CogBlog 2: Brain Injury Case Study of Louis Victor Leborgne (aka "Tan")

For this CogBlog, I wanted to look into a case study about an individual who suffered some kind of brain injury that altered their cognition. There was one example of a case of someone’s cognition being changed by some kind of brain damage mentioned in chapter two that interested me. The man known in psychology textbooks as “Tan”. He was given and remembered through history by this name because for a number of years it was the only sound he could make to try and communicate. I had heard of Tan before but I didn’t know much about why he was given his name besides that his condition lead to the eventual discovery of the Broca’s area of the brain. I wanted to learn more about this man’s case and how his impaired cognition occurred.

What I found when I did some research was that Tan, whose actual name was Louis Victor Leborgne, was an epileptic. Apparently he had been living with seizures for a long time in his life and until the development of his speech loss at age 30 he had been dealing with the seizures rather well. Knowing that he was epileptic could explain how Mr. Leborgne’s frontal lobe became damaged. Seizures occur when something interrupts the normal signal processing in the central nervous system. These interruptions, depending on where they occur in the brain have different resulting side effects, the most commonly known being the muscle spasms in generalized seizures. One type of seizure is the complex focal seizure which occurs in the temporal lobe, the area in the brain where Broca’s area is located.

Louis Victor Leborgne's brain. Damage can be clearly seen on the brain's frontal lobe.

Considering the above, it would probably be a reasonable reaction to say that the seizures must have done some damage to Mr. Leborgne’s Broca’s area. However, while doing research, I found another interesting factor in the state of Mr. Leborgne’s damaged brain. Many years after Mr. Leborgne’s death and subsequent autopsy in 2007, it was discovered that the damage in Mr. Leborgne’s brain was far more severe then was originally thought when Broca conducted his original autopsy in 1861. A team of researchers at the University of California lead by Nina Dronkers put the preserved brain through a high resolution volumetric MRI scan and found that alongside the damage to the Broca’s area there was also damage to the brain’s superior longitudinal fasciculus, which connects both the anterior and posterior language regions of the brain.

The results of the 2007 high resolution MRI of Leborgne's brain

This discovery would imply that Mr. Leborgne’s brain damage that resulted in his loss of speech might have been less extreme if only the Broca’s area had been affected. With this new evidence bringing more language related areas of the brain into the picture, it shows how extensive the damage to this man’s brain became over time and what damage to the language areas of the brain can do to a person. It is unknown to w

hether or not Mr. Leborgne’s many years of seizures were the sole cause of this brain damage, but with no recorded history of other serious trauma I would guess that in one way or another they were involved. Overall, the case of Mr. Leborgne is a fascinating case study to look at and serves as reminder of what can happen to even the most basic forms of cognition when the brain is damaged.