No effects of rhythmic visual stimulation on target discrimination: an online alpha entrainment experiment

Alpha frequency is a natural target for visual entrainment, since fluctuations in posterior alpha oscillations have been linked to visual target detection or discrimination. On the other hand, alpha oscillations also relate to attentional mechanisms, such as attentional orienting or selection.

Previous visual alpha entrainment studies focused on differential processing of targets presented in-phase with the preceding rhythmic stimulation relative to out-of-phase targets (an ‘SOA effect’), putatively related to the phase of entrained neuronal alpha oscillations. Fewer studies probed the consequences of rhythmic alpha stimulation for attention mechanisms related to alpha power. Here we asked whether alpha-stimulation of one hemifield has similar effects on reaction times as we see for increased alpha-synchronization in M/EEG studies (i.e. more alpha means impaired processing; functional inhibition).