Phase synchronized 6 Hz transcranial electric and magnetic stimulation boosts frontal theta activity and enhances working memory
Tiam Hosseinian,
Fatemeh Yavari,
Min-Fang Kuo,
Michael A. Nitsche,
Asif Jamil
Affiliations
Tiam Hosseinian
Department Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors, Ardeystrasse 67, Dortmund 44139, Germany
Fatemeh Yavari
Department Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors, Ardeystrasse 67, Dortmund 44139, Germany
Min-Fang Kuo
Department Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors, Ardeystrasse 67, Dortmund 44139, Germany
Michael A. Nitsche
Department Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors, Ardeystrasse 67, Dortmund 44139, Germany; Department Neurology, University Medical Hospital Bergmannsheil, Bochum, Germany; Corresponding authors at: Department Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors, Ardeystrasse 67, Dortmund 44139, Germany.
Asif Jamil
Department Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors, Ardeystrasse 67, Dortmund 44139, Germany; Laboratory for Neuropsychiatry and Neuromodulation, Harvard Medical School, Massachusetts General Hospital, 149 Thirteenth Street, Boston, MA, USA; Corresponding authors at: Department Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors, Ardeystrasse 67, Dortmund 44139, Germany.
Network-level synchronization of theta oscillations in the cerebral cortex is linked to many vital cognitive functions across daily life, such as executive functions or regulation of arousal and consciousness. However, while neuroimaging has uncovered the ubiquitous functional relevance of theta rhythms in cognition, there remains a limited set of techniques for externally enhancing and stabilizing theta in the human brain non-invasively. Here, we developed and employed a new phase-synchronized low-intensity electric and magnetic stimulation technique to induce and stabilize narrowband 6-Hz theta oscillations in a group of healthy human adult participants, and then demonstrated how this technique also enhances cognitive processing by assaying working memory. Our findings demonstrate a technological advancement of brain stimulation methods, while also validating the causal link between theta activity and concurrent cognitive behavior, which may ultimately help to not only explain mechanisms, but offer perspectives for restoring deficient theta-band network activity observed in neuropsychiatric diseases.
