[MUSIC] Aphasia, which is a difficulty with language, has been known for centuries. These slides which you can look at later and read completely later, I just want to show you this is a description from 1690 of a person who couldn't find his words. He used the wrong words, he couldn't find the words, they were jumbled. This is a cardinal sign of Aphasia. What I like about this description in 1843 was that it was by a physician and so he was quite analytical about what was happening to him. And obviously since he wrote this he recovered and we'll see that one of the signs of Aphasia. So what he says is he knew that he wanted to speak but he couldn't find the expressions. He had a thought and what I like about this is that he can tell us, he has the thought. But the sounds that had to express it were no longer at my dispossession. Beautifully said. A day later I find myself deprived for the use of almost all words if some of them remained in my grasp they were almost useless to me. I could no longer recall the ways to coordinate them, he didn't know how to put them together. So Aphasia as a problem has always existed, but has been recognized and described for centuries. In 1836, Marc Dax wrote the following, he says, I believe to be able to conclude, not that all diseases of the left hemisphere cause Aphasia. But that if there is an aphasia, one must look to the left hemisphere for the cause. So he really was the first person to say that aphasia is a disorder of the left hemisphere. He died right after writing this and it never reached a popular audience. And therefore about 15 years later Paul Broca who was a well known French neurologist. He also described concluded after some great hesitation but he did conclude that aphasia came from the left hemisphere. He has been awarded the common attribution for discovering the left hemisphere involvement in aphasia, but the historical record would suggest that Dax had figured it out before him, before Broca. So how did Broca come to have figured this out? Well he saw two patients, gentleman named Leborgne who could only say tan, tan, tan, tan and he was, he's nicknamed, Leborgne is nicknamed tan if you see in literature or if you see If you read things. He'll often be referred to as "tan". And Lelong who could say just a few words. "Oui", "non, "tois", "toujours" and a version of his own name "Lelo". Now, it may appear to you that using these words, you cannot convey any information. And I want to disabuse you of that notion. I about ten years ago, I met an older woman who had a pretty complete case of aphasia. And her only words were we yet she had full control of her facial expressions. And she had control over her, the tone, what we would call the prosody of her language. And so she and I had this conversation where she just said we but it was quite clear what she was trying to say to me because of her facial expressions and the tone of her voice. So these people can communicate, particularly to somebody who knows them well, there maybe some communication. But of course it is not the communication that they want to have and it is very frustrating for a person with aphasia. And, so Broca saw these two patients and they both died under his care in a situation where he could get their brains. He did get their brains. He preserved them in alcohol. They are to this day sitting in alcohol in Paris in the Musee Dupuytren and worth going to see. So this is a picture of Tan I believe and what you see here I hope, here's the cerebellum, here's the temporal cortex or temporal lobe. And then here's the frontal lobe and Tan had a non trivial huge lesion up in this frontal lobe area. So if we just schematize this so here's the frontal lobe. This is the area that Broca decided was responsible on the left side only for aphasia and today it's called Broca's area. You might noticed that it's right next to motor cortex and so Broca's area, a lesion in Broca's area produces what's called a non-fluent aphasia. In other words, the words don't come out well, but people with Broca's aphasia will understand speech relatively well. So I just gave you a couple more examples of people with aphasia. This is my aunt, who is a poet, and this is a poem that she wrote. After a stroke that she had in her mid 50's, and she says, I'm okay, right? Except symbol, spelled incorrectly, cant come out mouth in speech. Now, she wrote this after she had recovered. But she wrote it to reflect how she felt at that time. She says I draw a flag out hospital window wood WAV. All spelled imaginatively if I could SKIL stil inhand. So, she has skill in her hand, no skill in her mouth. And she recover from this, so that ten years after this stroke, you couldn't tell that she had this episode of aphasia. And one more example is Jill Bolte Taylor, who had a hemorrhagic stroke, she's a neuroscientist. She was and she continues to be a neuroscientist. She wrote a book, I actually listened to the book, and she read her own book. She has no trace of her, difficulty with language. So the Aphasia in the best circumstances can be people can recover from these strokes. Can be recovered from obviously the initial patients that broke they didn't recover from it. In the next seminar we're going to simply look at what are the brain circuits that produce language. [MUSIC]
