RT Journal Article
SR Electronic
T1 Persistent hippocampal neural firing and hippocampal-cortical coupling predict verbal working memory load
JF Science Advances
JO Sci Adv
FD American Association for the Advancement of Science
SP eaav3687
DO 10.1126/sciadv.aav3687
VO 5
IS 3
A1 Boran, Ece
A1 Fedele, Tommaso
A1 Klaver, Peter
A1 Hilfiker, Peter
A1 Stieglitz, Lennart
A1 Grunwald, Thomas
A1 Sarnthein, Johannes
YR 2019
UL http://advances.sciencemag.org/content/5/3/eaav3687.abstract
AB The maintenance of items in working memory relies on persistent neural activity in a widespread network of brain areas. To investigate the influence of load on working memory, we asked human subjects to maintain sets of letters in memory while we recorded single neurons and intracranial encephalography (EEG) in the medial temporal lobe and scalp EEG. Along the periods of a trial, hippocampal neural firing differentiated between success and error trials during stimulus encoding, predicted workload during memory maintenance, and predicted the subjects’ behavior during retrieval. During maintenance, neuronal firing was synchronized with intracranial hippocampal EEG. On the network level, synchronization between hippocampal and scalp EEG in the theta-alpha frequency range showed workload dependent oscillatory coupling between hippocampus and cortex. Thus, we found that persistent neural activity in the hippocampus participated in working memory processing that is specific to memory maintenance, load sensitive and synchronized to the cortex.