On the relationship between degree of hand-preference and degree of language lateralization

Metten Somers; Maartje F Aukes; Roel A Ophoff; Marco P Boks; Willemien Fleer; Kees C L de Visser; René S Kahn; Iris E Sommer

doi:10.1016/j.bandl.2015.03.006

On the relationship between degree of hand-preference and degree of language lateralization

Brain Lang. 2015 May:144:10-5. doi: 10.1016/j.bandl.2015.03.006. Epub 2015 Apr 13.

Authors

Metten Somers¹, Maartje F Aukes², Roel A Ophoff³, Marco P Boks², Willemien Fleer², Kees C L de Visser⁴, René S Kahn², Iris E Sommer²

Affiliations

¹ Brain Center Rudolf Magnus, Department of Psychiatry, University Medical Center Utrecht, Utrecht, The Netherlands. Electronic address: M.Somers@umcutrecht.nl.
² Brain Center Rudolf Magnus, Department of Psychiatry, University Medical Center Utrecht, Utrecht, The Netherlands.
³ Brain Center Rudolf Magnus, Department of Psychiatry, University Medical Center Utrecht, Utrecht, The Netherlands; Department of Human Genetics, David Geffen School of Medicine at UCLA, University of California, Los Angeles, CA, USA; Center for Neurobehavioral Genetics, Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, CA, USA.
⁴ Department of General Practice, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands.

PMID: 25880901
DOI: 10.1016/j.bandl.2015.03.006

Abstract

Language lateralization and hand-preference show inter-individual variation in the degree of lateralization to the left- or right, but their relation is not fully understood. Disentangling this relation could aid elucidating the mechanisms underlying these traits. The relation between degree of language lateralization and degree of hand-preference was investigated in extended pedigrees with multi-generational left-handedness (n=310). Language lateralization was measured with functional Transcranial Doppler, hand-preference with the Edinburgh Handedness Inventory. Degree of hand-preference did not mirror degree of language lateralization. Instead, the prevalence of right-hemispheric and bilateral language lateralization rises with increasing strength of left-handedness. Degree of hand-preference does not predict degree of language lateralization, thus refuting genetic models in which one mechanism defines both hand-preference and language lateralization. Instead, our findings suggest a model in which increasing strength of left-handedness is associated with increased variation in directionality of cerebral dominance.

Keywords: Asymmetry; Functional transcranial Doppler; Hand-preference; Language lateralization; Left-handedness.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Dominance, Cerebral / physiology*
Female
Functional Laterality / physiology*
Humans
Language*
Male
Models, Neurological