Word learning is mediated by the left arcuate fasciculus

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 110; no. 32; pp. 13168 - 13173
• Main Authors: López-Barroso, Diana, Catani, Marco, Ripollés, Pablo, Dell'Acqua, Flavio, Rodríguez-Fornells, Antoni, de Diego-Balaguer, Ruth
• Format: Journal Article
• Language: English
• Published: Washington, DC National Academy of Sciences 06.08.2013; National Acad Sciences
• Subjects: Adult; adults; Anatomy; Aural learning; Biological and medical sciences; Biological Sciences; Brain; Brain - anatomy & histology; Brain - physiology; Brain Mapping; Connected regions; Connectivity; Correlations; Diffusion Tensor Imaging; Female; Frontal Lobe - anatomy & histology; Frontal Lobe - physiology; Functional Laterality - physiology; Fundamental and applied biological sciences. Psychology; Hemispheres; Humans; image analysis; Information processing; Language; Learning; Magnetic Resonance Imaging; Male; NMR; Nuclear magnetic resonance; Psychomotor Performance - physiology; Temporal Lobe - anatomy & histology; Temporal Lobe - physiology; Verbal Learning - physiology; Vertebrates: nervous system and sense organs; Vocabulary; Words; Young Adult; Learning; ventral stream; Acquisition process; White matter; dorsal stream; Diffusion tensor imaging; white matter; diffusion tensor imaging
• ISSN: 0027-8424; 1091-6490; 1091-6490
• DOI: 10.1073/pnas.1301696110

Human language requires constant learning of new words, leading to the acquisition of an average vocabulary of more than 30,000 words in adult life. The ability to learn new words is highly variable and may rely on the integration between auditory and motor information. Here, we combined diffusion imaging tractography and functional MRI to study whether the strength of anatomical and functional connectivity between auditory and motor language networks is associated with word learning ability. Our results showed that performance in word learning correlates with microstructural properties and strength of functional connectivity of the direct connections between Broca's and Wernicke's territories in the left hemisphere. This study suggests that our ability to learn new words relies on an efficient and fast communication between temporal and frontal areas. The absence of these connections in other animals may explain the unique ability of learning words in humans.