Age-related differences in the areas of Broca and Wernicke using functional magnetic resonance imaging

Abstract

Previous studies have identified differences in the brain activation pattern between children and adults as well as between healthy subjects and patients using various imaging methods. Despite the increase of old people in the population, at present no study has applied a language task to investigate differences in adults. We used a simple paradigm to elicit activation in young and old adults to investigate differences in the activation of the classical Broca and Wernicke areas. Using functional magnetic resonance imaging, we applied a simple language paradigm to 10 right-handed subjects in each age group. Words and letter strings were presented separately with the instruction to decide for each pair if it represents a synonym (in case of words) or identical strings (in case of letters). The corresponding changes in the brain activation for words and letters were contrasted for each individual subject and compared by statistical parametric methods. For all subjects, the paradigm resulted in the activation of Broca and Wernicke areas in the left hemisphere only. Group analysis demonstrated a higher level of activation in Broca as well as in Wernicke areas for the young adults in comparison with the old adults. The applied, short paradigm provided consistent activation of the classical Broca and Wernicke areas in both age groups. These results demonstrate specific age-related differences in the processing of language stimuli during identical performance measures.