Small perturbations in a finger-tapping task reveal inherent nonlinearities of the underlying error correction mechanism

► We applied Nonlinear Dynamics to finger-tapping data and unveiled nontrivial features. ► Nonlinear features of the behavior are important even at small perturbation magnitudes. ► Few studies consistently include the perturbation within the modeling effort. ► We propose a simple mathematical model that correctly predicts nontrivial behavior. ► A single set of parameter values accounts for all perturbation types and magnitudes.