Are language skills related to structural features in Broca's and Wernicke's area?

Abstract

This study used structural magnetic resonance imaging to examine whether specific anatomical features of Broca's and Wernicke's areas are related to language functions in typically developing older subjects with no specific language expertize. Data from 231 subjects from the Zurich LHAB-study are used for this study. For these subjects, we obtained several psychometric measures from which we calculated performance measures reflecting specific psychological functions (language comprehension, verbal fluency, perceptual speed, visual memory, recognition of regularities, and logical thinking). From the MRI measurements, we calculated the cortical thickness and cortical surface of Broca's and Wernicke's areas. Applying multiple regression analyses, we identified a moderately strong relationship between language comprehension and the brain metrics from Broca's and Wernicke's areas and showed that approximately 10% of the variance in language comprehension performance is explained by the linear combination of all perisylvian brain metrics. The other psychological functions (verbal fluency, perceptual speed, visual memory, recognition of regularities, and logical thinking) are not related to these brain metrics. Subsequent detailed analyses revealed that the cortical thickness of Wernicke's area, in particular, contributed most to this structure-function relationship. The better performance in the language comprehension tests was related to a thicker cortex in Wernicke's area. Thus, this study demonstrates a structure-function relationship between the anatomical features of the perisylvian language areas and language comprehension, suggesting that particular anatomical features are associated with better language performance.

Lateralized behaviors in living humans: Application in the context of hominin brain evolution

“…As we previously demonstrated, there is a moderately strong relationship between language comprehension and the brain metrics from Broca's and Wernicke's areas (the cortical thickness of Wernicke's area, in particular), contributed most to this structure-function relationship (Jäncke et al, 2020). The trend during hominin evolution has been suggested to be a reduction in size on the left compared with the right hemisphere (Balzeau et al, 2014).…”

Sex differences of language abilities of preschool children with autism spectrum disorder and their anatomical correlation with Broca and Wernicke areas

“…Both Knaus (10) and Lai (15) analyzed cortical volumes of different brain regions in language studies of ASD. Jäncke (20) analyzed cortical thickness and cortical surface of region of interest, but did not include cortical volume. In this study, cortical volume, thickness, and surface area were all included.…”

“…The delineation of Broca area is currently relatively clear, containing the Brodmann areas 44 and 45, whereas there is no consensus on the delineation of some of the boundaries of Wernicke area (17)(18)(19)(20), and it is still controversial whether structures such as the superior temporal sulcus, for example, are delineated as Wernicke area. In this study, we have included the superior temporal sulcus in the Wernicke area by referring to related studies (20)(21)(22).…”

“…The delineation of Broca area is currently relatively clear, containing the Brodmann areas 44 and 45, whereas there is no consensus on the delineation of some of the boundaries of Wernicke area (17)(18)(19)(20), and it is still controversial whether structures such as the superior temporal sulcus, for example, are delineated as Wernicke area. In this study, we have included the superior temporal sulcus in the Wernicke area by referring to related studies (20)(21)(22). Due to the number of anatomical structures contained in Broca and Wernicke areas, we combined the corresponding brain areas for a clearer statistical analysis and finally analyzed only the cortical thickness, surface, and volume in Broca and Wernicke areas, with cortical thickness taken as the average of the thickness of each area and surface area and volume taken as the sum of the areas.…”

“…Due to the number of anatomical structures contained in Broca and Wernicke areas, we combined the corresponding brain areas for a clearer statistical analysis and finally analyzed only the cortical thickness, surface, and volume in Broca and Wernicke areas, with cortical thickness taken as the average of the thickness of each area and surface area and volume taken as the sum of the areas. A total of 10 brain areas contained in Broca and Wernicke areas (17)(18)(19)(20) were extracted in bilateral cerebral hemispheres using the FREESURFER v7.0 (16) software (Figure 1).…”