Manual asymmetries and hemispheric specialization: Insight from developmental studies

- The relationship between handedness and language lateralization is not direct.
- It is necessary to differentiate multiple individual patterns of lateralization.
- Hand preference for some activities develops in relation with language acquisition.
- The control of gestures and language shares a common neural system.
- Hemispheric specialization for visual attention also needs to be investigated.

The objective of this review is to obtain a better understanding of the relationship between manual asymmetries and hemispheric specialization by focusing on the development of hand preference and cerebral lateralization of language. We first sought to describe the development of manual asymmetries for different activities (i.e., grasping and manipulating objects vs. communicating through gestures), and the development of cerebral asymmetries, before examining available data on the association between hand preference and HS for language. We also analyzed behavioral studies on the relation between hand preference and language development, as well as more specific studies on the relation between the cerebral control of gestures and language. Finally, we aimed at providing a wider view on functional asymmetries by emphasizing the need to study hemispheric specialization for functions other than language, and in particular for visual attention.