Language comprehension in humans more complex than previously thought

A study conducted on the brain by researchers at the Northwestern University suggests that the long-held belief that Wernicke’s area is the prime area of language comprehension might not be accurate. Marek-Marsel Mesulam, lead study author and director of Northwestern’s Cognitive Neurology and Alzheimer’s Disease Center, performed language tests and brain MRIs on 72 patients with a rare form of language-affecting dementia called primary progressive aphasia (PPA) in which Wernicke’s area is damaged. He observed that these patients did not exhibit the same trouble with word meaning as stroke victims with similar brain damage. PPA and stroke damage the brain differently; in PPA, cortical areas degenerate, but their underlying fiber pathways that are necessary for communication between different language centers in the brain, remain intact. However, stroke damages large regions of brain. According to Mesulam, this strongly indicates that language comprehension is a complex process that relies on many interconnected brain regions, rather than one constrained area. 

Read in more detail in The Scientist.