RE: What do you know today that you didn't know yesterday?
October 23, 2022 at 11:58 am
(This post was last modified: October 23, 2022 at 12:08 pm by Anomalocaris.)
(October 21, 2022 at 11:28 pm)Anomalocaris Wrote: Bats and dolphins are not the only mammals who can use biological sonar to echo locate. Humans can learn to do it too. Some Blind people such as Daniel Kish make clicking sounds with their tongue and uses the faint echo to paint their surroundings and do things sighted people can not, such as identify from a distance whether visually identical objects are made of metal or wood. Some of those, Such as Ben Underwood, can do it with such dexterity, and process so much information from the echos so quickly, they can skateboard, play basketball, and ride bicycles.
Magnetic resonance imaging of the brains of human echo locators shows the primary visual cortex, part of the brain normally to process visual signals, have been repurposed to process auditory signals. They literally see with sound.
Also, the fact that humans can learn to echo located has been known to academia since the 1940s. Prior to that, it had been long been observed that some blind people walking with the aid of taps of their cane can consistently avoid obstacles in their path without actually having come into contact with the obstacles using their cane. The pervailing theory had been that these people had somehow sensitized their faces to tiny differences in airflow caused by nearby objects. Experiments in the 1940s showed this was not so. These people navigate using echos of the taps of their canes reflected back from the obstacles on their paths.