Ventral and dorsal pathways for language.
Built on an analogy between the visual and auditory systems, the following dual stream model for language processing was suggested recently: a dorsal stream is involved in mapping sound to articulation, and a ventral stream in mapping sound to meaning. The goal of the study presented here was to test the neuroanatomical basis of this model. Combining functional magnetic resonance imaging (fMRI) with a novel diffusion tensor imaging (DTI)-based tractography method we were able to identify the most probable anatomical pathways connecting brain regions activated during two prototypical language tasks. Sublexical repetition of speech is subserved by a dorsal pathway, connecting the superior temporal lobe and premotor cortices in the frontal lobe via the arcuate and superior longitudinal fascicle. In contrast, higher-level language comprehension is mediated by a ventral pathway connecting the middle temporal lobe and the ventrolateral prefrontal cortex via the extreme capsule. Thus, according to our findings, the function of the dorsal route, traditionally considered to be the major language pathway, is mainly restricted to sensory-motor mapping of sound to articulation, whereas linguistic processing of sound to meaning requires temporofrontal interaction transmitted via the ventral route.
Saur
Dorothee
D
Department of Neurology, University Medical Center Freiburg, Breisacher Strasse 64, 79106 Freiburg, Germany. dorothee.saur@uniklinik-freiburg.de
Kreher
Björn W
BW
Schnell
Susanne
S
Kümmerer
Dorothee
D
Kellmeyer
Philipp
P
Vry
Magnus-Sebastian
MS
Umarova
Roza
R
Musso
Mariacristina
M
Glauche
Volkmar
V
Abel
Stefanie
S
Huber
Walter
W
Rijntjes
Michel
M
Hennig
Jürgen
J
Weiller
Cornelius
C
D000293:Adolescent; D000328:Adult; D000368:Aged; D001931:Brain Mapping; D032882:Comprehension; D005260:Female; D006801:Humans; D007802:Language; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000502:physiology*