In the golden years of life, many of us notice that finding the right words can take a little longer than it used to. This common phenomenon often raises concerns about cognitive decline and the specter of dementia. However, a groundbreaking study conducted by the Baycrest Hospital and the University of Toronto offers a fresh perspective on what aspects of speech may truly indicate changes in brain health.
The researchers found that the overall speed of speech, rather than the struggle to find words, serves as a more telling indicator of cognitive health. This discovery sheds new light on the aging process, suggesting that slowing down in speech could signal changes in the brain, while difficulties in word retrieval might be a normal aspect of aging.
The study was published in the journal Aging, Neuropsychology, and Cognition.
The motivation behind this study stemmed from the need to distinguish between natural cognitive aging and early signs of neurodegenerative diseases like dementia. Previous research primarily focused on word-finding difficulties as a potential red flag for cognitive decline. However, this study aimed to explore whether other aspects of speech might offer more precise insights into our cognitive well-being as we age.
To delve into this question, the researchers enlisted 125 healthy volunteers, ranging in age from 18 to 90, to participate in a series of innovative assessments designed to analyze their speech characteristics and cognitive abilities. The participants underwent a picture-naming game, where they had to identify and name objects while ignoring irrelevant, distracting information.
This was followed by a task that required them to describe complex images, with their speech being recorded and analyzed for speed and hesitations using advanced Artificial Intelligence-based software. The final part of the study involved standard tests to assess executive function, a set of mental skills that help individuals manage time, pay attention, and juggle multiple tasks.
As expected, certain cognitive abilities and speech characteristics declined with age. Specifically, participants exhibited a decrease in the speed at which they were able to name pictures presented to them in the picture-naming game. This decline was consistent with expectations based on previous research linking aging to slower cognitive processing speeds.
However, one of the study’s primary discoveries was the distinction between word-finding difficulties and speech speed as indicators of cognitive health. The researchers found a compelling link between the speed at which individuals spoke and their executive function.
Executive function, which encompasses abilities such as managing conflicting information and staying focused, showed a direct correlation with both the participants’ ability to quickly name pictures and their overall speaking rate.
Intriguingly, the study revealed that the frequency and duration of pauses participants took to find the right words did not correlate with cognitive decline. This suggests that the occasional struggle to find words, a common concern among aging adults, might not necessarily indicate serious cognitive issues. Instead, a general slowing down in speech — apart from these pauses — emerged as a potentially more significant indicator of changes in brain health.
Furthermore, the study’s findings challenge some of the conventional wisdom regarding aging and speech. Many older adults worry about their need to pause to search for words, viewing it as a sign of cognitive deterioration. However, the results of this research suggest that such pausing is a normal part of aging and is not directly linked to a decline in other mental abilities.
On the contrary, a slowdown in the normal rate of speech, regardless of pausing, could be a more critical sign of changes in cognitive health. This distinction provides a new perspective on what aspects of speech might be more accurately reflective of underlying cognitive changes.
“Our results indicate that changes in general talking speed may reflect changes in the brain,” said Jed Meltzer, Baycrest’s Canada Research Chair in Interventional Cognitive Neuroscience and the lead author on this study. “This suggests that talking speed should be tested as part of standard cognitive assessments to help clinicians detect cognitive decline faster and help older adults support their brain health as they age.”
The study, however, is not without its limitations. The researchers acknowledge that further research is needed to confirm whether speech speed can predict individual brain health changes over time. Future studies could follow participants over several years to explore this relationship more deeply. Moreover, these findings could pave the way for new tools to detect cognitive decline early, allowing for timely interventions to maintain or improve brain health.
The study, “Cognitive components of aging-related increase in word-finding difficulty,” was authored by Hsi T. Wei, Dana Kulzhabayeva, Lella Erceg, Jessica Robin, You Zhi Hu, Mark Chignell and Jed A. Meltzer.
