De novo motor learning is a specific learning paradigm that allows investigation of how a new motor skill is learned from scratch. Motor task learning can induce increased corticospinal excitability and reorganization of connectivity observed within the motor cortex (M1). Several studies have investigated the plasticity mechanisms underlying motor learning using simple paradigms. The results obtained have been variable, with a major trend toward increased corticospinal excitability, while other results show no increase. We expect to observe a significant increase in excitability and enhanced intracortical reorganization mechanisms within M1 in our subjects during our de novo motor learning sessions.

The primary objective of this study is to measure changes in corticospinal excitability of the motor system across 3 de novo motor learning sessions separated by different time intervals.

The secondary objectives will be: 1) to measure learning across the three practice sessions, 2) to measure changes in inhibition and facilitation across the 3 learning sessions, and 3) to measure correlations between subjects' motor performance and corticospinal and intracortical changes.

Inclusion Criteria:

• right-handed
• healthy
• having signed an informed consent form

Exclusion Criteria:

• counter-indication to transcranial magnetic stimulation
• pregnancy