Language is looking for a new home
In the case of brain damage in early childhood, the language centers can migrate from the left to the right hemisphere. An amazing example of the flexibility of the brain.
Katharina was just eight years old when she suffered her first epileptic seizure. After that, the right side of her body was initially paralyzed and she could not speak fluently. Although the girl apparently still understood every word, she was unable to formulate a complete sentence. Katharina suffered from what is known as Broca's aphasia.
The neuropathological examination revealed that a congenital malformation of the cerebral vessels had damaged her left frontal lobe. This lesion was responsible for both the girl's epilepsy and loss of speech, since the center of speech production is usually located at the affected site. In the months that followed, more and more tissue died there. It was all the more astounding how well the little patient recovered: Despite extensive destruction of left-sided brain areas, the aphasia gradually disappeared! Six months after her first attack, Katharina was able to utter two-word sentences again, and after a year she was already speaking much more fluently, albeit with an unusual sentence structure. However, the girl kept having seizures, which is why the doctors considered brain surgery.
The big question was whether removing some parts of the left frontal lobe would make Katharina permanently lose her speech. The improvement in her language skills suggested that a significant remodeling had already taken place in her brain. To clarify the situation, the neurologists examined Katharina's brain using functional magnetic resonance imaging (fMRI). With this imaging method, those areas that are involved in certain cognitive functions can be identified.
While the girl was lying in the tube of the brain scanner, she had to solve special language tasks. For example, he heard different nouns and had to mentally list as many verbs as possible that went with them. This should appeal to the productive language regions. Another time, Katharina was listening to a radio play, which activated the sensory centers of language understanding.
After evaluating the data, the doctors found something amazing: the productive speech center was not in the left hemisphere, as usual, but in the right, he althy hemisphere. Since the damage to the left frontal lobe had triggered aphasia, the relevant area must have been there a year and a half earlier. How could this change of sides be explained? …