Activation of Broca's area during the production of spoken and signed language: a combined cytoarchitectonic mapping and PET analysis.
Broca's area in the inferior frontal gyrus consists of two cytoarchitectonically defined regions-Brodmann areas (BA) 44 and 45. Combining probabilistic maps of these two areas with functional neuroimaging data obtained using PET, it is shown that BA45, not BA44, is activated by both speech and signing during the production of language narratives in bilingual subjects fluent from early childhood in both American Sign Language (ASL) and English when the generation of complex movements and sounds is taken into account. It is BA44, not BA45, that is activated by the generation of complex articulatory movements of oral/laryngeal or limb musculature. The same patterns of activation are found for oral language production in a group of English speaking monolingual subjects. These findings implicate BA45 as the part of Broca's area that is fundamental to the modality-independent aspects of language generation.
Language Section, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bldg. 10, Rm. 6C420, MSC 1591, Bethesda, MD 20892, USA. horwitz@helix.nih.gov
Barry
B
Horwitz
Katrin
K
Amunts
Rajan
R
Bhattacharyya
Debra
D
Patkin
Keith
K
Jeffries
Karl
K
Zilles
Allen R
AR
Braun
D000328:Adult; D001931:Brain Mapping; D016022:Case-Control Studies; D004292:Dominance, Cerebral / Q000502:physiology; D005121:Extremities / Q000502:physiology; D005260:Female; D005625:Frontal Lobe / Q000033:anatomy & histology / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology; D009055:Mouth / Q000502:physiology; D019303:Multilingualism; D012813:Sign Language; D013060:Speech / Q000502:physiology; D014055:Tomography, Emission-Computed