Integration of sex/gender and utilization of ecological Momentary assessment of cognition in clinical populations: a scoping review.

Objectives: We aimed to describe the methods of smartphone-based cognitive ecological momentary assessment designs in clinical populations, with an intention to evaluate how the role of sex and/or gender has been considered in the design and analyses, particularly including female-specific physiology. Methods: This scoping review was conducted based on JBI scoping review methodology. On March 2nd, 2023, we searched for literature across four databases. Screening of the results and data extraction were conducted in duplicate according to the a priori methods in the pre-registered protocol. Results: 31 articles were included in this review. Participants ranged in age from 15-85 years old with various clinical disorders. Prompts were given between 1-7 times per day for 7-84 days. Executive function was the most frequently assessed cognitive domain. Over half the studies (n = 17, 55%) did not investigate the effects of sex and/or gender, and only one study considered the impact of hormonal therapy. Many studies (n = 14, 45%) used sex and gender interchangeably or incorrectly. Conclusions: Studies varied in design, with heterogeneity in the reporting of methodological information. The lack of attention to sex/gender on neuropsychological outcomes can lead to confusion and contradiction regarding its potential impact on cognition in clinical populations. This may hinder the identification of effective interventions for those assigned female at birth who have been overlooked or considered indistinguishable from their male counterparts. Given the well-documented impact of sex/gender on cognition, it is essential that future neuropsychological research, especially EMA-based studies, prioritize investigating sex/gender to ensure better outcomes for all.

Virtual Reality and Serious Videogame-Based Instruments for Assessing Spatial Navigation in Alzheimer's Disease: A Systematic Review of Psychometric Properties.

Over the past decade, research using virtual reality and serious game-based instruments for assessing spatial navigation and spatial memory in at-risk and AD populations has risen. We systematically reviewed the literature since 2012 to identify and evaluate the methodological quality and risk of bias in the analyses of the psychometric properties of VRSG-based instruments. The search was conducted primarily in July-December 2022 and updated in November 2023 in eight major databases. The quality of instrument development and study design were analyzed in all studies. Measurement properties were defined and analyzed according to COSMIN guidelines. A total of 1078 unique records were screened, and following selection criteria, thirty-seven studies were analyzed. From these studies, 30 instruments were identified. Construct and criterion validity were the most reported measurement properties, while structural validity and internal consistency evidence were the least reported. Nineteen studies were deemed very good in construct validity, whereas 11 studies reporting diagnostic accuracy were deemed very good in quality. Limitations regarding theoretical framework and research design requirements were found in most of the studies. VRSG-based instruments are valuable additions to the current diagnostic toolkit for AD. Further research is required to establish the psychometric performance and clinical utility of VRSG-based instruments, particularly the instrument development, content validity, and diagnostic accuracy for preclinical AD screening scenarios. This review provides a straightforward synthesis of the state of the art of VRSG-based instruments and suggests future directions for research.

Associations of physical activity and history of sports participation with subjective and objective measures of executive functioning in university students.

This study examined how physical activity and history of sports participation affect subjective and objective executive functioning in university students. A total of 215 university students aged 18-25 (81% female) completed a virtual assessment of executive function. The correlates were age, sex, physical activity, and history of sports participation. Structural equation modeling was used to examine objective executive function using a three-factor model (shifting, updating, inhibition). The Executive Function Index (EFI) was used to measure subjective executive functioning, and linear regression was used to examine total EFI scores. Physical activity (b = 0.12, p < .01) was a significant correlate of subjective but not objective executive functioning. Male sex and history of sports participation were significantly positively related to the objective measure of inhibition (b = 0.64, p < .01; b = 0.18, p < .05). These findings suggest that subjective and objective measures of executive functioning should be differentiated when investigating their relationship with physical activity and history of sports participation.

Electrophysiological variability during tests of executive functioning: A comparison of athletes with and without concussion and sedentary control participants.

OBJECTIVE: Sport participation may benefit executive functioning (EF), but EF can also be adversely affected by concussion, which can occur during sport participation. Neural variability is an emerging proxy of brain health that indexes the brain's range of possible responses to incoming stimuli (i.e., dynamic range) and interconnectedness, but has yet to be characterized following concussion among athletes. This study examined whether neural variability was enhanced by athletic participation and attenuated by concussion. METHOD: Seventy-seven participants (18-25 years-old) were classified as sedentary controls (n = 33), athletes with positive concussion history (n = 21), or athletes without concussion (n = 23). Participants completed tests of attention switching, response inhibition, and updating working memory while undergoing electroencephalography recordings to index neural variability. RESULTS: Compared to sedentary controls and athletes without concussion, athletes with concussion exhibited a restricted whole-brain dynamic range of neural variability when completing a test of inhibitory control. There were no group differences observed for either the switching or working memory tasks. CONCLUSIONS: A history of concussion was related to reduced dynamic range of neural activity during a task of response inhibition in young adult athletes. Neural variability may have value for evaluating brain health following concussion.

Psilocybin's effects on cognition and creativity: A scoping review.

BACKGROUND: Research on psilocybin has become increasingly popular during the current psychedelic renaissance, which began in the early 1990s. Psilocybin's effects on mental health are promising and there are ongoing efforts to investigate its clinical implementation and its effects on cognition. AIMS: The purpose of this study is to report trends in publications, methods, and findings from research examining the effects of psilocybin on cognition and creativity in adults. METHODS: We conducted an Open Science Framework preregistered scoping review, guided by the JBI Manual for Evidence Synthesis, on literature pertaining to psilocybin's effects on cognition and creativity. RESULTS/OUTCOMES: In the 42 included studies, psilocybin was primarily administered orally (83%) in a bodyweight-adjusted manner (74%) to healthy participants (90%). Of the few studies that explicitly reported safety outcomes (26%), only one reported serious adverse reactions. During the acute phase post-intake (i.e., minutes to hours), macrodoses tended to impair cognitive performance and creativity, whereas microdoses tended toward creative enhancement. The few macrodosing studies that included post-acute measures (i.e., 1-85 days) reported primarily null but some positive effects. CONCLUSIONS/INTERPRETATION: This scoping review identified a time-based variation of psilocybin macrodosing effects on cognition and creativity, in which impairment may be observed early post-intake but withdraw over time, and some positive effects may emerge afterward. These findings are limited by methodological concerns and inadequate assessment of long-term effects. We therefore recommend that future psilocybin research be conducted according to existing guidelines and include well-validated measures of cognition and creativity at multiple timepoints.

Associations between physical activity, affect regulation difficulties, and mental health among Canadian adolescents at two different points of the COVID-19 pandemic.

Objective. Although physical activity declined with social distancing measures and stay-at-home orders during the COVID-19 pandemic, youth who engaged in more physical activity experienced fewer mental health problems. If and how physical activity maintained its protective role throughout the ongoing pandemic remains unclear. This study models associations between three types of physical activity (indoor, outdoor, with parents), affect regulation, and anxious and depressive symptoms in two independent adolescent samples (T1: Summer 2020; T2: Winter 2020/21).Methods and Measures. Six hundred sixty-two Canadian adolescents (T1: Mage = 15.69, SD = 1.36; 52% girls; 5% trans+) and 675 Canadian adolescents (T2: Mage = 15.80, SD = 1.46; 50% girls; 6% trans+) participated in an online survey. Data included frequency of physical activity indoors, outdoors, and with parents, affect regulation difficulties, and measures of anxious and depressive symptoms.Results. Multiple-group path analysis showed indoor physical activity had an indirect effect on anxiety and depressive symptoms through affect dysregulation, but only at T1. Physical activity with parents was protective for adolescent anxiety and depressive symptoms at both T1 and T2 and had an indirect effect through affect dysregulation and suppression.Conclusion. Findings contribute to our understanding of how physical activity protects adolescent mental health, and point to strengthening family supports and recreation opportunities.

Current Posttraumatic Stress Symptoms Mediate the Relationship Between Adverse Childhood Experiences and Executive Functions.

Adverse childhood experiences (ACEs) and posttraumatic stress disorder (PTSD) are both associated with lower performances on executive function tasks. However, few researchers have evaluated ACEs, posttraumatic stress (PTS) symptoms, and executive function difficulties in conjunction. Using an online micropayment service, the current study assessed whether PTS symptoms mediated the relationship between ACEs and executive functions. In total, 83 participants (54.2% female, age: M = 28.86, SD = 7.71) were administered the ACE questionnaire, PTSD Checklist for DSM-5 (PCL-5), and the Executive Function Index (EFI). A higher number of reported ACEs was related to greater PTS symptom severity (ß = .40, p < .001) and worse self-rated executive functions (ß = -.32, p = .002). Controlling for the number of reported ACEs, current PTS symptom severity was related to worse executive functions (ß = -.45, p < .001). A bootstrapped 95% confidence interval (CI) indicated a significant indirect effect, ß = -.18 (95% CI: -.30, -.08), by which current PTS symptoms mediated the relationship between the number of reported ACEs and executive functions. These results suggest that psychological interventions targeting PTS symptoms, in the context of a history of childhood trauma, may concurrently improve executive functions in adult populations.

Intraindividual variability in executive and motor control tasks in children with attention deficit hyperactivity disorder.

OBJECTIVE: Emerging evidence highlights intraindividual variability (IIV) during executive function (EF) tasks as a reliable endophenotype of Attention Deficit/Hyperactivity Disorder (ADHD) and as contributing to motor dysregulation and hyperactive-impulsive behaviors. This study examined the relationship between EF and motor control in children with and without ADHD. METHOD: Ninety-seven children (6-13 years) completed standardized and experimental tasks of executive and motor control. Primary caregivers completed a semi-structured interview, and behavioral rating forms for ADHD symptoms and EF. RESULTS: Children with ADHD demonstrated lower performance on motor dexterity and sequencing tasks, and greater IIV during EF tasks with lower cognitive demand. IIV accounted for ADHD symptoms of hyperactivity, beyond age and motor dexterity. IIV from EF measures with lower cognitive demand was also sensitive to ADHD symptoms. CONCLUSION: IIV metrics may tap into the motor regulation challenges associated with ADHD, as well as attentional lapsing at lower levels of cognitive demand.

Sensitivity and Specificity of an Executive Function Screener at Identifying Children With ADHD and Reading Disability.

Objective: This study evaluated the sensitivity/specificity of a global sum score (GSS) from the Behavior Assessment System for Children, Second Edition, Executive Function screener (BASC-2-EF) at classifying children with/without ADHD and/or reading disability (RD). Method: The BASC-2 Teacher/Parent Rating Scales (TRS/PRS) were completed for children (8-12 years old; 43.1% female) with no diagnosis (n = 53), RD (n = 34), ADHD (n = 85), co-morbid RD/ADHD (n = 36), and other diagnoses (n = 15). Receiver operating characteristic (ROC) curve analyses evaluated the sensitivity/specificity of the BASC-2-EF GSS at discriminating between children with/without ADHD or RD. Results: Area under the curve (AUC) scores indicated the sensitivity/specificity of the BASC-2-EF GSS at discriminating between children with/without ADHD (TRS: AUC = .831, p < .001; PRS: AUC = .919, p < .001), with/without RD (TRS: AUC = .724, p = .001; PRS: AUC = .615, p = .101), and with ADHD or RD through post hoc analysis (TRS: AUC = .674, p = .006; PRS: AUC = .819, p < .001). Conclusion: The findings support utilizing the BASC-2-EF GSS when differentiating ADHD from RD and typical development.

Heading in the Right Direction: A Critical Review of Studies Examining the Effects of Heading in Soccer Players.

The practice of heading in soccer has become a public concern because of the potential for subconcussive impacts to cause cumulative concussive-like effects; however, experimental evidence for this hypothesis has been mixed. This systematic review used pre-defined search parameters to assess primary literature that examined changes in cognitive, behavioral, structural, and/or biological processes after acute heading exposure in youth and young adult soccer players. The findings were synthesized into a concise and comprehensive summary of the research following the preferred reporting items for systematic reviews and meta-analyses (PRISMA) format, and suggestions for standardization of acute heading protocols are described. A total of 1189 articles were considered for this review, with 19 articles meeting all of the inclusion criteria for full analysis. An attempt was made to identify methods with significant sensitivity and reliability by grouping studies based on their outcome measures. Because of lack of standardization across intervention types and data collection protocols, no sensitive and reliable methods could be identified conclusively to assess the effects of acute heading exposure in soccer players. Based on this review, there is not enough evidence to either support or refute the potential of effects of subconcussive events from acute soccer heading exposure. Recommendations for standardization of acute heading exposure studies based on the included literature are discussed. Standardization is required to better understand the impact of acute heading exposure in soccer players, while allowing for the development of guidelines that mitigate any potential risks and allowing athletes to remain active and develop their skills.

Personality and perceived stress during COVID-19 pandemic: Testing the mediating role of perceived threat and efficacy.

Prolonged stress is associated with poor physical and mental health outcomes. Understanding the mediators between personality and stress is critical for developing effective stress management interventions during a pandemic. Our study explored whether perceptions of threat from COVID-19 and efficacy to follow government recommendations for preventing COVID-19 would mediate the relationships between personality traits (e.g., neuroticism, conscientiousness-goal-striving, extroversion-activity and sociability) and perceived stress. In an online survey of a representative sample of Canadian adults (n = 1055), we found that higher neuroticism and extroversion were associated with higher levels of stress during the pandemic and a greater increase in stress levels compared to levels before the pandemic. Perceived threat and efficacy significantly mediated the relationship between neuroticism and stress, which suggested that individuals with higher neuroticism experienced higher levels of stress due to higher levels of perceived threat and lower levels of efficacy. Perceived threat did not mediate the relationship between extroverts and stress, which suggested that the source of stress may stem from elsewhere (e.g., inability to socialize). Our findings highlighted that personality traits could be an important factor in identifying stress-prone individuals during a pandemic and that stress management interventions need to be personality specific.

Preseason Baseline Neurocognitive Performances and Symptom Reporting on Immediate Post-Concussion Assessment and Cognitive Testing: A Comparison of Adolescent Student-Athletes Tested in Spanish and English.

CONTEXT: Student-athletes are commonly administered the Immediate Post-Concussion Assessment and Cognitive Testing (ImPACT) battery at preseason baseline and postconcussion. The ImPACT is available in many languages, but few researchers have examined differences in cognitive performances and symptom ratings based on the language of administration. OBJECTIVE: To examine differences in ImPACT neurocognitive composites and symptom reporting at preseason baseline testing between student-athletes who completed ImPACT in Spanish versus English. DESIGN: Cross-sectional study. SETTING: Preseason baseline testing for a high school concussion-management program in Maine. PATIENTS OR OTHER PARTICIPANTS: Adolescent student-athletes who completed testing in Spanish (n = 169) and English (n = 169) were matched on age, gender, and health and academic history. Language groups were compared on each outcome for the full sample and for gender-stratified subsamples. MAIN OUTCOME MEASURE(S): Neurocognitive composite scores and individual and total symptom severity ratings from the ImPACT battery. RESULTS: Athletes tested in Spanish displayed lower levels of neurocognitive performance on 2 of 5 composite scores (visual motor speed: P < .001, d = 0.51; reaction time: P = .004, d = 0.33) and reported greater symptom severity (P < .001, r = 0.21). When the analyses were stratified by gender, similar visual motor speed differences were observed between language groups among boys (P = .001, d = 0.49) and girls (P = .001, d = 0.49), whereas reaction time showed a larger group difference for boys (P = .012, d = 0.42) than for girls (P = .128, d = 0.21). Language-group differences in symptom reporting were similar for boys (P = .003, r = 0.22) and girls (P = .008, r = 0.21), with more frequent endorsement of physical and affective symptoms by athletes tested in Spanish. CONCLUSIONS: Language-group differences in total symptom severity were small (r = 0.21) and in neurocognitive performances were small to medium (d = 0.05-0.51). Versus previous authors who compared athletes tested in Spanish and English with ImPACT, we observed smaller effects, which may be attributable to close matching on variables related to neurocognitive performances and symptom reporting.

In it to win it: Competitiveness, concussion knowledge and nondisclosure in athletes.

OBJECTIVES: Despite having a general understanding of concussions, many athletes choose not to report symptoms of a sports-related concussion (SRC) which leads to a larger burden on our healthcare system due to longer recoveries, more Emergency Department visits, and future medical appointments. Thus, there is a need to identify factors, such as competitiveness, that may help to better explain the nondisclosure of concussion symptoms. The current study aimed to investigate the role of athletes' concussion knowledge and competitiveness on concussion nondisclosure. METHODS: Participants included 161 Canadian athletes (ages 14-32; 71% male) participating in collision sports (American football, rugby, hockey), soccer or rowing. Concussion knowledge, reporting and competitiveness were measured using the Rosenbaum Concussion Attitude and Knowledge Survey and Sports Orientation Questionnaire (SOQ). Two logistic regression models were performed to explain both history and future intention of playing despite experiencing concussion symptoms. RESULTS: Age, sex, and concussion knowledge were not significant for the regression models. The SOQ scores (measuring competitiveness) were significant for both regression models, such that higher competitiveness was associated with increased likelihood for past nondisclosure (b =.03, p =.03, OR = 1.03 (97.5% CI: 1.003,1.06)) and future nondisclosure intention (b =.05, p =.00, OR = 1.05 (97.5% CI: 1.03,1.08)). Regarding concussion knowledge, soccer players had significantly higher knowledge than those in collision sports and rugby, F(2, 158) = 140.5, p =.00; female athletes had significantly higher knowledge than males, t(66) = -4.26, p =.00; age was negatively associated with concussion knowledge (r = -0.35, p < .01). CONCLUSION: The results suggest that healthcare providers should be aware that athletes tend to have adequate concussion knowledge, but this knowledge does not explain past nondisclosure or future nondisclosure intention. Based on these findings, healthcare providers should focus on being able to identify highly competitive athletes who are most at risk of nondisclosure instead of exclusively aiming to increase concussion knowledge in athletes.

Correlates of Perceived Physical Activity Transitions during the COVID-19 Pandemic among Canadian Adults.

BACKGROUND: The purpose of this study was to explore socio-ecological predictors of moderate to vigorous physical activity (MVPA) as a result of the COVD-19 pandemic restrictions. METHOD: A representative sample of 1,055 English-speaking Canadians (18+ years) completed measures of MVPA during the COVID-19 restrictions and reflecting on MVPA prior to these restrictions, as well as demographics, COVID-19-related cognitions and behavior (i.e. perceived threat, social distancing), psychological factors (e.g. personality traits, habit, identity, strategic planning), social factors (e.g. dependent children, co-habitation), home environment affordances (exercise equipment, programming) and the neighborhood environment (e.g. access to outdoor recreation, neighborhood safety). RESULTS: Participants perceived that they had decreased weekly MVPA (p < .01) and the availability of home equipment and strategic planning were critical predictors (p < .01). Profiles by MVPA guidelines, however, showed that 58 per cent of the sample had not changed and 6 per cent had increased MVPA. Identity was the critical predictor of the different MVPA profiles, followed by habit, extraversion, availability of home equipment, and the age of the participant (p < .01). CONCLUSION: Pandemic restrictions have affected the MVPA of many Canadians, and variables across the socio-ecological spectrum explain who has been able to maintain MVPA during this unprecedented time.

Neuropsychological Impact of Trauma-Related Mental Illnesses: A Systematic Review of Clinically Meaningful Results.

A trauma history is present in approximately 90% of adults in the United States. Comparatively, lifetime post-traumatic stress disorder (PTSD) prevalence is only 8.3% (Kilpatrick et al. Journal of Traumatic Stress, 26, 537-547, 2013). A neuropsychological understanding of trauma is essential to effective trauma-informed assessments and treatments. Prior reviews have focused on PTSD, specific neuropsychological domains, and statistically rather than clinically significant results. The current systematic review investigated standardized test performance across neuropsychological domains in participants with trauma histories and any psychiatric diagnosis. The review was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. From 2350 records, the search returned 21 eligible studies: 8 for combat trauma, 2 for childhood trauma, 2 for intimate partner violence and sexual assault, 2 for accidental trauma, 1 for refugee trauma, and 6 for unspecified trauma. Mean neuropsychological scores ranged from low to high average, with one mean verbal memory score in the borderline range. These findings diverge from reports of between-group differences or experimental task performance, which suggest greater levels of static cognitive impairment. Current results are limited by lack of distinction between trauma types in the literature, a dearth of cognitive domains examined, wide use of self-report trauma measures, and publication and outcome reporting biases. Clinical implications for assessment and rehabilitation are discussed in relation to clinical significance, state versus trait based changes, intra-individual variability, changes from pre- to post-trauma, and within-group variability in resilience. Future directions are recommended in consideration of cultural factors, prospective and follow-up designs, and psychiatric diagnosis.

Developing an Executive Functioning Composite Score for Research and Clinical Trials.

OBJECTIVE: Executive functioning encompasses interactive cognitive processes such as planning, organization, set-shifting, inhibition, self-monitoring, working memory, and initiating and sustaining motor and mental activity. Researchers therefore typically assess executive functioning with multiple tests, each yielding multiple scores. A single composite score of executive functioning, which summarizes deficits across a battery of tests, would be useful in research and clinical trials. This study examines multiple candidate composite scores of executive functioning using tests from the Delis-Kaplan Executive Function System (D-KEFS). METHOD: Participants were 875 adults between the ages of 20 and 89 years from the D-KEFS standardization sample. Seven Total Achievement scores were used from three tests (i.e., Trail Making, Verbal Fluency, and Color-Word Interference) to form eight composite scores that were compared based on their psychometric properties and association with intelligence (IQ). RESULTS: The distributions of most composite scores were mildly to severely skewed, and some had a pronounced ceiling effect. The composite scores all showed a medium positive correlation with IQ. The composite scores were highly intercorrelated in the total sample and in four IQ subgroups (i.e., IQ <89, 90-99, 100-109, 110+), with some being so highly correlated that they appear redundant. CONCLUSIONS: This study is part of a larger research program developing a cognition endpoint for research and clinical trials with sound psychometric properties and utility across discrepant test batteries. Future research is needed to examine the reliability and ecological validity of these composite scores.

The Other Side of the Bell Curve: Multivariate Base Rates of High Scores on the Delis-Kaplan Executive Function System.

OBJECTIVE: Previous researchers have examined the frequency at which healthy participants obtain one or more low scores on neuropsychological test batteries, proposing five psychometric principles of multivariate base rates: (a) low scores are common, with their frequency contingent on (b) the low score cutoff used, (c) the number of tests administered/interpreted, and (d) the demographic characteristics and (e) intelligence of participants. The current study explored whether these principles applied to high scores as well, using the Delis-Kaplan Executive Function System (D-KEFS). METHOD: Multivariate base rates of high scores (≥75th, ≥84th, ≥91st, ≥95th, and ≥98th percentiles) were derived for a three-test, four-test, and full D-KEFS battery, using the adult portion of the normative sample (aged 16-89 years; N = 1050) stratified by education and intelligence. The full D-KEFS battery provides 16 total achievement scores (primary indicators of executive function). RESULTS: High scores occurred commonly for all batteries. For the three-test battery, 24.1% and 12.4% had 1 or more scores ≥95th percentile and ≥98th percentile, respectively. High scores occurred more often for longer batteries: 61.6%, 72.9%, and 87.8% obtained 1 or more scores ≥84th percentile for the three-test, four-test, and full batteries, respectively. The frequency of high scores increased with more education and higher intelligence. CONCLUSIONS: The principles of multivariate base rates also applied to high D-KEFS scores: high scores were common and contingent on the cutoff used, number of tests administered/interpreted, and education/intelligence of examinees. Base rates of high scores may help clinicians identify true cognitive strengths and detect cognitive deficits in high functioning people.

White Matter Integrity Is Associated With Intraindividual Variability in Neuropsychological Test Performance in Healthy Older Adults.

Inconsistency of performance across neuropsychological testing instruments (dispersion) shows sensitivity to acquired injury and neurodegenerative pathology in older adults. The underlying neural correlates have remained speculative however, in spite of known white matter degradation seen in conjunction with elevated inconsistency in related operationalizations of intraindividual variability. Consistently, these operationalizations have controlled for artifactual age-related variance to increase measurement sensitivity of CNS dysfunction. In this study, dispersion was examined alongside composite scores of memory and executive functioning from the Alzheimer's Disease Neuroimaging Initiative (ADNI). Forty-four healthy older adults (M = 72.0, SD = 6.4) underwent Diffusion Tensor Imaging (DTI) and neuropsychological testing spanning a range of cognitive domains. The results replicated previous findings, demonstrating reduced microstructural integrity with advanced age and increased integrity in high memory and executive functioning performers, across all major white matter tracts. With age first regressed from the composite scores, significant associations remained between greater executive functioning scores and greater microstructural integrity in the genu of the corpus callosum, right anterior corona radiata, anterior, posterior and rentrolenticular parts of right internal capsule, as well as right posterior thalamic radiation. With age regressed from the dispersion scores, greater values were primarily associated with decreased white matter integrity in the body and genu of corpus callosum, anterior corona radiata bilaterally and left superior longitudinal fasciculus. Dispersion is easily computed across speeded and accuracy-based measures and shows promise in detecting white matter damage, beyond that seen in the typical aging process. This appears to be the first investigation of neural correlates associated with increased dispersion.

Examining the Latent Structure of the Delis-Kaplan Executive Function System.

OBJECTIVE: The current study aimed to determine whether the Delis-Kaplan Executive Function System (D-KEFS) taps into three executive function factors (inhibition, shifting, fluency) and to assess the relationship between these factors and tests of executive-related constructs less often measured in latent variable research: reasoning, abstraction, and problem solving. METHOD: Participants included 425 adults from the D-KEFS standardization sample (20-49 years old; 50.1% female; 70.1% White). Eight alternative measurement models were compared based on model fit, with test scores assigned a priori to three factors: inhibition (Color-Word Interference, Tower), shifting (Trail Making, Sorting, Design Fluency), and fluency (Verbal/Design Fluency). The Twenty Questions, Word Context, and Proverb Tests were predicted in separate structural models. RESULTS: The three-factor model fit the data well (CFI = 0.938; RMSEA = 0.047), although a two-factor model, with shifting and fluency merged, fit similarly well (CFI = 0.929; RMSEA = 0.048). A bifactor model fit best (CFI = 0.977; RMSEA = 0.032) and explained the most variance in shifting indicators, but rarely converged among 5,000 bootstrapped samples. When the three first-order factors simultaneously predicted the criterion variables, only shifting was uniquely predictive (p < .05; R2 = 0.246-0.408). The bifactor significantly predicted all three criterion variables (p < .001; R2 = 0.141-242). CONCLUSIONS: Results supported a three-factor D-KEFS model (i.e., inhibition, shifting, and fluency), although shifting and fluency were highly related (r = 0.696). The bifactor showed superior fit, but converged less often than other models. Shifting best predicted tests of reasoning, abstraction, and problem solving. These findings support the validity of D-KEFS scores for measuring executive-related constructs and provide a framework through which clinicians can interpret D-KEFS results.

Resting State BOLD Variability Is Linked to White Matter Vascular Burden in Healthy Aging but Not in Older Adults With Subjective Cognitive Decline.

Background: Alzheimer's disease (AD) is the leading cause of dementia. A lack of curative treatments and a rapidly aging global population have amplified the need for early biomarkers of the disease process. Recent advances suggest that subjective cognitive decline (SCD) may be one of the earliest symptomatic markers of the AD cascade. Previous studies have identified changes in variability in the blood-oxygen-level-dependent (BOLD) signal in patients with AD, with a possible association between BOLD variability and cerebrovascular factors in the aging brain. The objective of the current study was to determine whether changes in BOLD variability can be identified in individuals with SCD, and whether this signal may be associated with markers of cerebrovascular integrity in SCD and older adults without memory complaints. Method: Data were obtained from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database from 19 participants with SCD and 19 similarly-aged controls. For each participant, a map of BOLD signal variability (SDBOLD) was computed as the standard deviation of the BOLD time-series at each voxel. Group comparisons were performed to examine differences in resting-state SDBOLD in SCD vs. healthy controls. Relationships were then examined between participant SDBOLD maps and neuroimaging markers of white matter vascular infarcts in each group separately. Results: Between-group comparisons showed no significant differences in whole-brain SDBOLD in individuals with SCD and controls. In the healthy aging group, higher white matter hyperintensity (WMH) burden was associated with greater SDBOLD in right temporal regions (p < 0.05), and lower scores on a measure of global executive functioning. These associations were not identified in individuals with SCD. Conclusion: The current study underscores previous evidence for a relationship between SDBOLD and white matter vascular infarcts in the healthy aging brain. The findings also provide evidence for a dissociable relationship between healthy aging and SCD, such that in healthy controls, increased WMH is associated with declines in executive function that is not observed in older adults who present with memory complaints. Further multimodal work is needed to better understand the contributions of vascular pathology to the BOLD signal, and its potential relationship with pathological aging.