Manual Skills, Handedness, and the Organization of Language in the Brain

Book excerpt: Whereas the cerebral specialization for skilled manual actions (praxis) seems closely linked to dominance for language, with both functions left lateralized in the vast majority of humans, the neural correlates of hand preference are still less well understood. Indeed, as a combination of inherited and non-inherited genomic factors (i.e., direct parental and concealed environmental contributions), handedness – in contrast to language – is less likely to have strong genetic indices and clearly lateralized functional organization. What about eye dominance, unimanual and bimanual object manipulation, and gestures, or attentional systems and the related egocentric or allocentric coding of space? Are these different categories functionally and structurally interconnected? Is their development and contribution to task performance linked, even if they are differently lateralized? How are they connected to language learning or its development? In trying to understand these relationships and their neural underpinnings we obtain a new insight into fundamental human behaviors, which depend either on shared or distinct cerebral resources that must, nevertheless, be harmonized by higher-order cerebral processing. In this Research Topic we assembled a dozen of original research contributions, as well as articles with more theoretically-driven perspectives, that directly speak to these issues. Hopefully this work will serve as a foundation for further discussions and will stimulate new research in this fascinating domain.