Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6256638 | Behavioural Brain Research | 2015 | 7 Pages |
â¢Motor leaning is associated with changes of primary motor cortex (M1) oscillations.â¢TACS (10 Hz, 20 Hz, sham, 35 Hz) was applied to left M1 during SRTT learning.â¢10 Hz and 20 Hz tACS likewise facilitated motor sequence learning compared to sham and 35 Hz tACS.â¢20 Hz tACS yielded less susceptibility to interference by a random pattern.â¢Motor-cortical beta oscillations may stabilize motor control.
At present it remains elusive to what extent motor-cortical alpha (8-12Â Hz) and beta (13-30Â Hz) oscillations are associated with motor sequence learning. In order to interact with motor-cortical oscillations, the present study applied transcranial alternating current stimulation (tACS) at 10Â Hz, 20Â Hz and sham stimulation over the left primary motor cortex (M1) during a serial reaction time task (SRTT) in 13 healthy volunteers. In a control experiment, tACS at 35Â Hz was applied in another sample of 13 volunteers. The participants performed the task with the right hand. A sequential pattern was interleaved by a randomly varying pattern serving as interference from sequence learning. Reaction times were determined as dependent variable.Both 10 and 20Â Hz tACS facilitated SRTT acquisition in contrast to sham and 35Â Hz tACS. After acquisition, the interfering condition led to increased reaction times comparable to baseline level during 10Â Hz, sham and 35Â Hz tACS. In contrast, during 20Â Hz tACS the initial learning success was retained despite interference. While motor-cortical tACS at 10 and 20Â Hz likewise facilitates the acquisition, tACS at 20Â Hz frequency additionally stabilizes the newly learned motor sequence indicated by less susceptibility to interference.