Tracing the structural origins of atypical language representation: consequences of prenatal mirror-imaged brain asymmetries in a dizygotic twin couple

Anna-Lisa Schuler,Sonja Lackner,Georg Langs,Ernst Schwartz,Rainer Seidl,Daniela Prayer,Lisa Bartha-Doering,Gregor Kasprian,Patric Kienast,András Jakab

doi:10.1007/s00429-018-1717-y

Anna-Lisa Schuler, Sonja Lackner + Show 8 more

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https://doi.org/10.1007/s00429-018-1717-y

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Abstract

We investigated the predictive value of prenatal superior temporal sulcus (STS) depth asymmetry in a special case of a female dizygotic twin that showed inverted prenatal asymmetry of this structure. For this purpose, we performed a follow-up investigation in this former fetus at the age of seven, where we assessed the functional language lateralization using task-based and resting-state functional magnetic resonance imaging (fMRI). As control group we employed her twin brother, who showed a typical folding pattern prenatally, as well as a complementary set of four age-matched children that had fetal MRI of their brains and typical STS depth asymmetry. We could show that the twin with the atypical fetal asymmetry of the STS also showed significantly differing rightward language lateralization in the frontal and temporal lobes. Additionally, resting-state data suggest a stronger connectivity between inferior frontal gyri in this case. The twin showed normal cognitive development. This result gives a first glimpse into the STS’ atypical asymmetry being a very early morphological marker for later language lateralization.

Highlights

IntroductionThe first associations between brain structure and function of language processing were made as early as in the nineteenth century
The associations between emerging asymmetry patterns of the human cerebral cortex observed on a structural and functional level have been the subject of an ongoing debate in clinical and cognitive neuroscience and have remained enigmatic to date.1 3 Vol.:(0123456789)Brain Structure and Function (2018) 223:3757–3767The first associations between brain structure and function of language processing were made as early as in the nineteenth century
We describe atypical cortical folding patterns in the brain of a female twin fetus, coupled with strongly atypical language lateralization, localization, and connectivity in childhood, compared to a group of typical contemporaries including her twin brother

Summary

Introduction

The first associations between brain structure and function of language processing were made as early as in the nineteenth century. The Austrian neuroanatomist Meynert (1868) was the first to show that lesions to the temporal lobes are involved in impaired language. An integration of these observations led his student Wernicke (1874) to draft the first model on the neural network of cognitive processing. In the twentieth century, the neuroscientist Norman Geschwind proposed the asymmetry of the temporal plane in the human brain (Geschwind and Levitsky 1968) and identified the inferior parietal lobule as an additional important player for language processing (Geschwind and Galaburda 1985)

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