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Blinking Shuts Off The Brain

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Blinking Shuts Off The Brain

The reason we don’t notice our own blinks? The brain momentarily shuts down visual senses when we blink…

A new study has revealed that blinking causes the brain to shut down parts of its visual system, even if light is still entering the eyes. The findings offer an explanation as to why we don’t notice our own blinks.

Researchers from the UCL Institute of Neurology at The University College London designed a special device to study the effects of blinking on the brain. The device, made with fiber optic cable, was placed in the mouth of volunteers who were made to wear light-proof goggles and lie in functional magnetic resonance imaging (fMRI) brain scanner.

The optical fiber illuminated the eyeballs through the roof of the mouth, providing constant light to the retina, even when the participants blinked.

Blinking Shuts Down Visual Cortex Of Brain

Blinking Shuts Down Visual Cortex Of Brain

This technique allowed scientists to analyze the effects of blinking on brain activity independently of the effect of eyelid closure on light entering the eye.

The study found that blinking suppressed brain activity in the visual cortex as well as parietal and prefrontal areas which are usually activated when people become conscious of visual events or objects in the outside world.

Davina Bristow of the UCL Institute of Neurology says:

“Blinking is necessary to keep the surfaces of the eyes moist. Most people blink around 15 times a minute and a blink lasts on average 100-150 milliseconds, which means that overall we spend at least 9 days per year blinking.

“We would immediately notice if the outside world suddenly went dark, especially if it was happening every few seconds. But we are rarely aware of our blinks, even though they cause a similar reduction in the amount of light entering the eye, and this gives us an uninterrupted view of the world.

“Transiently suppressing the brain areas involved in visual awareness during blinks may be a neural mechanism for preventing the brain from becoming aware of the eyelid sweeping down over the pupil during a blink and the world going dark.”


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