March 30, 2016

THE ROLE OF THE PARIETAL LOBE

As we discussed a few weeks ago in our first blog in this series, the brain’s primary role is to receive and interpret information. When we receive this information correctly and process it correctly, our brains can then respond in a way that is appropriate for us (both socially and biologically).

In March, we discussed the frontal lobe, particularly its role as the brain’s “CEO” and “quarterback”—it receives information from the occipital, parietal, and temporal lobes and organizes it in order to create a response. Our fight-or-flight instincts are born in the frontal lobe, but so are our higher-level functions, such as moral decision-making, prioritization, and more.

Today, we discuss the parietal lobe and its vital and unique role in allowing us to function.

THE CENTER OF SOMATOSENSORY INFORMATION

Let’s conduct a short experiment: close your eyes for a moment. Once they’re open, ask yourself the following questions.

●Were you aware of where your arms were?

●Did you know how your legs were positioned?

●Could you tell if your fingers were bent or not?

How about a more abstract question: with your eyes closed, could you tell how far up from the ground your head was? How far above you the ceiling was? The answers to these questions are not provided by your “traditional” five senses. You did not have to see, hear, smell, taste, or touch your limbs to know exactly where they were. You just sensed it.

If you have a functioning parietal lobe, you’re probably aware of all these things...but not consciously. You may not consider your body as separate from your brain (at least on a practical level), but your brain is the container for all of your sensory processing. That means while you know your legs are crossed or your arm is bent, the reason you know that is not because of your limbs—it’s because of your brain.

This information is known as somatosensory information (from the word soma, which means “body”). Your somatosensory cortex, part of your parietal lobe, provides you with a “body” sense, or the perception of your physical presence in space. Your somatosensory cortex is fed information from your skin and joint receptors, which allow you to process pressure, pain, vibration, touch, temperature, and joint position.

UNDERSTANDING THE WORLD AROUND US

The parietal lobe not only handles our perception of our bodies, but also of our sense of space in a three-dimensional world. Specifically, this function is handled by the posterior parietal lobe. Through this part of the brain, our bodies are capable of understanding our right from our left, to sense objects around us without touching them (to a limited degree), and to understand the difference between up and down.

Parietal lobes are the part of the brain that allow us to develop the incredible physical skills exhibited by ice skaters, gymnasts, and several other kinds of athletes who depend on their coordination and orientation to guide them. Without the parietal lobe, there is no such thing as movement, sports, coordination, or navigation. Motor skills would be possible...but they would be entirely ineffective.

Unfortunately, for people who have damaged parietal lobes, even basic functions are hampered. For an extreme example, consider the neurological disorder known as agnosia. Agnosia is the general inability to process sensory information. Some stroke victims suffer damage to their parietal lobes, which causes agnosia of your somatosensory perception.

This results in strange and distressing symptoms, such as unawareness of the right or left side of your body, the inability to account for it while moving, and even the sensation that your left arm belongs to someone else. It’s a rare example, but parietal senses are vital to our survival because it allows us to protect our bodies by being aware of where they are.

Thankfully, these symptoms can also help your neurologist diagnose where exactly your parietal lobe is lacking function. Where you are experiencing agnosia actually pinpoints which part of your brain is damaged. Inability to sense the left side of your body means your right parietal lobe is damaged, and vice versa. Through targeted therapies and exercises, doctors at Plasticity Brain Centers have been able to help patients determine exactly where they needed treatment in their parietal lobes.

THE PARIETAL LOBE’S SECOND FUNCTION

Because the parietal lobe provides such vital information, it is deeply integrated with the body’s other functions. For example, your spatial awareness gives you the ability to make decisions, plan, and navigate. In many ways, our parietal lobe has helped us become the explorers, pioneers, and astronauts that we are today.

These secondary functions are also how our neurologists localize the parts of your brain that need improvement. For example, eye movement is a clear indicator of parietal lobe function. Through eye-tracking exercises, joint positioning, and orientation tests, our specialists can more fully understand how your somatosensory information is being received and processed.

The Sensory Homunculus

One of the ways our doctors localize your parietal lobe’s function is through manipulation of your “sensory homunculus.” The sensory homunculus is the part of your brain that creates your brain’s understanding of your body. The sensory sensitivity of your body parts is directly related to how much space your parietal lobe devotes to that particular body part.

On our blog, you can see a model of how the body perceives itself based on sensory priorities. Your hands and your mouth, for example, receive and feed more information to your parietal lobe than your forearms. Our doctors use this model to start with larger representative body parts, moving to smaller and smaller parts in order to understand your brain’s current somatosensory function.

DIFFERENT FORMS OF THERAPY

Thanks to the nature of the parietal lobe, our therapies have to be creative in order to address processing issues in that part of the brain. Heat, vibration, joint position, and electricity can all accomplish serve as suitable forms of therapy—but strangely enough, so can a mirror.

Mirrors have been used to “trick” the parietal lobe into recognizing its other limbs again. Using the agnosia example from above, patients can stand in front of a mirror with their left limbs, but the parietal lobe will register it as the right limb—allowing it to perceive it again!

Similar tricks have been used to treat pain syndromes by shrinking the affected body part in a photo. This fools the brain into believing the body part is smaller than it is—which causes your sensory homunculus to respond by devoting less processing space to it.

In summary, the parietal lobe is a strange and vital part of your brain and body’s function. It provides our neurologists a rare opportunity to use unusual scientific techniques in order to manipulate and strengthen your body’s spatial awareness, perception of itself, and overall ability to navigate a three-dimensional world.

As we discussed a few weeks ago in our first blog in this series, the brain’s primary role is to receive and interpret information. When we receive this information correctly and process it correctly, our brains can then respond in a way that is appropriate for us (both socially and biologically).

In March, we discussed the frontal lobe, particularly its role as the brain’s “CEO” and “quarterback”—it receives information from the occipital, parietal, and temporal lobes and organizes it in order to create a response. Our fight-or-flight instincts are born in the frontal lobe, but so are our higher-level functions, such as moral decision-making, prioritization, and more.

Today, we discuss the parietal lobe and its vital and unique role in allowing us to function.

THE CENTER OF SOMATOSENSORY INFORMATION

Let’s conduct a short experiment: close your eyes for a moment. Once they’re open, ask yourself the following questions.

●Were you aware of where your arms were?

●Did you know how your legs were positioned?

●Could you tell if your fingers were bent or not?

How about a more abstract question: with your eyes closed, could you tell how far up from the ground your head was? How far above you the ceiling was? The answers to these questions are not provided by your “traditional” five senses. You did not have to see, hear, smell, taste, or touch your limbs to know exactly where they were. You just sensed it.

If you have a functioning parietal lobe, you’re probably aware of all these things...but not consciously. You may not consider your body as separate from your brain (at least on a practical level), but your brain is the container for all of your sensory processing. That means while you know your legs are crossed or your arm is bent, the reason you know that is not because of your limbs—it’s because of your brain.

This information is known as somatosensory information (from the word soma, which means “body”). Your somatosensory cortex, part of your parietal lobe, provides you with a “body” sense, or the perception of your physical presence in space. Your somatosensory cortex is fed information from your skin and joint receptors, which allow you to process pressure, pain, vibration, touch, temperature, and joint position.

UNDERSTANDING THE WORLD AROUND US

The parietal lobe not only handles our perception of our bodies, but also of our sense of space in a three-dimensional world. Specifically, this function is handled by the posterior parietal lobe. Through this part of the brain, our bodies are capable of understanding our right from our left, to sense objects around us without touching them (to a limited degree), and to understand the difference between up and down.

Parietal lobes are the part of the brain that allow us to develop the incredible physical skills exhibited by ice skaters, gymnasts, and several other kinds of athletes who depend on their coordination and orientation to guide them. Without the parietal lobe, there is no such thing as movement, sports, coordination, or navigation. Motor skills would be possible...but they would be entirely ineffective.

Unfortunately, for people who have damaged parietal lobes, even basic functions are hampered. For an extreme example, consider the neurological disorder known as agnosia. Agnosia is the general inability to process sensory information. Some stroke victims suffer damage to their parietal lobes, which causes agnosia of your somatosensory perception.

This results in strange and distressing symptoms, such as unawareness of the right or left side of your body, the inability to account for it while moving, and even the sensation that your left arm belongs to someone else. It’s a rare example, but parietal senses are vital to our survival because it allows us to protect our bodies by being aware of where they are.

Thankfully, these symptoms can also help your neurologist diagnose where exactly your parietal lobe is lacking function. Where you are experiencing agnosia actually pinpoints which part of your brain is damaged. Inability to sense the left side of your body means your right parietal lobe is damaged, and vice versa. Through targeted therapies and exercises, doctors at Plasticity Brain Centers have been able to help patients determine exactly where they needed treatment in their parietal lobes.

THE PARIETAL LOBE’S SECOND FUNCTION

Because the parietal lobe provides such vital information, it is deeply integrated with the body’s other functions. For example, your spatial awareness gives you the ability to make decisions, plan, and navigate. In many ways, our parietal lobe has helped us become the explorers, pioneers, and astronauts that we are today.

These secondary functions are also how our neurologists localize the parts of your brain that need improvement. For example, eye movement is a clear indicator of parietal lobe function. Through eye-tracking exercises, joint positioning, and orientation tests, our specialists can more fully understand how your somatosensory information is being received and processed.

The Sensory Homunculus

One of the ways our doctors localize your parietal lobe’s function is through manipulation of your “sensory homunculus.” The sensory homunculus is the part of your brain that creates your brain’s understanding of your body. The sensory sensitivity of your body parts is directly related to how much space your parietal lobe devotes to that particular body part.

On our blog, you can see a model of how the body perceives itself based on sensory priorities. Your hands and your mouth, for example, receive and feed more information to your parietal lobe than your forearms. Our doctors use this model to start with larger representative body parts, moving to smaller and smaller parts in order to understand your brain’s current somatosensory function.

DIFFERENT FORMS OF THERAPY

Thanks to the nature of the parietal lobe, our therapies have to be creative in order to address processing issues in that part of the brain. Heat, vibration, joint position, and electricity can all accomplish serve as suitable forms of therapy—but strangely enough, so can a mirror.

Mirrors have been used to “trick” the parietal lobe into recognizing its other limbs again. Using the agnosia example from above, patients can stand in front of a mirror with their left limbs, but the parietal lobe will register it as the right limb—allowing it to perceive it again!

Similar tricks have been used to treat pain syndromes by shrinking the affected body part in a photo. This fools the brain into believing the body part is smaller than it is—which causes your sensory homunculus to respond by devoting less processing space to it.

In summary, the parietal lobe is a strange and vital part of your brain and body’s function. It provides our neurologists a rare opportunity to use unusual scientific techniques in order to manipulate and strengthen your body’s spatial awareness, perception of itself, and overall ability to navigate a three-dimensional world.

Plasticity® Centers © 2021