In utero and peripartum antiretroviral exposure as predictor of cognition in 6- to 10-year-old HIV-exposed Ugandan children - a prospective cohort study.

OBJECTIVES: To quantify association between in utero/peripartum antiretroviral (IPA) exposure and cognition, i.e. executive function (EF) and socioemotional adjustment (SEA), in school-aged Ugandan children who were perinatally HIV-infected (CPHIV, n = 100) and children who were HIV-exposed but uninfected (CHEU, n = 101). METHODS: Children were enrolled at age 6-10 years and followed for 12 months from March 2017 to December 2018. Caregiver-reported child EF and SEA competencies were assessed using validated questionnaires at baseline, 6 and 12 months. IPA type - combination antiretroviral therapy (cART), intrapartum single-dose nevirapine ± zidovudine (sdNVP ± ZDV), nevirapine + zidovudine + lamivudine (sdNVP + ZDV + 3TC) - or no IPA (reference) was verified via medical records. IPA-related standardized mean differences (SMDs) with corresponding 95% confidence intervals (CIs) in cognitive competencies were estimated from regression models with adjustment for caregiver sociodemographic and contextual factors. Models were fitted separately for CPHIV and CHEU. RESULTS: Among CPHIV children, cART (SMD = -0.82, 95% CI: -1.37 to -0.28) and sdNVP ± ZDV (SMD = -0.41, 95% CI: -0.81 to -0.00) vs. no IPA predicted lower executive dysfunction over 12 months. Intrapartum sdNVP + ZDV + 3TC vs. no IPA predicted executive dysfunction (SMD = 0.80, 95% CI: 0.30-1.31), SEA problems (SMD = 0.63-0.76, 95% CI: 0.00-1.24) and lower adaptive skills (SMD = -0.36, 95% CI: -0.75-0.02) over 12 months among CHEU. Further adjustment for contextual factors attenuated associations, although most remained of moderate clinical importance (|SMD| > 0.33). CONCLUSIONS: Among CPHIV children, cART and sdNVP ± ZDV IPA exposure predicted, on average, lower executive dysfunction 6-10 years later. However, peripartum sdNVP + ZDV + 3TC predicted executive and SEA dysfunction among CHEU 6-10 years later. These data underscore the need for more research into long-term effects of in utero ART to inform development of appropriate interventions so as to mitigate cognitive sequelae.

Motor control and cognition deficits associated with protein carbamoylation in food (cassava) cyanogenic poisoning: Neurodegeneration and genomic perspectives.

A case-control design determined whether konzo, an upper motoneuron disease linked to food (cassava) toxicity was associated with protein carbamoylation and genetic variations. Exon sequences of thiosulfate sulfurtransferase (TST) or mercaptopyruvate sulfurtransferase (MPST), plasma cyanide detoxification rates, and 2D-LC-MS/MS albumin carbamoylation were assessed in 40 children [21 konzo-affected and 19 putatively healthy controls, mean (SD) age: 9.2 (3.0) years] subjected to cognition and motor testing using the Kaufman Assessment Battery and the Bruininks/Oseretsky Test, respectively. Konzo was significantly associated with higher levels of carbamoylated peptides 206-219 (LDELRDEGKASSAK, pep1) after adjusting for age, gender, albumin concentrations and BUN [regression coefficient: 0.03 (95%CI:0.02-0.05), p = 0.01]. Levels of pep1 negatively correlated with performance scores at all modalities of motor proficiency (r = 0.38 to 0.61; all p < 0.01) or sequential processing (memory)(r = - 0.59, p = 0.00) and overall cognitive performance (r = - 0.48, p = 0.00) but positively with time needed for cyanide detoxification in plasma (r = 0.33, p = 0.04). Rare potentially damaging TST p.Arg206Cys (rs61742280) and MPST p.His317Tyr (rs1038542246) heterozygous variants were identified but with no impact on subject phenotypes. Protein carbamoylation appears to be a reliable marker for cassava related neurodegeneration.

Caregiver mental health and HIV-infected child wellness: perspectives from Ugandan caregivers.

Prior studies indicate a substantial link between maternal depression and early child health but give limited consideration to the direction of this relationship or the context in which it occurs. We sought to create a contextually informed conceptual framework of this relationship through semi-structured interviews with women that had lived experience of caring for an HIV-infected child while coping with depression and anxiety symptoms. Caregivers explained their role in raising healthy children as complex and complicated by poverty, stigma, and isolation. Caregivers discussed the effects of their own mental health on child well-being as primarily emotional and behavioral, and explained how looking after a child could bring distress, particularly when unable to provide desired care for sick children. Our findings suggest the need for investigation of the reciprocal effects of child sickness on caregiver wellness and for integrated programs that holistically address the needs of HIV-affected families.

Lower sulfurtransferase detoxification rates of cyanide in konzo-A tropical spastic paralysis linked to cassava cyanogenic poisoning.

Using a matched case-control design, we sought to determine whether the odds of konzo, a distinct spastic paraparesis associated with food (cassava) cyanogenic exposure in the tropics, were associated with lower cyanide detoxification rates (CDR) and malnutrition. Children with konzo (N=122, 5-17 years of age) were age- and sex-matched with presumably healthy controls (N=87) and assessed for motor and cognition performances, cyanogenic exposure, nutritional status, and cyanide detoxification rates (CDR). Cyanogenic exposure was ascertained by thiocyanate (SCN) concentrations in plasma (P-SCN) and urine (U-SCN). Children with a height-for-age z-score (HAZNCHS)<-2 were classified as nutritionally stunted. CDR was measured as time required to convert cyanide to SCN, and expressed as ms/µmol SCN/mg protein or as mmolSCN/ml plasma/min. Mean (SD) U-SCN in children with konzo was 521.9 (353.6) µmol/l and was, significantly higher than 384.6 (223.7) µmol/l in those without konzo. Conditional regression analysis of data for age- and sex- matched case-control pairs showed that konzo was associated with stunting (OR: 5.8; 95% CI: 2.7-12.8; p<0.01; N=83 paired groups) and higher U-SCN (OR: 1.1; 95% CI: 1.02-1.20 per 50-µmol increase in U-SCN; p=0.02; N=47 paired groups). After adjusting for stunting and U-SCN, the odds of developing konzo was reduced by 63% (95% CI: 11-85%, p=0.03; N=41 paired groups) for each 5mmol SCN/(ml plasma/min)-increase in CDR. Linear regression analysis indicated a significant association between BOT-2 or KABC-II scores and both the HAZNCHS z-score and the U-SCN concentration, but not the CDR. Our findings provide evidence in support of interventions to remove cyanogenic compounds from cassava prior to human consumption or, peharps, enhance the detoxification of cyanide in those relying on the cassava as the main source of food.

Lower serum levels of selenium, copper, and zinc are related to neuromotor impairments in children with konzo.

We assessed the relationship between key trace elements and neurocognitive and motor impairments observed in konzo, a motor neuron disease associated with cassava cyanogenic exposure in nutritionally challenged African children. Serum concentrations of iron, copper, zinc, selenium, and neurotoxic lead, mercury, manganese, cadmium, and cobalt were measured in 123 konzo children (mean age 8.53 years) and 87 non-konzo children (mean age 9.07 years) using inductively coupled plasma mass spectrometry (ICPMS). Concentrations of trace elements were compared and related to performance scores on the Kaufman Assessment Battery for Children, 2nd edition (KABC-II) for cognition and Bruininks-Oseretsky Test, 2nd edition (BOT-2) for motor proficiency. Children with konzo had low levels of selenium, copper, and zinc relative to controls. Selenium concentration significantly correlated with serum 8,12-iso-iPF2α-VI isoprostane (Spearman r=0.75, p<0.01) and BOT-2 scores (r=0.31, p=0.00) in children with konzo. Elemental deficiency was not associated with poor cognition. Mean (SD) urinary level of thiocyanate was 388.03 (221.75) µmol/l in non-konzo compared to 518.59 (354.19) µmol/l in konzo children (p<0.01). Motor deficits associated with konzo may possibly be driven by the combined effects of cyanide toxicity and Se deficiency on prooxidant mechanisms. Strategies to prevent konzo may include dietary supplementation with trace elements, preferentially, those with antioxidant and cyanide-scavenging properties.

Designing and evaluating Brain Powered Games for cognitive training and rehabilitation in at-risk African children.

BACKGROUND: Valid, reliable, accessible, and cost-effective computer-training approaches can be important components in scaling up educational support across resource-poor settings, such as sub-Saharan Africa. The goal of the current study was to develop a computer-based training platform, the Michigan State University Games for Entertainment and Learning laboratory's Brain Powered Games (BPG) package that would be suitable for use with at-risk children within a rural Ugandan context and then complete an initial field trial of that package. METHODS: After game development was completed with the use of local stimuli and sounds to match the context of the games as closely as possible to the rural Ugandan setting, an initial field study was completed with 33 children (mean age = 8.55 ± 2.29 years, range 6-12 years of age) with HIV in rural Uganda. The Test of Variables of Attention (TOVA), CogState computer battery, and the Non-Verbal Index from the Kaufman Assessment Battery for Children, 2nd edition (KABC-II) were chosen as the outcome measures for pre- and post-intervention testing. The children received approximately 45 min of BPG training several days per week for 2 months (24 sessions). RESULTS: Although some improvements in test scores were evident prior to BPG training, following training, children demonstrated clinically significant changes (significant repeated-measures outcomes with moderate to large effect sizes) on specific TOVA and CogState measures reflecting processing speed, attention, visual-motor coordination, maze learning, and problem solving. CONCLUSIONS: Results provide preliminary support for the acceptability, feasibility, and neurocognitive benefit of BPG and its utility as a model platform for computerized cognitive training in cross-cultural low-resource settings.

Determinants of cognitive performance in children relying on cyanogenic cassava as staple food.

While risk factors for konzo are known, determinants of cognitive impairment in konzo-affected children remain unknown. We anchored cognitive performance (KABC-II scores) to serum levels of free-thyroxine (free-T4), thyroid-stimulating hormone (TSH), albumin, and motor proficiency (BOT-2 scores) in 40 children including 21 with konzo (median age: 9 years) and 19 without konzo (median age: 8 years). A multiple regression model was used to determine variables associated with changes in KABC-II scores. Age (ß: -0.818, 95% CI: -1.48, -0.152) (p = 0.018), gender (ß: -5.72; 95% CI: -9.87, -1.57 for females) (p = 0.009), BOT-2 score (ß: 0.390; 95% CI: 0.113, 0.667) (p = 0.008), and free-T4 (ß: 1.88; 95% CI: 0.009, 3.74) (p = 0.049) explained 61.1 % of variation in KABC-II scores. Subclinical hypothyroidism was not associated with poor cognition. A crude association was found between serum albumin and KABC-II scores (ß: 1.26; 95 % CI: 0.136, 2.39) (p = 0.029). On spot urinary thiocyanate reached 688 µmol/l in children without konzo and 1,032 µmol/L in those with konzo. Female gender and low serum albumin are risk factors common to cognitive and proportionally associated motor deficits in children exposed to cassava cyanogens. The two types of deficits may share common mechanisms.

A preliminary examination of the construct validity of the KABC-II in Ugandan children with a history of cerebral malaria.

BACKGROUND: Several diseases and adverse conditions affect the cognitive development of children in Sub-Saharan African. There is need to assess these children to determine which abilities are affected and the severity of the damage so as to plan interventions accordingly. However most psychological tests developed in the West have not been validated in this region making it impossible to know whether they measure what they were intended to in African children. OBJECTIVE: To examine the construct validity of the Kaufman Assessment Battery for Children, Second Edition (KABC-II) in Ugandan children. METHODS: Sixty five Ugandan children aged 7 to 16 years (Mean=9.90, SD=2.46) were tested using the KABC-II 44.59 months (SD=2.82) after an episode of cerebral malaria. The KABC-II scales of Sequential Processing, Simultaneous Processing, Planning and Learning were administered. In order to identify which factors result from administering the KABC-II in these children, factor analysis using principal component analysis with Varimax rotation was applied to the subtests making up the above scales. RESULTS: Five factors emerged after factor analysis comprising of subtests measuring Sequential Processing, Simultaneous Processing, Planning and Learning. The fifth scale comprised of subtests measuring immediate and delayed recall. CONCLUSION: This preliminary study in Ugandan children shows the KABC-II to have good construct validity with subtests measuring similar abilities loading on the same factor. The KABC-II can be used in assessing Ugandan children after a few modifications. Further analysis of its psychometric properties in Ugandan children is required.

Seizure Activity and Neurological Sequelae in Ugandan Children who have Survived an Episode of Cerebral Malaria

Background: Seizures are a common presenting feature in children with cerebral malaria (CM) and neurologic deficits have been described in survivors of CM. However few prospective studies have described the frequency of seizure activity and neurologic deficits in survivors of CM over time. Methods: Eighty-two children aged 3 to 12 years who survived an episode of CM were followed up and monitored for seizure activity and neurologic deficits at discharge; 3; 6 and 24 months. Seventy six children with uncomplicated malaria (UM) and 105 healthy community controls (CC) age 3 to 12 years were recruited as comparison groups and the frequency of seizures in the 6 to 24 month follow-up period was compared in the 3 groups. Results: Cumulative incidence of seizures increased over time in children with CM; with a total of 2 of 76 children (2.6) reporting seizures at 3 months; 3 of 74 children (4.1) at 6 months and 11 of 68 children (16.2) at 24 months (Chi square for trend = 9.36; P=0.002). In contrast; neurologic deficits almost completely resolved over time; occurring in 19 of 76 children with CM (25) at discharge; 2 of 74 children (2.7) at 6 months; and 1 of 68 (1.5) children at 24 months. Conclusions: During the 24 months following a CM episode; neurologic deficits resolve but the cumulative incidence of seizures increases in children with CM. Neurologic impairment after an episode of CM may not be limited to the neurologic deficits seen at discharge

Modality specificity of memory span tasks among Zaïrian children: A developmental perspective.

Digit span (DS) and visual memory span (VMS) tasks have been shown to be distinct in young children but fail to show modality specificity in older American children and adults (Fastenau, Conant, & Lauer, 1997, 1998). The present study examines the possibility that processing of VMS becomes automatized with written language training. In a sample of 139 Zaïrian children, separate factor analyses on K-ABC data for younger children (6.1-8.5 years) and older children (8.6-12.8 years) yielded two-factor solutions in both cases, which appear to represent verbal and visual-spatial abilities. Modality specificity of the visual span task is supported in both age groups. Findings of modality specificity in both Zaïrian age groups provides support for the theoretical distinction between verbal and visual memory span. Continued modality specificity of visual memory span tasks in older Zaïrian children suggests that the increased verbal loadings of these tasks seen for older American children may reflect differences in written language development.

An ecological paradigm for a health behavior analysis of "konzo", a paralytic disease of Zaire from toxic cassava.

Konzo is an irreversible paralytic disease afflicting tens of thousands of women and children in rural Zaire and throughout sub-Sahara Africa. The disease can occur where bitter, high-yield varieties of cassava that thrive in arid soils provide the basic nutritional staple. The paraparesis is related to upper motor neuron damage stemming from the consumption of insufficiently processed toxic cassava roots (manioc) and a diet poor in the sulfur-based amino acids necessary for the body to detoxify the cyanide in this plant. The ecological paradigm [Kelly (1968) Toward an ecological conception of preventive interventions, in Research Contributions from Psychology to Community Mental Health, ed. J. W. Carter, pp. 75-99, Behavioral Publications, New York] is adapted as the evaluative model for evaluating the potential effectiveness of a proposed health behavior/education intervention for konzo. This qualitative research model involves a consideration of the cycling of resources (human labor and material), adaptation (of personal and social practices related to the health issue), succession (of social institutions, values, customs), interdependence (of human social units), and feasibility (or the congruency of the proposed intervention and cultural traits of the host environment). Based on this evaluative model, a health behavior/education level of intervention focusing specifically on using focus groups and multichannel communication techniques to discourage unsafe manioc short-soaking tendencies among village women farmers seems feasible. Such an approach is not dependent on sophisticated technical or material inputs and is therefore readily sustainable without outside agency support once it is effectively initiated within that culture.

Economic advantage and the cognitive ability of rural children in Zaire.

Rural Zairian children (n = 32), 4 to 6 years old, were enrolled in a preschool educational and nutritional enrichment program throughout the school year. As part of the evaluative research for this program, cognitive and motor development of the children was assessed with the American Guidance Service (AGS) Early Childhood Screening Profiles (ECSP; Harrison et al., 1990) battery, adapted to the local Bantu dialect of Kituba. On the ECSP global indicator of cognitive ability, the children in the enrichment program performed significantly better than their counterparts in nearby villages, although the two groups did not differ significantly on motor development or anthropometric indicators of physical development. The results indicate that rural African children with reasonable nutritional status demonstrate significantly improved intellectual development in response to a comprehensive economic enhancement and educational enrichment program for them and their families.

Longitudinal neuropsychological and genetic linkage analysis of persons at risk for Huntington's disease.

OBJECTIVE: To determine (1) whether the neuropsychological profiles of healthy individuals at risk (AR) for Huntington's disease who were positive (AR/+) or negative (AR/-) for the Huntington's disease genetic marker differed from those of symptomatic patients with Huntington's disease and normal control individuals and (2) whether the neuropsychological performance of the two AR groups differed from each other on three assessments during a 4-year span. DESIGN: Case-control, double-blind study, with AR status determined by genetic linkage analysis (G8 probe), in addition to examination of trinucleotide repeats for most AR subjects. SETTING: The Neuropsychology Program in the Department of Psychiatry and the Department of Neurology at the University of Michigan Medical Center, Ann Arbor, a tertiary care center. PARTICIPANTS: Eight subjects matched as closely as possible for age, gender, and education in each of the following groups: AR/+, AR/-, normal control, and Huntington's disease. MEASURES: A battery of neuropsychological tasks, including measures of intelligence, memory, problem solving, and motor ability. RESULTS: Although both AR groups demonstrated variability on select intellectual subtests relative to normal subjects, they did not differ from each other on the three assessments during a 4-year span. Patients with Huntington's disease performed more poorly than the other groups across a range of neuropsychological measures. CONCLUSIONS: These results do not support previous evaluations concluding that AR/+ individuals demonstrate cognitive impairments as compared with AR/- individuals. Findings in earlier studies without genetic linkage analysis of lower performance of AR individuals, including children, as compared with normal controls may relate to extraneous environmental and familial issues that interfere with intellectual development.

A preliminary evaluation of the cognitive and motor effects of pediatric HIV infection in Zairian children.

Fourteen asymptomatic HIV-infected Zairian children under 2 years of age displayed social and motor developmental deficits on the Denver Developmental Screening Test when compared with 20 HIV-negative cohorts born to HIV-infected mothers and 16 control children. In a second study, 11 infected children over 2 years of age had sequential motor and visual-spatial memory deficits on the Kaufman Assessment Battery for Children and motor development deficits on the Early Childhood Screening Profiles. HIV infection affects central nervous system structures mediating motor and spatial memory development, even in seemingly asymptomatic children. Furthermore, maternal HIV infection compromises the labor-intensive provision of care in the African milieu and undermines global cognitive development in even uninfected children.

PIP: Language and motor skill deficits have been noted for HIV-infected children when tested with Stanford-Binet. With the McCarthy Scales of Children's Abilities, quantitative, verbal, and memory ability deficits have also been documented with infected children and are particularly significant for those children with accompanying neurological impairment from the virus. Deficits of visual-spatial integrative ability and memory have also been identified with the Kaufman Assessment Battery for Children. This paper reports results from a direct comparison of differences in cognitive and motor skills development between HIV-1-seropositive and HIV-1-seronegative children born to infected African mothers. Both subgroups were subsequently compared to a third group of HIV-negative children born to noninfected mothers in order to better assess some of the second-order effects of the epidemic upon the development of children who are not themselves infected, but who bear the consequences of the disease in the form of illness of the primary caregiver, and the hardship which that imposes upon the entire family. Such factors are most likely especially severe for nonaffluent families in developing countries. 14 asymptomatic HIV-infected Zairian children under 2 years old displayed social and motor developmental deficits on the Denver Developmental Screening Test when compared with 20 HIV-negative cohorts born to HIV-infected mothers and 16 control children. In the second study, 11 infected children over 2 years old had sequential motor and visual-spatial memory deficits on the Kaufman Assessment Battery for Children and motor development deficits on the Early Childhood Screening Profiles. The authors conclude that HIV infection affects central nervous system structures mediating motor and spatial memory development, even in seemingly asymptomatic children. Moreover, maternal HIV infection compromises the labor-intensive provision of care in the African milieu and undermines global cognitive development in even uninfected children.

Effects of depression on memory performance and metamemory in children.

OBJECTIVE: To investigate the effects of depression on memory performance and metamemory in children. METHOD: Performance on automatic memory tasks (frequency of occurrence), effortful memory tasks (Children's Auditory Verbal Learning Test), and a Metamemory Battery were examined in 21 unmedicated, depressed children and 21 nondepressed controls (matched for age, gender, and full-scale IQ). Subjects were divided into three groups based on depression severity (high depressed, low depressed, nondepressed). RESULTS: High depressed patients demonstrated performance deficits relative to nondepressed and low depressed children on the Children's Auditory Verbal Learning Test, Immediate Recall trial. Both groups of depressed children performed more poorly on the Metamemory Battery when compared to nondepressed children. Severity of depression differentiated overall performance. Metamemory performance of depressed subjects indicates possible difficulty with overestimation of memory abilities. No differences were found on automatic memory task performance. CONCLUSIONS: Memory impairment in depression varies as a function of severity and may be evident only when a certain level of depression is reached. Overestimation of memory ability by depressed children may be an attempt to compensate for feelings of inadequacy or inferiority. It may also lead depressives to use poor judgment in selecting appropriate solutions for problems. Targeting these cognitive distortions could be a focal point of clinical and educational interventions.

Effects of treatment for intestinal parasites and malaria on the cognitive abilities of schoolchildren in Zaire, Africa.

Ninety-seven Zairian schoolchildren were evaluated for cognitive ability, health status, and quality of home environment. Children successfully treated for serious types of chronic intestinal parasites demonstrated significant improvements in K-ABC Spatial Memory, supporting this task as one of the more sensitive measures to changes in general health and neurological integrity. These findings were not obtained for successful treatment of low-grade malaria infection. Children initially negative for intestinal parasites tended to come from more economically and socially favorable home environments. They also demonstrated more dramatic improvements in visual-spatial analysis tasks. The implication is that the home environment factors conducive to chronic infestation with intestinal parasites are markers for favorability of the developmental milieu affecting long-term intellectual development.

Improvements in cognitive performance for schoolchildren in Zaire, Africa, following an iron supplement and treatment for intestinal parasites.

Tested 47 first-year primary school children at a mission school in rural Zaire for cognitive ability with the Kaufman Assessment Battery for Children (K-ABC) adopted to the language of Kituba. Within a day of this test, each child was evaluated for blood hemoglobin (Hgb) level and the presence of intestinal parasites. Half of the children received an iron supplement (20 mg Fe) for 30 days and those children positive for the intestinal parasites of ankylostome or ascaris were randomly selected to receive either a vermifuge treatment or placebo. All of the children were again evaluated medically and cognitively 4 weeks after the initiation of treatment. Using discriminant analysis, performance on the Mental Processing Composite of the K-ABC 1 month after treatment in combination with increases in blood Hgb resulted in the successful classification of 74% in terms whether a child had received both iron supplement and vermifuge treatment (p = .007). With respect to our home evaluation for each child, factors related to the nutritional and economic well-being of the home environment proved a reliable marker for Simultaneous Processing ability. However, the present findings also suggest that over the short-term, changes in blood Hgb that accompany both vermifuge and iron supplement treatment together can improve certain aspects of cognitive ability, perhaps by means of heightened attentional capacity.

Verbal fluency and positron emission tomographic mapping of regional cerebral glucose metabolism.

Impairment in verbal fluency (VF) has been a consistently reported clinical feature of focal cerebral deficits in frontal and temporal regions. More recent behavioral activation studies with healthy control subjects using positron emission tomography (PET), however, have noted a negative correlation between performance on verbal fluency tasks and regional cortical activity. To see if this negative relationship extends to steady-state non-activation PET measures, thirty-three healthy adults were given a VF task within a day of their 18F-2-fluoro-2-deoxy-D-glucose PET scan. VF was found to correlate positively with left temporal cortical region metabolic activity but to correlate negatively with right and left frontal activity. VF was not correlated significantly with right temporal cortical metabolic activity. Some previous studies with normals using behavioral activation paradigms and PET have reported negative correlations between metabolic activity and cognitive performance similar to that reported here. An explanation for the disparate relationships that were observed between frontal and temporal brain areas and VF might be found in the mediation of different task demands by these separate locations, i.e., task planning and/or initiation by frontal regions and verbal memory by the left temporal area.

The effect of culture on a visual-spatial memory task.

The visual-spatial memory ability of 25 Zairian elementary school children was compared with that of 23 Scottish children, using a variation of Kearins's (1976) object placement task. The Scottish children demonstrated significantly better visual-spatial memory than the Zairian children when the easiest (small household objects) of three arrays was presented. The Scottish and Zairian children demonstrated a similar level of visual-spatial ability when the other two arrays (geometric shapes and a variety of natural pieces of wood) were presented, and there were no significant gender differences. Although the Australian Aboriginal children's performance on the visual-spatial task in Drinkwater's (1976) study was superior to the White children's performance (Kearins, 1976, 1981), the Zairian children's performance in this study was not. Perhaps the Aboriginal groups, over countless generations navigating the trackless desert of western Australia, were forced by their environment to develop an aptitude for direction finding that Zairians (whose ecological situation more closely resembles that of Europeans) have not.

The utility and generality of Mini-Mental State Examination scores in Alzheimer's disease.

The present study sought to evaluate the validity and generality of the Mini-Mental State Examination (MMSE) and its subsection scores. We gave the MMSE and other neuropsychological tests to 51 patients with probable Alzheimer's disease. On the basis of correlational and factor analyses, overall performance on the MMSE proved to have good concurrent validity with other comprehensive neuropsychological assessment instruments. However, the MMSE subsections should not be viewed as highly specific measures of cognition or memory.