Masking is a technique which was initially developed to analyze the micro-genesis of visual perception. Using this technique, researchers intended to control with maximum rigor the interruption of the perceptual process at a certain moment and, that way, they aimed to program with high precision the span of time during which the representation produced by the image of a visual stimulus is available to subjects. Researchers expected that this technique enabled the precise observation of the early operations that are involved in the processing of visual information. However, the phenomenon of masking turned out to be more complex than what was initially assumed. Next, you can observe how participants see the stimuli that are masked. You can see in the different experiments what happens when the time between the mask and the stimulus is increased.