Offline 20 Hz transcranial alternating current stimulation over the right inferior frontal gyrus increases theta activity during a motor response inhibition task

Ekaterina Lyzhko; Stefanie E Peter; Frauke Nees; Michael Siniatchkin; Vera Moliadze

doi:10.1016/j.neucli.2023.102887

Offline 20 Hz transcranial alternating current stimulation over the right inferior frontal gyrus increases theta activity during a motor response inhibition task

Neurophysiol Clin. 2023 Jun;53(3):102887. doi: 10.1016/j.neucli.2023.102887. Epub 2023 Jun 22.

Authors

Ekaterina Lyzhko¹, Stefanie E Peter², Frauke Nees², Michael Siniatchkin³, Vera Moliadze⁴

Affiliations

¹ Institute of Medical Psychology and Medical Sociology, University Medical Center Schleswig Holstein, Kiel University, Kiel, Germany; Department of Neuropediatrics, University Medical Center Schleswig Holstein, Kiel University, Kiel, Germany.
² Institute of Medical Psychology and Medical Sociology, University Medical Center Schleswig Holstein, Kiel University, Kiel, Germany.
³ Institute of Medical Psychology and Medical Sociology, University Medical Center Schleswig Holstein, Kiel University, Kiel, Germany; University Clinic of Child and Adolescent Psychiatry and Psychotherapy, University Hospital OWL, University of Bielefeld, Campus Bethel, Bielefeld, Germany.
⁴ Institute of Medical Psychology and Medical Sociology, University Medical Center Schleswig Holstein, Kiel University, Kiel, Germany. Electronic address: moliadze@med-psych.uni-kiel.de.

PMID: 37355398
DOI: 10.1016/j.neucli.2023.102887

Abstract

Objectives: Previous studies have shown that the right inferior frontal gyrus (rIFG) and the pre-supplementary motor area (preSMA) play an important role in motor inhibitory control. The aim of the study was to use theta frequency transcranial alternating current stimulation (tACS) to modulate brain activity in the rIFG and preSMA and to test the effects of stimulation using a motor response inhibition task.

Methods: In four sessions, 20 healthy participants received tACS at 6 Hz over preSMA or rIFG, or 20 Hz over rIFG (to test frequency specificity), or sham stimulation before task processing. After each type of stimulation, the participants performed the Go/NoGo task with simultaneous electroencephalogram (EEG) recording.

Results: By stimulating rIFG and preSMA with 6 Hz tACS, we were not able to modulate either behavioral performance nor the EEG correlate. Interestingly, 20 Hz tACS over the rIFG significantly increased theta activity, however without behavioral effects. This increased theta activity did not coincide with the stimulation area and was localized in the fronto-central and centro-parietal areas.

Conclusions: The inclusion of a control frequency is crucial to test for frequency specificity. Our findings are in accordance with previous studies showing that after effects of tACS are not restricted to the stimulation frequency but can also occur in other frequency bands.

Keywords: Go/NoGo-paradigm; Inferior frontal gyrus; Inhibition task; Pre-supplementary motor area; Transcranial alternating current stimulation; tACS.

MeSH terms

Electroencephalography
Humans
Inhibition, Psychological
Motor Cortex* / physiology
Prefrontal Cortex
Transcranial Direct Current Stimulation*