Alpha/beta power decreases during episodic memory formation predict the magnitude of alpha/beta power decreases during subsequent retrieval

Journal article

Episodic memory retrieval is characterised by the vivid reinstatement of information about a personally-experienced event. Growing evidence suggests that this reinstatement is supported by reductions in the spectral power of alpha/beta activity. Given that the amount of information that can be recalled depends on the amount of information that was originally encoded, information-based accounts of alpha/beta activity would suggest that retrieval-related alpha/beta power decreases similarly depend upon decreases in alpha/beta power during encoding. To test this hypothesis, seventeen human participants completed a sequence-learning task while undergoing concurrent MEG recordings. Regression-based analyses were then used to estimate how alpha/beta power decreases during encoding predicted alpha/beta power decreases during retrieval on a trial-by-trial basis. When subjecting these parameter estimates to group-level analysis, we find evidence to suggest that retrieval-related alpha/beta (7-15Hz) power decreases fluctuate as a function of encoding-related alpha/beta power decreases. These results suggest that retrieval-related alpha/beta power decreases are contingent on the decrease in alpha/beta power that arose during encoding. Subsequent analysis uncovered no evidence to suggest that these alpha/beta power decreases reflect stimulus identity, indicating that the contingency between encoding- and retrieval-related alpha/beta power reflects the reinstatement of a neurophysiological operation, rather than neural representation, during episodic memory retrieval.

Authors: Griffiths, BJ; Martín-Buro, MC; Staresina, BP; Hanslmayr, S; Staudigl, T

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: Elsevier
• Journal: Neuropsychologia
• Volume: 153
• Article number: 107755
• Publication date: 2021-01-28
• Acceptance date: 2021-01-14
• DOI: 10.1016/j.neuropsychologia.2021.107755
• EISSN: 1873-3514
• ISSN: 0028-3932
• Pmid: 33515568
• Language: English
• Keywords: FFR; memory, episodic; humans; mental recall