Echolocation is the ability for people to identify the position of objects around them with sound they produce. It is an extraordinary ability to determine where objects are, what size they are or even what texture they may be. The sounds produced are for example clapping, tapping or clicking. Human echolocation allows people to identify objects as the sound they produce creates a wave of a sound reflecting off of an object near them. Some blind people use this technique in order to help them place the objects near them. (http://theness.com/neurologicablog/index.php/human-echolocation/)

For most of us seeing something activates the visual cortex in the brain. For blind people who mastered the ability to echolocate the visual cortex is also activated. “Remarkably… the recordings containing echoes activated the visual cortex in the blind participants, but not the auditory cortex” (http://scienceblogs.com/neurophilosophy/2011/05/human_echolocation_activates_visual_parts_of_the_brain.php) When analysing these finding one certainly must wonder about the results. Why is it that blind people’s brains activate the visual and not the auditory cortex? Surely, it must come to mind that without actually seeing an image, and by seeing I mean neurons picking up signals our eyes are receiving and helping them recognize familiar objects, the visual cortex would not be activated.(http://www.amnh.org/exhibitions/brain/sensing_seeing.php) So without the intervention of the eyes why is the visual cortex activated instead of the auditory one?  Researchers conclude that “blindness can lead to extensive brain reorganisation. Such changes can produce cross-modal activation, whereby sensations activate brain regions that would not normally process them”(http://scienceblogs.com/neurophilosophy/2011/05/human_echolocation_activates_visual_parts_of_the_brain.php)

Ben Underwood, a teenager who used echolocation or Daniel Kish  both mastered this technique. National Geographic is currently running a program called “Test your brain” which shows just how much our brains deceive us and in fact do not show the reality we are convinced we see.

References:

http://scienceblogs.com/neurophilosophy/2011/05/human_echolocation_activates_visual_parts_of_the_brain.php

http://www.amnh.org/exhibitions/brain/sensing_seeing.php

http://theness.com/neurologicablog/index.php/human-echolocation/

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