Local brain-state dependency of effective connectivity: a pilot TMS–EEG study [version 2; peer review: 2 approved]
| Autor: | Matteo Fecchio, Victor H. Souza, Pantelis Lioumis, Mario Rosanova, Risto J. Ilmoniemi, Tuomas P. Mutanen, Ida Granö, Jaakko O. Nieminen, Aino Tervo |
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| Jazyk: | angličtina |
| Rok vydání: | 2022 |
| Předmět: | |
| Zdroj: | Open Research Europe, Vol 2 (2022) |
| Druh dokumentu: | article |
| ISSN: | 2732-5121 77971590 |
| DOI: | 10.12688/openreseurope.14634.2 |
| Popis: | Background Spontaneous cortical oscillations have been shown to modulate cortical responses to transcranial magnetic stimulation (TMS). However, whether these oscillations influence cortical effective connectivity is largely unknown. We conducted a pilot study to set the basis for addressing how spontaneous oscillations affect cortical effective connectivity measured through TMS-evoked potentials (TEPs). Methods We applied TMS to the left primary motor cortex and right pre-supplementary motor area of three subjects while recording EEG. We classified trials off-line into positive- and negative-phase classes according to the mu and beta rhythms. We calculated differences in the global mean-field amplitude (GMFA) and compared the cortical spreading of the TMS-evoked activity between the two classes. Results Phase affected the GMFA in four out of 12 datasets (3 subjects × 2 stimulation sites × 2 frequency bands). Two of the observed significant intervals were before 50 ms, two between 50 and 100 ms, and one after 100 ms post-stimulus. Source estimates showed complex spatial differences between the classes in the cortical spreading of the TMS-evoked activity. Conclusions TMS-evoked effective connectivity seems to depend on the phase of local cortical oscillations at the stimulated site. This work paves the way to design future closed-loop stimulation paradigms. |
| Databáze: | Directory of Open Access Journals |
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