New research indicates that the way people speak may hold critical clues to early signs of cognitive decline, particularly in relation to Alzheimer’s disease. A study conducted by researchers at the University of Toronto suggests that the pace of everyday speech might be a more significant indicator of cognitive health than previously considered factors, such as difficulty recalling specific words.
The study involved 125 healthy adults ranging in age from 18 to 90. Participants were tasked with describing a scene in detail, followed by an auditory challenge designed to test their word recall abilities. This challenge included showing images of common objects while playing audio that could either aid or mislead in finding the correct word. For instance, if a participant viewed a picture of a broom, they might hear the word “groom,” which could help trigger the correct response. Conversely, hearing a related word like “mop” could divert attention momentarily.
Researchers found a clear link between the speed of a participant’s natural speech during the first task and their ability to respond quickly in the second. This finding supports the processing speed theory, suggesting that a general slowdown in cognitive processing is central to cognitive decline, rather than a specific reduction in memory functions.
According to psychologist Hsi T. Wei, who led the study, “Older adults are significantly slower than younger adults in completing various cognitive tasks, including word-production tasks such as picture naming.” The study observed that older adults often produced more dysfluencies—like pauses and filler sounds such as “uh” and “um”—and exhibited a slower speech rate.
In a related commentary for The Conversation, dementia researcher Claire Lancaster noted that the findings from Toronto “have opened exciting doors,” emphasizing that speech speed could be a revealing factor for cognitive changes. The implications of these discoveries are broad, especially as advancements in artificial intelligence continue to evolve. Some AI algorithms have recently achieved an accuracy rate of 78.5 percent in predicting an Alzheimer’s diagnosis based solely on speech patterns.
Additional studies have also highlighted the association between speech-related issues and the presence of amyloid plaques—common indicators of Alzheimer’s disease. Research indicates that individuals with higher levels of these plaques are 1.2 times more likely to experience speech difficulties. Furthermore, a 2024 study from Stanford University found that longer pauses and slower speech rates correlate with increased levels of tangled tau proteins, another hallmark of the disease.
The researchers concluded that changes in speech could reflect the development of Alzheimer’s pathology, even in individuals who do not yet exhibit overt cognitive impairments. As scientists continue to explore the intricacies of human speech, the potential for using these findings in early diagnosis and intervention grows.
The study conducted by the University of Toronto was published in the journal Aging, Neuropsychology, and Cognition in 2023, marking a significant step forward in our understanding of cognitive health and communication. As research progresses, it may help shape future diagnostic approaches, offering hope for earlier detection and management of Alzheimer’s disease.
