Background

Blindsight is the presence of visual abilities even though a person experiences blindness because of damage to V1. The patient claims to be subjectively blind but makes accurate visual responses. In the video on the text tab, you can witness the visual guidance by patient T.N.

What makes T.N.’s case fascinating is that despite his complete perceptual blindness, he still makes visual responses. Indeed, in 2008, de Gelder et al. staged a stunning demonstration of this. T.N. was told that a cluttered corridor was empty and that he would not need his cane to walk down the corridor. Reluctantly, T.N. agreed. As he walked down the corridor, he was followed by another person (a prominent researcher in this area) to ensure that he would not stumble. When you watch the video, you can see that despite his total blindness, T.N. avoided the obstacles placed in front of him. He sidesteps a box and avoids a tripod. After completing the trip down the hallway, T.N. does not know what he has avoided or whether there was anything in his way at all. In other words, he made visually guided movements in the absence of conscious sight. This demonstration is a stunning example of blindsight.

You can witness these demonstration on the next tab.

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