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Excellent study. "While it has long been recognized that certain areas in the brain's left hemisphere enable us to understand and produce language, scientists are still figuring out exactly how those areas divvy up the highly complex processes necessary to comprehend and produce language. ... Two brain areas called Broca's region and Wernicke's region serve as the main computing hubs underlying language processing, with dense bundles of nerve fibers linking the two ... Working with patients suffering from language impairments because of a variety of neurodegenerative diseases, Wilsons' team used brain imaging and language tests to disentangle the roles played by the two pathways. ... The study marks the first time it has been shown that upper and lower tracts play distinct functional roles in language processing."

While the left hemisphere of the brain is where the processing and understanding of language is, different sections of the brain control different parts of language. Two separate areas of the brain control the ability to remember and understand specific words, and the other controls how we construct sentences and make sense of them. If one of these sections is damaged, the other can still work properly, so it is possible to be able to remember words and what they mean but not know how to create sentences.

Other, non-human primates have Broca's and Wernicke's areas in their brains, as do humans. In both species, the Broca's region represents non-linguistic hand and mouth movements. Evidence also suggests that both species may have mirror neurons in this region that are involved in understanding the actions and intentions of others. In both macaques and humans, this region is likely involved in producing orofacial expressions and in understanding the intentions behind orofacial expressions of others. In humans, it has evolved an additional communicative function, namely speech production. Interestingly however, it does not appear to be involved in monkey vocalizations, which are instead mediated by limbic and brainstem areas. In both species, the region represents non-linguistic hand and mouth movements. Evidence also suggests that both species may have mirror neurons in this region that are involved in understanding the actions and intentions of others. In both macaques and humans, this region is likely involved in producing orofacial expressions and in understanding the intentions behind orofacial expressions of others. In humans, it has evolved an additional communicative function, namely speech production. However, unlike in humans, Broca's area does not appear to be involved in monkey vocalizations, which are instead mediated by limbic and brainstem areas. Regarding Wernicke's area, which is responsible for language comprehension in humans, evidence suggests that the left superior temporal gyrus is specialized for processing species-specific calls in macaques, just as it is specialized for speech comprehension in humans.

Researchers from King's College London Institute of Psychiatry, in collaboration with Bellvitge Biomedical Research Institute (IDIBELL) and the University of Barcelona, mapped the neural pathways involved in word learning among humans. They found that the arcuate fasciculus, a collection of nerve fibres connecting auditory regions at the temporal lobe with the motor area located at the frontal lobe in the left hemisphere of the brain, allows the 'sound' of a word to be connected to the regions responsible for its articulation. Differences in the development of these auditory-motor connections may explain differences in people's ability to learn words. Researchers used diffusion tensor imaging to image the structure of the brain before a word learning task and functional MRI, to detect the regions in the brain that were most active during the task. They found a strong relationship between the ability to remember words and the structure of arcuate fasciculus, which connects two brain areas: the territory of Wernicke, related to auditory language decoding, and Broca's area, which coordinates the movements associated with speech and the language processing. In participants able to learn words more successfully their arcuate fasciculus was more myelinated i.e. the nervous tissue facilitated faster conduction of the electrical signal. In addition the activity between the two regions was more co-ordinated in these participants. Dr Catani concludes, "Now we understand that this is how we learn new words, our concern is that children will have less vocabulary as much of their interaction is via screen, text and email rather than using their external prosthetic memory. This research reinforces the need for us to maintain the oral tradition of talking to our children."