Human brain Forebrain The Cerebrum: Also known as the cerebral cortex, the cerebrum is the largest part of the human brain, and it is associated with higher brain function such as thought and action. Nerve cells make up the gray surface, which is a little thicker than our thumb. White nerve fibers beneath the surface carry signals between nerve cells in other parts of the brain and body. Its wrinkled surface increases the surface area, and is a six-layered structure found in mammals, called the neocortex. It is divided into four sections, called “lobes”. They are; the frontal lobe, the parietal lobe, the occipital lobe and the temporal lobe.brain lobes Function of lobes: Frontal lobe – The frontal lobe lies just beneath our forehead and is associated with our brain’s ability to reason, organize, plan, speak, move, make facial expressions, serial task, problem solve, control inhibition, spontaneity, initiate and self-regulate behaviors, pay attention, remember and control emotions...