Frontal lobe: Functions, structure, and damage
It is one of four paired lobes in the brain's cerebral cortex, and it plays vital roles in memory, attention, motivation, and numerous other daily tasks.
The frontal lobe, similarly to the other lobes of the cerebral cortex, is actually made up of two, paired lobes. Together, these comprise two-thirds of the human brain.
What is the frontal lobe?
The frontal lobe is located near the forehead and plays a vital role in motivation and memory.
The frontal lobe is part of the brain's cerebral cortex. Individually, the paired lobes are known as the left and right frontal cortex.
As the name implies, the frontal lobe is located near the front of the head, under the frontal skull bones and near the forehead. It was the last region of the brain to evolve, making it a relatively new addition to the structure.
All mammals have a frontal lobe, though the size and complexity vary between species. Most research suggests that primates have larger frontal lobes than many other mammals.
The two sides of the brain largely control operations on the opposite sides of the body. The frontal lobe is no exception.
So, the left frontal lobe affects muscles on the right side of the body. Similarly, the right frontal lobe controls muscles on the left side of the body. This can determine how the body is affected by a brain injury.
The brain is a complex organ, with billions of cells called neurons working together. Much of what these neurons do and how they work is not fully understood.
The frontal lobe works alongside other brain regions to control how the brain functions overall. Memory formation, for example, depends on sensory input, which depends on numerous areas of the brain. As such, it is a mistake to attribute any one role of the brain to a single region.
What is more, the brain may "rewire" itself to compensate for an injury. This does not mean the frontal lobe can recover from all injuries, but that other brain regions may change in response to an injury to the frontal lobe.
Functions of the frontal lobe
The frontal lobe plays a key role in future planning, including self-management and decision-making.
People with frontal lobe damage often struggle with gathering information, remembering previous experiences, and making decisions based on this input.
Some of the many other functions the frontal lobe plays in daily functions include:
- Speech and language production: Broca's area, a region in the frontal lobe, helps put thoughts into words. Damage to this area can undermine the ability to speak, to understand language, or to produce speech that makes sense.
- Some motor skills: The frontal lobe houses the primary motor cortex, which helps coordinate voluntary movements, including walking and running.
- Comparing objects: The frontal lobe helps categorize and classify objects, in addition to distinguishing one item from another.
- Forming memories: Virtually every brain region plays a role in memory, so the frontal lobe is not unique. However, research suggests it plays a key role in forming long-term memories.
- Understanding and reacting to the feelings of others: The frontal lobe is vital for empathy.
- Forming personality: The complex interplay of impulse control, memory, and other tasks helps form a person's key characteristics. Damage to the frontal lobe can radically alter personality.
- Reward-seeking behavior and motivation: Most of the brain's dopamine-sensitive neurons are in the frontal lobe. Dopamine is a brain chemical that helps support feelings of reward and motivation.
- Managing attention, including selective attention: When the frontal lobe cannot properly manage attention, then conditions, such as attention deficit disorder (ADHD), may develop.
Effects of damage to the frontal lobe
Damage to the frontal lobe may result in symptoms such as poor coordination.
One of the most infamous frontal lobe injuries happened to railroad worker Phineas Gage.
Gage survived after a railroad spike impaled a portion of his frontal lobe. Though Gage survived, he lost his eye and much of his personality.
Gage's personality dramatically changed, and the once mild-mannered worker struggled to stick to even simple plans. He became aggressive in speech and demeanor and had little impulse control.
Much of what we know about the frontal lobe comes from case reports on Gage. Those have been called into question since, however. Little is known for sure about Gage's personality before his accident, and many stories about him may be exaggerated or false.
The case demonstrates a larger point about the brain, which is that our understanding of it is constantly evolving. Hence, it is not possible to accurately predict the outcome of any given frontal lobe injury, and similar injuries may develop quite differently in each person.
In general, however, damage to the frontal lobe due to a blow to the head, a stroke, growths, and diseases, can cause the following symptoms:
- speech problems
- changes in personality
- poor coordination
- difficulties with impulse control
- trouble planning or sticking to a schedule
Treatment for damage to the frontal lobe
Treatment for frontal lobe injuries focuses on addressing the cause of the injury first. A doctor might prescribe medication to treat an infection, surgery to remove a growth, or medication to reduce the risk of a stroke.
Depending on the cause of the injury, lifestyle remedies may help, as well. For example, frontal lobe damage after a stroke may mean moving to a more healthful diet, and to more exercise to reduce the risk of a future stroke.
After the initial cause of the injury is addressed, treatment focuses on helping a person regain as much functioning as possible.
The brain can sometimes learn to work around an injury as other regions compensate for damage to the frontal lobe. Occupational, speech, and physical therapy can move this process along. These treatments can prove especially helpful in the early stages of recovery, as the brain begins to heal.
Frontal lobe damage can affect personality, emotion, and behavior. Individual, couple, and family counselling may help with the management of these changes.
Medications that address impulse control issues can also be useful, particularly for people who struggle with attention and motivation.
Treatment for frontal lobe damage is often varied, requiring ongoing care and continual re-evaluation of the treatment strategy. It may include speech and occupational therapists, doctors, psychotherapists, neurologists, imaging specialists, and other professionals.
Recovering from a frontal lobe injury is often a long process. Progress can come suddenly or infrequently and is impossible to fully predict. Recovery is closely tied to supportive care, regular cognitive challenges, and a lifestyle that supports good health.