The Parietal Lobe
The Parietal Lobe is the upper middle lobe of each cerebral hemisphere, located above the temporal lobe. Complex sensory information from the body is processed in the parietal lobe, which also controls the ability to understand language. The parietal lobe is a part of the brain positioned above (superior to) the occipital lobe and behind (posterior to) the frontal lobe.
The functions of the Parietal Lobe include:
- Information Processing
- Pain and Touch Sensation
- Spatial Orientation
- Visual Perception
Damage to the left parietal lobe
can result in right-left confusion, difficulty with writing (agraphia) and difficulty with mathematics (acalculia). It can also produce disorders of language (aphasia) and the inability to perceive objects normally (agnosia).
- Agraphia is inability to write resulting from brain damage.
- Acalculia is a difficulty performing simple mathematical tasks, such as adding, subtracting, multiplying and even simply stating which of two numbers is larger.
- Aphasia is an impairment of language ability.
- Agnosia is a loss of ability to recognize objects, persons, sounds, shapes, or smells. It is usually associated with brain injury.*
Damage to the right parietal lobe
can result in neglecting part of the body or space which can impair many self-care skills such as dressing and washing. Right side damage can also cause difficulty in making things (constructional apraxia), denial of deficits and drawing ability.
- Constructional apraxia is characterized by an inability or difficulty to build, assemble, or draw objects.*
Damage to both the right and left parietal lobes
can cause a visual attention and motor syndrome. This is the inability to voluntarily control the gaze, inability to integrate components of a visual scene (simultanagnosia), and the inability to accurately reach for an object with visual guidance (optic ataxia).
- Simultanagnosia is characterized by the inability of an individual to perceive more than a single object at a time.
- Optic Ataxia is a lack of voluntary coordination of muscle movements.*
Right parietal-temporal lesions can produce significant changes in personality. Damage to the areas between the parietal lobes and the temporal lobes can also result in changes in personality and memory.
It is very important to understand that a traumatic brain injury from a fall, assault, car crash, or other event, which causes damage to the Parietal Lobe does NOT mean that all the impairments discussed above will definitely manifest. So you can have some of the impairments and not others. This where neuropsychological testing becomes vital for doctors in accessing injury and treatment protocol.
Too many times the people who live, work, socialize or interact with a person, who has sustained parietal lobe damage, do not understand how the person is able to do many things appropriately but cannot do certain other things. This problem can lead to overlay or manifestation of other problems like depression.
For additional information you can read my prior blog posts:
* Definitions from Wikipedia.