Toronto, November 11, 2025 – The way we speak in everyday conversation may hold important clues about brain health, according to new research from Baycrest , the University of Toronto and York University. The study found that subtle features of speech timing, such as pauses, fillers ('uh,' 'um') and word-finding difficulty, are strongly linked to executive function, the set of mental skills that support memory, planning and flexible thinking.
The study is one of the first to demonstrate a direct link between natural speech patterns and essential cognitive functions, opening new avenues of research to better understand the mind. It builds on previous research that showed that faster talking speed is linked to preserved thinking in older adults (Wei et al., 2024).
"The message is clear: speech timing is more than just a matter of style, it's a sensitive indicator of brain health," says Dr. Jed Meltzer, Senior Scientist at Baycrest's Rotman Research Institute and senior author on this study, titled " Natural Speech Analysis Can Reveal Individual Differences in Executive Function Across the Adult Lifespan ."
Participants were asked to describe complex pictures in their own words while also completing standard tests of executive function. Using artificial intelligence, researchers analyzed the recordings and identified hundreds of subtle features, including pauses, filler words and timing patterns. These features reliably predicted performance on cognitive tests, even after accounting for age, sex and education.
Executive functions decline with age and are often compromised early in dementia, but they are hard to track with traditional testing, which is time-consuming and vulnerable to practice effects, the improvements in performance due to familiarity. Natural speech, by contrast, is an everyday behaviour that can be measured repeatedly, unobtrusively and at scale. It also provides information about processing speed as a sensitive measure of cognitive integrity in an ecologically valid manner, without the need for imposed time limits — something that is challenging to capture with most traditional cognitive tasks.
Given the ease, convenience and sensitivity of natural speech analysis, it is an ideal choice for repeated assessments, which could identify individuals who are experiencing cognitive decline at a higher rate than expected and may be at high risk for developing dementia. "This research sets the stage for exciting opportunities to develop tools that could help track cognitive changes in clinics or even at home. Early detection is critical for any cure or intervention, as dementia involves progressive degeneration of the brain that may be slowed," says Dr. Meltzer.
The researchers emphasize the need for longitudinal studies, following individuals' speech over time, to separate normal aging from early signs of disease. They note that combining naturalistic speech with other measures could make early detection of cognitive decline more precise and accessible.
This research was supported by the Mitacs Accelerate program and the Natural Sciences and Engineering Research Council of Canada (NSERC).
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