Friday 2 October 2015

Blindsight — like "a black shadow moving against a completely black background"

In the video below, a blind man, who usually walks with a cane, makes his way along a corridor strewn with obstacles. Amazingly, he finds his way safely past every hazard. This is an example of blindsight.



‘Importantly, the participant claimed that not only was he not aware of having seen anything; he was not even aware of having moved out of the way of the objects. He insisted he had just walked straight down the hallway ... he was “at a loss to explain or even describe his actions”.

More at:

http://www.bbc.com/future/story/20150925-blindsight-the-strangest-form-of-consciousness / London National Hospital ophthalmologist Michael Sanders human consciousness half blind healthy eyes brain operation cure headaches destroyed region crucial for vision everything left of his nose was invisible to him blind spot second sight guiding his behaviour beyond conscious awareness psychologists Elizabeth Warrington Lawrence Weiskrantz clever tests screen blind spot point at a circle take a guess almost always right single line screen decide horizontal vertical nothing had appeared accuracy 80% guess guessing randomly blindness healthy eyes watching the world passing information unconscious guiding behaviour blindsight fractured conscious state sceptical accepted phenomenon fundamental questions human mind decisions awareness illusion of control conscious mind direct our actions purpose vivid internal life zombies acting without awareness parts of the brain normally not visible Marco Tamietto Tilburg University view functions difficult to observe consciousness minds vivid sense of awareness feeling being experiencing the world close to consciousness subjective experience Christopher Allen Cardiff University blindsight participant is still perceiving lack awareness of perception tasks test what blindsight patients are capable of without conscious visual awareness sense emotion happy sad angry surprised unconsciously mimic expressions conscious level change in attitude synchronisation of emotional expressions pictures blind field mirroring expressions show physiological signs of stress see a picture of a frightened face pay attention bodily reactions in danger bodily changes understand what’s going on in the world something interesting problematic blindsight patient blind across the whole of his visual field normally walked with a white cane corridor furniture trip him up not aware seen anything aware distinguish movement fast high-contrast film sense of knowing vision controversy truly reflect visual experiences experiments Allen’s lab Cardiff UK /