Brain imaging studies of blind people as they read words in Braille show activity in precisely the same part of the brain that lights up when sighted readers read. The findings challenge the textbook notion that the brain is divided up into regions that are specialized for processing information coming in via one sense or another, the researchers say.
"The brain is not a sensory machine, although it often looks like one; it is a task machine," said Dr. Amir Amedi of the Hebrew University of Jerusalem, head of the team of researchers whose work on the topic is reported in the latest issue of Current Biology.
"A particular area fulfills a unique function, in this case reading, regardless of sensory input modality," he said. Amedi is affiliated with the Institute for Medical Research Israel-Canada and the Edmond and Lily Safra Center for Brain Sciences at the Hebrew University.
Unlike other tasks that the brain performs, reading is a recent invention, about 5,400 years old. Braille has been in use for less than 200 years. "That's not enough time for evolution to have shaped a brain-module dedicated to reading," Amedi explained.
Nevertheless, brain scans have shown that a very specific part of the brain, known as the Visual Word Form Area or VWFA for short (first discovered in sighted people by Dr. Laurent Cohen of Paris, a co-author of the current article), has been co-opted for this purpose. But no one knew what might happen in the brains of blind people who learn to read despite the fact that they've had no visual experience at all.
In the new study, Amedi's team, which included his doctoral student Lior Reich, used functional magnetic resonance imaging (fMRI) to measure the neural activity in eight people who had been blind since birth while they read Braille words or nonsense Braille. If the brain were organized around processing sensory information, one might expect that Braille reading would depend on regions dedicated to processing tactile information, Amedi explained. If instead the brain is task-oriented, you'd expect to find the peak of activity across the entire brain in the VWFA, right where it occurs in sighted readers, and that is exactly what the researchers saw.
Further comparison of brain activity in the blind and sighted readers showed that the patterns in the VWFA were indistinguishable between the two.
"The main functional properties of the VWFA as identified in sighted are present as well in the blind, and are thus independent of the sensory-modality of reading, and even more surprisingly do not require any visual experience," the researchers wrote. "To the best of our judgment, this provides the strongest support so far for the metamodal theory of brain function," which suggests that brain regions are defined by the computations they perform. "Hence, the VWFA should also be referred to as the tangible word-form area, or more generally as the (metamodal) word-form area."
The researchers suggest that the VWFA is a multisensory integration area that binds simple features into more elaborate shape descriptions, making it ideal for the relatively new task of reading.
"Its specific anatomical location and strong connectivity to language areas enable it to bridge a high-level perceptual word representation and language-related components of reading," they said. "It is therefore the most suitable region to be taken over during reading acquisition, even when reading is acquired via touch without prior visual experience."
Amedi said he and his research associates plan to examine brain activity as people learn to read Braille for the first time in order to find out how rapidly this takeover happens. “What we want to find out is: how does the brain change to process information in words and is it instantaneous?"
For further information: Jerry Barach, Dept. of Media Relations, the Hebrew University, Tel: 02-588-2904.
Orit Sulitzeanu, Hebrew University spokesperson, Tel: 054-8820016.
Jerry Barach | Hebrew University of Jerusalem
For a chimpanzee, one good turn deserves another
27.06.2017 | Max-Planck-Institut für Mathematik in den Naturwissenschaften (MPIMIS)
New method to rapidly map the 'social networks' of proteins
27.06.2017 | Salk Institute
An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.
Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...
Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.
Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...
Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.
As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...
Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.
With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...
Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine
Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...
19.06.2017 | Event News
13.06.2017 | Event News
13.06.2017 | Event News
28.06.2017 | Awards Funding
28.06.2017 | Earth Sciences
28.06.2017 | Physics and Astronomy