How many lateralities?

Abstract

It is commonly assumed that cerebral asymmetry is unidimensional, but evidence increasingly suggests that different brain circuits are independently lateralized. This might explain why the search for a laterality gene has provided multiple candidates, each with weak linkage. An alternative possibility is that there is a single genetically invariant source of lateralization, perhaps cytoplasmic, and subject to many influences, some genetic, some epigenetic, and some random. This could further explain why laterality is associated with a variety of disorders, such as dyslexia, schizophrenia, stress disorders, and depression.