Anatomical connections of the visual word form area.
The visual word form area (VWFA), a region systematically involved in the identification of written words, occupies a reproducible location in the left occipitotemporal sulcus in expert readers of all cultures. Such a reproducible localization is paradoxical, given that reading is a recent invention that could not have influenced the genetic evolution of the cortex. Here, we test the hypothesis that the VWFA recycles a region of the ventral visual cortex that shows a high degree of anatomical connectivity to perisylvian language areas, thus providing an efficient circuit for both grapheme-phoneme conversion and lexical access. In two distinct experiments, using high-resolution diffusion-weighted data from 75 human subjects, we show that (1) the VWFA, compared with the fusiform face area, shows higher connectivity to left-hemispheric perisylvian superior temporal, anterior temporal and inferior frontal areas; (2) on a posterior-to-anterior axis, its localization within the left occipitotemporal sulcus maps onto a peak of connectivity with language areas, with slightly distinct subregions showing preferential projections to areas respectively involved in grapheme-phoneme conversion and lexical access. In agreement with functional data on the VWFA in blind subjects, the results suggest that connectivity to language areas, over and above visual factors, may be the primary determinant of VWFA localization.
Inserm, U 1127, F-75013, Paris, France, Sorbonne Universités, UPMC Univ Paris 06, F-75013, Paris, France, CNRS, F-75013, Paris, France, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France.
Florence
F
Bouhali
Sorbonne Universités, UPMC Univ Paris 06, F-75013, Paris, France, CNRS, F-75013, Paris, France, Natbrainlab, Department of Forensic and Neurodevelopmental Sciences, Institute of Psychiatry, King's College London, London, United Kingdom, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France.
Michel
M
Thiebaut de Schotten
INSERM, Cognitive Neuroimaging Unit, Gif sur Yvette 91191, France, Commissariat à l'Energie Atomique, Direction des Sciences du Vivant, IBM, Neurospin center, Gif sur Yvette 91191, France, Université Paris-Sud 11, 91405 Orsay, France, and.
Philippe
P
Pinel
INSERM, Cognitive Neuroimaging Unit, Gif sur Yvette 91191, France, Commissariat à l'Energie Atomique, Direction des Sciences du Vivant, IBM, Neurospin center, Gif sur Yvette 91191, France, Université Paris-Sud 11, 91405 Orsay, France, and.
Cyril
C
Poupon
INSERM, Cognitive Neuroimaging Unit, Gif sur Yvette 91191, France, Commissariat à l'Energie Atomique, Direction des Sciences du Vivant, IBM, Neurospin center, Gif sur Yvette 91191, France, Université Paris-Sud 11, 91405 Orsay, France, and.
Jean-François
JF
Mangin
Collège de France, 75005 Paris, France, INSERM, Cognitive Neuroimaging Unit, Gif sur Yvette 91191, France, Commissariat à l'Energie Atomique, Direction des Sciences du Vivant, IBM, Neurospin center, Gif sur Yvette 91191, France, Université Paris-Sud 11, 91405 Orsay, France, and.
Stanislas
S
Dehaene
Inserm, U 1127, F-75013, Paris, France, Sorbonne Universités, UPMC Univ Paris 06, F-75013, Paris, France, AP-HP, Hôpital de la Pitié Salpêtrière, Department of Neurology, F-75013, Paris, France, CNRS, F-75013, Paris, France, Institut du Cerveau et de la Moelle épinière, ICM, F-75013, Paris, France laurentcohen2@gmail.com.
Laurent
L
Cohen
D000328:Adult; D001931:Brain Mapping; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D005625:Frontal Lobe / Q000502:physiology*; D007839:Functional Laterality; D006801:Humans; D007802:Language; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000033:anatomy & histology / Q000502:physiology; D011932:Reading; D013702:Temporal Lobe / Q000502:physiology*; D014793:Visual Cortex / Q000502:physiology*; D055815:Young Adult
diffusion imaging; language; reading; visual word form area; white matter