Response to perturbations as a built-in feature in a mathematical model for paced finger tapping

GONZÁLEZ, CLAUDIA R.; BAVASSI, M. LUZ; LAJE, RODRIGO

Physical Review E

APS Physics

Año: 2019 vol. 100

2470-0045

Paced finger tapping is one of the simplest tasks to study sensorimotor synchronization. The subject isinstructed to tap in synchrony with a periodic sequence of brief tones, and the time difference (called asynchrony)between each response and the corresponding stimulus is recorded. Despite its simplicity, this task helps tounveil interesting features of the underlying neural system and the error-correction mechanism responsible forsynchronization. Perturbation experiments are usually performed to probe the subject?s response, for example,in the form of a ?step change,? i.e., an unexpected change in tempo. The asynchrony is the usual observable insuch experiments and it is chosen as the main variable in many mathematical models that attempt to describe thephenomenon. In this work we show that although asynchrony can be perfectly described in operational terms,it is not well defined as a model variable when tempo perturbations are considered. We introduce an alternativevariable and a mathematical model that intrinsically takes into account the perturbation and make theoreticalpredictions about the response to novel perturbations based on the geometrical organization of the trajectoriesin phase space. Our proposal is relevant to understand interpersonal synchronization and the synchronization tononperiodic stimuli.