AsianScientist (Aug. 14, 2024) –Researchers in Singapore have detected signs of dementia in the natural speech of senior Singaporeans. The study was conducted by linguists from the Department of English, Linguistics, and Theatre Studies (ELTS) at the National University of Singapore (NUS) in collaboration with researchers from the NUS Yong Loo Lin School of Medicine (NUS Medicine). The results were published in the journal Alzheimer’s & Dementia.
The researchers analyzed natural speech data from 148 Singaporeans in their 60s and 70s without cognitive issues and those with mild cognitive impairment (MCI) to pinpoint language cues of dementia. Half the participants were cognitively healthy, meaning they could think clearly learn, and remember. The other half experienced mild cognitive impairment (MCI), a condition in which individuals have relatively more memory or thinking complications than others their age.
Out of the 74 subjects with MCI, 38 were diagnosed with amnestic MCI, which affects memory, and 36 were diagnosed with non-amnestic MCI, which affects thinking skills other than memory.
Amnestic MCI has a higher risk of progressing to Alzheimer’s disease. Non-amnestic MCI is associated with an increased risk of progressing to other types of dementia, such as Lewy Body Dementia. Overall, an estimated 10 to 20 percent of people aged 65 or older with MCI will develop dementia.
Study participants were told to speak for 20 minutes in English on various topics such as work, retirement, family life and public affairs. The interviews were conducted with minimal involvement from the interviewers and were recorded using simple digital voice recorders in a standard office setting.
The recordings produced 267,310 words, which were transcribed and tagged as nouns or verbs using Part-of-Speech tagger software. The research team found that individuals with MCI linked to memory loss tended to speak less and used fewer but more abstract nouns. This speech pattern is similar to that observed in patients with Alzheimer’s disease, a specific form of dementia. However, their use of verbs was not affected.
The study also identified difficulties with imageability, which refers to how easily a word’s meaning brings to mind a mental image in the natural speech of individuals with amnestic MCI.
Principal investigator Bao Zhiming, a professor in the Department of ELTS at NUS, highlighted Singapore’s unique environment for this research due to its diverse language use, including four official languages and various dialects. “Previous studies had analysed targeted and smaller volumes of language data through word-based fluency tests, structured interviews and picture narrations. Our study has never been done before as it focused on unstructured and spontaneous speech that is easy to collect and analyse,” he added.
Luwen Cao, also from the NUS Department of ELTS, added, “Our findings are a significant breakthrough as traditional diagnoses of dementia are done following a battery of neuropsychological and neurological tests. The study of natural speech to detect linguistic signs of early cognitive decline is a reliable, non-invasive and cost-effective tool that could possibly help medical practitioners in the early diagnosis, intervention and management of the progressive disease.”
The researchers emphasized the critical need for innovative strategies to address the increasing incidence of dementia in Singapore, considering the rapidly aging population. “Ultimately, our research aims to contribute to healthy aging in Singapore. Singapore is aging fast; a quarter of Singaporeans are over 60. By exploring innovative diagnostic tools and intervention strategies, we hope to improve the quality of life for older adults and reduce the burden on healthcare systems. Our work is one step towards ensuring that our aging population enjoy longer, healthier lives,” said Bao.
The team’s future plans involve working with the neurologists at the Yeo Boon Khim Mind Science Centre (YBK MSC) to develop language-focused intervention approaches designed to tackle the language challenges faced by individuals with amnestic MCI.
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Source: National University of Singapore ; Image: Shelly Liew/ Asian Scientist Magazine
The article can be found at Reversal of the concreteness effect can be detected in the natural speech of older adults with amnestic, but not non-amnestic, mild cognitive impairment
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