Acceso usuarios
Claire Gérard, Michael Rosenfeld
Recently, a number of experiments have been conducted to test the hypothesis that an internal clock mediates estimation and reproduction of time. We attempted to separate possible biological and cognitive components by comparing experts' and novices' performances in an experiment that requires isochronous rhythmic behaviours. Expert subjects (high-level pianists, percussionists, and singers) and novices completed three tasks : (a) Spontaneous Motor Tempo Task (SMT) ; (b) continuation task for which a sequence of 3 or 7 isochronous « inductor stimuli » had to be continued, with the inter-stimuli interval (ISI) being 400, 600 or 800 ms ; (c) synchronization task for which the ISI was 400, 600 and 800 ms. Contrary to previous assumptions, for the SMT the average inter-response interval (IRI) of 600 ms was not obtained with novices or with experts. In the continuation task, the number of inductors did not affect the subjects' performances, and a difference in the variability of the IRI was observed between experts and novices, mainly at the end of their sequence of taps. In the synchronization task, the variability of IRI was greater when the tempo was slower ; the novices were significantly less regular than the experts. The particularly regular behaviour of percussionists suggests a reconsideration of the respective contribution of the biological, cognitive and motor components of temporal adjustments.
