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The cerebrum - As the name suggests, the frontal lobes are located at the front of the brain, just in front of the parietal lobe. Both left and right frontal lobes are composed of three parts: the prefrontal cortex, the premotor cortex and the primary motor cortex. The prefrontal cortex is located at the very front of the lobes, just at the level of the forehead. This area is considered to control our ability to plan and reason and is home to our personalities. The premotor cortex lies behind the prefrontal cortex and controls head and eye movement and spatial orientation. The primary motor cortex is located at the back of the frontal lobes and is responsible for all voluntary movements.
- The frontal lobes are key in controlling movements, including fine motor skills and some spontaneous movement. Since these skills are located in the primary motor cortex, damage to this area can result in loss of motor abilities. However, according to The Brain from Top to Bottom, which motor skills are lost largely depends upon which specific part of the primary motor cortex is damaged. In other words, every part of the primary motor cortex corresponds to a specific body part's movement.
- The left hemisphere's frontal lobe, also known as "Broca's area," controls our ability to speak. More specifically, this area controls the muscles in charge of the mouth, tongue and larynx. People suffering damage here have a disorder called "Broca's aphasia," which is characterized by the inability to form complete sentences. They also often lose the ability to use articles, conjunctions and pronouns, and sometimes lose the power of speech altogether.
- Damage to the frontal lobes can bring extraordinary changes to an individual's personality. For example, damage to the left frontal lobe can result in a person behaving in an "emotionally blunted," listless or indifferent manner, yet show no other signs of being depressed. People with injury to the right frontal lobe can become tactless, lack inhibition, behave euphorically, yet have outbursts of aggression and irritability.
- People with damage to the prefrontal cortex of the frontal lobes often have difficulty making decisions and solving problems. They might have trouble ordering information in a logical way to arrive at a decision or have difficulty switching from one manner of thinking to another to reach a conclusion. This does not mean that people with frontal lobe injuries are wholly incapable of solving a problem or taking a decision, but that their strategy for approaching problems tends to be impractical and sometimes nonsensical.
