The findings suggest that even when an individual does not receive normal visual input from birth, regions in the brain that are activated by landscapes, faces and objects may be ready to be used when people are able to see later in life – for example, following surgery or by using a prosthesis.
In sighted individuals, visual input is processed using a ‘brain map’ with different regions activated by faces, body parts, scenes and objects.
Researchers wanted to see if this map was present in those who were born without sight.
As part of a study published in Proceedings of the National Academy of Sciences, blind participants listened to sounds from four categories – laughing, kissing and lip smacking for faces, handclapping and footsteps for body parts, forest and beach sounds for scenes and a clock, washing machine and car for objects.
A scanner measuring brain activity found that the brain responded in a different way to each category, even though they had no visual input. Researchers found the layout of their brain map was largely the same as sighted people.
Professor Hans Op de Beeck, from the KU Leuven Laboratory of Biological Psychology, highlighted to OT that the results addressed the question of how brain function depends on learning and development.
“Our results show that the brain has a strong resilience for major changes in the input that it gets,” he emphasised.
Further research would investigate how a brain map was able to develop in individuals with only auditory stimulation, how the auditory information was being processed, and whether there were any behavioural differences between blind individuals with a strong brain map and those with a weaker brain map.