Abstract (eng)
Why is it that some people seem to learn new languages faster and easier than others? The present study investigates the neuroanatomical basis of language learning aptitude, with a focus on the shape of the transverse temporal gyrus/gyri (TTG/TTGs) within the Sylvian fissure of the auditory cortex. The size and shape of the first TTG (i.e., Heschl’s gyrus; HG) and of additional posterior TTG(s), when present, are highly variable both between brain hemispheres and individuals. Previous work has shown the shape of the TTG to be related to musical and linguistic abilities. Specifically, one study found that high language learning aptitude correlated with more TTGs in the right hemisphere, even though language functions are generally left-lateralized. In this study, we used TASH (Toolbox for the Automated Segmentation of Heschl’s Gyrus) and the newly developed MCAI (Multivariate Concavity Amplitude Index) toolbox, to automatically extract TTG's morphology and shape from 82 MRI scans and relate it to partici-pants’ language aptitude scores. In contrast to the previous results, we found that what sets aver-age form high language aptitude apart was less TTGs in the right hemisphere, with more surface area in the first right TTG and second left TTG. Furthermore, high executive working memory function and many languages learned in life were associated with high language learning aptitude. This corroborates previous findings of the importance of left lateralization, secondary auditory cortex and working memory in language learning and it opens questions on how aptitude relates to seeking experiences.