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bioRxiv · 10.1101/2021.05.28.446230

Frontal language areas do not emerge in the absence of temporal language areas: A case study of an individual born without a left temporal lobe

Abstract

Language relies on a left-lateralized fronto-temporal brain network. How this network emerges ontogenetically remains debated. We asked whether frontal language areas emerge in the absence of temporal language areas through a deep-data investigation of an individual (EG) born without her left temporal lobe. Using fMRI methods that have been validated to elicit reliable individual-level responses, we find that--as expected for early left hemisphere damage--EG has a fully functional language network in her right hemisphere (comparable to that in n=145 controls) and performs normally on language assessments. However, we detect no response to language in EGs left frontal lobe (replicated across two sessions, 3 years apart). Another network--the multiple demand network--is robustly present in frontal lobes bilaterally, suggesting that EGs left frontal cortex can support non-linguistic cognition. The existence of temporal language areas therefore appears to be a prerequisite for the emergence of the frontal language areas.

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Tuckute, G., Paunov, A., Kean, H., Small, H., Mineroff, Z., Blank, I., Fedorenko, E.. 2021-05-28. Frontal language areas do not emerge in the absence of temporal language areas: A case study of an individual born without a left temporal lobe. https://doi.org/10.1101/2021.05.28.446230

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