Tool manipulation similar among blind and sighted


London: Blind people think about manipulating tools in the same regions of the brain as do the people who can see, says a study.

Support TwoCircles

The researchers say this adds to the evidence that the brain has a fairly defined organisation, while still being able to adapt to unusual conditions, such as not having any vision.

When you look at a glass in front of you on the desk, it sets off a lot of reactions in your brain. Part of your brain categorises it: “That’s a glass!”

Another part of the brain thinks about the glass’s shape and size, its exact location, and what you would have to do with your hand and arm if you were going to reach out and grab it.

All that activity goes on even if you just look at the glass. These complicated set of thoughts link visual information and motor control.

Few years ago, Bradford Z. Mahon, Jens Schwarzbach and Alfonso Caramazza of the University of Trento, Italy investigated the first part.

They found that blind people categorised the glass in the same part of the brain as people with vision, even though it seems on the surface to be linked directly to visual information.

For the new study, the researchers wanted to see if the same was true for the second part — thinking about how to manipulate the object.

To do that, they scanned the brains of blind and sighted volunteers while they thought about tools and other objects.

Each person lay in a Magnetic Resonance Imaging (MRI) scanner while they heard a set of words from a category – either tools, like saw, scissors, fork; animals, like butterfly, turtle, cat; and objects you don’t manipulate, like bed, fence, and table.

Functional MRI scanning showed which parts of the brain are active when the volunteer heard each word.

Blind people tended to think about a tool in the same part of the brain as a sighted person.

And like sighted people, a non-tool like a cat or a fence generally didn’t spark those same regions of the brain, says a university release.

The research is published in Psychological Science, a journal of the Association for Psychological Science.