The superior colliculus refers to the rostral bump on the lateral part of the midbrain. It is in fact a pair of two colliculi, superior and inferior, on either side of the midbrain that together constitutes the tectum. Out of the two, the superior one is a layered, visual structure. Its upper layer gets visual signals from the retina, while the lower layers get multiple signals from various other parts of the brain. This colliculus is not restricted to a visual role alone, and performs another important function of providing orientation to the eyes and head. One of the key projections of the colliculus is to spinal cord region. This helps the head to respond to different sensory stimuli. Movement of the eyes is also connected with the cells present in the lower layers of the colliculus. In mammals and other higher animals, the brain processes inputs in correlation with the superior colliculus. In lower animals it helps to perceive any sudden movement that occurs before the retina.
Written and medically reviewed by the Healthline Editorial Team
In Depth: Superior colliculus