A Reflexive system of the human eye produces a conscious visual experience

Reflexive system of the human eye

Human eye are not only for seeing, and also have other important biological functions, including automatic visual reflexes.

According to a new study from the University of Pennsylvania, the reflexive system of the human eye produces a conscious, visual experience. The researchers said, the high light sensitivity sometimes experienced by people with eye disease, migraine headaches and concussions.

However, researchers created a special pulse of light that stimulates only the melanopsin cells, a blue-light sensitive protein in the eye.

Melanopsin

Melanopsin is a part of our visual system, it controls several important biological responses to light, said, lead author, Manuel Spitschan. If we have a visual experience that assists these reflexes, as the normal light that stimulates melanopsin will also stimulate the cone cells of the eye.

To solve this problem, the researchers developed a special kind of light pulse that stimulates melanopsin, but is invisible to the cones. These lights switch between computer-designed “rainbows” of light.

For testing, researchers recorded people pupil response who watches these light pulses. They confirmed that the light pulse invisible to the cones brings a slow, reflexive constriction of the pupil. They then measured brain activity and found that the visual pathway of the brain answer to the melanopsin stimulus.

“This was a particularly exciting finding,” said senior author Geoffrey K. Aguirre, MD, PhD, an associate professor of Neurology at Penn. A neural response within the occipital cortex  suggests that people have a conscious experience of melanopsin stimulation is explicitly visual.

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