The Parietal Lobes and Their (Dys)Function
Just behind the frontal lobes are the parietal lobes, and they are situatied on top of the head–just where the “crown” would be, for those barbers out there. They are divided into two lobes, the left and the right, and they serve a variety of roles with regards to the “perceiving” part of the brain.
- Visual attention
- Touch perception
- Goal-directed movements
- Object manipulation
- The integration of various senses enabling the understanding of concepts
While the first function of these lobes is to integrate sensory information making cognition (understanding) possible, their second function is to provide us with a spatial relationship with the world around us. “Individuals with damage to the parietal lobes often show striking deficits, such as abnormalities in body image and spatial relations (Kandel, Schwartz & Jessel, 1991).” Personally, I have difficulty figuring out what size container it takes to hold leftovers in the fridge. You would not believe how many times I’ve had to either get a second, bigger container, or would have a huge dish for just a little bit of soup! Over the years, though, I’ve gotten better, I think because of doing it over and over.
Damage to the left parietal lobe can cause difficulty with left-right confusion, mathematics, or difficulty in writing. As I’ve mentioned before, the capacity for language and making word-choices (aphasia) can be affected here. When I took the PSAT or the Pre-Standardized Aptitude Test only months before my accident in 1989, I scored a 79 out of 80 possible in the math section! No lie, I only missed one question in the math section, which put me in the 99th percentile. Yeah, I was that good.
And along comes April, and I survive (barely) a severe traumatic brain injury, and my math skills are gone. No longer could I add multiple numbers, multiply numbers in the hundreds, or divide large numbers–all in my head. I was devastated, but I didn’t know how bad it was until I started multiply numbers on paper, and would bring the zero down, and forget to carry numbers, etc… I didn’t know it, but I had confused a good number of rules or shortcuts which when used at the appropriate times, could speed things along while providing the correct answer. It was awful. And I was equally confused as to why the synthesis of these rules–which I was convinced were right–weren’t working to provide the answer. Even now, I have a hard time balancing a checkbook, so it’s a good thing I married someone who is both smart and beautiful!
Damage to the right parietal lobe often causes many survivors to neglect part of the body or space. Like a painting, the left side may be filled in beautifully, but on the right third there is nothing. This can also include the survivor not washing one side or the other. Often they may forget to shave part of their face. Damage here can also cause the survivor to deny his weaknesses. “I’m just as good as I was before my injury,” can often be heard from someone who has sustained damage to the right parietal lobe.
If someone has damage to both sides they may have difficulty controlling their gaze, like their eyes may shift involuntarily, or they may have problems picking something up that they’re looking at. They may misjudge distances or even be off target while trying to reach for the object.
While damage to any part of the brain can be catastrophic, injury to the parietal lobes–especially the right lobe–affects the survivor’s memory and personality. God knows I have had major changes to my personality. While I’ve always been gregarious and outgoing, my TBI has only accentuated these characteristics. At the same time, I never had a problem with anger prior to my injury. Since 1989, I have flown into a rage at times and didn’t know why. Now if I do lose my temper in front of my son, my wife always tells him that it is my TBI and not me yelling. So I start over…and do better.
Keep getting better, and I’ll talk to you soon!