These higher-order networks' regions also had swap frequencies that varied monotonically with familial relatedness of the individuals in question. We posit that the proposed graph matching technique provides a novel way to study inter-subject differences in FC and enables quantification of how FC may vary with age, relatedness, sex, and behavior.

Brain working memory network indices as landmarks of intelligence

Identifying the neural correlates of intelligence has long been a goal in neuroscience. Recently, the field of network neuroscience has attracted researchers' attention as a means for answering this question. In network neuroscience, the brain is considered as an integrated system whose systematic properties provide profound insights into health and behavioral outcomes. However, most network studies of intelligence have used univariate methods to investigate topological network measures, with their focus limited to a few measures. Furthermore, most studies have focused on resting state networks despite the fact that brain activation during working memory tasks has been linked to intelligence. Finally, the literature is still missing an investigation of the association between network assortativity and intelligence. To address these issues, here we employ a recently developed mixed-modeling framework for analyzing multi-task brain networks to elucidate the most critical working memory task network topological properties corresponding to individuals' intelligence differences. We used a data set of 379 subjects (22-35 y/o) from the Human Connectome Project (HCP). Each subject's data included composite intelligence scores, and fMRI during resting state and a 2-back working memory task. Following comprehensive quality control and preprocessing of the minimally preprocessed fMRI data, we extracted a set of the main topological network features, including global efficiency, degree, leverage centrality, modularity, and clustering coefficient. The estimated network features and subject's confounders were then incorporated into the multi-task mixed-modeling framework to investigate how brain network changes between working memory and resting state relate to intelligence score. Our results indicate that the general intelligence score (cognitive composite score) is associated with a change in the relationship between connection strength and multiple network topological properties, including global efficiency, leverage centrality, and degree difference during working memory as it is compared to resting state. More specifically, we observed a higher increase in the positive association between global efficiency and connection strength for the high intelligence group when they switch from resting state to working memory. The strong connections might form superhighways for a more efficient global flow of information through the brain network. Furthermore, we found an increase in the negative association between degree difference and leverage centrality with connection strength during working memory tasks for the high intelligence group. These indicate higher network resilience and assortativity along with higher circuit-specific information flow during working memory for those with a higher intelligence score. Although the exact neurobiological implications of our results are speculative at this point, our results provide evidence for the significant association of intelligence with hallmark properties of brain networks during working memory.

Intelligence Polygenic Score Is More Predictive of Crystallized Measures: Evidence From the Adolescent Brain Cognitive Development (ABCD) Study

Findings in adults have shown that crystallized measures of intelligence, which are more culturally sensitive than fluid intelligence measures, have greater heritability; however, these results have not been found in children. The present study used data from 8,518 participants between 9 and 11 years old from the Adolescent Brain Cognitive Development (ABCD) Study. We found that polygenic predictors of intelligence test performance (based on genome-wide association meta-analyses of data from 269,867 individuals) and of educational attainment (based on data from 1.1 million individuals) predicted neurocognitive performance. We found that crystallized measures were more strongly associated with both polygenic predictors than were fluid measures. This mirrored heritability differences reported previously in adults and suggests similar associations in children. This may be consistent with a prominent role of gene-environment correlation in cognitive development measured by crystallized intelligence tests. Environmental and experiential mediators may represent malleable targets for improving cognitive outcomes.

Human and chimpanzee shared and divergent neurobiological systems for general and specific cognitive brain functions

A long-standing topic of interest in human neurosciences is the understanding of the neurobiology underlying human cognition. Less commonly considered is to what extent such systems may be shared with other species. We examined individual variation in brain connectivity in the context of cognitive abilities in chimpanzees (n = 45) and humans in search of a conserved link between cognition and brain connectivity across the two species. Cognitive scores were assessed on a variety of behavioral tasks using chimpanzee- and human-specific cognitive test batteries, measuring aspects of cognition related to relational reasoning, processing speed, and problem solving in both species. We show that chimpanzees scoring higher on such cognitive skills display relatively strong connectivity among brain networks also associated with comparable cognitive abilities in the human group. We also identified divergence in brain networks that serve specialized functions across humans and chimpanzees, such as stronger language connectivity in humans and relatively more prominent connectivity between regions related to spatial working memory in chimpanzees. Our findings suggest that core neural systems of cognition may have evolved before the divergence of chimpanzees and humans, along with potential differential investments in other brain networks relating to specific functional specializations between the two species.

Two sides of the same coin: distinct neuroanatomical patterns predict crystallized and fluid intelligence in adults

Background

Crystallized intelligence (Gc) and fluid intelligence (Gf) are regarded as distinct intelligence components that statistically correlate with each other. However, the distinct neuroanatomical signatures of Gc and Gf in adults remain contentious.

Methods

Machine learning cross-validated elastic net regression models were performed on the Human Connectome Project Young Adult dataset (N = 1089) to characterize the neuroanatomical patterns of structural magnetic resonance imaging variables that are associated with Gc and Gf. The observed relationships were further examined by linear mixed-effects models. Finally, intraclass correlations were computed to examine the similarity of the neuroanatomical correlates between Gc and Gf.

Results

The results revealed distinct multi-region neuroanatomical patterns predicted Gc and Gf, respectively, which were robust in a held-out test set (R² = 2.40, 1.97%, respectively). The relationship of these regions with Gc and Gf was further supported by the univariate linear mixed effects models. Besides that, Gc and Gf displayed poor neuroanatomical similarity.

Conclusion

These findings provided evidence that distinct machine learning-derived neuroanatomical patterns could predict Gc and Gf in healthy adults, highlighting differential neuroanatomical signatures of different aspects of intelligence.