title: Testing the co-existence of two timing strategies for motor control in a unique task: The synchronisation spatial-tapping task.
abstract: The control of rhythmic action sequences may involve two distinct timing strategies, i.e., event-based and emergent timing, which are usually revealed through finger-tapping and circle-drawing tasks, respectively. There is a lively debate concerning the possibility of coexistence of the two modes of timing for the execution of a single task. If one considers emergent timing as simply an absence of explicit representation of a time interval, then by definition, the two modes of timing cannot coexist. However, if one considers that emergent timing engages control of another motor parameter, e.g., a control of movement through space rather than time, then the possibility of coexistence needs to be reassessed. In the present study, we designed a hybrid of finger-tapping and circle-drawing tasks for which the demands for space and time control were present at the same time in order to reassess the coexistence hypothesis. Seventy-eight participants performed a spatial-tapping task in which finger taps were to be produced in synchrony with a regular metronome to 6 visual targets presented around a virtual circle. The metronome set ten distinct tempi (1100-300 ms). Using autocorrelation analyses on timing variables, we show that motor timing was event-based at slow tempi and emergent at faster tempi. Through an analysis of the trajectory, we confirm that an increase in the spatial control of movement took place congruently with a switch from event-based to emergent timing modes. At these fast tempi, timing and spatial errors were correlated but only at the specific target location for which a dynamical anchor point was revealed. Hence, we conclude that the coding of emergent timing has a spatial nature from which emerge timing regularities. This spatio-temporal strategy insures the performance of sequential motor actions when cognitive effort is too high for the use of pure event-based timing strategies.
authors.affiliation: SCALab, UMR CNRS 9193, France; Univ Lille, BP 60149, 59653 Villeneuve d'ascq Cedex, France.
authors.forename: Mariama
authors.initials: M
authors.lastname: Dione
authors.affiliation: SCALab, UMR CNRS 9193, France; Univ Lille, BP 60149, 59653 Villeneuve d'ascq Cedex, France. Electronic address: yvonne.delevoye@univ-lille3.fr.
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Delevoye-Turrell
mesh_terms: D000293:Adolescent; D000328:Adult; D001288:Attention / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D009048:Motor Skills / Q000502:physiology*; D009949:Orientation / Q000502:physiology*; D010364:Pattern Recognition, Visual / Q000502:physiology; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology*; D065853:Spatial Learning / Q000502:physiology; D013998:Time Perception / Q000502:physiology*; D055815:Young Adult
keywords: Anchor point; Coexistence; Rhythmicity; Spatial control; Timing control; Trajectory