Grey matter correlates of three language tests in non-demented older adults

PLoS One. 2013 Nov 5;8(11):e80215. doi: 10.1371/journal.pone.0080215. eCollection 2013.

Abstract

Language has been extensively investigated by functional neuroimaging studies. However, only a limited number of structural neuroimaging studies have examined the relationship between language performance and brain structure in healthy adults, and the number is even less in older adults. The present study sought to investigate correlations between grey matter volumes and three standardized language tests in late life. The participants were 344 non-demented, community-dwelling adults aged 70-90 years, who were drawn from the population-based Sydney Memory and Ageing Study. The three language tests included the Controlled Oral Word Association Task (COWAT), Category Fluency (CF), and Boston Naming Test (BNT). Correlation analyses between voxel-wise GM volumes and language tests showed distinctive GM correlation patterns for each language test. The GM correlates were located in the right frontal and left temporal lobes for COWAT, in the left frontal and temporal lobes for CF, and in bilateral temporal lobes for BNT. Our findings largely corresponded to the neural substrates of language tasks revealed in fMRI studies, and we also observed a less hemispheric asymmetry in the GM correlates of the language tests. Furthermore, we divided the participants into two age groups (70-79 and 80-90 years old), and then examined the correlations between structural laterality indices and language performance for each group. A trend toward significant difference in the correlations was found between the two age groups, with stronger correlations in the group of 70-79 years old than those in the group of 80-90 years old. This difference might suggest a further decline of language lateralization in different stages of late life.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age Factors
  • Aged
  • Aged, 80 and over
  • Brain / physiology*
  • Brain Mapping
  • Female
  • Functional Laterality / physiology
  • Humans
  • Language Tests*
  • Magnetic Resonance Imaging
  • Male
  • Temporal Lobe / physiology

Grants and funding

The current study was financially supported by the National Health and Medical Research Council of Australia Program Grant (ID 350833) and Project Grant (ID 510175) (http://www.nhmrc.gov.au/grants), as well as by an Australian Research Council Discovery Grant (ID DP0774213) (http://www.arc.gov.au/ncgp/dp/dp_default.htm). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.