Functional MRI evidence for adult motor cortex plasticity during motor skill learning

Abstract

Performance of complex motor tasks, such as rapid sequences of finger movements, can be improved in terms of speed and accuracy over several weeks by daily practice sessions. This improvement does not generalize to a matched sequence of identical component movements, nor to the contralateral hand. Here we report a study of the neural changes underlying this learning using functional magnetic resonance imaging (MRI) of local blood oxygenation level-dependent (BOLD) signals evoked in primary motor cortex (M1). Before training, a comparable extent of M1 was activated by both sequences. However, two ordering effects were observed: repeating a sequence within a brief time window initially resulted in a smaller area of activation (habituation), but later in larger area of activation (enhancement), suggesting a switch in M1 processing mode within the first session (fast learning). By week 4 of training, concurrent with asymptotic performance, the extent of cortex activated by the practised sequence enlarged compared with the unpractised sequence, irrespective of order (slow learning). These changes persisted for several months. The results suggest a slowly evolving, long-term, experience-dependent reorganization of the adult M1, which may underlie the acquisition and retention of the motor skill.

The effects of single-trial averaging upon the spatial extent of fMRI activation

“…For example, in presurgical planning, the spatial extent of a language or motor activation relative to the location of a tumor helps to determine the margins of a resection [1]. In studies of motor training, the differences in the spatial extent of activation between trained and untrained states have been interpreted in terms of cortical plasticity [2]. In between-group studies, such as those between hyperactive and normal subjects [3], or between the elderly and young [4], differences in spatial extent of activation may be interpreted in terms of hypoactive or dysfunctional cortex.…”

Atypical within-session motor procedural learning after traumatic brain injury but well-preserved between-session procedural memory consolidation

“…The course of procedural learning in healthy individuals is well-documented in the finger opposition sequence (FOS) learning paradigm, the task used in the current study, with three distinguishable phases described (Karni et al, 1995(Karni et al, , 1998Korman et al, 2003;Walker, 2005): (i) Acquisition phase-fast within-session learning followed by a saturation phase with no additional improvement in performance despite continued practice. (ii) Consolidation phase-a latent phase lasting several hours, wherein sensitivity to interference decreases and additional, delayed "offline" gains emerge.…”

“…Only in the second week (during the 4 daily sessions) the patients' performance was characterized by a series of loses during the sessions and gains between-sessions, with the latter overriding the within-session losses. Therefore, additional analyses were run to explore this apparently differential behavior of the patients in the 1st vs. 2nd week of the study, focusing on two distinct time-windows (that have been previously explored in young healthy adults; Karni et al, 1995): the immediate and delayed effects of the first training session; the effects of training sessions 2-5 at week 2 and retention a month later.…”

Benefits of Combined Mental and Physical Training in Learning a Complex Motor Skill in Basketball

“…At the neurological level, compelling evidence exists that the imagination and the execution of the movement share common neuronal substrates (Karni, 1995;Jackson, 2003;Miller, 2010). Drawing on this compelling evidence of the functional and neurophysiological relationship between imagined and actual movements, several authors have proposed mental practice with motor imagery as an effective strategy to improve motor learning (Feltz & Landers, 1983;Driskell et al, 1994;Schuster et al, 2011).…”