Humans move their eyes in coordination with each other in order to stabilize their vision and obtain a three-dimensional effect.However, it is believed that at least 5% of the total population has difficulty aligning their eyes, such as strabismus.
Until now, it was not clear what kind of brain network works to align both eyes with visual images.Therefore, the research groups of Kyushu University, International University of Health and Welfare, and Fukuoka International University of Health and Welfare have 29 healthy people with normal stereoscopic vision participate in the experiment, and have a brain mechanism to move both eyes separately. Examined.
In the experiment, images that were slightly shifted horizontally or vertically were presented to the right and left eyes, and while monitoring the movements of both eyes, the cranial nerve activity was examined using a cerebral porcelain meter that measures a very small magnetic field in the brain. ..Interestingly, when I saw a misaligned image with both eyes, my eyes were unintentionally (automatically) moving horizontally or vertically to counteract the misalignment.When we investigated the relationship between this eye movement and activity in various brain regions, we found that about 100 milliseconds after the image was presented (before the eye started to move, the timing to generate the command for eye movement), it was for vision. Extensive brain activity was observed in the brain region, cerebellum, and frontal region, and the eyes were moving about 150 milliseconds later.Immediately before the eye moved, the brain activity pattern was similar regardless of the direction of the image shift, and commonality was observed, but at the timing of the eye movement, the brain activity between the horizontal and vertical eye movements. Was different.That is, at the timing of eye movement, the brain network for horizontally aligning the eyes and the brain network for vertically aligning the eyes may be different.
The findings revealed in this study are expected to lead to an understanding of the causes of disorders in the coordinated movement of both eyes, and the development of new rehabilitation and devices for strabismus correction.
Paper information:[Scientific Reports] Large-scale cortico-cerebellar computations for horizontal and vertical vergence in humans
