Parietal alpha oscillatory peak frequency mediates the effect of practice on visuo-spatial working memory performance

Bertaccini R, Ellena G, Macedo-Pascual J, Carusi F, Trajkovic J, Poch C, Romei V.

Visuospatial working memory (WM) requires the activity of a spread network, including right parietal regions, to sustain storage capacity, attentional deployment, and active manipulation of information. Notably, while the electrophysiological correlates of such regions have been explored using many different indices, evidence for a functional involvement of the individual frequency peaks in the alpha (IAF) and theta bands (ITF) is still poor despite their relevance in many influential theories regarding WM. Interestingly, there is also a parallel lack of literature about the effect of short-term practice on WM performance. Here, we aim to clarify whether the simple repetition of a change detection task might be beneficial to WM performance, and to which degree these effects could be predicted by IAF and ITF. To this purpose, 25 healthy participants performed a change detection task at baseline and in a retest session, while also IAF and ITF were measured. Results show that task repetition improves WM performance. In addition, right parietal IAF, but not ITF, accounts for performance gain such that faster IAF predicts higher performance gain. Our findings align with recent literature suggesting that the faster the posterior alpha, the finer the perceptual sampling rate, the higher the WM performance gain.