ERIC Number: EJ976687
Record Type: Journal
Publication Date: 2012-Sep
Pages: 8
Abstractor: As Provided
ISBN: N/A
ISSN: ISSN-0093-934X
EISSN: N/A
Available Date: N/A
Colateralization of Broca's Area and the Visual Word form Area in Left-Handers: fMRI Evidence
Van der Haegen, Lise; Cai, Qing; Brysbaert, Marc
Brain and Language, v122 n3 p171-178 Sep 2012
Language production has been found to be lateralized in the left hemisphere (LH) for 95% of right-handed people and about 75% of left-handers. The prevalence of atypical right hemispheric (RH) or bilateral lateralization for reading and colateralization of production with word reading laterality has never been tested in a large sample. In this study, we scanned 57 left-handers who had previously been identified as being clearly left (N = 30), bilateral (N = 7) or clearly right (N = 20) dominant for speech on the basis of fMRI activity in the inferior frontal gyrus (pars opercularis/pars triangularis) during a silent word generation task. They were asked to perform a lexical decision task, in which words were contrasted against checkerboards, to test the lateralization of reading in the ventral occipitotemporal region. Lateralization indices for both tasks correlated significantly (r = 0.59). The majority of subjects showed most activity during lexical decision in the hemisphere that was identified as their word production dominant hemisphere. However, more than half of the sample (N = 31) had bilateral activity for the lexical decision task without a clear dominant role for either the LH or RH, and three showed a crossed frontotemporal lateralization pattern. These findings have consequences for neurobiological models relating phonological and orthographic processes, and for lateralization measurements for clinical purposes. (Contains 2 tables and 1 figure.)
Descriptors: Evidence, Word Recognition, Phonology, Handedness, Brain Hemisphere Functions, Diagnostic Tests, Reading Processes, Task Analysis, Correlation, Role, Models, Neurology, Biology, Measurement, Lateral Dominance, Speech
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Publication Type: Journal Articles; Reports - Research
Education Level: N/A
Audience: N/A
Language: English
Sponsor: N/A
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Author Affiliations: N/A