Computer artwork of a section through a healthy brain. The highly folded area in grey is the cerebrum, which is responsible for conscious thought, emotion and voluntary movement. At centre is a ventricle (cavity) - green - which is filled with cerebrospinal fluid that cushions the brain. The cauliflower-like structure at bottom right (blue) is the cerebellum, which controls voluntary muscular movement and maintains posture and balance. The brainstem, which controls subconscious functions such as breathing and the regulation of heart rate, and also connects the brain to the spinal cord is shown in orange at bottom. The limbic system is shown in red, the thalamus in green.