Cognitive development and educational attainment across the life span

Abstract: In this thesis I explore two strands of research: in the first half I explore the effects of language learning on brain structure and cognitive function. In the second half I study to what extent educational attainment alter the rate of cognitive decline in old age. These different strands of research are united through the concept of brain plasticity, which is the brain’s ability to change its structural configuration in response to new experiences. In Study I we charted the neural underpinning of foreign language learning in a sample of younger adults. A total of 56 younger adults were randomized to either a 10-week beginner’s course in Italian or a control condition. For those studying Italian we found that grey-matter change in the right hippocampus was associated with how much time they spent practicing, rather than with how good they became suggesting that effort, rather than achieved proficiency, is what drives neuroplastic change. Study II presents the largest (to date) randomized trial looking into the causal effects of language learning as cognitive engagement in older age, specifically foreign language learning. 160 people between ages 65 and 75 were randomized to either an 11-week beginner’s course in Italian, or an 11-week relaxation training course. While we predicted that language learning would improve cognitive function, specifically associative memory, we found no evidence to support this hypothesis. Study III and IV address the question of whether or not educational attainment affects the rate of cognitive decline in old age. While it is clear that educational attainment is associated with level of cognitive function, we find no evidence that it alters the rate of decline in old age. Study III address this question using a novel statistical approach while Study IV presents a meta-analysis on the subject, arriving at similar conclusions.