Alyssa Arentoft

Neuropsychological, Cognitive, and Theoretical Considerations for Evaluation of Bilingual Individuals

As the number of bilinguals in the USA grows rapidly, it is increasingly important for neuropsychologists to be equipped and trained to address the unique challenges inherent in conducting ethical and competent neuropsychological evaluations with this population. Research on bilingualism has focused on two key cognitive mechanisms that introduce differences between bilinguals and monolinguals: (a) reduced frequency of language-specific use (weaker links), and (b) competition for selection within the language system in bilinguals (interference). Both mechanisms are needed to explain how bilingualism affects neuropsychological test performance, including the robust bilingual disadvantages found on verbal tasks, and more subtle bilingual advantages on some measures of cognitive control. These empirical results and theoretical claims can be used to derive a theoretically informed method for assessing cognitive status in bilinguals. We present specific considerations for measuring degree of bilingualism for both clients and examiners to aid in determinations of approaches to testing bilinguals, with practical guidelines for incorporating models of bilingualism and recent experimental data into neuropsychological evaluations. This integrated approach promises to provide improved clinical services for bilingual clients, and will also contribute to a program of research that will ultimately reveal the mechanisms underlying language processing and executive functioning in bilinguals and monolinguals alike.

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.

State of Multicultural Neuropsychological Assessment in Children: Current Research Issues

Scientific attention to cultural considerations in child neuropsychological assessment has not developed parallel to the focus these issues have received in adult and elderly neuropsychological assessment. There are limited data on the presence, magnitude, etiology, and implications of culture-related differences in cognitive test performance among children. This preliminary report reviews the available empirical literature on the current state of multicultural neuropsychological assessment in children. The review identified articles by searching PubMed and PsycINFO databases, and the tables of contents of Developmental Neuropsychology and Child Neuropsychology from 2003–2008. Of the 1,834 abstracts reviewed, ten papers met inclusion criteria for the review. Five studies were completed in America; four of these compared performance between ethnic groups while the fifth examined neighborhood level poverty indicators exclusively within African-American children. Of the five international studies, all established local normative data and/or were exploratory investigations of neuropsychological functions in specific cultural groups, including Taiwanese infants, South African youth, and bilingual British children. Taken together, the results yield important clinical and research data that begin to inform many of the complex and fascinating mechanisms by which ethnic identity and culture impact cognitive development and the neuropsychological assessment of children. A critique of the existing literature and directions for future research are provided.

Plasma BDNF is reduced among middle-aged and elderly women with impaired insulin function: Evidence of a compensatory mechanism

Brain-derived neurotrophic factor (BDNF) plays a regulatory role in neuronal differentiation and synaptic plasticity and has been linked to glucose regulation and cognition. Associations among plasma BDNF, cognition, and insulin function were explored. Forty-one participants with impaired insulin function (IIF), ranging from insulin resistance to type 2 diabetes mellitus (T2DM), were matched with 41 healthy controls on gender, age, education, and IQ. Participants received complete medical, neurological, psychiatric, and neuropsychological evaluations. IIF individuals had significantly lower plasma BDNF levels than controls, particularly females, and higher BDNF levels were associated with poorer explicit memory in IIF females, suggesting that higher levels within this group may reflect the bodys efforts to respond to damage. After accounting for age, education, and HbA1c, BDNF significantly predicted 13.1-23.5% of the variance in explicit memory in IIF women. These findings suggest that BDNF elevations within diseased groups may not always be a marker of health.

Characterization and Sociocultural Predictors of Neuropsychological Test Performance in HIV+ Hispanic Individuals

Hispanic individuals in the U.S. have been disproportionately impacted by HIV/AIDS, yet little is known regarding the neuropsychological sequelae of HIV within the Hispanic population. This study characterized neuropsychological (NP) test performance of HIV+ English-speaking Hispanic participants (n = 51) and investigated the combined roles of sociocultural factors (e.g., ethnicity, socioeconomic status [SES] proxy, and reading level) on NP test performance among our HIV+ Hispanic and non-Hispanic White participants (n = 49). Results revealed that the pattern of NP impairment in HIV+ Hispanic participants is consistent with the frontal-striatal pattern observed in HIV-associated CNS sequelae, and the overall prevalence of global NP impairment was high compared to previous reports with more ethnically homogeneous, non-Hispanic White cohorts. Multivariate prediction models that considered both sociocultural factors and CD4 count revealed that reading level was the only unique predictor of global NP functioning, learning, and attention/working memory. In contrast, ethnicity was the only unique predictor of abstraction/executive functioning. This study provides support for the use of neuropsychological evaluation in detecting HIV-associated NP impairment among HIV+ Hispanic participants and adds to the growing literature regarding the importance of considering sociocultural factors in the interpretation of NP test performance.

Functional disability in medication management and driving among individuals with HIV: a 1-year follow-up study

Approximately 50% of individuals with HIV report cognitive deficits that can affect social or occupational functioning. The present study used a longitudinal design (1 year) to examine the relationship between cognitive factors and incidental functional deficits in medication management and driving ability among a cohort of 101 HIV+ participants. Participants were classified into groups of functionally “stable” and “disabled” for each laboratory-based functional task (i.e., Medication Management Task–Revised, MMT–R, and PC-based driving simulator). We hypothesized that participants who exhibited a functional deficit in either MMT–R or driving at follow-up assessment would demonstrate significantly poorer baseline cognitive performance at study entry than participants who remained functionally stable. As hypothesized, participants who demonstrated significantly lower baseline performance in learning/memory and executive functioning also demonstrated functional disability on the MMT–R at follow-up when compared to functionally stable participants. Poor baseline performance in speed of information processing was associated with a deficit in driving ability at follow-up assessment. Our results suggest that lower baseline cognitive functioning predicts downstream functional disability, and that deficits in learning/memory and information processing speed are particularly predictive of deficits in medication management and driving ability.

Increased neurocognitive intra-individual variability is associated with declines in medication adherence in HIV-infected adults.

OBJECTIVE There is cross-sectional evidence that neurocognitive intra-individual variability (IIV), or dispersion, is elevated in human immunodeficiency virus (HIV) disease and is associated with declines in activities of daily living, including medication adherence. METHODS This longitudinal study extends this literature by examining whether increased neurocognitive IIV in HIV-positive persons over time predicts declines in medication adherence above and beyond changes in mean level of performance over a 6-month observation. RESULTS After controlling for drug use, declines in mean performance, and changes in depressive symptoms, results confirmed that increases in IIV were associated with overall poorer antiretroviral medication adherence. HIV-positive individuals with the greatest increases in dispersion demonstrated marked reductions in adherence by the third month that exceeded what was observed in less variable individuals. CONCLUSIONS Our results indicate that increases in dispersion are associated with poorer declines in medication adherence in HIV disease, which may have implications for the early detection and remediation of suboptimal antiretroviral adherence.

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.

The effects of HIV and aging on subcortical shape alterations: A 3D morphometric study

Standard volumetric neuroimaging studies have demonstrated preferential atrophy of subcortical structures among individuals with HIV. However, to our knowledge, no study has investigated subcortical shape alterations secondary to HIV and whether advancing age impacts that relationship. This study employed 3D morphometry to examine the independent and interactive effects of HIV and age on shape differences in nucleus accumbens, amygdala, caudate, hippocampus, pallidum, putamen, and thalamus in 81 participants ranging in age from 24 to 76 including 59 HIV+ individuals and 22 HIV‐seronegative controls. T1‐weighted MRI underwent a preprocessing pipeline followed by automated subcortical segmentation. Parametric statistical analyses were used to determine independent effects of HIV infection and age on volume and shape in each region of interest (ROI) and the interaction between age and HIV serostatus in predicting volume/shape in each ROI. Significant main effects for HIV were found in the shape of right caudate and nucleus accumbens, left pallidum, and hippocampus. Age was associated with differences in shape in left pallidum, right nucleus accumbens and putamen, and bilateral caudate, hippocampus, and thalamus. Of greatest interest, an age × HIV interaction effect was found in the shape of bilateral nucleus accumbens, amygdala, caudate, and thalamus as well as right pallidum and putamen such that increasing age in HIV participants was associated with greater shape alterations. Traditional volumemetric analyses revealed main effects for both HIV and age but no age × HIV interaction. These findings may suggest that age and HIV infection conferred additional deleterious effects on subcortical shape abnormalities beyond the independent effects of these factors. Hum Brain Mapp 38:1025–1037, 2017.

Quality of Education Predicts Performance on the Wide Range Achievement Test-4th Edition Word Reading Subtest

The current study examined whether self-rated education quality predicts Wide Range Achievement Test-4th Edition (WRAT-4) Word Reading subtest and neurocognitive performance, and aimed to establish this subtests construct validity as an educational quality measure. In a community-based adult sample (N = 106), we tested whether education quality both increased the prediction of Word Reading scores beyond demographic variables and predicted global neurocognitive functioning after adjusting for WRAT-4. As expected, race/ethnicity and education predicted WRAT-4 reading performance. Hierarchical regression revealed that when including education quality, the amount of WRAT-4s explained variance increased significantly, with race/ethnicity and both education quality and years as significant predictors. Finally, WRAT-4 scores, but not education quality, predicted neurocognitive performance. Results support WRAT-4 Word Reading as a valid proxy measure for education quality and a key predictor of neurocognitive performance. Future research should examine these findings in larger, more diverse samples to determine their robust nature.