Modulation of neural oscillations during working memory update, maintenance, and readout: An hdEEG study

Abstract

Working memory (WM) performance is very often measured using the n‐back task, in which the participant is presented with a sequence of stimuli, and required to indicate whether the current stimulus matches the one presented n steps earlier. In this study, we used high‐density electroencephalography (hdEEG) coupled to source localization to obtain information on spatial distribution and temporal dynamics of neural oscillations associated with WM update, maintenance and readout. Specifically, we a priori selected regions from a large fronto‐parietal network, including also the insula and the cerebellum, and we analyzed modulation of neural oscillations by event‐related desynchronization and synchronization (ERD/ERS). During update and readout, we found larger θ ERS and smaller β ERS respect to maintenance in all the selected areas. γLOW and γHIGH bands oscillations decreased in the frontal and insular cortices of the left hemisphere. In the maintenance phase we observed decreased θ oscillations and increased β oscillations (ERS) in most of the selected posterior areas and focally increased oscillations in γLOW and γHIGH bands in the frontal and insular cortices of the left hemisphere. Finally, during WM readout, we also found a focal modulation of the γLOW band in the left fusiform cortex and cerebellum, depending on the response trial type (true positive vs. true negative). Overall, our study demonstrated specific spectral signatures associated with updating of memory information, WM maintenance, and readout, with relatively high spatial resolution.

Theta Oscillations and Source Connectivity During Complex Audiovisual Object Encoding in Working Memory

“…2005; Raghavachari et al, 2006;Semprini et al, 2020;Yu et al, 2020). Studies of human EEG have shown that increased theta activity is associated with item encoding in working memory (Jensen and Tesche, 2002;Proskovec et al, 2019).…”

Cognitive deficits for facial emotions among male adolescent delinquents with conduct disorder

“…A larger number of previous studies revealed that, compared with happy and neutral faces, angry faces significantly improved the working memory capacity for facial identity (111)(112)(113)(114)(115), and the working memory sensitivity for fearful faces was higher than that for neutral faces (116). Working memory is an ability that preserves and updates information in a short period of time (117)(118)(119). The stronger working memory processing on negative emotional faces among adolescent delinquents may imply difficulty in refreshing negative information, and thus cause aggressive behaviors.…”

A Focused Review of Gamma Neuromodulation as a Therapeutic Target in Alzheimer’s Spectrum Disorders

“…During the “retention” or “maintenance” intervals of WM tasks, frontal gamma synchronization may be a relatively specific marker of prefrontal gamma activity. In support of this model, Semprini and colleagues demonstrated that the maintenance phase of the N-Back (a WM task) was associated with significant gamma synchronization, especially in frontal, and dorsal-lateral prefrontal (DLPFC) areas [ 27 ]; in contrast, gamma activity during the encoding and retrieval phases were relatively attenuated (with theta and beta activity being more prominent). Tallon-Baudry and colleagues similarly demonstrated significant frontal (e.g., F3, F4) gamma synchronization during the maintenance interval of a visual WM task (delayed match to sample, or DMS), compared to control intervals where maintenance were not required [ 21 ].…”