USask graduate hopes to improve treatment plans for speech difficulties

The project aims to investigate the factors that may cause individuals with diverse types of aphasias to unintentionally produce speech errors such as adding, removing, or altering a sound in a word. These types of errors, known as phonological paraphasias, can make carrying on a conversation difficult as unintended words or non-words are produced during speech.

“After volunteering with a book club for individuals with aphasia, I wanted to know more about post-stroke speech errors and whether they were impacted by the type of task the individual was doing,” said Hangs, who began research on the honours project during her undergraduate studies.

Supervised by Dr. Zhi Li (PhD), assistant professor in linguistics in USask’s College of Arts and Science, Hangs used AphasiaBank, a publicly available collection of interviews between clinicians and individuals with post-stroke aphasias, to analyze how different genres of conversation—such as fictional storytelling versus telling a story about one’s life—affected the number of words and speech errors produced.

She then conducted statistical analyses to see how these outcomes were related to factors such as age, sex, and type of aphasia.

For example, results showed that fictional storytelling produced more than five times as many word errors than storytelling about one’s life. Those with global aphasia, which occurs from damage to the brain’s language centres, produced more than eight times more word errors than those with any other type of aphasia and had the most trouble completing various speech tasks.

In one such task, participants were asked to recall the fairytale Cinderella and provide a summary of the story. Researchers evaluated how well the subjects remember the story and could correctly describe its events and ending. Hangs found that this task elicited over four times more word errors than any other tasks in the study.

Hangs said results from the vast amount of research can help people to be patient and understanding when speaking with individuals with aphasia and identify certain types of conversations that may be more challenging.

“No known research has looked at how age, sex, aphasia type, genre, or task affects how many speech errors people with aphasia make,” said Hangs. “These findings show how these variables affect how many word and non-word errors people with aphasia make, which leads to a greater understanding of how speech-language pathologists can treat them.”

This article first ran as part of the 2022 Young Innovators series, an initiative of the USask Research Profile and Impact office in partnership with the Saskatoon StarPhoenix.