Reading is such a new ability in human evolutionary history that the existence of a “reading area” could not be specified in our genes. A kind of recycling process has to take place in the brain while learning to read: Areas evolved for the recognition of complex objects, such as faces, become engaged in translating letters into language. Some regions of our visual system thereby turn into interfaces between the visual and language systems.
“Until now it was assumed that these changes are limited to the outer layer of the brain, the cortex, which is known to adapt quickly to new challenges,” says project leader Falk Huettig from the Max Planck Institute for Psycholinguistics. The Max Planck researchers together with Indian scientists from the Centre of Bio-Medical Research (CBMR) Lucknow and the University of Hyderabad have now discovered what changes occur in the adult brain when completely illiterate people learn to read and write. In contrast to previous assumptions, the learning process leads to a reorganization that extends to deep brain structures in the thalamus and the brainstem. The relatively young phenomenon of human writing, therefore, changes brain regions that are very old in evolutionary terms and already core parts of mice and other mammalian brains.