platforms2026

Alpha oscillations (8-13 Hz) are thought to gate sensory processing through rhythmic fluctuations in cortical excitability, with amplitude lateralization and phase both playing key roles in spatial attention. However, no study has manipulated alpha phase across both hemispheres within a single trial simultaneously. To address this gap, we employed a modified Posner cueing task with two spatially separated flickering stimuli designed to independently entrain alpha oscillations in each hemisphere at opposing phases. We hypothesized that performance would be optimal when the target appeared at the excitatory alpha phase and the distractor at the suppressive phase, and worst for the reverse condition. Two participants completed the task while MEG data was recorded to verify neural entrainment and alpha lateralization. A 20 Hz flickering technical error prevented assessment of phase-dependent behavioral effects. Accordingly, no significant modulation of reaction times or accuracy was observed across phase conditions. Nevertheless, MEG results confirmed robust neural entrainment at 20 Hz in both participants, and a significant alpha lateralization effect consistent with the spatial attention manipulation (permutation test, p = .02). These findings demonstrate proof of concept for the paradigm design and validate the lateralization component, while highlighting the need to correct the flicker frequency in future work.