Anticipatory cue‐related alpha desynchronization reflects top‐down disinhibitory control during verbal working memory task

Abstract

AbstractBackgroundWorking memory deficits are common in mild cognitive impairment (MCI) and cause troubles in routine activities. Frontal theta event‐related synchronization (ERS) and parietal alpha event‐related desynchronization (ERD) are known to be associated with working memory capacity. However, their association with working memory performance, including at the trial‐by‐trial level, has yet to be determined.Method54 healthy adults (mean age (SD) = 28.4 (7.4)) completed the N‐back working memory task at three conditions (N = 1, 2, and 3). Single‐trial ERS/ERD was measured during N‐back and in response to an anticipatory cue at the beginning of each trial. Anticipatory cue‐related power changes at the trial level were used to assess neural oscillation before target correct (TC) and target non‐correct (TNC) responses.Result2‐way ANOVA showed significant effect of response type (p=0.01) and interaction between N‐back condition and response type (p=0.03) on alpha ERD. Post‐hoc comparisons revealed less alpha ERD in TC vs. TNC responses during 2‐ and 3‐back conditions (p’s < 0.02), and less alpha ERD in TC trials of 2‐ and 3‐back compared to 1‐back condition (p’s < 0.001). Finally, no significant effect was observed in theta band.ConclusionGiven that alpha ERD has been associated with top‐down disinhibitory control, our findings suggest that less anticipatory disinhibition prior to the processing of a working memory item of information promotes correct processing and high‐capacity working memory