Eine Netzwerkanalyse von Motorischem Lernen
Zusammenfassung der Projektergebnisse
Motor skill learning is a fundamental aspect of human behavior that underlies most of our daily activities. In this project, we aimed to characterize network interactions underling motor learning using two common experimental paradigms: motor sequence learning (MSL) and visuomotor adaptation (VMA). In part one of the project, we focused on probing critical nodes of the motor learning network using non-invasive electric stimulation and measuring the effect on neurophysiological parameters using functional magnetic resonance imaging (fMRI) and electroencephalography (EEG). The first study investigated the immediate effects of transcranial direct stimulation (tDCS) to M1 and cerebellum, using fMRI measured concurrently to task performance and stimulation. The results of the study showed that cerebellar tDCS enhanced MSL, as well as learning-specific activity in regions of the motor learning network, while no apparent behavioral or activation differences were found under M1 tDCS. In addition, we found that interaction from putamen to cerebellum was altered under cerebellar tDCS, effectively leading to decreased inhibition of the cerebellum. These results suggest that cerebellar tDCS has both a local and a remote effect on neuroplasticity in motor learning networks. Next, we investigated the potential added benefit of modulating neural oscillations using alternating current stimulation (tACS) during MSL. We found that cerebellar 10Hz tACS diminished learning as well as increased learning-specific alpha (8-12Hz) power in premotor cortex (PMC). Learning-specific alpha coherence between PMC and cerebellum was enhanced following cerebellar tACS, suggestive of a role in motor learning. Interestingly, further analysis of this data using a novel machine-learning approach revealed, that despite the lack of effect on learning, 10Hz tACS to the motor cortex resulted in unique signatures of neuroplasticity in the theta (4-8Hz) and alpha frequency bands. In the second part of the project, we investigated neurophysiological markers of visuomotor adaptation on motor learning networks using EEG and fMRI. In the fMRI study, we analyzed interactions within the cortico-striato-cerebellar motor learning network. We found that a negative modulation of cerebellar to PMC is essential for adaptation to a visual perturbation. In the EEG study, we investigated the contribution of cerebellar oscillations to the process of VMA. We found patterns of theta power changes in cerebellum and supplementary motor area (SMA) with adaptation that followed directly the fMRI activation pattern. In addition, a correlation analysis showed that better adaptation was associated with increased theta power in those locations. These results suggest that theta oscillations may be key to communication transfer within cortico-cerebellar loops underlying VMA. The results of the project could have direct implications to rehabilitation strategies in stroke or movement disorders patients.
Projektbezogene Publikationen (Auswahl)
- Cerebellar–premotor cortex interactions underlying visuomotor adaptation. NeuroImage (2020) 220, 117142
Tzvi Elinor, Koeth Fabian, Karabanov Anke N., Siebner Hartwig R., & Krämer Ulrike M.
(Siehe online unter https://doi.org/10.1016/j.neuroimage.2020.117142) - “Beneficial effects of cerebellar tDCS on motor learning are associated with altered effective connectivity: a simultaneous tDCS-fMRI study”. Neuroimage (2020) 223, 117363
Liebrand Matthias, Karabanov Anke, Antonenko Daria, Flöel Agnes, Siebner Hartwig R., Classen Joseph, Krämer Ulrike M., & Tzvi Elinor
(Siehe online unter https://doi.org/10.1016/j.neuroimage.2020.117363) - (2021). “The role of alpha oscillations in a premotor-cerebellar loop in modulation of motor learning: insights from transcranial alternating current stimulation”. Neuroimage, 118410
Schubert Christine, Dabbagh Alhuda, Classen Joseph, Krämer Ulrike M. & Tzvi Elinor
(Siehe online unter https://doi.org/10.1016/j.neuroimage.2021.118410) - (2022). ”Classification of EEG Sig-nals Reveals a Focal Aftereffect of 10 Hz Motor Cortex Transcranial Alternating Current Stimulation”. Cerebral Cortex Communications, Volume 3, Issue 1, tgab067
Tzvi Elinor, Alizadeh Jalal, Schubert Christine, Classen Joseph
(Siehe online unter https://doi.org/10.1093/texcom/tgab067) - (2022). ”Coherent theta oscillations in the cerebellum and supplementary motor area mediate visuomotor adaptation”. Neuroimage 118985
Tzvi Elinor, Gajiyeva Leila, Bindel Laura, Hartwigsen Gesa, Classen Joseph
(Siehe online unter https://doi.org/10.1016/j.neuroimage.2022.118985)
