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Our brains may be what make us who we are. As the seat of consciousness, the home to our memories, and the processing center for all of our experiences, the brain affects every second of our lives. Over time, experiences shape the structure and function of the brain, but one thing remains constant: all vertebrates have a cerebrum. This “new” part of the brain is a recent evolutionary development, with older structures such as the cerebellum and brain stem predating this complex organ.

Most scientists believe that conscious experience, including a sense of self, occurs in the cerebrum, which means that all animals with a cerebrum have the capacity for consciousness. The size of the brain’s lobes, the extent of their development, and numerous other factors--including social relationships--all affect the extent to which an animal is consciously aware.

Doctors typically divide the lobes of the brain, or cerebrum, into four distinct regions: the frontal, parietal, occipital, and temporal lobes. Some researchers now also refer to the limbic lobe as a fifth lobe, though most textbooks do not label the limbic lobe as a separate region.

How the Lobes of the Brain Interact

The lobes of the brain are not separated from one another by bones or other barriers, and must constantly interact with one another to process and synthesize information. All of the lobes are either physically connected to one another, or connect via nerve signals, and researchers sometimes debate the precise point at which one lobe begins and another ends.

The brain is divided into left and right hemispheres, and each lobe crosses both hemispheres. Thus doctors and researchers sometimes refer to two distinct lobes—the left frontal lobe and right frontal lobe, for example.

Do Different Brain Regions Control Different Functions?

Doctors originally divided the brain into four separate regions for the sake of conveniently labeling anatomical functions. We now know that the lobes of the brain roughly correlate with a variety of functions. The temporal lobe, for instance, plays a key role in auditory processing, while the frontal lobe helps regulate attention and memory.

This doesn't mean that brain regions “control” these functions. Many functions overlap across brain regions, and the functioning of one region often depends on another. Moreover, some research suggests that when there is damage to one region of the brain, other regions may compensate, suggesting that the brain is highly malleable.

This all means that the brain is an unpredictable organ. Much remains to be understood, and our understanding of which brain regions do what changes with each new brain study.

Frontal Lobe

Situated at the front of the cerebrum, above the temporal lobe and in front of the parietal lobe lies the frontal lobe. This lobe is separated from the parietal lobe by a group of tissues called the central sulcus, and from the temporal lobe by a fold called the Sylvian fissure or lateral sulcus.

At the back of the frontal lobe lies the primary motor cortex, which controls and processes most voluntary movements. Thus damage to the frontal lobe can impede or even eliminate voluntary mobility.

Other functions of the frontal lobe include:

  • Regulating reward and motivation. Most dopamine-sensitive neurons are located in the frontal lobe. Dopamine is a neurotransmitter that helps with feelings of reward, pleasure, attention, planning, and memory.
  • Regulating behavior and decision-making. “Normal” social interactions are heavily regulated by this brain lobe. People with frontal lobe damage may behave inappropriately in social situations. In some cases, they may know how to respond, but be unable to make the correct choice.
  • Predicting consequences of actions.
  • Retention of non-task-based long-term memories.
  • Processing memories derived from the limbic system.
  • Impulse control. People with frontal lobe damage may experience difficulties with addiction, aggressive behavior, or socially inappropriate choices.
  • Regulating attention, particularly selective attention; issues with the frontal lobe and with the dopamine system it regulates can cause difficulties with planning, symptoms of ADHD, and problems with executive function.
  • Assessing similarities and differences between people and objects.

The frontal lobe is the largest lobe in healthy human brains.

Learn more about the frontal lobe.

Parietal Lobe

Located above the occipital lobe and behind the frontal lobe, the parietal lobe plays a key role in sensory perception and integration, including spatial reasoning and your sense of your body's movement within the world. Without the parietal lobe, you would still take in sensory information from your eyes, ears, and other sensory organs. But you might not be able to understand the information, or assign meaning to it.

Other functions of the parietal lobe include:

  • Touch perception, including the ability to discriminate two objects via touch, and the ability to simultaneously identify two different objects while touching them.
  • Understanding numbers and the relationship between them.
  • Spatial reasoning and understanding; some studies suggest that different regions of the parietal lobe help “map” different spatial locations.
  • Processing visual signals.
  • Coordinating eye, arm, and hand motions.
  • Language processing: damage to the parietal lobe can lead to difficulty speaking or understanding language.

The parietal lobe is the smallest lobe of the brain.

Learn more about the parietal lobe.

Occipital Lobe

Located beneath the parietal lobe and above the temporal lobe, the occipital lobe is the brain's processing hub, containing most of the brain's visual cortex. Most neuroscientists refer to the the brain's main visual cortex as Brodmann area 17, or V1 for visual one. This region is indispensable for sight, and is located within the occipital lobe's calcarine sulcus. Because of its role in visual processing, damage to the occipital lobe—particularly bilateral lesions—can lead to blindness, even when the eyes and their associated nerves are totally intact.

Most research suggests that visual processing is the most significant function of the occipital lobe. Each region of the lobe has a “map” of the visual world. These areas include:

  • The primary visual cortex (V1), which helps the brain determine location, spatial navigation, and color.
  • The ventral stream, which helps the brain understand what it is seeing.
  • The dorsomedial stream: This region is not as well-understood as the primary visual cortex (v1) or ventral stream (V2), but some research suggests this region receives input from V1 and V2. Other inputs come from brain regions that appear unlinked to visual processing, suggesting that the occipital lobe may have functions that neuroscientists have not yet identified.

Learn more about the occipital lobe.

Temporal Lobe

Located just beneath the temples, the temporal lobe is located beneath the parietal and occipital lobes on the underside of the cerebrum. It plays a key role in auditory processing, including assigning meaning to signal from your ears. Other vital functions of the temporal lobe include:

  • Processing conscious memories in conjunction with the hippocampus and amygdala. 
  • Forming, processing, and storing visual memories. 
  • Assigning meaning to visual inputs and memories. 
  • Producing speech. People with temporal lobe dysfunction may be able to understand language but have great difficulty speaking. 
  • Recognizing language. The temporal lobe also helps people understand and interpret language, so extensive temporal lobe damage may impede both the understanding and production of language. 
  • Regulating unconscious emotional processes such as hunger and thirst. 
  • Aiding in the maintenance of homeostasis. Homeostasis allows the body to maintain relatively constant internal conditions such as a stable body temperature and heart rate. 

Learn more about the temporal lobe.

Limbic Lobe

The limbic lobe is a C-shaped structure deep within the cerebrum, surrounding the brain's thalamus. Though some textbooks refer to it as a distinct lobe of the brain, most doctors recognize it as a group of organs that intersects every area of the brain, with portions in the frontal, temporal, occipital, and parietal lobes.

The limbic lobe comprises the brain-based portion of the limbic system, an evolutionarily older part of the brain that drives instinct and unconscious emotions. The limbic system gathers information from the environment, produces chemical reactions, and sends signals to the brain that aid in the processing of emotions, storing memories, and establishing scripts for reacting to future stimuli. For example, children who grow up in an abusive environment may develop a lower threshold for anxiety, with the limbic system throwing the body more readily into a fight-or-flight response.

The limbic system contains a number of sub-organs, including the amygdala and hippocampus. It also directly interacts with the endocrine system, which means that emotional reactions that affect the limbic system may affect other body regions, such as the reproductive system. Some functions of the limbic lobe include:

  • Regulating desire, appetite, and sexual arousal.
  • Coordinating the fight-or-flight response.
  • Coordinating spatial memory, which can play a role in spatial reasoning abilities.
  • Coordinating social skills.
  • Creating and processing some memories, including autobiographical memories.
  • Regulating attention and some emotions, including disgust.

Learn more about the limbic lobe.