Like much of what we know about the brain, knowledge of the areas involved in spoken and written language comes mainly from studying the loss of those abilities to trauma or disease.
Pélagie Beeson, who studies the neural substrates of written language, will talk Monday about “The Literate Brain.” She will describe where those language centers lie and how she and her colleagues formulate therapies to restore function after those areas are damaged.
The lecture, part of the UA College of Science’s series “The Evolving Brain,” is at 7 p.m. in Centennial Hall on the University of Arizona Mall.
Beeson is a professor and head of the Department of Speech, Language and Hearing Sciences at the University of Arizona, with a joint appointment in the Department of Neurology.
Speech and writing problems usually develop after damage to the left hemisphere of the brain, though a small number of people (usually left-handers) develop those skills in the right hemisphere, she said.
Through years of cataloging symptoms and imaging the brain, specialists such as Beeson and her research group have developed a pretty good understanding of where those centers are and can usually predict, before the brain is imaged, where the damage has occurred, based on symptoms.
Beeson’s Aphasia Research Project sees clients at least six months and sometimes years or decades after loss of speech or writing function.
That six-month period, during which there is ongoing therapy, is also the period in which the brain repairs itself to the extent that it can.
Subjects can continue to improve through behavioral therapy by harnessing other, usually nearby, parts of the brain, to perform functions previously performed by damaged cells, she said.
This is especially true for younger patients, whose “elastic” brains can often develop language capabilities in the right hemisphere, Beeson said. That elasticity vanishes with youth.
Aphasia is the term applied to the acquired impairment of language, usually after stroke or trauma, but sometimes occurring with progressive neurological diseases.
It can be spoken, written or both. The acquired impairment of reading is known as alexia, and the impairment of spelling and writing is called agraphia.
Researchers in the UA’s Aphasia Research Project have developed an algorithm called a “decision tree” that personalizes treatment based on symptoms and performance on a battery of tests.
Functional Magnetic Resonance Imaging of the brain, during which a subject performs reading and writing tasks, further refines the picture of the impairment by allowing researchers to see what parts of the brain “light up” when certain tasks are performed.
Those who suffer a stroke or brain injury have a wide variety of aphasia symptoms — ranging from those who have no understandable speech to those who talk easily and form sentences but “can’t pull up the right word,” Beeson said.
Beeson said she’s never had to advertise for subjects for her research.
She receives a steady stream of referrals from neurologists and therapists in the Tucson area and from elsewhere in the country.
Her department recently kept its No. 5 spot in the annual U.S. News and World Report ranking of speech-language pathology programs.
Part of the center’s charge is to spread the word about new therapies through publishing results and reporting them at conferences, she said.
Promulgation of the latest therapies is part of the charge given by the National Institute on Deafness and Other Communication Disorders, one of the National Institutes of Health, which partly funds the research.