We live up to 15 seconds in the past at any given point in time. It allows our brain to process the perfusion of visual stimuli coming its way. This is because it is tasked with constantly uploading rich visual information from its environment. This is a complex and laborious task, which is why, the brain averages out what it sees from up to 15 seconds in the past. It smoothens out the discontinuous stream of inputs and consolidates everything for our ease.
The findings are another leaf in the chapter of continuity field (the process of merging objects every 15 seconds to create a focused picture). Perception is at the core of this function. And this sophisticated assimilation process is crucial for our sanity, according to a recently published paper in the journal Science Advances.
To test this out, researchers from the University of Aberdeen and the University of California, Berkeley, USA, incorporated several intervals of time in the middle of a moving picture. They started with one second and gradually increased the gap. It was observed that the same ‘illusory misjudgement’ took place for up to 15 seconds.
There is a broader phenomenon driving it all called serial dependence, which is the forming of visual perception based on past and present impetuses. “This happens accidentally but the brain compares what it sees in the ‘now’ with memories from the recent past (ie. up to 15 seconds in the past), sometimes confusing the two to be similar. This automatically reduces the number of frames it sees in a second,” says Manipal-based cognitive psychologist Abhimanyu Rana.
What makes this important? “Consider this: When we focus closely on objects at a distance, the higgledy-piggledy images in front of the retina can bewilder us with its sheer volume. It is nothing but a muddled display of light, shadow, and movement thrown at us,” says Rana.
To give you an example, he says, imagine watching television or looking at your phone screen up close and personal, while things play on the screen. “What will you see? Pretty much a confusing hotch-potch. If this was all you could see, your life would turn into an exhausting mess. That is why this ‘procrastination’ of the brain is a good thing. It keeps us alive and thriving,” he explains.
But even the best of processes have drawbacks. “The delay works perfectly for day-to-day survival of the brain but in surgical procedures, real-time information is crucial. This kind of lag could prove detrimental for surgeons performing high-risk operations,” says Shirish Hastak, Regional Director, Neurology, Stroke and Neurocritical Care, Global Hospital, Parel, Mumbai, adding, “Precision is the most important thing when conducting surgery and this illusory instability can have life-changing consequences.” It’s the same with radiologists, he says.
“Radiologists screening for tumours can make errors in judgement too. This is because they’re analysing several X-ray images based on what they see currently and also what they remember from previous images. This could make for an inaccurate diagnosis. Perhaps, this temporary sluggishness actually works in our favour.
The findings are another leaf in the chapter of continuity field (the process of merging objects every 15 seconds to create a focused picture) and perception is at the core of this function. This is a sophisticated assimilation process that is crucial for our sanity.
Why it is important:
✥ When we focus closely on objects at a distance, the higgledy-piggledy images in front of the retina can bewilder us
✥ Our brain uses its judgment to process all this information, making it comprehensible
✥ In the absence of this, all we would see is a muddled display of light, shadow, and movement that
makes no sense