Thesis
Modulating Brain Network Connectivity Using Transcranial Alternating Current Stimulation
Masters by Research, Murdoch University
2024
Abstract
Concurrent application of transcranial alternating current stimulation (tACS) over distant cortical regions has been shown to modulate functional connectivity between stimulated regions; however, the precise mechanisms of how functional connectivity is modulated between cortical regions remain unclear. Here, we investigated how dual-site tACS (ds-tACS) applied over the bilateral primary motor cortices (M1s) modulate the functional connectivity between M1s. Using a cross-over sham-controlled triple-blind within-subject design, 37 (27 female, age 18-37 yrs) healthy participants received tACS (1.0mA, 20Hz) over the bilateral M1s for 20 min. Before and after tACS, functional connectivity between M1s was assessed using imaginary coherence (ImCoh) measured via resting-state electroencephalography (EEG) and interhemispheric inhibition (IHI) via dual-site transcranial magnetic stimulation (TMS) protocol. Additionally, manual dexterity was assessed using the Purdue pegboard. While ImCoh remained unchanged after the simulation, spectral power analysis showed a significant decrease in beta (20 Hz) power during the tACS session. ds-tACS but not sham strengthened IHI between M1s and improved bimanual assembly performance. These results suggest that improvement in bimanual performance may be explained by the modulation in M1-M1 IHI, rather than by coupling in the oscillatory activity. Since functional connectivity underlies many clinical symptoms in neurological and psychiatric disorders, these findings are invaluable in developing non-invasive therapeutic interventions that target neural networks to alleviate symptoms.
Details
- Title
- Modulating Brain Network Connectivity Using Transcranial Alternating Current Stimulation
- Authors/Creators
- Brooke H Lebihan
- Contributors
- Ann-Maree Vallence (Supervisor) - Murdoch University, Centre for Healthy AgeingHakuei Fujiyama (Supervisor) - Murdoch University, Centre for Healthy Ageing
- Awarding Institution
- Murdoch University; Masters by Research
- Identifiers
- 991005741582907891
- Murdoch Affiliation
- School of Psychology
- Resource Type
- Thesis
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