title: Linear versus non-linear measures of temporal variability in finger tapping and their relation to performance on open- versus closed-loop motor tasks: comparing standard deviations to Lyapunov exponents.
abstract: The nature of temporal variability during speeded finger tapping was examined using linear (standard deviation) and non-linear (Lyapunov exponent) measures. Experiment 1 found that right hand tapping was characterised by lower amounts of both linear and non-linear measures of variability than left hand tapping, and that linear and non-linear measures of variability were often negatively correlated with one another. Experiment 2 found that increased non-linear variability was associated with relatively enhanced performance on a closed-loop motor task (mirror tracing) and relatively impaired performance on an open-loop motor task (pointing in a dark room), especially for left hand performance. The potential uses and significance of measures of non-linear variability are discussed.
authors.affiliation: Department of Psychology, University of Toledo, OH 43606, USA. stephen.christman@utoledo.edu
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Christman
authors.forename: Ryan
authors.initials: R
authors.lastname: Weaver
mesh_terms: D000328:Adult; D005260:Female; D005583:Fourier Analysis; D007839:Functional Laterality; D006801:Humans; D016014:Linear Models; D008297:Male; D009043:Motor Activity; D017711:Nonlinear Dynamics; D011930:Reaction Time; D013998:Time Perception