Statistical analysis for finger tapping with a periodic external stimulus

In this paper we outline an experiment in which seven subjects attempted to tap in synchrony with a pacing stimulus with the interstimulus interval that varied in a cycle (T,T+dT,T, T-dT) repeating every fourth interval, where T represents an unexpected step change of an interstimulus interval. Conditions included three levels of T = (400, 500, and 600 msec.) with four levels of dT = 1, 3, 5, and 7% of T). The statistical analysis indicated that small changes in T lead to rapid matching of the interresponse intervals to the new interstimulus intervals even when the variation in the input is not apparent to subjects.