Dynamic modulation of cortico-muscular coupling during real and imagined sensorimotor synchronisation.

People have a natural and intrinsic ability to coordinate body movements with rhythms surrounding them, known as sensorimotor synchronisation. This can be observed in daily environments, when dancing or singing along with music, or spontaneously walking, talking or applauding in synchrony with one another. However, the neurophysiological mechanisms underlying accurately synchronised movement with selected rhythms in the environment remain unclear. Here we studied real and imagined sensorimotor synchronisation with interleaved auditory and visual rhythms using cortico-muscular coherence (CMC) to better understand the processes underlying the preparation and execution of synchronised movement. Electroencephalography (EEG), electromyography (EMG) from the finger flexors, and continuous force signals were recorded in 20 participants during tapping and imagined tapping with discrete stimulus sequences consisting of alternating auditory beeps and visual flashes. The results show that the synchronisation between cortical and muscular activity in the beta (14-38 Hz) frequency band becomes time-locked to the taps executed in synchrony with the visual and auditory stimuli. Dynamic modulation in CMC also occurred when participants imagined tapping with the visual stimuli, but with lower amplitude and a different temporal profile compared to real tapping. These results suggest that CMC does not only reflect changes related to the production of the synchronised movement, but also to its preparation, which appears heightened under higher attentional demands imposed when synchronising with the visual stimuli. These findings highlight a critical role of beta band neural oscillations in the cortical-muscular coupling underlying sensorimotor synchronisation.

Nijhuis P ，Keller PE ，Nozaradan S ，Varlet M ... -  《-》

Dynamic Modulation of Beta Band Cortico-Muscular Coupling Induced by Audio-Visual Rhythms.

Human movements often spontaneously fall into synchrony with auditory and visual environmental rhythms. Related behavioral studies have shown that motor responses are automatically and unintentionally coupled with external rhythmic stimuli. However, the neurophysiological processes underlying such motor entrainment remain largely unknown. Here, we investigated with electroencephalography (EEG) and electromyography (EMG) the modulation of neural and muscular activity induced by periodic audio and/or visual sequences. The sequences were presented at either 1 or 2 Hz, while participants maintained constant finger pressure on a force sensor. The results revealed that although there was no change of amplitude in participants' EMG in response to the sequences, the synchronization between EMG and EEG recorded over motor areas in the beta (12-40 Hz) frequency band was dynamically modulated, with maximal coherence occurring about 100 ms before each stimulus. These modulations in beta EEG-EMG motor coherence were found for the 2-Hz audio-visual sequences, confirming at a neurophysiological level the enhancement of motor entrainment with multimodal rhythms that fall within preferred perceptual and movement frequency ranges. Our findings identify beta band cortico-muscular coupling as a potential underlying mechanism of motor entrainment, further elucidating the nature of the link between sensory and motor systems in humans.

Varlet M ，Nozaradan S ，Trainor L ，Keller PE ... -  《-》

The influence of pacer-movement continuity and pattern matching on auditory-motor synchronisation.

Zelic G ，Nijhuis P ，Charaf SA ，Keller PE ，Davis C ，Kim J ，Varlet M ... -  《-》

Sensorimotor Synchronization and Neural Entrainment to Imagined Rhythms in Individuals With Proficient Imagery Ability.

Whitton SA ，Sreenan B ，Luo C ，Jiang F ... -  《-》

The Effects of Motor Expertise on Sensorimotor Rhythm Desynchronization during Execution and Imagery of Sequential Movements.

The purpose of the study was to investigate sensorimotor rhythm desynchronization during the performance of a motor execution and motor imagery task of different complexity, while varying motor musical expertise of subjects. We compared EEG patterns of professional pianists and non-pianists, who either executed or imagined finger tapping movements of different complexity. Results show that the power in alpha (8-12 Hz) and beta (13-30 Hz) rhythms decreases with the complexity of both performed and imagined movements. Motor expertise influenced alpha rhythm desynchronization in the motor execution task - in the group of pianists there were differences in alpha power decrease depending on the complexity of the performed movement. There was no such relationship among non-pianists. In the imagery task, there was a tendency toward an interaction of motor expertise and low and high alpha rhythm components. In the beta band, there was an interaction of frequency and area of the skull occurring in the movement execution condition - high and low beta rhythm components had different topography.

Zabielska-Mendyk E ，Francuz P ，Jaśkiewicz M ，Augustynowicz P ... -  《-》