Measuring motor speed through typing: a surrogate for the finger tapping test

Motor speed is an important indicator and predictor of both cognitive and physical function. One common assessment of motor speed is the finger-tapping test (FTT), which is typically administered as part of a neurological or neuropsychological assessment. However, the FTT suffers from several limitations, including infrequent in-person administration, the need for a trained assessor and dedicated equipment, and potential short-term sensory-motor fatigue. In this article, we propose an alternative method of measuring motor speed, with face validity to the FTT, that addresses these limitations by measuring the interkeystroke intervals (IKI) of familiar and repeated login data collected in the home during a subject's regular computer use. We show significant correlations between the mean tapping speeds from the FTT and the median IKIs of the nondominant (r = .77) and dominant (r = .70) hands, respectively, in an elderly cohort of subjects living independently. Finally, we discuss how the proposed method for measuring motor speed fits well into the framework of unobtrusive and continuous in-home assessment.