sond0075: November 2011 Archives

Seeing in the dark

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Above is a link to an article I found on Stumbleupon one day. It is about a man that had the visual cortex of his brain destroyed by two consecutive strokes. This rendered him permanently blind in both eyes. It is common for stroke victims to develop full or partial blindness, however this man's case was unusual because both hemispheres were damaged, leaving him completely blind. This type is known as selective bilateral occipital damage. Researches began to examine him while he was recovering and discovered something very interesting, despite his complete loss of visual imagery, he maintained the ability to decipher emotion on a person's face. This ability was proven by examining his amygdala activity (used for emotive processing) during these tests. To go further, researches designed an obstacle course by arranging boxes, chairs, ect down a long hallway to see if the man could navigate around without any assistance. He required an aide and a cane to maneuver, but successfully navigated the course without running into anything. This information shows that his eyes were still fully functioning and able to gather information from his surroundings, however he cannot create a definite image of it. He has maintained his spatial awareness through his subconscious.

This case reminds me of the man from the last exam that suffered from epilepsy and had his corpus collosum severed. He was able to retain information and process it without being consciously aware of it.

While I believe that this case of "seeing in the dark" is fully plausible, I have a problem with the study of the obstacle course. The main was given an aide to help him move about, and I think this may have had some role in the success of him completing the course. The aide could have unintentionally given the blind man cues as to which direction to move (i.e. slightly pulling toward and away to avoid the obstacles.) This would apply to Occam's Razor of critical thinking because the claim may be better explained by more simple factors.

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This page is an archive of recent entries written by sond0075 in November 2011.

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