Hodor. Anyone who watches “Game of Thrones” recognizes that as the name of a popular character on the show, a large oaf of a man that carries a child across Westeros. Fans also recognize that as the sole word Hodor can say on the show. A Penn State neuroscience student explained the neurological condition that afflicts Hodor in an article for The Conversation.

Jordan Gaines Lewis, a Ph.D student at the Penn State College of Medicine, studying neuroscience recently wrote an article breaking down Hodor’s mental condition, which limits him to just one word. Lewis said that Hodor suffers from expressive aphasia, a loss of the ability to produce language.

Lewis cited Paul Broca, a French physician who performed an autopsy on a man named Louis-Victor Leborgne. Much like Hodor, Leborgne could speak just one word: tan. Similar to Hodor, that one word became Leborgne’s nickname.

“Broca’s autopsy determined tissue damage, or a ‘lesion’, in the frontal lobe of Leborgne’s left brain hemisphere, just next to a brain fold called the lateral sulcus,” Lewis said. “Over the next two years, Broca acquired brains from 12 more patients with Leborgne’s symptoms — all of the autopsy evidence was strikingly consistent.”

That autopsy evidence showed lesions located in a small area of the brain now known as “Broca’s area.” Lewis said the region of the brain is active during language comprehension tasks, interpretation of movement, and comprehending gestures of speech like a wave. In 2007, a group of researchers at the University of California looked at Lebrogne’s brain again, along with the brain of a similar patient, using an MRI. They found lesions extending deeper than Broca reported.

“This evidence of widespread damage is unsurprising. Leborgne, Lelong — and even Hodor — are actually more extreme examples of individuals with expressive aphasia,” Lewis said. “More commonly, a person with the disorder will express themselves in ‘telegraphic speech’, which usually comprises three or so words, including a noun and a verb. For example, someone may say, ‘Anne, dog, walk’ to mean ‘I walked the dog with Anne today.'”

Lewis said that expressive aphasia is most commonly caused by a stroke. She added that expressive aphasia affects 12 percent of stroke patients, while 35 percent of stroke sufferers experience some sort of language difficulty. According to Lewis, the neurological condition can also be caused by a tumor, hemorrhage, hematoma, or trauma.

“It has been reported that Leborgne suffered from epileptic seizures as a child — some have speculated that he may have experienced head trauma during one such episode,” Lewis said.

She points out that Hodor’s life isn’t well-documented in the book series by George R.R. Martin, but “like the other characters in the show, Hodor too may have a quite an interesting backstory.”

If you’re in State College on Wednesday night, you can ask Kristian Nairn, the actor who plays Hodor, yourself. Nairn is in the middle of a DJ tour, playing electronic music around the world for his “Rave of Thrones” show. Hodor will play at Levels tonight, so perhaps Lewis will have the chance to ask Nairn about his character’s mysterious case of expressive aphasia.