Abstract
Language is a uniquely human ability that evolved at some point in the roughly 6,000,000 years since human and chimpanzee lines diverged1,2. Even in the most linguistically impoverished environments, children naturally develop sophisticated language systems3. In contrast, reading is a learnt skill that does not develop without intensive tuition and practice. Learning to read is likely to involve ontogenic structural brain changes4,5,6, but these are nearly impossible to isolate in children owing to concurrent biological, environmental and social maturational changes. In Colombia, guerrillas are re-integrating into mainstream society and learning to read for the first time as adults. This presents a unique opportunity to investigate how literacy changes the brain, without the maturational complications present in children. Here we compare structural brain scans from those who learnt to read as adults (late-literates) with those from a carefully matched set of illiterates. Late-literates had more white matter in the splenium of the corpus callosum and more grey matter in bilateral angular, dorsal occipital, middle temporal, left supramarginal and superior temporal gyri. The importance of these brain regions for skilled reading was investigated in early literates, who learnt to read as children. We found anatomical connections linking the left and right angular and dorsal occipital gyri through the area of the corpus callosum where white matter was higher in late-literates than in illiterates; that reading, relative to object naming, increased the interhemispheric functional connectivity between the left and right angular gyri; and that activation in the left angular gyrus exerts top-down modulation on information flow from the left dorsal occipital gyrus to the left supramarginal gyrus. These findings demonstrate how the regions identified in late-literates interact during reading, relative to object naming, in early literates.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Hauser, M. D., Chomsky, N. & Fitch, W. T. The faculty of language: what is it, who has it, and how did it evolve? Science 298, 1569–1579 (2002)
Fisher, S. E. & Marcus, G. F. The eloquent ape: genes, brains and the evolution of language. Nature Rev. Genet. 7, 9–20 (2006)
Senghas, A., Kita, S. & Ozyurek, A. Children creating core properties of language: evidence from an emerging sign language in Nicaragua. Science 305, 1779–1782 (2004)
Draganski, B. et al. Neuroplasticity: changes in grey matter induced by training. Nature 427, 311–312 (2004)
Castro-Caldas, A. et al. Influence of learning to read and write on the morphology of the corpus callosum. Eur. J. Neurol. 6, 23–28 (1999)
Petersson, K. M., Silva, C., Castro-Caldas, A., Ingvar, M. & Reis, A. Literacy: a cultural influence on functional left–right differences in the inferior parietal cortex. Eur. J. Neurosci. 26, 791–799 (2007)
Turkeltaub, P. E., Gareau, L., Flowers, D. L., Zeffiro, T. A. & Eden, G. F. Development of neural mechanisms for reading. Nature Neurosci. 6, 767–773 (2003)
Price, C. J. & Mechelli, A. Reading and reading disturbance. Curr. Opin. Neurobiol. 15, 231–238 (2005)
Damasio, A. R. & Damasio, H. The anatomic basis of pure alexia. Neurology 33, 1573–1583 (1983)
Sowell, E. R. et al. Longitudinal mapping of cortical thickness and brain growth in normal children. J. Neurosci. 24, 8223–8231 (2004)
Price, C. J. et al. How reading differs from object naming at the neuronal level. Neuroimage 29, 643–648 (2006)
Lundberg, I., Olofsson, Å. & Wall, S. Reading and spelling skills in the first school years predicted from phonemic awareness skills in kindergarten. Scand. J. Psychol. 21, 159–173 (1980)
Morais, J., Cary, L., Alegria, J. & Bertelson, P. Does awareness of speech as a sequence of phones arise spontaneously? Cognition 7, 323–331 (1979)
Carreiras, M. & Grainger, J. Sublexical representations and the ‘front end’ of visual word recognition. Lang. Cogn. Process. 19, 321–331 (2004)
Booth, J. R. et al. Development of brain mechanisms for processing orthographic and phonologic representations. J. Cogn. Neurosci. 16, 1234–1249 (2004)
Wagner, R. K. & Torgesen, J. K. The nature of phonological processing and its causal role in the acquisition of reading skills. Psychol. Bull. 101, 192–212 (1987)
Brambati, S. M. et al. Neuropsychological deficits and neural dysfunction in familial dyslexia. Brain Res. 1113, 174–185 (2006)
Hoeft, F. et al. Neural basis of dyslexia: a comparison between dyslexic and nondyslexic children equated for reading ability. J. Neurosci. 26, 10700–10708 (2006)
Silani, G. et al. Brain abnormalities underlying altered activation in dyslexia: a voxel based morphometry study. Brain 128, 2453–2461 (2005)
Steinbrink, C. et al. The contribution of white and gray matter differences to developmental dyslexia: insights from DTI and VBM at 3.0 T. Neuropsychologia 46, 3170–3178 (2008)
Dougherty, R. F. et al. Temporal-callosal pathway diffusivity predicts phonological skills in children. Proc. Natl Acad. Sci. USA 104, 8556–8561 (2007)
Robichon, F. & Habib, M. Abnormal callosal morphology in male adult dyslexics: Relationships to handedness and phonological abilities. Brain Lang. 62, 127–146 (1998)
Rumsey, J. M. et al. Corpus callosum morphology, as measured with MRI, in dyslexic men. Biol. Psychiatry 39, 769–795 (1996)
Pugh, K. R. et al. Neurobiological studies of reading and reading disability. J. Commun. Disord. 34, 479–492 (2001)
Shaywitz, B. A. et al. Disruption of posterior brain systems for reading in children with developmental dyslexia. Biol. Psychiatry 52, 101–110 (2002)
Paulesu, E. et al. A cultural effect on brain function. Nature Neurosci. 3, 91–96 (2000)
Binder, J. R. & Mohr, J. P. The topography of callosal reading pathways. A case-control analysis. Brain 115, 1807–1826 (1992)
Dejerine, J. Contribution a l’étude anatomo-pathologique et clinique des differentes varietés de cecité verbale. Mem. Soc. Biol. Fr. 4, 61–90 (1892)
Geschwind, N. Disconnexion syndromes in animals and man. Brain 88, 237–294 (1965)
Price, C. J. The anatomy of language: contributions from functional neuroimaging. J. Anat. 197, 335–359 (2000)
Oldfield, R. C. The assessment and analysis of handedness: the Edinburgh inventory. Neuropsychologia 9, 97–113 (1971)
Peña-Casanova, J. Programa Integrado de Exploración Neuropsicológica: Test Barcelona (Masson, 1995)
Folstein, M. F., Folstein, S. & McHugh, P. R. ‘Mini-mental state’: a practical method for grading the cognitive state of patients for the clinician. J. Psych. Res 12, 189–198 (1975)
Wechsler, D. Wechsler Memory Scale Revised (Psychological Corporation, 1987)
Raven, J. C. Progressive Matrices: A Perceptual Test of Intelligence (Lewis, 1938)
Snodgrass, J. G. & Vanderwart, M. A standardized set of 260 pictures: Norms for name agreement, image agreement, familiarity, and visual complexity. J. Exp. Psychol. Hum. Learn. Mem. 6, 174–215 (1980)
Spreen, O. & Strauss, E. A Compendium of Neuropsychological Tests (Oxford Univ. Press, 1991)
Cuetos Vega, F., Rodríguez, B. & Ruano Hernández, E. (1996). Batería de Evaluación de los Procesos Lectores de los Niños de Educación Primaria (PROLEC) (T.E.A. Ediciones, 1996)
Ashburner, J. & Friston, K. J. Unified segmentation. Neuroimage 26, 839–851 (2005)
Reis, A. & Castro-Caldas, A. Illiteracy. A bias for cognitive development. J. Int. Neuropsychol. Soc. 3, 444–450 (1997)
Reis, A., Guerreiro, M. & Petersson, K. M. A sociodemographic and neuropsychological characterization of an illiterate population. Appl. Neuropsychol. 10, 191–204 (2003)
Cohen, L. et al. The visual word form area: spatial and temporal characterization of an initial stage of reading in normal subjects and posterior split-brain patients. Brain 123, 291–307 (2000)
Jones, D. K., Horsfield, M. A. & Simmons, A. Optimal strategies for measuring diffusion in anisotropic systems by magnetic resonance imaging. Magn. Reson. Med. 42, 515–525 (1999)
Jenkinson, M., Bannister, P., Brady, M. & Smith, S. Improved optimization for the robust and accurate linear registration and motion correction of brain images. Neuroimage 17, 825–841 (2002)
Behrens, T. E., Berg, H. J., Jbabdi, S., Rushworth, M. F. & Woolrich, M. W. Probabilistic diffusion tractography with multiple fibre orientations: What can we gain? Neuroimage 34, 144–155 (2007)
Behrens, T. E. J. et al. Characterization and propagation of uncertainty in diffusion-weighted MR imaging. Magn. Reson. Med. 50, 1077–1088 (2003)
Weiskopf, N., Hutton, C., Josephs, O. & Deichmann, R. Optimal EPI parameters for reduction of susceptibility-induced BOLD sensitivity losses: A whole-brain analysis at 3 T and 1.5 T. Neuroimage 33, 493–504 (2006)
Stephan, K. E., Marshall, J. C., Penny, W. D., Friston, K. J. & Fink, G. R. Interhemispheric integration of visual processing during task-driven lateralization. J. Neurosci. 27, 3512–3522 (2007)
Friston, K. J., Harrison, L. & Penny, W. Dynamic causal modelling. Neuroimage 19, 1273–1302 (2003)
Penny, W. D., Stephan, K. E., Mechelli, A. & Friston, K. J. Modelling functional integration: a comparison of structural equation and dynamic causal models. Neuroimage 23, S264–S274 (2004)
Acknowledgements
We thank K. Friston for advice on data analyses and A. Leff, T. Münte and T. Shallice for their help with the presentation of the manuscript. This work was funded by a CONSOLIDER-INGENIO grant from the Spanish Ministry of Education and Science and by the Wellcome Trust.
Author Contributions M.C., M.L.S., J.T.D. and C.J.P. designed the experiments, performed the data analyses and wrote the paper. S.B., A.E. and A.L. performed experiment one.
Author information
Authors and Affiliations
Corresponding authors
Supplementary information
Supplementary Information
This file contains Supplementary Methods and Notes, Supplementary References, Supplementary Tables S1-S2 and Supplementary Figures S1 and S2 with Legends. (PDF 240 kb)
Rights and permissions
About this article
Cite this article
Carreiras, M., Seghier, M., Baquero, S. et al. An anatomical signature for literacy. Nature 461, 983–986 (2009). https://doi.org/10.1038/nature08461
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1038/nature08461
This article is cited by
-
Brain structure, phenotypic and genetic correlates of reading performance
Nature Human Behaviour (2023)
-
Atypical connectivity in the cortico-striatal network in NF1 children and its relationship with procedural perceptual-motor learning and motor skills
Journal of Neurodevelopmental Disorders (2022)
-
Stroke disconnectome decodes reading networks
Brain Structure and Function (2022)
-
Is human face recognition lateralized to the right hemisphere due to neural competition with left-lateralized visual word recognition? A critical review
Brain Structure and Function (2022)
-
Periods of synchronized myelin changes shape brain function and plasticity
Nature Neuroscience (2021)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.