Faculty Collaboration Database

Language lateralization in left-handed and ambidextrous people: fMRI data. Neurology 2002 Jul 23;59(2):238-44

Date

07/24/2002

Pubmed ID

12136064

DOI

10.1212/wnl.59.2.238

Scopus ID

2-s2.0-0037162337 (requires institutional sign-in at Scopus site)   431 Citations

Abstract

BACKGROUND: It is generally accepted that most people have left-hemispheric language dominance, though the actual incidence of atypical language distribution in non-right-handed subjects has not been extensively studied. The authors examined language distribution in these subjects and evaluated the relationships between personal handedness, family history of sinistrality, and a language laterality index (LI) measured with fMRI.

METHODS: The authors used whole-brain fMRI to examine 50 healthy, non-right-handed subjects (Edinburgh Handedness Inventory quotient between -100 and 52) while they performed language activation and nonlinguistic control tasks. Counts of active voxels (p < 0.001) were computed in 22 regions of interest (ROI) covering both hemispheres and the cerebellum. LI were calculated for each ROI and each entire hemisphere using the formula [L - R]/[L + R].

RESULTS: Activation was predominantly right hemispheric in 8% (4/50), symmetric in 14% (7/50), and predominantly left hemispheric in 78% (39/50) of the subjects. Lateralization patterns were similar for all hemispheric ROI. Associations were observed between personal handedness and LI (r = 0.28, p = 0.046), family history of sinistrality and LI (p = 0.031), and age and LI (r = -0.49, p < 0.001).

CONCLUSIONS: The incidence of atypical language lateralization in normal left-handed and ambidextrous subjects is higher than in normal right-handed subjects (22% vs 4-6%). These whole-brain results confirm previous findings in a left-handed cohort studied with fMRI of the lateral frontal lobe. Associations observed between personal handedness and LI and family history of handedness and LI may indicate a common genetic factor underlying the inheritance of handedness and language lateralization.

Author List

Szaflarski JP, Binder JR, Possing ET, McKiernan KA, Ward BD, Hammeke TA

Author

Jeffrey R. Binder MD Professor in the Neurology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Adult
Aging
Brain Mapping
Female
Functional Laterality
Humans
Language
Linear Models
Magnetic Resonance Imaging
Male
Psychomotor Performance
Reference Values