Your brain is like a time machine, says study

California January 22 ANI A new study shows that our brains are constantly uploading rich visual stimuli, like our social media feeds. Instead of seeing the latest image in real-time, we actually see earlier versions because the refresh time of our brains is about 15 seconds.

The findings were added to a growing body of research about the mechanism behind the continuity field, a function of perception in which our brain merges what we see on a constant basis to give us a sense of visual stability.

If our brains were constantly updating in real-time, the world would be a jittery place with constant fluctuations in shadow, light and movement, and we'd feel like we were hallucinating all the time, said David Whitney, a UC Berkeley professor of psychology, neuroscience and vision science.

Our brain is like a time machine. It keeps sending us back in time. The study lead author Mauro Manassi, a postdoctoral fellow at Whitney's lab at the University of Washington, said it was like we have an app that consolidates our visual input every 15 seconds into one impression so we can handle everyday life.

Manassi and Whitney looked at the mechanism behind change blindness, in which we don't notice subtle changes that occur over time, such as the difference between actors and their stunt doubles or movie bloopers, for the study.

They recruited about 100 study participants from Amazon Mechanical Turk's crowdsourcing platform and had them view close-ups of faces morphing according to ages or gender in 30 second time-lapse videos.

The images in the videos did not include head or facial hair, just eyes, brows, nose mouth, chin and cheeks, so there would be few clues, such as receding hairlines, to the ages of the faces.

When asked to identify the face they saw after viewing the video, the participants almost consistently picked a frame they viewed halfway through the video instead of the final one, which would have represented the most updated image.

Whitney said that our brain is procrastinating.

It's too much work to update images, so it sticks to the past because the past is a good predictor of the present. He said that we recycle information from the past because it's faster, more efficient, and less work.

The results showed that the brain operates with a slight lag when processing visual stimuli, which has positive and negative implications.

The delay is great for preventing us from feeling bombarded by visual input in everyday life but it can also result in life-or-death consequences when surgical precision is needed, Manassi said.

Radiologists screen for tumours, surgeons and doctors need to be able to see what is in front of them in real-time; if their brains are biased to what they saw less than a minute ago, they might miss something, he added.

Whitney said that change blindness revealed how the continuity field is a purposeful function of consciousness and what it means to be human.

He said that we're not literally blind.