Gating of memory encoding of time-delayed cross-frequency MEG networks revealed by graph filtration based on persistent homology

Research output: Contribution to journalArticlepeer-review


  • Jarang Hahm
  • Hyekyoung Lee
  • Eunjoo Kang
  • Yu Kyeong Kim
  • Chun Kee Chung
  • Hyejin Kang
  • Dong Soo Lee

External organisations

  • Seoul National University
  • Kangwon National University


To explain gating of memory encoding, magnetoencephalography (MEG) was analyzed over multi-regional network of negative correlations between alpha band power during cue (cue-alpha) and gamma band power during item presentation (item-gamma) in Remember (R) and No-remember (NR) condition. Persistent homology with graph filtration on alpha-gamma correlation disclosed topological invariants to explain memory gating. Instruction compliance (R-hits minus NR-hits) was significantly related to negative coupling between the left superior occipital (cue-alpha) and the left dorsolateral superior frontal gyri (item-gamma) on permutation test, where the coupling was stronger in R than NR. In good memory performers (R-hits minus false alarm), the coupling was stronger in R than NR between the right posterior cingulate (cue-alpha) and the left fusiform gyri (item-gamma). Gating of memory encoding was dictated by inter-regional negative alpha-gamma coupling. Our graph filtration over MEG network revealed these inter-regional time-delayed cross-frequency connectivity serve gating of memory encoding.


Original languageEnglish
Article number41592
JournalScientific Reports
Publication statusPublished - 7 Feb 2017


  • Attention, Network topology