How does the brain process visual information with extreme precision?

A team of scientists has revealed new research that could overturn "more than 100 years of thinking about how our brains process visual information."

“Just as a self-driving car must coordinate its movement on the road in relation to its surroundings, the brain must coordinate the movement of the eyes, head and body, while also maintaining a coherent understanding of the visual world,” said cognitive neuroscientist Will Harrison, from the University of the Sunshine Coast. “The prevailing hypothesis for more than 100 years has been that the brain achieves this by constantly predicting what the world will look like if it performs a certain movement. However, such predictions require enormous amounts of computing power.”

The answer may be much simpler, Harrison explained: the brain can calculate the true locations of objects by simply combining information about where the eyes are pointing and where visual information falls on the retina.

It turns out that the parts of the brain that receive the first visual signals from the eyes in monkeys, animals with a visual system similar to humans, also receive information about where the eyes are pointing.

To test this idea, Harrison and his colleagues conducted an experiment in which participants performed a difficult visual discrimination task while moving their eyes around a screen. Using a high-speed eye tracker, Harrison found that people tracked the location of objects via eye movements with much greater temporal precision than previously thought.

The scientists then developed a mathematical model to simulate how the brain calculates the true location of an object.

The effectiveness of the model confirmed that optical stabilization may involve much simpler calculations than previously thought.

“What this research changes is decades of conventional wisdom about how our brains process visual information,” Harrison added. “We hope our revised theory will help explain how the brain coordinates other complex actions across many different senses.”

The study was published in the journal Proceedings of the National Academy of Sciences.