Weber's Law for Timing and Time Perception: Reconciling the Poisson Clock with Scalar Expectancy Theory (SET)

The pacemaker-counter model is the most prominent psychological account of timing and time perception. It has been often assumed that an intemal pacemaker generates pulses according to a Poisson process and that these pulses are accumulated over time. According to Scalar Expectancy Theory (SET), the number of accumulated pulses represents the elapsed duration to be timed. Although the Poisson process provides a plausible cognitive and physiological mechanism for tim-ing and time perception, its implementation into the framework of SET remains a theoretical chal-lenge. The present contribution shows that a merger of Creelman's (1962) and Treisman's (1963) counting models enables such an implementation, which can account for Weber's law and scalar timing. We demonstrate this for the fundamental principles of counting and timing, as well as for a temporal bisection task.