There is growing recognition among psychologists of the brain's ability to adapt to damage, even in adulthood. The characteristic is known as plasticity. Evidence supporting this concept is provided by a case study published in the latest issue of the journal Neurocase.
The study documents the recovery of language performance in a man known as FV who had a tumour removed from a relatively large section of his brain, including Broca's area - considered since the nineteenth century to be a vital neural centre for speech production.
Broca's area is named after the nineteenth century French surgeon Paul Broca for his work with a patient who, following localised damage to the rear part of his left frontal lobe, lost the ability to produce speech, with the exception of the syllable 'tan', hence his nickname 'Tan tan'. The man's comprehension, meanwhile, remained intact, leading to the popular conclusion that Broca's area is important for speech production, but not comprehension.
The researchers thoroughly tested FV's language skills before, during and after his tumour was surgically removed. In addition to standard neuropsychological tests, the researchers also used a narrative task that required FV to tell the story played out in a children's picture book - a test the researchers said was sensitive to deficits not detected by standard measures.
The results showed that FV's tumour and its subsequent removal did not lead to severe language deficits and FV quickly regained most of his speech production abilities. Because his tumour had grown slowly, other areas of FV's brain, adjacent to Broca's area, had been able to take over language functions, although the narrative task did expose some subtle deficits in functions that obviously hadn't been allocated to adjacent areas. These included an inability to talk about other people's speech.
The researchers state the importance of linguistic and neuropsychological assessment before, during and after surgery in order to prevent such subtle deficits in similar cases.
Reference: Plaza, M., Gatignol, P., Leroy, M., & Duffau, H. (2009). Speaking without Broca's area after tumor resection.Neurocase; 15(4): 294-310.
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