Load effects on spatial working memory performance are linked to distributed alpha and beta oscillations

Abstract

Increasing spatial working memory (SWM) load is generally associated with declines in behavioral performance, but the neural correlates of load‐related behavioral effects remain poorly understood. Herein, we examine the alterations in oscillatory activity that accompany such performance changes in 22 healthy adults who performed a two‐ and four‐load SWM task during magnetoencephalography (MEG). All MEG data were transformed into the time‐frequency domain and significant oscillatory responses were imaged separately per load using a beamformer. Whole‐brain correlation maps were computed using the load‐related beamformer difference images and load‐related accuracy effects on the SWM task. The results indicated that load‐related differences in left inferior frontal alpha activity during encoding and maintenance were negatively correlated with load‐related accuracy differences on the SWM task. That is, individuals who had more substantial decreases in prefrontal alpha during high‐relative to low‐load SWM trials tended to have smaller performance decrements on the high‐load condition (i.e., they performed more accurately). The same pattern of neurobehavioral correlations was observed during the maintenance period for right superior temporal alpha activity and right superior parietal beta activity. Importantly, this is the first study to employ a voxel‐wise whole‐brain approach to significantly link load‐related oscillatory differences and load‐related SWM performance differences.

Shaping information processing: the role of oscillatory dynamics in a working-memory task

“…In support for its circuit role, we demonstrate that increases (rather than decreases) in beta power index a stronger decoding and maintenance of task-relevant features, i.e., the decodability of stimuli preceded by high beta power was boosted and generalized for longer durations. This is in line with previous studies demonstrating that beta power correlates with stimulus information maintained in working memory as well as subsequent decision outcomes (Haegens et al, 2017; Lautz et al, 2017; Proskovec et al, 2019). Here we go one step further, by directly linking the power of beta oscillations to the quality of information content in neural activity patterns.…”

The electrophysiological underpinnings of variation in verbal working memory capacity

“…This finding was not predicted by any hypothesis because the literature concerning this relationship is too scarce. Probably the only comparable study is a spatial WM MEG experiment 37,38 . Both publications reported a negative correlation between beta (15-20 Hz) and behavioral performance.…”

Musical instrument training program improves verbal memory and neural efficiency in novice older adults

“…The temporal area, such as the STG, is involved in music processing (Koelsch et al, 2002), acquiring musical instrumental skills (Chen et al, 2012), and language processing (Hickok & Poeppel, 2004). These regions have also been associated with WM (Langer, Von Bastian, Wirz, Oberauer, & Jäncke, 2013; Proskovec, Wiesman, Heinrichs‐Graham, & Wilson, 2019; Salmi et al, 2018; Voytek & Knight, 2010) and verbal memory (Garrido et al, 2002; Ystad, Eichele, Lundervold, & Lundervold, 2010). In light of these observations, we propose that our Key‐HIT program, which may broadly engage the neural networks including lPu‐rSTG, induces neurocognitive improvement not specific to musical skills, such as improvements in verbal memory and neural efficiency associated with VWM.…”