RE: What do you know today that you didn't know yesterday?
February 9, 2022 at 4:05 pm
(This post was last modified: February 9, 2022 at 4:13 pm by Anomalocaris.)
There is a rare and very puzzling stroke symptom associated with neurological basis of vision and visual perception. The stroke victim becomes completely blind as far as the victim perceive vision. He/she reports being able to see nothing, being unable to even perceive light or dark. They are clinically totally blind.
But if you throw an object at them they can catch it in mid air. If you ask them to navigate an obstacle course quickly, they can do by adroitly avoiding all obstacles that a person with normal vision can see. They can even walk around obstacles on normal sidewalks and cross busy streets.
They apparently retain all the ability to process vision unconsciously to support motor activity, but have no conscious visual perception whatsoever.
There is another condition which is the opposite. A stroke victim insist he/she retain perfect vision against all contrary evidence, they can not react to or describe what is around them. Yet they believe they see.
There is a third condition where a stroke victim person exhibit normal conscious visual perception, can accurately describe what they see across their entire vision field. However, they are only able to process vision unconsiciously to support motor activity from one side. Throw the ball at them from one side and they catch it in the air effortlessly. Throw the ball from the other side and they can’t catch it.
Finally there is an extremely rare stroke condition where the victim only consciously perceive moving objects in their field of view. If it ain’t moving, it is totally invisible to them.
But if you throw an object at them they can catch it in mid air. If you ask them to navigate an obstacle course quickly, they can do by adroitly avoiding all obstacles that a person with normal vision can see. They can even walk around obstacles on normal sidewalks and cross busy streets.
They apparently retain all the ability to process vision unconsciously to support motor activity, but have no conscious visual perception whatsoever.
There is another condition which is the opposite. A stroke victim insist he/she retain perfect vision against all contrary evidence, they can not react to or describe what is around them. Yet they believe they see.
There is a third condition where a stroke victim person exhibit normal conscious visual perception, can accurately describe what they see across their entire vision field. However, they are only able to process vision unconsiciously to support motor activity from one side. Throw the ball at them from one side and they catch it in the air effortlessly. Throw the ball from the other side and they can’t catch it.
Finally there is an extremely rare stroke condition where the victim only consciously perceive moving objects in their field of view. If it ain’t moving, it is totally invisible to them.
