Cerebrum

The cerebrum is the part of the brain that developed latest in the evolution of humans and is largely responsible for higher level processes like thought, perception, judgment, and imagination. The cerebrum is covered by the cerebral cortex, a layer of neurons that covers the right and left hemispheres of the brain. The highly-wrinkled nature of the cerebral cortex produces a larger surface area, allowing the presence of a greater number of neurons and thus a more efficient brain.

The cerebrum consists of four lobes: frontal, parietal, occipital, and temporal, and each controls specific functions. The frontal lobe is considered the most significant in terms of intelligence and personality. Toward the back of the frontal lobe is the motor cortex, the area that controls voluntary movement. Researchers have successfully mapped the motor cortex and determined which areas of the motor cortex correspond to movements in specific areas of the body.

The parietal lobe lies behind the frontal lobe and contains the somatosensory cortex, the area responsible for the perception of external stimuli as well as orientation and recognition. This area enables a person to position his body, write, sense temperature and pain, and process language.

The temporal lobe lies under and to the side of the frontal and parietal lobes and contains the auditory cortex, the part of the brain that processes auditory stimuli. It is also largely responsible for speech development, memory, self-identification, and body image as well as emotions and behavior.

The occipital lobe is at the very back of the brain and specializes in vision. The occipital lobe contains the visual cortex, a mechanism that enables one to differentiate colors and shapes from signals it receives from the eyes. Overstimulation of the occipital lobe by flickering lights or video games can cause blurred vision and seizures, and damage to the occipital lobe can cause hallucinations and vision loss.