A psychological pulse train: how young children use this cognitive framework to structure simple rhythms.

This paper examines the reproduction of both regular rhythms and irregular sequences by 5- and 7-year-old children, concentrating on the important role played by their organization around a pulse train. It is shown that: (a) the closer rhythms are to a regular beat the easier they are to reproduce and the greater are the improvements with age; (b) memory capacity is limited by the number of pulses around which the rhythm is organized rather than by the number of elements it contains; (c) all the children's productions contain two interval lengths that are in a ratio close to 1:2 and arranged in preferential sequences which we have called "stereotypes"; (d) arrhythmic sequences can only be reproduced if the intervals undergo a systematic distortion towards regularity. These results are interpreted in relation to a pulse-train hypothesis which states that on hearing a rhythm an "internal clock" or "time base" is evoked around which the rhythm is structured.