Signs of cognitive decline, particularly related to Alzheimer’s disease, may be detectable through speech patterns rather than simply the content of what individuals say. A recent study conducted by researchers at the University of Toronto suggests that the pace of speech could serve as a more reliable indicator of cognitive health than traditional measures, such as word-finding difficulties.
The study, which involved 125 healthy adults aged between 18 and 90, aimed to understand how speech characteristics change with age. Participants were tasked with describing a scene in detail and were subsequently shown images of everyday objects while listening to audio designed to either confirm or mislead their responses. For instance, when presented with a picture of a broom, the audio might say “groom” to aid in recall, or introduce a related term like “mop” to create confusion.
The findings indicated that individuals who spoke more quickly during the first task also provided faster responses in the second task. This aligns with the processing speed theory, which posits that a general slowdown in cognitive processing is central to cognitive decline, rather than a specific impairment in memory functions.
Dr. Hsi T. Wei, a psychologist at the University of Toronto, explained, “It is clear that older adults are significantly slower than younger adults in completing various cognitive tasks, including word-production tasks such as picture naming, answering questions, or reading written words.” The study also noted that older adults tend to exhibit more speech dysfluencies, such as pauses and filler words like “uh” and “um,” in their natural speech.
In an article for The Conversation, dementia researcher Claire Lancaster emphasized the significance of these findings, stating that the research “has opened exciting doors… showing that it’s not just what we say but how fast we say it that can reveal cognitive changes.”
Recent advancements in artificial intelligence have further illuminated this area, with algorithms achieving up to 78.5 percent accuracy in predicting Alzheimer’s diagnoses based solely on speech patterns. Other studies have established a correlation between higher amyloid plaque levels—common indicators of Alzheimer’s—and an increased likelihood of experiencing speech-related difficulties. Specifically, individuals exhibiting more signs of amyloid plaques are approximately 1.2 times more likely to encounter these challenges.
Moreover, a 2024 study from Stanford University found that longer pauses and slower speech rates were linked to elevated levels of tau proteins, another significant indicator of Alzheimer’s disease. The researchers concluded, “This suggests that speech changes reflect the development of Alzheimer’s disease pathology even in the absence of overt cognitive impairment.”
As research progresses, scientists are making strides in understanding the nuances of human speech and its implications for brain health. The 2023 study was published in the journal Aging, Neuropsychology, and Cognition, paving the way for further investigation into how speech may reveal deeper insights into cognitive functioning and potential declines.
