Race-norming of neuropsychological tests

The influence of early life socio-environmental factors on executive performance in a healthy adult sample

OBJECTIVE

Attempts have been made (with research efforts encouraged) to deconstruct the "race" concept into language, cultural, and life experience variables that can help explain performance differences found between ethnic groups (Romero et al., 2009). The extant empirical literature reveals that early environmental factors and life experiences (e.g., socioeconomic status) are related to cognitive test performance in adulthood (Byrd et al., 2006). This study examined the explanatory value of early life childhood resources in the relationship between ethnicity and neuropsychological test performance in adulthood.

PARTICIPANTS/ METHODS

Neurologically and psychologically healthy African American (n = 40), Caucasian (n = 14), and Hispanic (n = 107) college students ranging from 19-38 years of age. On average, participants had completed around 13 years of education, indicating that the majority were in the early stages of their undergraduate studies and mostly consisted of females (72%). Each participant completed a comprehensive neuropsychological battery that included tests of executive function and an extensive background questionnaire.

RESULTS

A one-way analysis of variance (ANOVA) revealed that the CA group was significantly older (F (2, 160) = 18.38, p = .045) compared to the AA and H groups, but the groups did not differ in terms of number of years of educations or gender. Also, an ANOVA revealed significant group test performance differences on the Stroop-C [F (2, 160) = 1.53, p = .047], but not on the TMT-B and COWAT. Furthermore, a Tukey post hoc revealed that there were no significant differences in test performance on Stroop-C between the groups. Hierarchical multiple regression analyses revealed that group performance differences on executive function tests were medium or non-existent and only partially explained by years of education and early life financial resources.

CONCLUSION

The results are discussed in light of the existing literature, study strengths and limitations, as well as directions for future research. This research can aid in pinpointing variables crucial for interpreting differences in neuropsychological assessments among diverse populations, holding potential implications for intervention research and policy settings. It is particularly relevant in the context of the continuously evolving social, political, and economic landscapes of societies.

Mild Cognitive Impairment Subtype Performance in Comparison to Healthy Older Controls on the NIH Toolbox and Cogstate

BACKGROUND

Early detection is necessary for the treatment of dementia. Computerized testing has become more widely used in clinical trials; however, it is unclear how sensitive these measures are to early signs of neurodegeneration. We investigated the use of the NIH Toolbox-Cognition (NIHTB-CB) and Cogstate-Brief computerized neuropsychological batteries in the identification of mild cognitive impairment (MCI) versus healthy older adults [healthy control (HC)] and amnestic (aMCI) versus nonamnestic MCI (naMCI). Exploratory analyses include investigating potential racial differences.

METHODS

Two hundred six older adults were diagnosed as aMCI (n = 58), naMCI (n = 15), or cognitively healthy (HC; n = 133).

RESULTS

The NIH Toolbox-CB subtests of Flanker, Picture Sequence Memory, and Picture Vocabulary significantly differentiated MCI from HC. Further, subtests from both computerized batteries differentiated patients with aMCI from those with naMCI. Although the main effect of race differences was noted on tests and in diagnostic groups was significant, there were no significant race-by-test interactions.

CONCLUSIONS

Computer-based subtests vary in their ability to help distinguish MCI subtypes, though these tests provide less expensive and easier-to-administer clinical screeners to help identify patients early who may qualify for more comprehensive evaluations. Further work is needed, however, to refine computerized tests to achieve better precision in distinguishing impairment subtypes.

Neuropsychological Test Norms for the Assessment of HIV-Associated Neurocognitive Impairment Among South African Adults

Reliable and valid neurocognitive (NC) test batteries that assess multiple domains of cognitive functioning are vital tools in the early detection of HIV-associated NC impairment. The HIV Neurobehavioral Research Center's International Neurobehavioral Battery (HNRC Battery) is one such diagnostic tool and has shown cultural validity in several international neuroHIV studies. However, no published norms are currently available for the full HNRC Battery in South Africa. To accurately interpret NC test results, appropriate reference norms are required. In light of this challenge, data were collected from 500 healthy, HIV-uninfected participants to develop demographically corrected South African norms. When demographically corrected United States of America (U.S.) norms were applied to the performance scores of our neurologically intact, HIV-negative sample, an impairment rate of 62.2% was observed compared to a 15.0% impairment rate when the newly generated South African norms were applied. These results reiterate the findings of other low- and middle-income countries, highlighting the need for localized, country-specific norms when interpreting NC performance.

The influence of culture and cognitive reserve on the clinical presentation of behavioural-variant frontotemporal dementia

Characterisation of the clinical profile of behavioural-variant frontotemporal dementia (bvFTD) has predominantly been based on Western samples. Some small studies have suggested that the clinical profile may differ in culturally and linguistically diverse populations. Additionally, there is evidence that patients from non-English speaking backgrounds may have more cognitive reserve, allowing them to tolerate more disease pathology before clinical symptoms emerge. This study aims to characterise the clinical profiles of patients with bvFTD from culturally diverse backgrounds. BvFTD patients were classified as Australian-born (Australian) or Culturally and Linguistically Diverse-English-speaking (CALD-English) and Culturally and Linguistically Diverse-Language Other Than English (CALD-LOTE). Clinical features, cognitive test performance and cognitive reserve were compared between groups. Voxel-based morphometry was used to examine the neural correlates of cognitive reserve. 107 patients with bvFTD (53 Australian, 36 CALD-English, 18 CALD-LOTE) and 51 controls were included. Analysis of neuropsychiatric features revealed more elation in Australian patients compared to CALD-English patients, with trends for CALD-LOTE patients to report more irritability. CALD-LOTE patients also had higher cognitive reserve and showed relatively greater verbal than non-verbal cognitive impairment. Neuroimaging analyses revealed that higher cognitive reserve was associated with lower integrity in the frontal-temporal regions associated with typical disease pathology in bvFTD. Our findings support the hypothesis that cognitive reserve may delay early cognitive decline in culturally and linguistically diverse patients, although these patients may still show poor verbal performance due to cultural testing biases. Clinically, these results highlight the need to consider cultural and linguistic background to inform the assessment of dementia.

Health disparities in aging: Improving dementia care for Black women

In the United States, 80% of surveyed Black patients report experiencing barriers to healthcare for Alzheimer's disease and related dementias (ADRD), delaying the time-sensitive treatment of a progressive neurodegenerative disease. According to the National Institute on Aging, Black study participants are 35% less likely to be given a diagnosis of ADRD than white participants, despite being twice as likely to suffer from ADRD than their white counterparts. Prior analysis of prevalence for sex, race, and ethnicity by the Centers for Disease Control indicated the highest incidence of ADRD in Black women. Older (≥65 years) Black women are at a disproportionately high risk for ADRD and yet these patients experience distinct inequities in obtaining clinical diagnosis and treatment for their condition. To that end, this perspective article will review a current understanding of biological and epidemiological factors that underlie the increased risk for ADRD in Black women. We will discuss the specific barriers Black women face in obtaining access to ADRD care, including healthcare prejudice, socioeconomic status, and other societal factors. This perspective also aims to evaluate the performance of intervention programs targeted toward this patient population and offer possible solutions to promote health equity.

The Naming Assessment in Multicultural Europe (NAME): Development and Validation in a Multicultural Memory Clinic

OBJECTIVE

Traditional naming tests are unsuitable to assess naming impairment in diverse populations, given the influence of culture, language, and education on naming performance. Our goal was therefore to develop and validate a new test to assess naming impairment in diverse populations: the Naming Assessment in Multicultural Europe (NAME).

METHOD

We carried out a multistage pilot study. First, we generated a list of 149 potentially suitable items - e.g. from published cross-linguistic word lists and other naming tests - and selected those with a homogeneous age of acquisition and word frequency across languages. We selected three to four colored photographs for each of the 73 remaining items; 194 controls selected the most suitable photographs. Thirteen items were removed after a pilot study in 15 diverse healthy controls. The final 60-item test was validated in 39 controls and 137 diverse memory clinic patients with subjective cognitive impairment, neurological/neurodegenerative disease or psychiatric disorders in the Netherlands and Turkey (mean age: 67, SD: 11). Patients were from 15 different countries; the majority completed primary education or less (53%).

RESULTS

The NAME showed excellent reliability (Spearman-Brown coefficient: 0.95; Kuder-Richardson coefficient: 0.94) and robust correlations with other language tests (ρ = .35-.73). Patients with AD/mixed dementia obtained lower scores on most (48/60) NAME items, with an area under the curve of 0.88. NAME scores were correlated with age and education, but not with acculturation or sex.

CONCLUSIONS

The NAME is a promising tool to assess naming impairment in culturally, educationally, and linguistically diverse individuals.

The Future of Cognitive Screening in Neurodegenerative Diseases

Cognitive screening instruments (CSI) have variable sensitivity and specificity to the cognitive changes associated with dementia syndromes, and the most recent systematic review found insufficient evidence to support the benefit of cognitive screening tools in older adults residing within the community. Consequently, there is a critical need to improve CSI methods, which have not yet incorporated advances in psychometrics, neuroscience, and technology. The primary goal of this article is to provide a framework for transitioning from legacy CSIs to advanced dementia screening measurement. In line with ongoing efforts in neuropsychology and the call for next-generation digital assessment for early detection of AD, we propose a psychometrically advanced (including application of item response theory methods), automated selective assessment model that provides a framework to help propel an assessment revolution. Further, we present a three-phase model for modernizing CSIs and discuss critical diversity and inclusion issues, current challenges in differentiating normal from pathological aging, and ethical considerations.

Performance Comparisons on the Saint Louis University Mental Status Examination Between Black and White Veterans and Education Classification in a Large Outpatient Sample from the Southern United States

Objective

An increasing scientific literature recognizes that traditional cut-off scores for cognitive screeners may not be optimal for use in patients who differ in race/ethnicity from the screeners’ normative/reference group. There is also literature on how racial/ethnic contextual factors, such as stereotype threat or perceived discrimination, may influence performance on cognitive testing. The current study examined the characteristics of SLUMS (a cognitive screening measure) performance in a large (n = 602) sample of Black (n = 229) and White (n = 373) veterans in a VA hospital located in the Southern United States.

Method

SLUMS data were gathered from retrospective electronic chart review between January 2013 and February 2020. Race/ethnicity of veterans was gathered by chart review and race of hospital providers who administered the SLUMS by personal communication.

Results

Black veterans were 1.99 times more likely to be classified by total SLUMS score as being within the dementia range compared with White veterans. Differences in item level performance were only found between Black and White veterans with ≥ high school education. Race of clinical provider (i.e., Black or White) administering the SLUMS did not significantly impact veteran performance on the SLUMS.

Conclusion

This is the first large sample study of differences in SLUMS performance between Black and White veterans. Findings replicate earlier research on Black and White performance differences on individual SLUMS items and provide an analysis of examiner–examinee racial discordance. This study underscores the importance of researching cognitive measures in groups who differ from the original normative/references samples.

Racial differences in positive findings on embedded performance validity tests

INTRODUCTION

Embedded performance validity tests (PVTs) may show increased positive findings in racially diverse examinees. This study examined positive findings in an older adult sample of African American (AA) and European American (EA) individuals recruited as part of a study on aging and cognition.

METHOD

The project involved secondary analysis of deidentified National Alzheimer's Coordinating Center data (N = 22,688). Exclusion criteria included diagnosis of dementia (n = 5,550), mild cognitive impairment (MCI; n = 5,160), impaired but not MCI (n = 1,126), other race (n = 864), and abnormal Mini Mental State Examination (MMSE < 25; n = 135). The initial sample included 9,853 participants (16.4% AA). Propensity score matching matched AA and EA participants on age, education, sex, and MMSE score. The final sample included 3,024 individuals with 50% of participants identifying as AA. Premorbid ability estimates were calculated based on demographics. Failure rates on five raw score and six age-adjusted scaled score PVTs were examined by race.

RESULTS

Age, education, sex, MMSE, and premorbid ability estimate were not significantly different by race. Thirteen percent of AA and 3.8% of EA participants failed two or more raw score PVTs (p < .0001). On age-adjusted PVTs, 20.6% of AA and 5.9% of EA participants failed two or more (p < .0001).

CONCLUSIONS

PVT failure rates were significantly higher among AA participants. Findings indicate a need for cautious interpretation of embedded PVTs with underrepresented groups. Adjustments to embedded PVT cutoffs may need to be considered to improve diagnostic accuracy.

Racial and Ethnic Differences in Amyloid PET Positivity in Individuals With Mild Cognitive Impairment or Dementia: A Secondary Analysis of the Imaging Dementia-Evidence for Amyloid Scanning (IDEAS) Cohort Study

Importance

Racial and ethnic groups with higher rates of clinical Alzheimer disease (AD) are underrepresented in studies of AD biomarkers, including amyloid positron emission tomography (PET).

Objective

To compare amyloid PET positivity among a diverse cohort of individuals with mild cognitive impairment (MCI) or dementia.

Design, Setting, and Participants

Secondary analysis of the Imaging Dementia-Evidence for Amyloid Scanning (IDEAS), a single-arm multisite cohort study of Medicare beneficiaries who met appropriate-use criteria for amyloid PET imaging between February 2016 and September 2017 with follow-up through January 2018. Data were analyzed between April 2020 and January 2022. This study used 2 approaches: the McNemar test to compare amyloid PET positivity proportions between matched racial and ethnic groups and multivariable logistic regression to assess the odds of having a positive amyloid PET scan. IDEAS enrolled participants at 595 US dementia specialist practices. A total of 21 949 were enrolled and 4842 (22%) were excluded from the present analysis due to protocol violations, not receiving an amyloid PET scan, not having a positive or negative scan, or because of small numbers in some subgroups.

Exposures

In the IDEAS study, participants underwent a single amyloid PET scan.

Main Outcomes and Measures

The main outcomes were amyloid PET positivity proportions and odds.

Results

Data from 17 107 individuals (321 Asian, 635 Black, 829 Hispanic, and 15 322 White) with MCI or dementia and amyloid PET were analyzed between April 2020 and January 2022. The median (range) age of participants was 75 (65-105) years; 8769 participants (51.3%) were female and 8338 (48.7%) were male. In the optimal 1:1 matching analysis (n = 3154), White participants had a greater proportion of positive amyloid PET scans compared with Asian participants (181 of 313; 57.8%; 95% CI, 52.3-63.2 vs 142 of 313; 45.4%; 95% CI, 39.9-50.9, respectively; P = .001) and Hispanic participants (482 of 780; 61.8%; 95% CI, 58.3-65.1 vs 425 of 780; 54.5%; 95% CI, 51.0-58.0, respectively; P = .003) but not Black participants (359 of 615; 58.4%; 95% CI, 54.4-62.2 vs 333 of 615; 54.1%; 95% CI, 50.2-58.0, respectively; P = .13). In the adjusted model, the odds of having a positive amyloid PET scan were lower for Asian participants (odds ratio [OR], 0.47; 95% CI, 0.37-0.59; P < .001), Black participants (OR, 0.71; 95% CI, 0.60-0.84; P < .001), and Hispanic participants (OR, 0.68; 95% CI, 0.59-0.79; P < .001) compared with White participants.

Conclusions and Relevance

Racial and ethnic differences found in amyloid PET positivity among individuals with MCI and dementia in this study may indicate differences in underlying etiology of cognitive impairment and guide future treatment and prevention approaches.

Brain-phenotype models fail for individuals who defy sample stereotypes

Individual differences in brain functional organization track a range of traits, symptoms and behaviours1-12. So far, work modelling linear brain-phenotype relationships has assumed that a single such relationship generalizes across all individuals, but models do not work equally well in all participants13,14. A better understanding of in whom models fail and why is crucial to revealing robust, useful and unbiased brain-phenotype relationships. To this end, here we related brain activity to phenotype using predictive models-trained and tested on independent data to ensure generalizability15-and examined model failure. We applied this data-driven approach to a range of neurocognitive measures in a new, clinically and demographically heterogeneous dataset, with the results replicated in two independent, publicly available datasets16,17. Across all three datasets, we find that models reflect not unitary cognitive constructs, but rather neurocognitive scores intertwined with sociodemographic and clinical covariates; that is, models reflect stereotypical profiles, and fail when applied to individuals who defy them. Model failure is reliable, phenotype specific and generalizable across datasets. Together, these results highlight the pitfalls of a one-size-fits-all modelling approach and the effect of biased phenotypic measures18-20 on the interpretation and utility of resulting brain-phenotype models. We present a framework to address these issues so that such models may reveal the neural circuits that underlie specific phenotypes and ultimately identify individualized neural targets for clinical intervention.

Development of rehabilitation services in an Inuit sociocultural context: challenges, strategies and considerations for the future

In recent years, a new rehabilitation programme has been developed on the Hudson Bay coast of Nunavik. The purpose of this article is to reflect on the experience of an occupational and physical therapy programme development in an Inuit sociocultural context. To do so, the challenges encountered during the first years following the implementation of rehabilitation services and the strategies implemented by the professionals to overcome them were identified, examined in the light of the literature, and discussed with members of the rehabilitation team. The challenges encountered and strategies implemented were divided into 10 major themes: (1) diverse clinical needs; (2) communication issues; (3) acquisition of cross-cultural interaction and population-specific knowledge; (4) adaptation of clinical practice to Nunavimmiut; (5) client engagement in rehabilitation; (6) professional isolation; (7) lack of awareness around the objectives and scope of rehabilitation practice; (8) use of culturally safe assessment tools; (9) staff turnover; (10) large geographic area to be served. This exercise highlighted the need to adapt clinical rehabilitation practices to Nunavimmiut’s worldviews and culture, as well as to adopt a reflective practice in order to improve the quality, relevance and effectiveness of rehabilitation services.

Pharmacogenomics and clinical cultural competency: pathway to overcome the limitations of race

Global migration trends are accelerating population admixture. Increasing population diversity met with minority health disparities necessitates thoughtful training of health professional students. Health professional accreditation standards emphasize pharmacogenomics and clinical cultural competency (CCC); however, published studies focus on students’ knowledge in pharmacogenomics alone. This report reviews considerations for integrating CCC into required pharmacogenomic education in pharmacy and other health disciplines. By coupling both topics during didactic training and active learning exercises repeated throughout the existing curriculum, students can become adept at these individualized patient care skills and retain their knowledge into their careers. Moving beyond race as a proxy for healthcare decision-making, the CCC of clinicians coupled with patients’ genetic test results could empower clinicians to address health disparities and facilitate discussions about the role of race in clinical practice. Ultimately, an integrated approach of teaching pharmacogenomics and CCC could dismantle race-norming or race-based clinical practices.

The Frequency of Low Scores on ImPACT in Adolescent Student-Athletes: Stratification by Race and Socioeconomic Status Using Multivariate Base Rates

This study examined the associations between the frequency of low scores on the Immediate Post-Concussion Assessment and Cognitive Test (ImPACT) by race and socioeconomic status (SES), using the proxy of Title I school status, among adolescent student-athletes and calculated multivariate base rates. There were 753 participants assigned to groups based on race (White: n = 430, 59.8%; Black: n = 289, 40.2%) and SES. Black student-athletes obtained more low neurocognitive test scores, which was associated with lower SES. The current study offers a resource to clinicians involved in concussion management who may wish to consider race and SES when interpreting ImPACT test performances.

Cognitive impairment in racially/ethnically diverse older adults: Accounting for sources of diagnostic bias

INTRODUCTION

The Kaiser Healthy Aging and Diverse Life Experiences (KHANDLE) study enrolled Asian, Black, Latino, and White adults ages 65+ without prior dementia diagnosis (N = 1709). We evaluated the prevalence of cognitive impairment (mild cognitive impairment or dementia) accounting for potential biases.

METHODS

A random subgroup (N = 541) received clinical evaluation and others were evaluated if they failed a cognitive screen. Diagnoses were made under two conditions: (1) demographics-blind, based on clinical exam and demographically adjusted neuropsychological test scores; and (2) all available information (clinical exam, demographics, and adjusted and unadjusted test scores).

RESULTS

Cognitive impairment prevalence was 28% for blinded-adjusted diagnosis and 25% using all available information. Black participants had higher impairment rates than White (both conditions) and Latino (blinded-adjusted diagnosis) participants. Incomplete assessments negatively biased prevalence estimates for White participants.

DISCUSSION

Racial/ethnic disparities in cognitive impairment were amplified by attrition bias in White participants but were unaffected by type of test norms and diagnosticians' knowledge of demographics.

Validation of Discrete and Regression-Based Performance and Cognitive Fatigability Normative Data for the Paced Auditory Serial Addition Test in Multiple Sclerosis

Cognitive fatigability is an objective performance decrement that occurs over time during a task requiring sustained cognitive effort. Although cognitive fatigability is a common and debilitating symptom in multiple sclerosis (MS), there is currently no standard for its quantification. The objective of this study was to validate the Paced Auditory Serial Addition Test (PASAT) discrete and regression-based normative data for quantifying performance and cognitive fatigability in an Ontario-based sample of individuals with MS. Healthy controls and individuals with MS completed the 3″ and 2″ versions of the PASAT. PASAT performance was measured with total correct, dyad, and percent dyad scores. Cognitive fatigability scores were calculated by comparing performance on the first half (or third) of the task to the last half (or third). The results revealed that the 3″ PASAT was sufficient to detect impaired performance and cognitive fatigability in individuals with MS given the increased difficulty of the 2″ version. In addition, using halves or thirds for calculating cognitive fatigability scores were equally effective methods for detecting impairment. Finally, both the discrete and regression-based norms classified a similar proportion of individuals with MS as having impaired performance and cognitive fatigability. These newly validated discrete and regression-based PASAT norms provide a new tool for clinicians to document statistically significant cognitive fatigability in their patients.

Overview of Ten Child Mental Health Clinical Outcome Measures: Testing of Psychometric Properties with Diverse Client Populations in the U.S

While many standardized assessment measures exist to track child mental health treatment outcomes, the degree to which such tools have been adequately tested for reliability and validity across race, ethnicity, and class is uneven. This paper examines the corpus of published tests of psychometric properties for the ten standardized measures used in U.S. child outpatient care, with focus on breadth of testing across these domains. Our goal is to assist care providers, researchers, and legislators in understanding how cultural mismatch impacts measurement accuracy and how to select tools appropriate to the characteristics of their client populations. We also highlight avenues of needed research for measures that are in common use. The list of measures was compiled from (1) U.S. state Department of Mental Health websites; (2) a survey of California county behavioral health agency directors; and (3) exploratory literature scans of published research. Ten measures met inclusion criteria; for each one a systematic review of psychometrics literature was conducted. Diversity of participant research samples was examined as well as differences in reliability and validity by gender, race or ethnicity, and socio-economic class. All measures showed adequate reliability and validity, however half lacked diverse testing across all three domains and all lacked testing with Asian American/Pacific Islander and Native American children. ASEBA, PSC, and SDQ had the broadest testing.

Adverse childhood events and cognitive function among young adults: Prospective results from the national longitudinal study of adolescent to adult health

BACKGROUND

Adverse childhood experiences (ACEs) may have lasting impacts on cognition.

OBJECTIVE

To determine if ACE exposure is prospectively associated with cognition in young adults. We hypothesized that deprivation- and threat-type ACEs as well as higher cumulative ACE exposure predict poorer cognition.

PARTICIPANTS & SETTING

Participants were from the National Longitudinal Study of Adolescent to Adult Health (Add Health), a prospective cohort investigation of U.S. adolescents followed to adulthood. Current study participants were 18-24 years old (Wave III), 24-32 years old (Wave IV), and 31-42 years old (Wave V). The maximum Wave IV sample was 12,288 adults; Wave V was 1277 adults.

METHODS

History of ACEs were assessed at Wave III. Three cognitive indicators were assessed at Wave IV and Wave V using the Rey Auditory Verbal Learning Test (immediate and delayed verbal memory) and the Digit-Span Backward Task (working memory).

RESULTS

The deprivation ACE of not-having-basic-needs met was associated with poorer working (β = 0.14, CI95 -0.26, -0.01), immediate (β=-0.29, CI95 -0.43, -0.15), and delayed memory (β=-0.27, CI95 -0.43, -0.12) at Wave IV; poorer immediate (β=-0.47, CI95-0.79, -0.16) and delayed memory (β=-0.33, CI95 -0.65, -0.01) at Wave V. The threat ACE of sexual abuse was associated with poorer immediate (β=-0.40, CI95 -0.62, -0.17) and delayed memory (β=-0.29, CI95 -0.55, -0.03) at Wave IV. Higher cumulative ACEs predicted poorer delayed memory (β =-0.05, CI95 -0.10, -0.01) at Wave V.

CONCLUSIONS

Higher ACEs, especially deprivation-type, were prospectively linked to poorer cognition. Early wide-scale screening/tailored treatments addressing ACEs and cognitive function may be warranted.

UDSNB 3.0 Neuropsychological Test Norms in Older Adults from a Diverse Community: Results from the Einstein Aging Study (EAS)

BACKGROUND

The Uniform Data Set, Version 3 Neuropsychological Battery (UDSNB3.0), from the database of the University of Washington's National Alzheimer's Coordinating Center (NACC), is widely used to characterize cognitive performance in clinical and research settings; however, norms for underrepresented community-based samples are scarce.

OBJECTIVE

We compared UDSNB 3.0 test scores between the Einstein Aging Study (EAS), composed of racially/ethnically diverse, community-dwelling older adults aged≥70 and the NACC, and report normative data from the EAS.

METHODS

Analyses included 225 cognitively normal EAS participants and comparable data from 5,031 NACC database participants. Linear regression models compared performance between the samples, adjusting for demographics (sex, age, education, race/ethnicity), depressive symptoms, and whether English was the first language. Linear regression models to examine demographic factors including age, sex, education and race/ethnicity as predictors for the neuropsychological tests were applied in EAS and NACC separately and were used to create a demographically adjusted z-score calculator.

RESULTS

Cognitive performance across all domains was worse in the EAS than in the NACC, adjusting for age, sex, education, race/ethnicity, and depression, and the differences remained in visuo-construction, visuospatial memory, confrontation naming, visual attention/processing speed, and executive functioning after further adjusting for whether English was the first language. In both samples, non-Hispanic Whites outperformed non-Hispanic Blacks and more education was associated with better cognitive performance.

CONCLUSION

Differences observed in demographic, clinical, and cognitive characteristics between the community-based EAS sample and the nationwide NACC sample suggest that separate normative data that more accurately reflect non-clinic, community-based populations should be established.

Latent Structure of a Brief Clinical Battery of Neuropsychological Tests Administered In-Home Via Telephone

Objective

To examine the factor structure and sociodemographic correlates of a battery of clinical neuropsychological tests administered in-home and via telephone.

Method

Participants included 280 healthy adults who completed a 35–40 min battery consisting of seven auditory-verbal neuropsychological tests (i.e., 10 variables) that included digit span, list learning and memory, prospective memory, verbal fluency, and oral trail making.

Results

After removing oral trail making part A, a three-factor model comprised of executive functions, memory and attention demonstrated the best fit to the data. Nevertheless, the shared variance between the nine remaining neuropsychological variables was also adequately explained by a single-factor model and a two-factor model comprised of executive functions and memory. Factor scores were variably associated with education, race/ethnicity, and IQ, but not with sex or age.

Conclusions

Findings provide preliminary support for the feasibility and factor structure and sociodemographic correlates of a brief telephone-based screening neuropsychological battery comprised mostly of commonly administered clinical measures. Future studies are needed to determine the test–retest reliability, sensitivity, and ecological relevance of this battery, as well as equivalency to in-person assessment.

Developing the Canadian Indigenous Cognitive Assessment for Use With Indigenous Older Anishinaabe Adults in Ontario, Canada

Background and Objectives

Dementia is a growing public health issue for aging Indigenous populations. Current cognitive assessments present varying degrees of cultural, educational, and language bias, impairing their application in Indigenous communities. Our goal is to provide Anishinaabe communities in Canada with a brief cognitive test that can be administered within the community setting by community health workers or professionals. The purpose of this study was to adapt the Kimberly Indigenous Cognitive Assessment (KICA) for use as a brief cognitive test with Anishinaabe populations in Canada.

Research Design and Methods

We used a community-based participatory research approach coupled with two-eyed seeing to provide an equitable space for Indigenous knowledge. Adaptation of the KICA was accomplished over 22 months using an iterative cycle of monthly consultations between an 11-member expert Anishinaabe language group (EALG) and the investigators, with ad hoc consultations with an Indigenous Elder, a community advisory council, and the KICA authors. Face validity was established with two pilot studies using cognitive interviewing with Indigenous older adults (n = 15) and a focus group consultation with local health professionals (n = 7).

Results

Each question of the KICA was scrutinized by the EALG for cultural appropriateness, language and translation, and cultural safety. Every domain required adaptation to reflect cultural values, specificity of language, tone, and a culturally safe approach. Orientation, verbal comprehension and fluency, praxis, and naming domains required the most adaptations. The first pilot for face validity resulted in additional changes; the second confirmed satisfactory adaptation of all changes.

Discussion and Implications

The research resulted in the new Canadian Indigenous Cognitive Assessment. The findings reveal important cultural and linguistic considerations for cross-cultural cognitive assessment in Indigenous contexts. This new culturally appropriate and safe brief cognitive test may improve case finding accuracy and lead to earlier diagnosis and improved dementia care for Indigenous peoples.

Factor Consistency of Neuropsychological Test Battery Versions in the NACC Uniform Data Set

The proprietary neuropsychological tests (Form C1) of the National Alzheimer's Coordinating Center (NACC) Uniform Data Set were replaced with nonproprietary versions (Form C2) chosen to closely model their proprietary counterparts. Correlations between analogous test pairs as measured in previous work were good (0.68-0.78), but it is unclear whether the paired tests represent the same set of common factors of cognition or if important factors specific to C1 or C2 only exist. The authors performed multiple factor analysis to analyze correlated C1 and C2 data. They included participants who completed both neuropsychological batteries within 1 year with no change in cognitive status. They found that the C1 and C2 neuropsychological test pairs are strongly related and are represented by the same principal factors. These findings support the use of the C2 test results in conjunction with C1 in longitudinal analyses of NACC data.

Group differences in normal neuropsychological test performance for older non-Hispanic White and Black/African American adults

OBJECTIVE

Although researchers have documented the influence of cultural factors on neuropsychological test performance, few studies have examined the distribution of test scores among neurologically healthy older adults from different ethnic groups. The objective of this study was to determine whether there are group differences in neuropsychological test score distributions with ethnicity-specific norms for non-Hispanic White and Black/African American older adults.

METHOD

Participants from the National Alzheimer's Coordinating Center were selected if they were not diagnosed with dementia within 5 years (Mage = 75.26, SDage = 6.98; Meducation = 15.70, SDeducation = 2.91). Groups were formed based on self-identified ethnicity of White (n = 5,311) or Black/African American (n = 1,098). All participants completed neuropsychological testing, including the Mini Mental State Exam, Logical Memory Immediate and Delayed, Digit Span Forward and Backward, Trail Making Test A & B, Animal Naming, Vegetable Naming, Digit Symbol, and Boston Naming Test.

RESULTS

Based on combined ethnicity norms, the scores of Black participants were overrepresented in the below-average and low-average clinical ranges, and the scores of White participants were overrepresented in the high-average and superior clinical ranges for all 11 neuropsychological measures. When group specific norms were used, the unbalanced pattern of score categorization was no longer present for any of the neuropsychological measures.

CONCLUSIONS

These findings emphasize the importance of developing and using ethnically and culturally appropriate neuropsychological test norms as well as the risk of interpreting some Black individual's scores as below average when they likely are not. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Neuropsychological Test Norms in Cognitively Intact Oldest-Old

OBJECTIVES

Individuals aged 90 or older (oldest-old), the fastest growing segment of the population, are at increased risk of developing cognitive impairment compared with younger old. Neuropsychological evaluation of the oldest-old is important yet challenging in part because of the scarcity of test norms for this group. We provide neuropsychological test norms for cognitively intact oldest-old.

METHODS

Test norms were derived from 403 cognitively intact participants of The 90+ Study, an ongoing study of aging and dementia in the oldest-old. Cognitive status of intact oldest-old was determined at baseline using cross-sectional approach. Individuals with cognitive impairment no dementia or dementia (according to DSM-IV criteria) were excluded. Participants ranged in age from 90 to 102 years (mean=94). The neuropsychological battery included 11 tests (Mini-Mental Status Examination, Modified Mini-Mental State Examination, Boston Naming Test - Short Form, Letter Fluency Test, Animal Fluency Test, California Verbal Learning Test-II Short Form, Trail Making Tests A/B/C, Digit Span Forward and Backwards Test, Clock Drawing Test, CERAD Construction Subtests), and the Geriatric Depression Scale.

RESULTS

Data show significantly lower scores with increasing age on most tests. Education level, sex, and symptoms of depression were associated with performance on several tests after accounting for age.

CONCLUSIONS

Provided test norms will help to distinguish cognitively intact oldest-old from those with cognitive impairment. (JINS, 2019, 25, 530-545).

Uncorrected versus demographically-corrected scores on the NIH Toolbox Cognition Battery in persons with traumatic brain injury and stroke

OBJECTIVE

The association between demographic characteristics and neurocognitive performance is well established; however, clinicians may have difficulty selecting when to use uncorrected versus demographically corrected scores. We compared these score types in individuals with traumatic brain injury (TBI) and stroke, on the National Institutes of Health Toolbox-Cognition Battery (NIHTB-CB).

RESEARCH METHOD

Adults with TBI and stroke were demographically matched to controls, and completed the NIHTB-CB. Published "corrected scores" are adjusted for age, education, sex, and race/ethnicity; "uncorrected scores" were created using census data to represent the average adult in the U.S.

POPULATION

RESULTS

Effect sizes for the TBI and stroke groups versus controls were larger using corrected scores compared with uncorrected scores for the fluid composite (uncorrected to corrected effect sizes: TBI: d = 0.66, p < .001 to 0.83, p < .001; stroke d = 0.97, p < .001 to 1.10, p < .001). For the crystallized composite, effect sizes for the TBI and stroke groups versus controls were smaller and nonsignificant using corrected scores (uncorrected to corrected effect sizes: TBI d = 0.23, p = .03 to 0.20, p = .06; stroke d = 0.40, p < .001 to 0.17, p = .09). In the injury groups, demographic characteristics accounted for up to 33% of variance in uncorrected scores (p < .001), but <5% of variance in corrected scores (p > .06).

CONCLUSIONS

Corrected scores were more sensitive to neurocognitive impairments in the brain-injured groups. Corrected scores have the advantage of controlling for variance associated with premorbid factors rather than changes in neurological functioning; are more helpful in characterizing acquired neurocognitive changes; and can aid in the interpretation of test performance. (PsycINFO Database Record

Apolipoprotein E epsilon 4 (APOE-ε4) genotype is associated with decreased 6-month verbal memory performance after mild traumatic brain injury

INTRODUCTION

The apolipoprotein E (APOE) ε4 allele associates with memory impairment in neurodegenerative diseases. Its association with memory after mild traumatic brain injury (mTBI) is unclear.

METHODS

mTBI patients (Glasgow Coma Scale score 13-15, no neurosurgical intervention, extracranial Abbreviated Injury Scale score ≤1) aged ≥18 years with APOE genotyping results were extracted from the Transforming Research and Clinical Knowledge in Traumatic Brain Injury Pilot (TRACK-TBI Pilot) study. Cohorts determined by APOE-ε4(+/-) were assessed for associations with 6-month verbal memory, measured by California Verbal Learning Test, Second Edition (CVLT-II) subscales: Immediate Recall Trials 1-5 (IRT), Short-Delay Free Recall (SDFR), Short-Delay Cued Recall (SDCR), Long-Delay Free Recall (LDFR), and Long-Delay Cued Recall (LDCR). Multivariable regression controlled for demographic factors, seizure history, loss of consciousness, posttraumatic amnesia, and acute intracranial pathology on computed tomography (CT).

RESULTS

In 114 mTBI patients (APOE-ε4(-)=79; APOE-ε4(+)=35), ApoE-ε4(+) was associated with long-delay verbal memory deficits (LDFR: B = -1.17 points, 95% CI [-2.33, -0.01], p = .049; LDCR: B = -1.58 [-2.63, -0.52], p = .004), and a marginal decrease on SDCR (B = -1.02 [-2.05, 0.00], p = .050). CT pathology was the strongest predictor of decreased verbal memory (IRT: B = -8.49, SDFR: B = -2.50, SDCR: B = -1.85, LDFR: B = -2.61, LDCR: B = -2.60; p < .001). Seizure history was associated with decreased short-term memory (SDFR: B = -1.32, p = .037; SDCR: B = -1.44, p = .038).

CONCLUSION

The APOE-ε4 allele may confer an increased risk of impairment of 6-month verbal memory for patients suffering mTBI, with implications for heightened surveillance and targeted therapies. Acute intracranial pathology remains the driver of decreased verbal memory performance at 6 months after mTBI.

Cultural effects on neurodevelopmental testing in children from six European countries: an analysis of NUTRIMENTHE Global Database

Cultural background is an important variable influencing neuropsychological performance. Multinational projects usually involve gathering data from participants from different countries and/or different cultures. Little is known about the influence of culture on neuropsychological testing results in children and especially in European children. The objectives of this study were to compare neuropsychological performance of children from six European countries (Belgium, Germany, Italy, The Netherlands, Poland and Spain) using a comprehensive neuropsychological battery and to apply a statistical procedure to reduce the influence of country/cultural differences in neuropsychological performance. As expected, the results demonstrated differences in neuropsychological performance among children of the six countries involved. Cultural differences remained after adjusting for other confounders related to neuropsychological execution, such as sex, type of delivery, maternal age, gestational age and maternal educational level. Differences between countries disappeared and influence of culture was considerably reduced when standardised scores by country and sex were used. These results highlight the need for developing specific procedures to compare neuropsychological performance among children from different cultures to be used in multicentre studies.

Demographically Corrected Normative Standards for the English Version of the NIH Toolbox Cognition Battery

Demographic factors impact neuropsychological test performances and accounting for them may help to better elucidate current brain functioning. The NIH Toolbox Cognition Battery (NIHTB-CB) is a novel neuropsychological tool, yet the original norms developed for the battery did not adequately account for important demographic/cultural factors known to impact test performances. We developed norms fully adjusting for all demographic variables within each language group (English and Spanish) separately. The current study describes the standards for individuals tested in English. Neurologically healthy adults (n=1038) and children (n=2917) who completed the NIH Toolbox norming project in English were included. We created uncorrected scores weighted to the 2010 Census demographics, and applied polynomial regression models to develop age-corrected and fully demographically adjusted (age, education, sex, race/ethnicity) scores for each NIHTB-CB test and composite (i.e., Fluid, Crystallized, and Total Composites). On uncorrected NIHTB-CB scores, age and education demonstrated significant, medium-to-large associations, while sex showed smaller, but statistically significant effects. In terms of race/ethnicity, a significant stair-step effect on uncorrected NIHTB-CB scores was observed (African American<Hispanic<White). After applying normative corrections, NIHTB-CB no longer demonstrated any significant associations with demographic factors. The previously developed norms still maintained significant associations with demographic factors, and demonstrated more variable impairment rates in segments of the healthy normative sample. Similar to other neuropsychological tests, demographic factors demonstrated significant associations with unadjusted NIHTB-CB scores. Application of fully corrected scores will help account for unwanted variance that is associated with non-clinical factors to more accurately reflect effects of disease-related changes in brain function.

Socioeconomic Status and Neuropsychological Functioning: Associations in an Ethnically Diverse HIV+ Cohort

OBJECTIVE

There is limited research examining the relationship between socioeconomic status (SES) and neuropsychological functioning, particularly in racial/ethnic minority and HIV+ populations. However, there are complex associations between poverty, education, HIV disease, race/ethnicity, and health outcomes in the US.

METHOD

We explored these relationships among an ethnically diverse sample of 134 HIV+ adults using a standardized SES measure (i.e., the Hollingshead scale), a comprehensive NP test battery, and a functional evaluation (i.e., Patient's Assessment of Own Functioning Inventory and Modified Instrumental Activities of Daily Living Scale).

RESULTS

Bivariate analyses showed that adult SES was significantly, positively correlated with neuropsychological performance on specific tests within the domains of verbal fluency, attention/concentration, learning, memory, processing speed, and executive functioning, and childhood SES was significantly linked to measures of verbal fluency, processing speed, and executive functioning. In a series of linear regressions, controlling for SES significantly attenuated group differences in NP test scores between racial/ethnic minority individuals and non-Hispanic White individuals. Finally, SES scores significantly differed across HIV-Associated Neurocognitive Disorder (HAND) diagnoses. In a binary logistic regression, SES was the only independent predictor of HAND diagnosis.

CONCLUSIONS

HIV+ individuals with lower SES may be more vulnerable to HIV-associated neuropsychological sequelae due to prominent health disparities, although the degree to which this is influenced by factors such as test bias remains unclear. Overall, our results suggest that SES is significantly linked to neuropsychological test performance in HIV+ individuals, and is an important factor to consider in clinical practice.

Effects of stereotype threat, perceived discrimination, and examiner race on neuropsychological performance: simple as black and white?

The purpose of the current study was to examine the predictive roles of stereotype threat and perceived discrimination and the mediating role of examiner-examinee racial discordance on neuropsychological performance in a non-clinical sample of African American and Caucasian individuals. Ninety-two African American (n = 45) and Caucasian (n = 47) adults were randomly assigned to either a stereotype threat or non-threat condition. Within each condition, participants were randomly assigned to either a same race or different race examiner. All participants underwent neuropsychological testing and completed a measure of perceived discrimination. African Americans in the stereotype threat condition performed significantly worse on global NP (Mz = -.30, 95% confidence interval [CI] [-0.07, -0.67] than African Americans in the non-threat condition (Mz = 0.09, CI [0.15, 0.33]. African Americans who reported high levels of perceived discrimination performed significantly worse on memory tests when tested by an examiner of a different race, Mz = -1.19, 95% CI [-1.78, -.54], than African Americans who were tested by an examiner of the same race, Mz = 0.24, 95% CI [-0.24, 0.72]. The current study underscores the importance of considering the role of contextual variables in neuropsychological performance, as these variables may obscure the validity of results among certain racial/ethnic groups.

Caring for older adults with mild cognitive impairment: an update for nurses

Mild cognitive impairment (MCI) is a mild decline in single or multiple cognitive domains, while global cognition and basic activities of daily living remain intact. Nurses play an important role in early detection of MCI and providing care to maintain maximum independence for individuals with MCI. This article seeks to provide nurses with a review of the most recent research regarding the etiology and diagnosis of MCI, related risk and protective factors, patient and family experiences, and current interventions. This update provides research evidence to inform nursing practice of MCI care.

Using monolingual neuropsychological test norms with bilingual Hispanic americans: application of an individual comparison standard

Conventional neuropsychological norms developed for monolinguals likely overestimate normal performance in bilinguals on language but not visual-perceptual format tests. This was studied by comparing neuropsychological false-positive rates using the 50th percentile of conventional norms and individual comparison standards (Picture Vocabulary or Matrix Reasoning scores) as estimates of preexisting neuropsychological skill level against the number expected from the normal distribution for a consecutive sample of 56 neurologically intact, bilingual, Hispanic Americans. Participants were tested in separate sessions in Spanish and English in the counterbalanced order on La Bateria Neuropsicologica and the original English language tests on which this battery was based. For language format measures, repeated-measures multivariate analysis of variance showed that individual estimates of preexisting skill level in English generated the mean number of false positives most approximate to that expected from the normal distribution, whereas the 50th percentile of conventional English language norms did the same for visual-perceptual format measures. When using conventional Spanish or English monolingual norms for language format neuropsychological measures with bilingual Hispanic Americans, individual estimates of preexisting skill level are recommended over the 50th percentile.

Explaining differences in episodic memory performance among older African Americans and Whites: the roles of factors related to cognitive reserve and test bias

Older African Americans tend to perform poorly in comparison with older Whites on episodic memory tests. Observed group differences may reflect some combination of biological differences, measurement bias, and other confounding factors that differ across groups. Cognitive reserve refers to the hypothesis that factors, such as years of education, cognitive activity, and socioeconomic status, promote brain resilience in the face of pathological threats to brain integrity in late life. Educational quality, measured by reading test performance, has been postulated as an important aspect of cognitive reserve. Previous studies have not concurrently evaluated test bias and other explanations for observed differences between older African Americans and Whites. We combined data from two studies to address this question. We analyzed data from 273 African American and 720 White older adults. We assessed DIF using an item response theory/ordinal logistic regression approach. DIF and factors associated with cognitive reserve did not explain the relationship between race, and age- and sex-adjusted episodic memory test performance. However, reading level did explain this relationship. The results reinforce the importance of considering education quality, as measured by reading level, when assessing cognition among diverse older adults.

Demographically corrected norms for African Americans and Caucasians on the Hopkins Verbal Learning Test-Revised, Brief Visuospatial Memory Test-Revised, Stroop Color and Word Test, and Wisconsin Card Sorting Test 64-Card Version

Memory and executive functioning are two important components of clinical neuropsychological (NP) practice and research. Multiple demographic factors are known to affect performance differentially on most NP tests, but adequate normative corrections, inclusive of race/ethnicity, are not available for many widely used instruments. This study compared demographic contributions for widely used tests of verbal and visual learning and memory (Brief Visual Memory Test-Revised, Hopkins Verbal Memory Test-Revised) and executive functioning (Stroop Color and Word Test, Wisconsin Card Sorting Test-64) in groups of healthy Caucasians (n = 143) and African Americans (n = 103). Demographic factors of age, education, gender, and race/ethnicity were found to be significant factors on some indices of all four tests. The magnitude of demographic contributions (especially age) was greater for African Americans than for Caucasians on most measures. New, demographically corrected T-score formulas were calculated for each race/ethnicity. The rates of NP impairment using previously published normative standards significantly overestimated NP impairment in African Americans. Utilizing the new demographic corrections developed and presented herein, NP impairment rates were comparable between the two race/ethnicities and were unrelated to the other demographic characteristics (age, education, gender) in either race/ethnicity group. Findings support the need to consider extended demographic contributions to neuropsychological test performance in clinical and research settings.

Assessment of cognition in early dementia

Better tools for assessing cognitive impairment in the early stages of Alzheimer's disease (AD) are required to enable diagnosis of the disease before substantial neurodegeneration has taken place and to allow detection of subtle changes in the early stages of progression of the disease. The National Institute on Aging and the Alzheimer's Association convened a meeting to discuss state of the art methods for cognitive assessment, including computerized batteries, as well as new approaches in the pipeline. Speakers described research using novel tests of object recognition, spatial navigation, attentional control, semantic memory, semantic interference, prospective memory, false memory and executive function as among the tools that could provide earlier identification of individuals with AD. In addition to early detection, there is a need for assessments that reflect real-world situations in order to better assess functional disability. It is especially important to develop assessment tools that are useful in ethnically, culturally and linguistically diverse populations as well as in individuals with neurodegenerative disease other than AD.

A comparison of screening batteries in the detection of neurocognitive impairment in HIV-infected Spanish speakers

BACKGROUND

A substantial number of Spanish-speaking individuals from Mexico and Central America are now living in the United States. These individuals are at heightened risk for HIV infection and, due to late diagnosis and limited resources, for HIV-associated neurocognitive disorders (HAND). Early detection is key, yet adequate methods for detecting HAND in Spanish speakers, especially in resource-poor areas, remains problematic. Therefore, it is necessary to identify accurate yet efficient neurocognitive screening tools that are appropriate for use in resource-limited AIDS clinics serving Spanish-speaking patients.

METHODS

Twenty-one Spanish-speaking, HIV-positive adults who migrated from Mexico or Central America underwent neuromedical and neurocognitive evaluation in Spanish. The concordance of three neurocognitive screening measures (the HIV Dementia Scale [HDS], the Mini-Mental State Examination [MMSE], and the NEUROPSI) with a comprehensive neuropsychological battery was examined. In addition, accuracy in detecting neurocognitive impairment using standard and alternative cutoff scores was examined.

RESULTS

The HDS and the NEUROPSI showed high correlation with the comprehensive neuropsychological battery. The HDS and the NEUROPSI also had the highest sensitivity (67% and 75%, respectively) and specificity (50% and 38%, respectively). Both measures also showed greater sensitivity than the MMSE to very mild forms of HAND.

CONCLUSION

In this small sample of HIV-positive Spanish speakers from Mexico and Central America living in the United States, the HDS and the NEUROPSI demonstrated reasonable accuracy in detecting neurocognitive impairment, while the MMSE demonstrated very poor accuracy. The HDS and the NEUROPSI were equally sensitive in detecting mild HAND. Continued test development is required to capture this disorder, especially in resource-limited settings.

Neuropsychological testing of culturally and linguistically diverse individuals: the case of Greek-speaking individuals

PURPOSE OF REVIEW

The aim of this review is to update clinicians and researchers regarding neuropsychological tools that have been normed in Greece, thereby assisting them to improve diagnostic accuracy when undertaking neuropsychological assessment of Greek-speaking individuals.

RECENT FINDINGS

A growing number of neuropsychological tests of cognition have been normed in the healthy Greek adult population and the findings reported in the English-language literature. Neuropsychological Greek normative studies have revealed performance differences in Greek speakers. In general, research findings indicate that population-specific norms are required for accurate neuropsychological assessment of the Greek adult population.

SUMMARY

Validating neuropsychological tests of cognition in healthy Greek adults improves clinicians' and researchers' ability to accurately assess, diagnose and manage Greek individuals with cognitive disorders. Normative studies in Greek-speaking clinical populations and studies examining performance differences between native Greek speakers and the Greek diaspora are directions for future research.