Those with it are at an increased risk of developing a dementia, making early detection critical. Researchers at Apple and the University of Tübingen believe the key might lie in iOS app usage habits. To this end, they propose a machine learning approach to reveal differences in patterns between users with and without cognitive impairment. It achieves an area under the receiver operating characteristics of 0.79, they report, indicating that it's able to correctly spot symptomatic subjects about 80% of the time. "The ubiquity of smartphone usage in many people's lives make it a rich source of information about a person's mental and cognitive state," wrote the research team in a preprint paper.