RT Journal Article
SR Electronic
T1 Disentangling the roles of neocortical alpha/beta and hippocampal theta/gamma oscillations in human episodic memory formation
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2020.01.22.915330
DO 10.1101/2020.01.22.915330
A1 Benjamin J. Griffiths
A1 María Carmen Martín-Buro
A1 Bernhard P. Staresina
A1 Simon Hanslmayr
YR 2020
UL http://biorxiv.org/content/early/2020/10/12/2020.01.22.915330.abstract
AB Episodic memory formation relies on at least two distinct capabilities: 1) our ability to process a vast amount of sensory information, and 2) our ability to bind these sensory representations together to form a coherent memory. The first process is thought to rely on a reduction in neocortical alpha/beta power, while the second is thought to be supported by hippocampal theta-gamma phase-amplitude coupling. However, most studies investigating human episodic memory use paradigms where the two cognitive capabilities overlap. As such, empirical support for the distinction of the two associated neural phenomena is lacking. Here, we addressed this by asking seventeen human participants (11 female, 6 male) to complete a sequence-learning paradigm that temporally separated information representation from mnemonic binding, while MEG recordings were acquired. We found that a decrease in neocortical alpha/beta power during the perception of the sequence correlated with enhanced memory performance. Similar power decreases during mnemonic binding, however, had no bearing on memory formation. In contrast, an increase in hippocampal theta/gamma phase-amplitude coupling during mnemonic binding correlated with enhanced memory performance, but similar coupling during sequence perception bared no relation to later memory performance. These results demonstrate that alpha/beta power decreases and hippocampal theta/gamma phase-amplitude coupling represent two temporally dissociable processes in episodic memory, with the former relating to information representation while the latter relates to mnemonic binding.Competing Interest StatementThe authors have declared no competing interest.