Rescuing stimuli from invisibility: Inducing a momentary release fromvisual masking with pre-target entrainment

摘要

At near-threshold levels of stimulation, identical stimulus parameters can result in verydifferent phenomenal experiences. Can we manipulate which stimuli reach consciousness?Here we show that consciousness of otherwise masked stimuli can be experimentallyinduced by sensory entrainment. We preceded a backward-masked stimulus with a seriesof rapid visual events presented at 12 Hz for 800 ms. Peaks in visual sensitivity (d') wereobserved when the target appeared at the time that the next entraining stimuli would haveoccurred. Observers' sensitivity for identical masked near-threshold stimuli increased byfactors as large as 55%, but only at this precise moment in time. These data thus reveal thatawareness of near-threshold stimuli can be manipulated by entrainment to rhythmicevents, supporting the functional role of induced oscillations in underlying cortical excit-ability, and suggest a plausible mechanism of temporal attention.