ABSTRACT
In nineteenth-century France, researchers were trying to establish the idea of lateralization, or that the two main hemispheres of the brain were responsible for different functions. In particular, they sought to prove that the left hemisphere was responsible for language. Fortunately for them, a patient named Monsieur Leborgne entered Bicêtre Hospital in 1839 unable to speak any words or phrases other than the word ‘tan’, usually spoken twice in succession. It was not until nearly 20 years later that the now nicknamed ‘patient tan’ was transferred to the care of Pierre Paul Broca, who began to evaluate the man’s cognitive abilities. His intelligence appeared unaffected by his condition, though he did also show progressive right-side paralysis. Upon Leborgne’s death, Broca evaluated his brain and found a large area in the left hemisphere had been nearly obliterated, likely due to the effects of an ischemic insult. Other, reoccurring ischemic attacks likely contributed to his progressive paralysis as well. Broca continued to study other patients with speech limitations, referred to by the new term ‘aphasias’, which were separate from intellectual deficits. For his contributions, the region that was now known to control the production of speech, Broadmann’s area 44, was dubbed ‘Broca’s area’. Subsequent research into the neurological aspects of language have identified other key regions, including Wernicke’s area (Broadmann’s area 22), which is responsible for comprehension of language, and the arcuate and uncinate fasciculi, which connect the areas to the motor system and to one another. Today, though the field goes by many names, speech and language pathology is a young and booming area of science that actively explores how language can be disrupted, as well as how it can be improved through various therapies and treatment options.
