Time, space, and short-term memory.

This article describes a linear timekeeping system that can account for four main results from the human time-production literature: (1) Variability of interresponse intervals (IRIs) in repetitive finger-tapping tasks increases with mean IRI; (2) The difference between mean and required IRI is a roughly sinusoidal function of required IRI (the "oscillator signature"); (3) The function relating standard deviation of IRI to relative phase, phi, in bimanual tapping has minima at relative phases of 0, 0.5, and 1, and maxima close to 0.5 (the "seagull" effect); (4) In the production of polyrhythms, the ratios that can be produced get "simpler" as response frequency increases. It is shown that all these phenomena can be accounted for with a linear timekeeper model. The model is rendered spatially with delay lines whose lengths provide a basis for varying time intervals. The model makes new predictions about timing, provides an account of time perception and time production, and predicts the existence of short-term memory.