People who know more than one language may have a better chance of maintaining their cognitive abilities late into life or after experiencing neurodegenerative conditions, according to an expert at the University of Alberta. Tanya Dash, an assistant professor in the Faculty of Rehabilitation Medicine, is a speech-language pathologist and cognitive neuroscientist who studies the interaction between language and cognition in older adults and people recovering from strokes.
“I use various methodologies like behavioral assessments and neuroimaging techniques,” says Dash. “My work involves diverse age groups, as well as individuals who have lost their language abilities.”
Dash explains that language interacts with other cognitive domains such as attention, memory, and executive functions, all of which are essential for daily communication and activities. The effects of these interactions become more evident when someone suffers a stroke or other neurodegenerative diseases.
“When someone has a stroke, Alzheimer’s disease, or another neurodegenerative condition, the language areas in the frontal and temporal lobes of the brain may be damaged,” she says. “This damage affects their ability to understand or produce language.”
Different types of impairments, such as aphasia and dementia, can cause difficulties in using language at the word, sentence, or discourse level. Dash notes that there is significant variability in symptoms, so no two people with aphasia or dementia will have the same experience.
The good news for bilingual individuals is that they may have some protection against these conditions. “There’s a huge amount of literature showing that, especially in Alzheimer’s disease, bilingualism delays the onset of symptoms by up to five years,” Dash notes. “However, some have contested this idea, and it is less clear whether bilingualism reduces the risk of developing dementia or slows the progression of the disease once symptoms appear.
“One of my goals is to answer these questions with prospective studies to determine which aspects of bilingualism, if any, delay the onset of these conditions.”
Regarding stroke, Dash mentions that some studies suggest bilingual people who experience stroke-induced aphasia show reduced symptom impact and have a better prognosis for recovery.
