Time Intervals Produced by Silent Chronometric Counting are Involuntarily Affected by Number Word Magnitudes

Abstract Chronometric counting is a method to approximate the duration of a time interval by keeping track of the accumulation of its one-second subintervals. The ordinality of the number words is instrumental to this method, but whether also the magnitudes of these words affect the approximations remains unclear. The participants performed self-initiated and silent chronometric counting in different directions to produce target intervals prospectively. Two experiments were conducted. In Experiment 1, counting from 1- to 6-s target intervals started or stopped at zero. In Experiment 2, 1- or 2-s target intervals were counted with low-magnitude (1–3) or high-magnitude (4–6) number words. The participants were found to overproduce target intervals towards their shorter durations (Experiments 1 and 2) and, at a trend level, with downward rather than upward counting (Experiment 1 but not Experiment 2). They also produced target intervals as longer in duration with high- than low-magnitude number words (Experiment 2). The main findings suggest an involuntary magnitude effect of endogenously activated number words on subjective time.