A continuity field merges what we see over short periods of time

Apr 1, 2014 14:57 GMT  ·  By

Investigators from the University of California in Berkeley (UCB) and the Massachusetts Institute of Technology (MIT) in Cambridge have discovered the existence of a continuity field in the human brain, which is responsible for merging together images of similar objects we see within a 15-second interval. 

The existence of this delay in visual processing may go a long way towards explaining why continuity bloopers in movies – such as when a character's clothes change from a scene to another – go largely unnoticed by most people. Vision scientists with the two universities say that a mechanism in our brain is responsible for blinding us to these changing visual cues.

The new investigation was also able to find a positive aspect to this type of temporary blindness. The team says that this continuity field helps stabilize what we see over time, since objects in the real world do not suddenly change in nature, shape or size. A coffee mug remains a coffee mug all the time, and does not spontaneously change into a spoon. The brain save energy by assuming this is always true.

Details of the new study were published in the March 30 issue of the top scientific journal Nature Neuroscience. UCB associate professor of psychology David Whitney is the senior author of the research, while MIT postdoctoral fellow Jason Fischer is the lead author. Fischer conducted this research while a PhD student at UCB, in Whitney's laboratory.

“The continuity field smoothes what would otherwise be a jittery perception of object features over time. Essentially, it pulls together physically but not radically different objects to appear more similar to each other. This is surprising because it means the visual system sacrifices accuracy for the sake of the continuous, stable perception of objects,” Whitney explains.

The downside of not having this continuity field in our minds could be a hypersensitivity to visual cue fluctuations. This means that every change in movement, lighting, shadow distribution and countless other factors could elicit a response from the brain. This would be highly impractical for concentrating on activities, and would make us see each other's faces as constantly morphing.

In a series of experiments, the investigators were also able to determine that the objects merged by the continuity field have to be spaced relatively close together in order for the effect to work. “The brain has learned that the real world usually doesn’t change suddenly, and it applies that knowledge to make our visual experience more consistent from one moment to the next,” Fischer explains.