Alpha‐band desynchronization reflects memory‐specific processes during visual change detection

• Published in: Psychophysiology 2019-11, Vol.56 (11), p.e13442-n/a
• Main Authors: Erickson, Molly A., Smith, Dillon, Albrecht, Matthew A., Silverstein, Steven
• Format: Article
• Language: English
• Subjects: alpha oscillations; beta oscillations; EEG; Gating; individual differences; Memory; Short term memory; Synchronization; visual working memory
• ISSN: 0048-5772; 1469-8986; 1540-5958
• DOI: 10.1111/psyp.13442

Recent work investigating physiological mechanisms of working memory (WM) has revealed that modulation of alpha and beta frequency bands within the EEG plays a key role in WM storage. However, the nature of that role is unclear. In the present study, we examined event‐related desynchronization of alpha and beta (α/β‐ERD) elicited by visual tasks with and without a memory component to measure the impact of a WM demand on this electrophysiological marker. We recorded EEG from 60 healthy participants while they completed three variants on a typical change detection task: one in which participants passively viewed the sample array, passive (WM−); one in which participants viewed and attended the sample array in search of a target color but did not memorize the colors, active (WM−); and one in which participants encoded, attended to, and memorized the sample array, active (WM+). Replicating previous findings, we found that active (WM+) elicited robust α/β‐ERD in frontal and posterior electrode clusters and that α‐ERD was significantly associated with WM capacity. By contrast, α/β‐ERD was significantly smaller in the passive (WM−) and active (WM−) tasks, which did not consistently differ from one another. Furthermore, no such relationship was observed between WM capacity and desynchronization in the passive (WM−) or active (WM−) tasks. Taken together, these results suggest that α‐ERD during memory formation reflects a memory‐specific process such as consolidation or maintenance, rather than serving a generalized role in perceptual gating or engagement of attention. Recently, task‐related desynchronization of the alpha and beta within the EEG during visual working memory (WM) formation and maintenance has been linked to individual differences in WM capacity. Here, we demonstrate that alpha/beta desynchronization elicited by a visual WM task appears to support a memory‐specific cognitive subprocess (e.g., consolidation), rather than a subprocess that is necessary, but not sufficient, for successful memory storage (e.g., encoding).