Digital memory tests on smartphones and tablets can detect subtle cognitive decline more quickly than traditional neuropsychological assessments. This is the finding of a study by the German Centre for Neurodegenerative Diseases (DZNE), carried out in collaboration with university hospitals in Germany, the University of Wisconsin–Madison and the start-up neotiv.
The researchers see opportunities in this approach to accelerate the development of new dementia drugs and, in the long term, to support mainstream care. People with mild cognitive impairment (MCI) have an increased risk of developing dementia. Although they are generally still able to function independently, measurable changes in their memory and thinking skills are already visible.
Cognitive testing
Traditional cognitive tests usually take place under the supervision of a healthcare professional and consist of verbal or written tasks. Because these tests are relatively time-consuming, they are often only administered once or twice a year.
According to Dr David Berron, a researcher at DZNE and co-founder of neotiv, digital technology offers new possibilities. In the study, participants used the neotivTrials app at home, which allows so-called digital biomarkers of cognitive function to be collected. “The results show that we can not only identify cognitive problems, but also track changes over time,” said Berron. The study was recently published in npj Digital Medicine.
Subtle changes
The study involved 202 adults from Germany and the United States, aged between 52 and 85. Fifty participants had been diagnosed with MCI. The participants used the app for seven to twelve months and carried out a memory test on average once every two weeks. This allowed researchers to collect data much more frequently than is possible with conventional methods.
According to lead author Dr Sarah Polk, this is a significant advantage. “The tests can be carried out at home, at a time of the participant’s choosing. A smartphone or tablet is sufficient. No hospital visits or appointments are required,” she says.
The high frequency of measurements made it possible to detect a decline in cognitive performance in participants with MCI within just a few months. With traditional testing methods, it would take much longer for such changes to become apparent.
Years of clinical observations
To assess the reliability of the digital measurements, the researchers compared the app results with long-term clinical data available for all participants. This data had been collected over an average period of eight years using established diagnostic methods.
The researchers observed a strong correlation between the long-term trends in the clinical data and the changes that the app was able to detect within just a few months. “It was impressive to see that a few months of digital monitoring yielded a signal corresponding to years of clinical observations,” said Polk. “That gives confidence that this method actually measures what it is intended to measure.”
Accelerating dementia research
According to the researchers, a key application of the technology lies in clinical trials of new drugs for dementia, and in particular Alzheimer’s disease. In such trials, it is essential to determine whether a treatment can slow cognitive decline.
Because digital tests detect changes more quickly, researchers could determine sooner whether an experimental drug is effective. This could shorten the duration of clinical trials and accelerate the development of new therapies.
In the longer term, the researchers see potential for application in everyday practice. Digital monitoring can help doctors track patients’ cognitive development more accurately and evaluate treatments on an individual basis.
Various memory tasks
The app contains four different memory tasks, each of which engages different areas of the brain. It was striking that some tasks were severely impaired in participants with MCI right from the start, whilst other tasks continued to show gradual decline. This is consistent with the progressive nature of Alzheimer’s disease, in which different areas of the brain are affected at different stages.
According to Berron, the greatest promise may lie even earlier in the disease process. “It is conceivable that very subtle cognitive changes occur even before MCI becomes clinically detectable. We are now investigating whether digital tests can also pick up on those very earliest signs.” If follow-up research confirms these results, smartphone-based memory tests could become an important tool for the early detection, monitoring and treatment of cognitive disorders.
Digital Alzheimer’s test
Last year, Swedish researchers developed a digital cognitive test that could help general practitioners identify possible Alzheimer’s disease at an earlier stage. Their study showed that the tablet-based test provides a detailed and objective assessment of cognitive functioning, helping physicians determine which patients may benefit from further Alzheimer’s diagnostics.
Unlike traditional pen-and-paper assessments, the digital tool evaluates multiple cognitive domains, including memory, processing speed, attention, orientation, delayed recall and recognition. It also captures additional data such as reaction times and tapping speed, offering a more comprehensive picture of cognitive performance.
The BioCog test was evaluated in primary care among patients presenting with memory complaints. Researchers found that the richer dataset improved the ability to identify individuals likely to have underlying Alzheimer’s pathology. The tool is designed to complement emerging blood tests for Alzheimer’s biomarkers, such as phosphorylated tau. By combining cognitive test results with blood-based diagnostics, clinicians can improve diagnostic accuracy, identify suitable candidates for new Alzheimer’s treatments and reduce unnecessary referrals to specialist memory clinics.
