Interactions between new and pre-existing dynamics in bimanual movement control

• Published in: Experimental brain research Vol. 197; no. 3; pp. 269 - 278
• Main Author: Serrien, Deborah J
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Berlin/Heidelberg : Springer-Verlag 01.08.2009; Springer-Verlag; Springer; Springer Nature B.V
• Subjects: Accuracy; Adult; Behavior; Biological and medical sciences; Biomechanical Phenomena; Biomedical and Life Sciences; Biomedicine; Brain Mapping; Brain research; Degenerative and inherited degenerative diseases of the nervous system. Leukodystrophies. Prion diseases; Electroencephalography; Evoked Potentials, Motor - physiology; Female; Functional Laterality - physiology; Fundamental and applied biological sciences. Psychology; Hand - innervation; Hand - physiology; Humans; Learning - physiology; Male; Medical sciences; Motor control and motor pathways. Reflexes. Control centers of vegetative functions. Vestibular system and equilibration; Motor Cortex - physiology; Motor Skills - physiology; Movement - physiology; Neurology; Neuropsychological Tests; Neurosciences; Research Article; Schedules; Skills; Vertebrates: nervous system and sense organs; Young Adult; Functional connectivity; Motor acquisition; EEG; Coherence; Learning; Accuracy; Acquisition process; Coordination; Electrophysiology; Motor skill; Tapping task; Electroencephalography
• ISSN: 0014-4819; 1432-1106
• DOI: 10.1007/s00221-009-1910-6

Motor skills are commonly acquired through practice. This process not only involves acquisition of the particular task demands but also requires overcoming pre-existing modes. In the present study, interactions between new and intrinsic dynamics were evaluated. Accordingly, bimanual finger tapping with a 2:1 ratio was performed according to two training schedules: continuous (consecutive trials) and interrupted (non-consecutive trials with intermediate 1:1 in-phase performances). In addition, in-phase and anti-phase were probed before and after training. Behavioral output was assessed by means of temporal accuracy and variability, whereas neural activation patterns were determined by EEG coherence. Results showed that continuous practice resulted in improved performance with reduced coherence across the motor network. For interrupted practice, behavioral execution ameliorated, although it was inferior to performance with continuous practice. In terms of neural changes, the degree of intrahemispheric and midline connectivity did not reduce with interrupted practice, whereas interhemispheric connectivity increased. This signifies that short-term motor consolidation of the 2:1 task was disrupted due to intermediate performance of the in-phase mode. Furthermore, the probed in-phase and anti-phase pattern showed no behavioral changes, although neural alterations occurred that depended on training schedule and coordination mode. Overall, the observations illustrate bidirectional interactions between new and inherent dynamics during motor acquisition, raising issues about effective methods for learning skills and scheduling of practices in neurorehabilitation.