Gamma flicker triggers attentional selection without awareness.
Gamma band modulations in neural activity have been proposed to mediate attentional processes. To support a causal link between gamma activity and attentional selection, we attempt to evoke gamma oscillations by a 50-Hz subliminal flicker. We find that a subliminal 50-Hz flicker at a target location, before target presentation, speeds up and enhances target detection and discrimination. This effect is specific to the middle of the gamma range because it is not evident at <35-Hz flicker. It requires 300 ms to build up, dissipates within 250 ms of flicker offset, and shows a tendency to invert after 500 ms. The results are discussed in relation to a role for gamma band neural synchrony in the allocation of visual attention.
Bauer
Frank
F
Department of Psychology, Leopoldstrasse 13, Ludwig Maximilian University, 80802 Munich, Germany.
Cheadle
Samuel W
SW
Parton
Andrew
A
Müller
Hermann J
HJ
Usher
Marius
M
D001364:Awareness; D005425:Flicker Fusion; D006801:Humans; D014785:Vision, Ocular