Incidental learning and memory, as well as processing speed, were examined in human immunodeficiency virus (HIV)-positive adults and a seronegative control group.

Participants completed a computerized Symbol-Digit Modalities Test (cSDMT) with two blocked conditions: a set of trials with the standard symbol–digit pairings and the second set with a rearranged symbol–digit pairings.

HIV-positive adults showed slower overall reaction time compared to the HIV-negative group. More importantly, the most cognitively impaired HIV-positive group showed no interference in the rearranged set of symbol–digit pairings from the standard pairings on the cSDMT.

The relative slowing, or interference, in the HIV-negative group and two HIV-positive groups (unimpaired and impaired) was quite large (between 122 and 131 ms). We argue that the lack of such relative slowing in the most cognitively impaired HIV-positive group indicates a deficit in incidental learning and memory.

The Weigl Colour-Form Sorting Test is a brief, widely used test of executive function. So far, it is unknown whether this test is specific to frontal lobe damage. Our aim was to investigate Weigl performance in patients with focal, unilateral, left or right, frontal, or non-frontal lesions.

We retrospectively analysed data from patients with focal, unilateral, left or right, frontal (n = 37), or non-frontal (n = 46) lesions who had completed the Weigl. Pass/failure (two correct solutions/less than two correct solutions) and errors were analysed.

A greater proportion of frontal patients failed the Weigl than non-frontal patients, which was highly significant (p < 0.001). In patients who failed the test, a significantly greater proportion of frontal patients provided the same solution twice. No significant differences in Weigl performance were found between patients with left versus right hemisphere lesions or left versus right frontal lesions. There was no significant correlation between performance on the Weigl and tests tapping fluid intelligence.

The Weigl is specific to frontal lobe lesions and not underpinned by fluid intelligence. Both pass/failure on this test and error types are informative. Hence, the Weigl is suitable for assessing frontal lobe dysfunction.

Studies examining the impact of adolescent and young adult cannabis use on structural outcomes have been heterogeneous. One already-identified moderator is sex, while a novel potential moderator is extent of aerobic fitness. Here, we sought to investigate the associations of cannabis use, sex, and aerobic fitness levels on brain volume. Second, we explored brain–behavior relationships to interpret these findings.

Seventy-four adolescents and young adults (36 cannabis users and 38 controls) underwent 3 weeks of monitored cannabis abstinence, aerobic fitness testing, structural neuroimaging, and neuropsychological testing. Linear regressions examined cannabis use and its interaction with sex and aerobic fitness on whole-brain cortical volume and subcortical regions of interests.

No main-effect differences between cannabis users and nonusers were observed; however, cannabis-by-sex interactions identified differences in frontal, temporal, and paracentral volumes. Female cannabis users generally exhibited greater volume while male users exhibited less volume compared to same-sex controls. Positive associations between aerobic fitness and frontal, parietal, cerebellum, and caudate volumes were observed. Cannabis-by-fitness interaction was linked with left superior temporal volume. Preliminary brain–behavior correlations revealed that abnormal volumes were not advantageous in either male or female cannabis users.

Aerobic fitness was linked with greater brain volume and sex moderated the effect of cannabis use on volume; preliminary brain–behavior correlations revealed that differences in cannabis users were not linked with advantageous cognitive performance. Implications of sex-specific subtleties and mechanisms of aerobic fitness require large-scale investigation. Furthermore, present findings and prior literature on aerobic exercise warrant examinations of aerobic fitness interventions that aimed at improving neurocognitive health in substance-using youth.

In the present study, we explored numerical problems in individuals with aphasia. We investigate whether numerical deficits, usually accompanying aphasia, can be observed on number comprehension tasks that do not necessarily require an oral response.

Individuals with aphasia were classified into anterior, posterior, and global subgroups according to the lesion type. To investigate numerical cognition, we used a relatively recent tool, the Numerical Activities of Daily Living (NADL).

The results showed that individuals with aphasia have problems with tasks of basic number comprehension as well as in most NADL. In the formal part of the NADL, anterior aphasic patients made comparatively more errors than the posterior aphasic patients. Global aphasic patients presented an invariably poor performance on almost all tasks.

The results provide insight into how numerical deficits may impair an individual with aphasia in activities of daily living. This study is a preliminary attempt to start the validation process of the NADL for the Greek population.

Neuropsychological tests of episodic memory often include a measure of memory retention to facilitate the diagnosis of memory disorders. However, the traditional percent retention (PR) score has limited interpretability when smaller amounts of information are both initially learned and later recalled, creating a pseudo-ceiling effect. To improve psychometrics of PR, we investigated a scoring procedure that incorporates levels of certainty into estimates of memory retention based on learning level.

Word-list recall data from adults with traumatic brain injury were modeled using a uniform prior in the Bayesian framework. From the resultant posterior probability distributions, we derived a measure referred to as retention probability (RPr), which distinguishes the retention of relatively good and poor learners. PR and RPr scores were compared on their distributional properties and associations with theoretically related memory measures.

Significant distributional differences between PR and RPr were observed. RPr removed the conspicuous ceiling of PR, resulting in stronger correlational and predictive relationships with other memory measures.

A Bayesian procedure for quantifying memory retention has psychometric advantages and potentially widespread applicability for measuring the change in behavioral features over time. Future directions are briefly discussed. A sample RPr calculator is provided for interactive exploration of the method.

This study aims to generate country-specific norms for two episodic memory tasks and a verbal fluency test among middle-aged and older adults using nationally representative data from nine low-, middle-, and high-income countries.

Data from nine countries in Africa, Asia, Europe, and Latin America were analyzed (n = 42,116; aged 50 years or older). Episodic memory was assessed with the word list memory (three trials of immediate recall) and word list recall (delayed recall). Verbal fluency was measured through the animal naming task. Multiple linear regression models with country-specific adjustments for gender, age, education, and residential area were carried out.

Both age and education showed high influence on test performance (i.e. lower cognitive performance with increasing age and decreasing years of education, respectively), while the effect of sex and residential area on cognitive function was neither homogeneous across countries nor across cognitive tasks.

Our study provided sex-, age-, education-, and residential area-specific regression-based norms that were obtained from one of the largest normative study worldwide on verbal recall and fluency tests to date. Findings derived from this study will be especially useful for clinicians and researchers based at countries where cognitive norms are limited.

It is uncertain if long-term levels of low-density lipoprotein-cholesterol (LDL-C) affect cognition in middle age. We examined the association of LDL-C levels over 25 years with cognitive function in a prospective cohort of black and white US adults.

Lipids were measured at baseline (1985–1986; age: 18–30 years) and at serial examinations conducted over 25 years. Time-averaged cumulative LDL-C was calculated using the area under the curve for 3,328 participants with ≥3 LDL-C measurements and a cognitive function assessment. Cognitive function was assessed at the Year 25 examination with the Digit Symbol Substitution Test [DSST], Rey Auditory Visual Learning Test [RAVLT], and Stroop Test. A brain magnetic resonance imaging (MRI) sub-study (N = 707) was also completed at Year 25 to assess abnormal white matter tissue volume (AWMV) and gray matter cerebral blood flow volume (GM-CBFV) as secondary outcomes.

There were 15.6%, 32.9%, 28.9%, and 22.6% participants with time-averaged cumulative LDL-C <100 mg/dL, 101–129 mg/dL, 130–159 mg/dL, and ≥160 mg/dL, respectively. Standardized differences in all cognitive function test scores ranged from 0.16 SD lower to 0.09 SD higher across time-averaged LDL-C categories in comparison to those with LDL-C < 100 mg/dL. After covariate adjustment, participants with higher versus lower time-averaged LDL-C had a lower RAVLT score (p-trend = 0.02) but no differences were present for DSST, Stroop Test, AWMV, or GM-CBFV.

Cumulative LDL-C was associated with small differences in memory, as assessed by RAVLT scores, but not other cognitive or brain MRI measures over 25 years of follow-up.

Demographic trends and the globalization of neuropsychology have led to a push toward inclusivity and diversity in neuropsychological research in order to maintain relevance in the healthcare marketplace. However, in a review of neuropsychological journals, O’Bryant et al. found systematic under-reporting of sample characteristics vital for understanding the generalizability of research findings. We sought to update and expand the findings reported by O’Bryant et al.

We evaluated 1648 journal articles published between 2016 and 2019 from 7 neuropsychological journals. Of these, 1277 were original research or secondary analyses and were examined further. Articles were coded for reporting of age, sex/gender, years of education, ethnicity/race, socioeconomic status (SES), language, and acculturation. Additionally, we recorded information related to sample size, country, and whether the article focused on a pediatric or adult sample.

Key variables such as age and sex/gender (both over 95%) as well as education (71%) were frequently reported. Language (20%) and race/ethnicity (36%) were modestly reported, and SES (13%), and acculturation (<1%) were more rarely reported. SES was more commonly reported in pediatric than adult samples, and the opposite was true for education. There were differences between the present results and those of O’Bryant et al., though the same general trends remained.

Reporting of demographic data in neuropsychological research appears to be slowly changing toward greater comprehensiveness, though clearly more work is needed. Greater systematic reporting of such data is likely to be beneficial for the generalizability and contextualization of neurocognitive function.

Leukoaraiosis, or white matter rarefaction, is a common imaging finding in aging and is presumed to reflect vascular disease. When severe in presentation, potential congenital or acquired etiologies are investigated, prompting referral for neuropsychological evaluation in addition to neuroimaging. T2-weighted imaging is the most common magnetic resonance imaging (MRI) approach to identifying white matter disease. However, more advanced diffusion MRI techniques may provide additional insight into mechanisms that influence the abnormal T2 signal, especially when clinical presentations are discrepant with imaging findings.

We present a case of a 74-year-old woman with severe leukoaraoisis. She was examined by a neurologist, neuropsychologist, and rheumatologist, and completed conventional (T1, T2-FLAIR) MRI, diffusion tensor imaging (DTI), and advanced single-shell, high b-value diffusion MRI (i.e., fiber ball imaging [FBI]).

The patient was found to have few neurological signs, no significant cognitive impairment, a negative workup for leukoencephalopathy, and a positive antibody for Sjogren’s disease for which her degree of leukoaraiosis would be highly atypical. Tractography results indicate intact axonal architecture that was better resolved using FBI rather than DTI.

This case illustrates exceptional cognitive resilience in the face of severe leukoaraiosis and the potential for advanced diffusion MRI to identify brain reserve.

Cannabis use is associated with relative cognitive weaknesses as observed by cross-sectional as well as longitudinal research. Longitudinal studies, controlling for relevant confounds, are necessary to differentiate premorbid from post-initiation contributions to these effects.

We followed a sample of adolescents and young adults across ten years. Participants provided neurocognitive data and substance use information at two-year intervals. Participants who initiated cannabis and/or alcohol use were identified (n = 86) and split into alcohol-only initiators (n = 39) and infrequent (n = 29) and moderately frequent (n = 18) cannabis initiators. Participants completed the Rey Auditory Verbal Learning Task (RAVLT) and the Iowa Gambling Task (IGT). Group differences before and after substance use initiation and the extent to which alcohol, nicotine, and cannabis use frequencies contributed to cognitive functions over time were examined.

After controlling for parental education, RAVLT new learning was worse in moderately frequent cannabis users prior to use initiation. RAVLT total learning and delayed recall showed significant declines from pre- to post-initiation in moderately frequent cannabis users. Regression analyses confirmed that frequencies of cannabis, but not alcohol, use contributed to post-initiation variations. Nicotine use showed an independent negative association with delayed memory. Findings for the IGT were not significant.

Verbal learning and memory may be disrupted following the initiation of moderately frequent cannabis use while decreased new learning may represent a premorbid liability. Our use of a control group of alcohol-only users adds interpretive clarity to the findings and suggests that future studies should carefully control for comorbid substance use.

Research on the lateralizing value of neuropsychological tests is limited among Latino people with epilepsy (PWE). This study aims to evaluate the utility of two confrontation naming measures in laterality determination.

Data were collected from 71 Latino PWE who completed the Vocabulario Sobre Dibujos (VSD) and the Pontón-Satz Modified Boston Naming Test (MBNT). Raw and standardized scores were examined to determine diagnostic accuracy for predicting left hemisphere (LH) epilepsy for the full sample and using a sample-specific median split of educational attainment.

The MBNT demonstrated adequate classification accuracy (65.7%, 77.1%) as did the VSD (54.3%, 74.3%) for predicting LH seizure laterality using raw and standardized scores, respectively. For participants with ≥ 9 years of education (HEdu), receiver operator characteristic curve analyses showed a raw/percentile cutoff of ≤ 26/≤ 5th on the VSD, yielding 53%–58% sensitivity/87%–83% specificity. A raw score cutoff of ≤ 17 on MBNT produced 47% sensitivity/78% specificity for HEdu participants.

The VSD was found to have greater flexibility in determining cutoff scores using either raw or standardized scores for predicting seizure laterality. This study provides interpretation guidance, emphasizing education as a pertinent variable, to optimize lateralization accuracy for Latino PWE.

This study examines the relationship of serum total tau, neurofilament light (NFL), ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1), and glial fibrillary acidic protein (GFAP) with neurocognitive performance in service members and veterans with a history of traumatic brain injury (TBI).

Service members (n = 488) with a history of uncomplicated mild (n = 172), complicated mild, moderate, severe, or penetrating TBI (sTBI; n = 126), injured controls (n = 116), and non-injured controls (n = 74) prospectively enrolled from Military Treatment Facilities. Participants completed a blood draw and neuropsychological assessment a year or more post-injury. Six neuropsychological composite scores and presence/absence of mild neurocognitive disorder (MNCD) were evaluated. Within each group, stepwise hierarchical regression models were conducted.

Within the sTBI group, increased serum UCH-L1 was related to worse immediate memory and delayed memory (R2Δ = .065–.084, ps < .05) performance, while increased GFAP was related to worse perceptual reasoning (R2Δ = .030, p = .036). Unexpectedly, within injured controls, UCH-L1 and GFAP were inversely related to working memory (R2Δ = .052–.071, ps < .05), and NFL was related to executive functioning (R2Δ = .039, p = .021) and MNCD (Exp(B) = 1.119, p = .029).

Results suggest GFAP and UCH-L1 could play a role in predicting poor cognitive outcome following complicated mild and more severe TBI. Further investigation of blood biomarkers and cognition is warranted.