Motion induced blindness (MIB) is a compelling visual illusion where stationary objects can disappear from your perception when they are surrounded by a moving background. This phenomenon demonstrates that our brains do not simply absorb what our eyes see; instead, they actively construct our reality. The way our brains process visual information can lead to surprising perceptual experiences, illustrating the dynamic and interpretive nature of sight.
Experiencing Motion Induced Blindness
Motion induced blindness can be experienced firsthand. A common demonstration involves focusing on a central fixation point while other stimuli move around it. For instance, you might see a display with bright blue crosses rotating around a fixed central white disc, with a stationary yellow disc placed towards one of the corners of the square.
To experience the illusion, fixate your gaze on the central white disc. While maintaining your focus, attend to the yellow disc as you observe the motion of the blue crosses. After about 10 seconds, the yellow disc may begin to disappear from your awareness, even though it remains physically present on the screen. The static object might vanish completely, as if briefly erased, only to spontaneously reappear several seconds later. This cyclical disappearance and reappearance can continue for as long as you maintain your steady gaze.
The Brain’s Perceptual Filtering
Motion induced blindness arises from the brain’s complex processes of visual perception, particularly its tendency to filter and prioritize information. One hypothesis suggests that MIB is caused by a competition between the neural representations of the static target and the moving background within the brain’s visual processing centers. This competition can occur at various levels of cortical processing.
Another explanation involves the concept of perceptual filling-in, where the brain actively replaces missing or unchanging visual information with surrounding patterns. If a static object remains invariant against a continuously moving background, the visual system may interpret it as an artifact and effectively remove it from conscious awareness, filling the space with the surrounding motion. Attentional suppression also plays a role, as the brain might actively suppress stable, unchanging stimuli in a busy, dynamic visual field to focus on more relevant, moving information.
Beyond the Lab How It Appears
The principles underlying motion induced blindness extend beyond controlled laboratory settings, offering insights into the broader mechanisms of visual perception.
For example, our brains constantly filter out consistent, unchanging sensory input, such as the continuous sensation of clothing on our skin or the steady hum of a refrigerator. This filtering allows us to focus on new or more relevant stimuli in our environment. While not direct instances of MIB, these everyday occurrences illustrate the brain’s general tendency to prioritize dynamic information and suppress static, predictable input to prevent sensory overload. This active filtering process, exemplified by MIB, underscores that what we consciously perceive is a highly curated version of the vast amount of sensory data our eyes receive.