title: Motor sequence learning: acquisition of explicit knowledge is concomitant to changes in motor strategy of finger opposition movements.
abstract: Motor sequence learning is not a unitary phenomenon, but involves optimizing different components that include declarative and procedural aspects. In this work we designed an experimental approach that allows monitoring all the aspects of sequence learning using a finger opposition task and a movement-by-movement analysis. Subjects performed a visuomotor sequence learning paradigm with (Explicit) or without (Implicit) instructions and we measured response time (RT) and touch duration (TD) for each finger opposition movement of the sequence. Our results indicated that sequence learning induced a double-faced effect on motor performance: a decrease of RT and an increase of TD. However, the above changes manifested differently among subjects: all subjects that, by the end of session, had complete recall of the sequence order, reached an equal level of performance by the last sequence block while in those who had on average only a poor recall of the sequence order, learning was evident only as a slight decrease of RT across sequence blocks, while no kinematic changes (i.e., changes in TD) occurred. Our results indicate that, in the absence of specific instructions, learning evolves from an early stage in which only small decreases of RT are observed to a phase in which progressive knowledge of the sequential structure allows for dramatic changes of RT, together with a progressive change of motor performance (i.e., changes in TD).
authors: Dept. of Experimental Medicine, Section of Human Physiology, University of Genoa, Italy.
authors: Clara
authors: C
authors: Moisello
authors: Laura
authors: L
authors: Avanzino
authors: Andrea
authors: A
authors: Tacchino
authors: Piero
authors: P
authors: Ruggeri
authors: M Felice
authors: MF
authors: Ghilardi
authors: Marco
authors: M
authors: Bove
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001696:Biomechanical Phenomena; D005260:Female; D005385:Fingers / Q000502:physiology*; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D008297:Male; D009068:Movement / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D012691:Serial Learning / Q000502:physiology*; D013997:Time Factors; D055815:Young Adult