The parietal lobe of the brain, also called the association cortex, is responsible for sensory processing, navigation and control, and many other functions
The parietal lobe of the brain, also called the association cortex, is located parallel to the deep groove that divides the brain into right and left halves. It serves multiple functions, include:
- Helps sense temperature changes through touch
- Helps sense pressure changes
- Retains short-term memory
- Interprets visual information
- Recognizes writing on the skin by touch (graphesthesia)
- Helps judge the size and shape of objects
- Helps judge distance
- Helps sense direction
- Helps feel the position of the limbs even when the eyes are closed (right lobe)
- Controls language and mathematical problems solving skills (left lobe)
- Helps exhibit emotions through facial expressions
- Integration of the sensory input via touch and pressure with the visual area in the brain
What happens when the parietal lobe gets damaged?
Damage to the parietal lobe results in abnormalities related to the sensations of touch. It produces signs and symptoms that include:
- Unsteady gait
- Difficulty talking, speaking, reading, and writing
- Difficulty solving mathematical problems
- Inability to visualize and create images
- Astereognosis (difficulty recognizing an object with touch)
- Agraphesthesia (inability to detect or identify basic shapes or letters drawn onto the skin)
- Sensory inattention (inability to recognize sensations in another hand if the person joins both hands)
- Contralateral neglect (less awareness of the nondominant side and the environment around it, making the person prone to injuries)
- Optic ataxia (loss in the ability to guide the hand and arm with the help of eyes)
- Optic apraxia (inability to voluntarily control visual gaze)
What conditions affect the parietal lobe?
The parietal lobe can be damaged by:
- Traumatic injury
- Infection
- Tumor
- Vascular diseases (diseases that affect the blood vessels of the brain)
- Stroke
- Alzheimer’s disease
Diseases associated with parietal lobe dysfunction include:
Gerstmann's syndrome: Lateral damage to the parietal lobe can result in Gerstmann's syndrome, with reduced blood flow affecting the functions of the lobe. A person affected with this syndrome experiences difficulty recognizing movements and the left and right sides of something, such as their environment, and may be unable to recognize their own fingers. People with Gerstmann’s syndrome may face problems with reading and writing, as well as solving mathematical equations.
- Parietal lobe epilepsy: A rare type of epilepsy, parietal lobe epilepsy causes sensory disturbances, such as heat, numbness, hallucinations, weakness, dizziness, and distortion of space along with seizures.
- Amorphosynthesis: This condition causes a loss of perception on one side of the body, typically a sign of a lesion on the left side of the parietal lobe. Sensory impairment may be experienced.
- Balint syndrome: Balint syndrome is a rare disorder that is caused by damage to both sides of the parietal lobe. The condition is typically characterized by:
- Optic ataxia (inability to direct the hand to an object under visual guidance)
- Optic apraxia (loss of coordination between eye movements in response to stimuli)
- Simultanagnosia (inability to capture multiple features from the visual environment)