Normative Data Study of Verbal Fluency and Naming Tests in Elderly People in Costa Rica.

OBJECTIVE: To generate normative data for the Verbal Fluency Test (VFT) and the Boston Naming Test (BNT) in the Costa Rican population. METHOD: The sample consisted of 563 healthy older people (aged 59-90 years). Polynomial multiple regression analyses were run to evaluate the effects of the age, sex, and education variables on VFT and BNT scores. RESULTS: The results showed a significant linear effect of education on the four-letter VF scores and an effect of sex on the letter P score, with females performing better than males. The explained variance ranged from 20.9% to 28.3%. A linear effect of age and education was also found for the four semantic VF scores, with scores decreasing with increasing age and lower education. The sex variable was significant for all semantic categories, with females performing better than males except in the animal category. The explained variance ranged from 21.7% to 30.9%. In the BNT, a linear effect of education was found, so that the more education, the better the score. In addition, a sex effect was also found, with males having higher scores than females. The predictors of the model explained 9.6% of the variance. CONCLUSIONS: This is the first study that generates normative data for the VF and BNT in the Costa Rican population over 59 years of age based on demographic variables. The use of these normative data will help clinicians in Costa Rica to better understand language functioning in the elderly, allowing for better classification and diagnosis in the future.

Neuropsychological Test Performance in Cognitively Normal Spanish-speaking Nonagenarians with Little Education.

To find associations of age, sex, and education with neuropsychological test performance in cognitively normal Spanish-speaking Costa Rican nonagenarians with little education; to provide norms; and to compare their performance with similar Puerto Ricans. For 95 Costa Ricans (90-102 years old, 0-6 years of education), multiple regression assessed associations with demographics of performance on six neuropsychological tests. Analyses of covariance compared them with 23 Puerto Ricans (90-99 years old). Younger age and being female-but not education-were associated with better performance on some neuropsychological tests, in particular episodic memory. The Puerto Ricans performed better on learning and memory tasks. In cognitively intact Spanish-speaking nonagenarians with little or no education, education did not affect test performance. Additional studies of the effect of education on cognitive performance are warranted in other samples with extremely low education or old age. National differences in performance highlight the importance of group-specific norms.

Heritability of cognitive functions in families of successful cognitive aging probands from the Central Valley of Costa Rica.

We sought to identify cognitive phenotypes for family/genetic studies of successful cognitive aging (SCA; maintaining intact cognitive functioning while living to late old age). We administered a battery of neuropsychological tests to nondemented nonagenarians (n = 65; mean age = 93.4 ± 3.0) and their offspring (n = 188; mean age = 66.4 ± 5.0) from the Central Valley of Costa Rica. After covarying for age, gender, and years of education, as necessary, heritability was calculated for cognitive functions at three pre-defined levels of complexity: specific neuropsychological functions (e.g., delayed recall, sequencing), three higher level cognitive domains (memory, executive functions, attention), and an overall neuropsychological summary. The highest heritability was for delayed recall (h² = 0.74, se = 0.14, p < 0.0001) but significant heritabilities involving memory were also observed for immediate recall (h² = 0.50), memory as a cognitive domain (h² = 0.53), and the overall neuropsychological summary (h² = 0.42). Heritabilities for sequencing (h² = 0.42), fluency (h² = 0.39), abstraction (h² = 0.36), and the executive functions cognitive domain (h² = 0.35) were also significant. In contrast, the attention domain and memory recognition were not significantly heritable in these families. Among the heritable specific cognitive functions, a strong pleiotropic effect (i.e., evidence that these may be influenced by the same gene or set of genes) for delayed and immediate recall was identified (bivariate statistic = 0.934, p < 0.0001) and more modest but significant effects were found for four additional bivariate relationships. The results support the heritability of good cognitive function in old age and the utilization of several levels of phenotypes, and they suggest that several measures involving memory may be especially useful for family/genetic studies of SCA.