A never ending stream of information flows through our eyes every day. Light enters the pupil, where it is focused by the cornea onto the retina at the rear, where it is then processed and passed to the brain via the optic nerve. But modern medicine is beginning to discover that that stream of data is actually a two way street.
Not only is information being sent to the brain from the eyes, but the eyes are receiving info from the brain as well. The difference is that this info is harder to detect, and much harder to interpret.
As the eyes move and track the world around them they make millions of small, rapid motions each and every day. Some of them intentional, as they track moving objects, or read text across a page. Others are more reflexive, and require little to no cognitive control. It's these motions that tell doctors, researchers, and scientists a lot about the health and well being of the brain and central nervous system.
A team from Okinawa Institute of Science and Technology Graduate University has investigated how changes in the coordination between the cerebellum, the region of the brain in charge of sensorimotor coordination, and involuntary eye movements. Their results are being published in the medical journal eLife.
But determining which eye movements are involuntary, and which aren't is very difficult. The only way to know for sure is to detect which part of the brain the signal to move is coming from, which involves tracing and following individual nerves and neurons from the brain to the eyes.
"One of the many challenges in studying neurons is to figure out the underlying cause of the different electrical signals," Prof. Erik De Schutter, co-author and head of OIST's Computational Neuroscience Unit said. "We want to know what these spikes are actually telling us."
These movements can be used to diagnose a number of neurological mental health conditions, including autism, schizophrenia, and Alzheimer's disease.