„The Hierarchy within the Brain“ – A fMRI Study of Neuroanatomical Correlation of Semantic Structures of Superordination in Contrast to Synonymy

This fMRI study looks for anatomical correlations to the semantic structure of super- and subordination. A homogeneous group of eleven students was presented a series of 1000 words during an MRI. A series of 820 nonsense words consisting of random consonants was the baseline. At irregular times in between two sequential meaningful words were shown. The students had to decide whether these two words were in a meaningful order. Three groups of words were shown: Words with a concrete vs. abstract content and largest semantic distance, synonyms and terms in relation of hyponymy and superordination. The following linguistic considerations were posed as background: In the context of semantic hierarchy of the vocabulary synonyms are on the identical level while the relation of superordination and hyponymy forms a treelike structure. Concrete vs. abstract terms were selected to design a paradigm in accordance with the oddball-principle. At the recognition of superordinated terms in contrast to the recognition of synonyms a higher activity could be demonstrated bilaterally in BA 10, in left cerebral hemisphere in BA 21, BA 44 and BA 47, and in right cerebral hemisphere in BA 19 and 45.. The latter region was the maximally activated one. Thus it was shown that hierarchization of the vocabulary, as derived from theoretical-linguistic reflections, has a neuroanatomic correlation. This result has consequences for psycholinguistic reflections as well as for the research of language acquisition. There are also new aspects considering semantic paraphasia in correlation to destruction of the WERNICKE or the BROCA area.