People who are born blind are capable of learning to perceive the shape of the human body through soundscapes that translate images into sound.
With a little training, soundscapes representing the outlines and silhouettes of bodies cause the brain's visual cortex-and specifically an area dedicated in normally sighted people to processing body shapes-to light up with activity.
With no more than 70 hours of training on average, study participants could recognize the presence of a human form. What's more, they were able to detect the exact posture of the person in the image and imitate it.
The researchers first taught people to perceive simple dots and lines. Then those individuals learned to connect the lines with junctions or curves, gradually working up to more and more complex images.
The success of the sensory substitution approach suggests great potential for its use in therapy more broadly, the researchers say.
In the current study, the researchers used an algorithm they call vOICe, which translates images in black and white. But they've since developed a newer algorithm, EyeMusic, which incorporates color information through the use of different musical instruments.
The study has been published in the Cell Press journal Current Biology.