Synchronous information presented in 40-Hz flicker enhances visual feature binding

Recent neurophysiological studies have encouraged speculation that the synchronization of spatially distributed neural assemblies (at around 40 Hz in the neocortex) is responsible for the binding of discrete stimulus components into coherent wholes during visual object perception. Using a novel paradigm, we demonstrated specific figural priming under 40-Hz stimulus modulation conditions. Further, under these conditions, observers were not aware of the prime's existence, nor did the prime act as a stimulus-driven attentional cue. These findings provide the first psychophysical support for a theory of preattentive coding of visual objects, based on an externally entrained and thereby synchronized 40-Hz feature-binding mechanism.