Slow oscillation electrical brain stimulation during waking promotes EEG theta activity and memory encoding

Research output: Contribution to journalJournal articleResearchpeer-review

The application of transcranial slow oscillation stimulation (tSOS; 0.75 Hz) was previously shown to enhance widespread endogenous EEG slow oscillatory activity when applied during a sleep period characterized by emerging endogenous slow oscillatory activity. Processes of memory consolidation typically occurring during this state of sleep were also enhanced. Here, we show that the same tSOS applied in the waking brain also induced an increase in endogenous EEG slow oscillations (0.4-1.2 Hz), although in a topographically restricted fashion. Applied during wakefulness tSOS, additionally, resulted in a marked and widespread increase in EEG theta (4-8 Hz) activity. During wake, tSOS did not enhance consolidation of memories when applied after learning, but improved encoding of hippocampus-dependent memories when applied during learning. We conclude that the EEG frequency and related memory processes induced by tSOS critically depend on brain state. In response to tSOS during wakefulness the brain transposes stimulation by responding preferentially with theta oscillations and facilitated encoding.
Original languageEnglish
JournalProceedings of the National Academy of Science of the United States of America
Issue number36
Pages (from-to)15460-5
Number of pages5
Publication statusPublished - 2009

Bibliographical note

Keywords: Adult; Analysis of Variance; Brain; Electric Stimulation Therapy; Germany; Humans; Learning; Memory; Oscillometry; Theta Rhythm; Wakefulness

ID: 21458617