Blind People React to Light

            Recent studies by the University of Montreal and the Brigham and Women’s hospital in Boston have shown that people who are completely blind can be influenced by light. The presence or absence of light affects bodily functions such as heart rate, attentiveness, mood, and reflexes. An experiment was conducted where blind people were exposed to a blue light, the light was turned on and off, and the participants were asked whether the light was on or off. The results were surprisingly positive. Aside from chance, it can be explained by light perception in the ganglion cells of the retina, which are different from the cells that process light for sight.

            The next part of the experiment was to have the participants match sounds with lights on and off to test their attentiveness. Even though they can not visually see the light, they were more attentive to the sounds when the light was shining into their eyes. They did this experiment while the participants were having a brain scan with a functional MRI (fMRI) to quantitatively measure their alertness, memory, and cognition recognition. The task of matching sounds was completed more efficiently when light was present.

            The conclusion is that to perceive light, even without converting it to images, is accomplished in order to pay attention and monitor the environment. This article is interesting because it can explain why cognitive performance is improved in the presence of light and leads us to wonder what else can be done to improve such performance.

http://www.iflscience.com/brain/completely-blind-people-still-able-react-light