Transcranial alternating current stimulation at theta frequency to left parietal cortex impairs associative, but not perceptual, memory encoding

Alyssa Meng, Max Kaiser, Tom A. de Graaf, Felix Dücker, Alexander T. Sack, Peter De Weerd, Vincent van de Ven*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

3 Citations (Web of Science)


Neural oscillations in the theta range (4-8 Hz) are thought to underlie associative memory function in the hippocampal-cortical network. While there is ample evidence supporting a role of theta oscillations in animal and human memory, most evidence is correlational. Non-invasive brain stimulation (NIBS) can be employed to modulate cortical oscillatory activity to influence brain activity, and possibly modulate deeper brain regions, such as hippocampus, through strong and reliable cortico-hippocampal functional connections. We applied focal transcranial alternating current stimulation (tACS) at 6 Hz over left parietal cortex to modulate brain activity in the putative cortico-hippocampal network to influence associative memory encoding. After encoding and brain stimulation, participants completed an associative memory and a perceptual recognition task. Results showed that theta tACS significantly decreased associative memory performance but did not affect perceptual memory performance. These results show that parietal theta tACS modulates associative processing separately from perceptual processing, and further substantiate the hypothesis that theta oscillations are implicated in the cortico-hippocampal network and associative encoding.

Original languageEnglish
Article number107444
Number of pages8
JournalNeurobiology of Learning and Memory
Early online date23 Apr 2021
Publication statusPublished - Jul 2021


  • Theta oscillations
  • Associative memory
  • Transcranial alternating current stimulation
  • Non-invasive brain stimulation
  • Network stimulation
  • TASK
  • TACS

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