Hollywood is so inconsistent in its movies and TV shows, but you’re not likely to notice. A new study says it’s all for your own good though.

Want an example?

Image source: Movie Mistakes

Image source: Movie Mistakes

How about how Harry Potter at one moment sleeping while wearing a crewneck shirt and in the next waking up sweaty from his bad dream wearing a henley. There’s a whole website devoted to finding such mistakes that our brain glosses over without a second thought.

The study authors suggest that most people miss things like this due to a concept known as “continuity field,” which generally allows subtle mistakes to go unnoticed.

“The continuity field smoothes what would otherwise be a jittery perception of object features over time,” David Whitney, associate professor of psychology at University of California-Berkeley, said in a statement.

“Essentially, it pulls together physically but not radically different objects to appear more similar to each other,” the study’s senior author added. “This is surprising because it means the visual system sacrifices accuracy for the sake of the continuous, stable perception of objects.”

The reason this happens, lead author Jason Fischer, lead author and MIT postdoctoral fellow, said is probably because the brain knows that things don’t change that rapidly in real life. Not having continuity field, the researchers said, could give a visual perception similar to being on a hallucinogenic drug.

To test this concept, Whitney and Fischer, while he was still studying at UC Berkeley, instructed study participants to watch gratings on a computer screen as they appeared at different angles every five seconds.

While doing so, participants had to match a white bar to the angle of the grating they had just seen. Instead of being able to perform this task perfectly, the study authors found that they most often averaged the angle of the last three gratings they had seen.

“Even though the sequence of images was random, participants’ perception of any given image was biased strongly toward the past several images that came before it,” Fischer said, calling it “perceptual serial dependence.”

Take a look at what the study participants watched (the dark, somewhat blurry bars are the gratings):

To understand what a lack of continuity field looks like, the authors offered this commercial for the water flavor enhancer, MiO, as an example:

Their findings were published in the journal Nature Neuroscience.

Featured image via Shutterstock.

(H/T: EurekAlert)