To investigate differences in white matter microstructure between illiterate and low-literate elderly Brazilians.
High literacy levels are believed to partially counteract the negative effects of neurodegenerative diseases. Investigating the impact of low literacy versus illiteracy on brain structure can contribute knowledge about cognitive reserve in elderly populations with low educational attainment. Fractional anisotropy is a measure derived from diffusion tensor imaging sequences that positively correlate with the integrity of the brain’s white matter microstructure.
Older adults who participated in an epidemiological study to investigate brain aging in Brazil and had magnetic resonance scans with the diffusion tensor imaging acquisition were selected (n=31). Participants were divided into two groups: (a) low-literate (n=21), with 3.4 (1.4) years of education, 79.8 (3.8) years of age, 17 cognitively healthy and four with cognitive impairment-no dementia; and (b) illiterate (n=10) with no formal schooling, 80.7 (4.1) years of age, six cognitively healthy and four with cognitive impairment-no dementia. We contrasted the two groups’ white matter microstructure measures using whole-brain and region of interest approaches.
The low-literate participants had significantly higher fractional anisotropy values in the right superior longitudinal fasciculus than did the illiterate ones.
Although our results are preliminary because of the sample size, they suggest that low literacy, versus illiteracy, is associated with higher fractional anisotropy values, which are indirect measurements of white matter microstructure. This finding provides insight into a possible mechanism by which literacy, even at low levels, may contribute to cognitive reserve.
*Departamento de Clínica Médica, Faculdade de Medicina, and
†Programa de Pós-graduação em Neurociências, Universidade Federal de Minas Gerais, Minas Gerais, Brazil
‡D’Or Institute for Research and Education (IDOR), Rio de Janeiro, Brazil
§Institute of Biomedical Sciences and National Center for Structural and Bioimaging Biology, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
Supported in part by grants from Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), grant number MCT-CNPq/MS-SCTIE-DECIT/CT-Saúde (17/2006); and Fundação de Apoio à Pesquisa de Minas Gerais (FAPEMIG) Edital Universal (2007).
The authors declare no conflicts of interest.
Correspondence: Paulo Caramelli, MD, PhD, Departamento de Clínica Médica, Faculdade de Medicina, Universidade Federal de Minas Gerais, Av. Prof Alfredo Balena, 190 Belo Horizonte, Minas Gerais, Brazil 30130-100 (e-mail: email@example.com).
Received February 1, 2018
Accepted August 27, 2018