Citizen science study sheds fresh light on dementia risk factors and cognition

How a person rates their own memory is more strongly associated with dementia risk factors than their performance in standard cognitive tests, according to new research from Trinity College Dublin.

The study, conducted by neuroscientists at Trinity’s School of Psychology, gathered data from 3,327 people through a smartphone app to investigate how well-known risk factors for dementia, such as hypertension or loneliness, are linked to reduced cognitive abilities. The research was published in Alzheimer’s & Dementia, The Journal of the Alzheimer’s Association.

They found, for the first time, that a person’s subjective impression of their own memory problems had stronger links to modifiable risk factors for dementia than their performance on objective standardized tests measuring cognitive impairments.

The research adds to our understanding of very early changes to brain health in otherwise healthy adults and highlights the value of subjective cognitive assessments in healthy adults. Unlike most prior studies, cognitive ability was assessed in two ways—using standardized cognitive tests and by simply asking people to report on their own memory problems.

The study subjects were volunteers who completed a set of gamified cognitive tests and questionnaires in the smartphone app Neureka. This free app, developed by neuroscientists in Trinity, aims to improve our understanding of disorders of the mind by analyzing rich data provided by its 26,000 users.

“The links between dementia and our lifestyle, health, and environment are subject to much research, with the hope of identifying what factors can be modified to avoid or delay dementia,” explains Anna M Rosická, Ph.D. Candidate at the School of Psychology, Trinity who led the study.

“We know that dementia is often preceded by both objective and subjective cognitive impairments, but these two types of impairments have surprisingly little overlap. Our research found that subjective memory impairment has a stronger link to risk factors, including depression, low socio-economic status, hearing impairments, loneliness, and history of smoking. This implies a potentially greater value of subjective cognitive assessments in otherwise healthy adults, as people might become aware of their very early cognitive impairments before these can be objectively measured.”

A caveat of the study is that the data was collected at a single time-point rather than assessing participants longitudinally. As a follow-on, the researchers recommend a long-term analysis to exclude alternative explanations.

“In spite of this drawback, the study showcases the great potential of remote, self-administered smartphone assessments in studying and detecting the earliest stages of cognitive decline and dementia risk factors. This can be particularly valuable in settings where access to standard in-person assessments is limited, such as low- and middle-income countries,” Associate Professor Claire Gillan, who supervised the research, added.

The study gathered data from 3,327 participants aged 18–84 through the smartphone app Neureka. Participants were recruited using various methods including television and radio publicity, online advertising and organized efforts such as the SciStarter project since the app had been made available to the public in 2020.

The research team quantified the associations of 13 previously established dementia risk factors with both subjective memory problems and three gamified cognitive tests, which served as objective measures of planning, working memory, and flexibility.