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New research from our Department of Psychology has shown that the brains of sighted and blind people adapt in a similar way when they learn to use sound echoes to understand the world without vision.

The study is the first of its kind to use MRI scans to analyse the brain activity of sighted and blind adults before and after they are trained in echolocation.  

Echolocation is a physiological process that allows us to understand the world around us through sound waves reflected back to the sender.  

It’s best known in bats and marine mammals such as dolphins, but it’s also used by some people who are blind or visually impaired to navigate their surroundings.   

Our researchers wanted to explore whether the brains of fully sighted people adapt to learning echolocation in the same way that the brains of blind people do.  

Learning how to echolocate 

Over the course of ten weeks, they trained twelve blind participants and fourteen sighted participants in echolocation in our Department of Psychology laboratories. 

They performed tasks such as identifying the size and orientation of shapes, or finding their way around, using only clicking sounds and without using vision.   

MRI scans were conducted before and after the training to determine whether any changes had taken place in the participants’ brains.  

The scans revealed that after learning echolocation, the primary ‘visual’ cortex part of the brain in both the sighted and blind participants had reorganized and developed sensitivity to sound echoes.  

Previously it was thought that such reorganization would only be possible in people who are blind, and that it would require much more extensive training.   

Positive implications 

The findings suggest that similar brain plasticity principles apply in both blind and sighted people.  

It has positive implications for those experiencing progressive sight loss because it demonstrates that the brain adapts successfully regardless of when echolocation is learned.  

The study has been published in the scientific journal Cerebral Cortex.  

Dr Thaler’s research helps inform training workshops at Durham University for visually impaired and blind people and for professionals who work with them. 

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