Language at the Interface Between the Skull and the Brain

The biological underpinnings of human language are difficult to study. Current genetic and neuroimaging approaches have paved the way towards a deeper understanding of the biological machinery which enables us to learn and use languages. Not surprisingly, most of this fruitful research has been conducted on the brain. Nonetheless, brain and skull shapes influence one another, during prenatal and early postnatal development and growth. This close interrelation is suggestive of their developmental dependency on common progenitor tissue interactions and signalling pathways during embryogenesis. Also, in later stages, brain growth is able to affect the correct mechanics of skull morphogenesis and ossification, by modifying the tensile forces acting on plastic suture sites and ultimately on stem cell behaviour. Vice-versa skull growth patterns modify brain landmarks, fluid dynamics, and overall structural homeostasis. Indeed, craniofacial defects, such as craniosynostosis, are frequently associated with cognitive and language impairment and/or brain abnormalities. This same close interdependence is believed to have affected the brain and its braincase during human evolution. Changes in the hominin skull during our speciation are suggestive of deeper changes in the hominin brain that brought about our distinctive mode of cognition, including our language-readiness. On the whole, this intimate cross-talk between the bone and the brain suggests that ‘osteo’ considerations are expected to shed light on ‘neuro’ considerations (and vice versa).

In this Research Topic, we wish to pursue a more accurate knowledge of the cross-talk between skull and brain, regarding our species-specific linguistic abilities. We are particularly interested in studies delving into the links between skull abnormal development and language impairment, and into paleoneurological aspects of language evolution. In general, papers aimed at bridging the gap between skull and brain in the context of language development, evolution and function, will be welcome. Although studies of this kind are quite new, we believe that they can help physicians in their daily practice, particularly, if they succeed in shedding light on the presentation of many pathological conditions in which linguistic, cognitive, and craniofacial symptoms may co-occur.

Given the cross-domain nature of this challenging task, researchers from different fields with a broad interest in brain and skull, and in language and cognition, are welcome to contribute to this Research Topic, including neuroscientists, physicians, speech therapists, neurologists, psychologists, geneticists, paleoanthropologists, and ethologists.