Test–retest reliability of pre-cue and anticipatory alpha activity in visual spatial attention

Alpha-band activity over the parietal-occipital cortex is a canonical neural marker of visual spatial attention. However, the ongoing debate surrounds whether this activity represents as an active mechanism in gating visual information processing or if it merely reflects an epiphenomenal consequence of anticipatory attentional shifts. Despite this debate, the temporal stability of alpha activity in visual spatial attention, an essential aspect for this discussion, remains ambiguous. Notably, our recent findings highlighted the significant impact of pre-cue alpha power on anticipatory alpha activity in spatial attention tasks, yet the reliability of these pre-cue alpha effects remained unexplored. Here we evaluated the short-term test–retest reliability of both pre-cue and anticipatory alpha activity in healthy young adults who engaged in the same spatial cueing paradigm over two consecutive days. Reliability was gauged using the intraclass coefficient (ICC). Our results demonstrated excellent reliability of pre-cue alpha power, alpha event-related desynchronization (ERD) and individual alpha frequency (IAF), and moderate reliability of alpha lateralization index (LI). Additionally, by categorizing participants into higher and lower pre-cue alpha power sub-groups based on median-splitting, we observed no significant differences in ICCs between the two sub-groups for anticipatory alpha ERD, LI and IAF, except for a significantly higher ICC of pre-cue alpha power in the higher sub-group than the lower sub-group. Taken together, by examining the short-term reliability of alpha-band activity in visual spatial attention for the first time, our study lays a foundational step for the ongoing discourse regarding its functional implications in visual spatial attention.