Study details

For the study, researchers showed participants detailed images and asked them to describe those images in their own words. The participants also completed established tests designed to measure executive function.

The researchers then used artificial intelligence to examine the recordings, detecting hundreds of subtle speech features, including the length and frequency of pauses, the use of filler words, and timing-related speech patterns.

They found that these markers consistently predicted how well the participants performed on cognitive tests, even after the researchers controlled for factors like age, sex, and education.

Executive function naturally gets weaker with age and is often affected during the early stages of dementia, but standard cognitive tests can be difficult to repeat frequently, as they take time and participants often improve by becoming familiar with the tests, the researchers said.

But natural speech patterns could offer an alternative. Since speaking is a part of daily life, it can be measured repeatedly and easily on a large scale. The researchers noted that speech provides a valuable insight into processing speed and overall cognitive function in real-world situations, without requiring strict time limits common in cognitive tests.

The researchers said they believe speech analysis could become a practical way to identify people whose cognitive decline is progressing more rapidly than expected and who might face a higher risk of developing dementia.

"[S]peech timing is more than a matter of style, it's a sensitive indicator of brain health," said Jed Meltzer, senior scientist at Baycrest's Rotman Research Institute and senior author of the study.

"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," he added.

"And some of the things that they were looking at in this study are things where everybody gets a little worse on these measures over time, but they’re picking up a signature where [in] some people, it's just that much more so, and those are the ones who are vulnerable," she added.

Whitson agreed that difficulty finding words can just be a normal part of aging.

"Usually it starts with proper nouns, so the person who's saying, 'I can remember everything about that actor, but I can't think of their name right now,'" she said.

Whitson added that there are limitations to the study. "Speech patterns are very dependent on culture and even families," she said, and this study doesn't address that aspect of speech differences.

In addition, this data was all "drawn from one time point," Whitson added. So there's nothing to compare someone's speech patterns to, meaning a person's use of the word "uh" might be normal and something they picked up as a child, not a sign of cognitive decline.

While not every "um" is a sign you need to talk to your doctor, Whitson noted there are some red flags to watch for.

"The kinds of things I would worry about, number one ... having a lot of difficulty expressing oneself, particularly with ordinary dictionary words, not just struggling to come up with the name of someone or the title of a book or movie," she said.

Lapses in short-term memory can also be concerning, Whitson said. "That usually presents with either repeating one's questions in a very short time span," she said.

"Other things is getting lost in familiar places, or repeatedly forgetting important appointments," she added. Misplacing items and having no idea how that item got there in the first place is another red flag, Whitson said.