The vertebrate brain is divided into three regions: the hindbrain, the midbrain, and the forebrain, with the size of each region of the brain varying from species to species. The hindbrain may be considered an extension of the spinal cord and coordinates motor reflexes; thus, it is often described as the most primitive portion of the brain. The midbrain is responsible for processing visual information, and finally, the forebrain is the center for processing sensory information in fish, amphibians, reptiles, birds, and mammals.