, Volume 18, Issue 2, pp 339-346
Date: 12 Feb 2011

Long-range correlation properties in motor timing are individual and task specific

Abstract

1/f β noise represents a specific form of (long-range) correlations in a time series that is pervasive across many sensorimotor variables. Recent studies have shown that the precise properties of the correlations demonstrated by a group of test participants may vary as a function of experimental conditions or factors characterizing the group. Our purpose in the present study was to clarify whether long-range correlations affect sensorimotor performance generally or in a task-specific manner and whether each individual produces characteristic long-range correlations that are reliable across several runs of the same task. We analyzed the series of time intervals produced by 43 participants in two timing tasks: unimanual rhythmic tapping and circle drawing. We found that a participant’s 1/f β properties in tapping were not related to the 1/f β properties in circle drawing. However, within each task, individual differences were reliable, and a Cronbach’s alpha of .59 showed a high degree of within-subjects reproducibility of the long-range correlations. Thus, long-range correlations represent a consistent and distinctive characteristic of individuals performing a particular task, rather than a ubiquitous generic property of sensorimotor time series. The implications of these results are discussed from both a theoretical and a methodological perspective.

H.N. Zelaznik and N. Rheaume were supported by NSF-ITR–Skill Learning in Humanoid Robots, Grant 0427260. R. Balasubramaniam was supported by grants from NSERC and CFI and by a Conseiller pour la Science et la Technologie sabbatical grant from the Ambassador of France to Canada. We thank Anna Brewer, Brenda Irvin, Albert Pinter, and Lindsey Singleton for help in data collection.