As we age, it’s common to notice a slower retrieval of words, which often raises fears about cognitive decline and the potential onset of dementia.
However, recent research conducted by Baycrest and the University of Toronto introduces a novel perspective, emphasising the pace of speech as a more critical marker of brain health than the occasional struggle to find the right words, a phenomenon typically considered a regular aspect of ageing. This study is pioneering in examining the correlation between natural variations in speech patterns and overall brain health in healthy individuals.
Dr. Jed Meltzer of Baycrest, holding the Canada Research Chair in Interventional Cognitive Neuroscience and serving as the principal investigator for this study, shared, “Our findings suggest that alterations in the overall speed of speech could mirror changes in the brain. This highlights the importance of including speech speed assessments in routine cognitive evaluations to aid clinicians in detecting cognitive decline more promptly, thereby supporting older individuals in maintaining their brain health as they advance in age.”
In this research, 125 volunteers between 18 and 90 underwent three distinct evaluations. The initial test involved a picture-naming task that required participants to identify and name images while ignoring unrelated auditory distractions. This setup aimed to assess the subjects’ recognition and naming abilities.
Subsequently, the study involved participants describing complex images for one minute each, with their responses being analysed for speech pace and frequency of pauses through AI-based tools developed in collaboration with Winterlight Labs.
Lastly, the participants took standardised cognitive tests to measure mental functions that deteriorate with age, such as executive function, which encompasses the ability to process conflicting information, concentrate, and resist distractions.
Contrary to expectations, while many cognitive abilities diminished with age, including the speed of word retrieval, this decline was not directly correlated with a reduction in other mental capacities. Interestingly, the study found that participants’ frequency and duration of pauses when searching for words did not significantly relate to brain health indicators. Instead, the ability to quickly name pictures, which corresponded to their overall speech speed, was associated with executive function. That implies that not the hesitancy in finding words but rather the general speed of speech, including during pauses, is a more telling indicator of brain health.
These findings suggest that while many older adults worry about their pauses during speech as a sign of cognitive decline, such pauses are a normal aspect of ageing. More critical, however, is the observation that a slowdown in regular speech pace better reflects underlying changes in brain health.
Looking ahead, the research team plans to replicate this study over several years with the same group of participants to determine if speech speed indeed predicts brain health as individuals age. That could pave the way for developing early detection tools for cognitive decline, enabling healthcare professionals to recommend interventions to preserve or enhance brain health in older adults.
This study received financial support from the Natural Sciences and Engineering Research Council of Canada (NSERC) through a Discovery Grant, an Internship Grant from the Mitacs Accelerate Program, and a Connaught Innovation Award.
More information: Hsi T. Wei et al, Cognitive components of aging-related increase in word-finding difficulty, Aging Neuropsychology and Cognition. DOI: 10.1080/13825585.2024.2315774
Journal information: Aging Neuropsychology and Cognition Provided by Baycrest Centre for Geriatric Care
