A study from the University of California at Berkeley showed that the ability to determine the exact location and size of objects varies from person to person.
Do you think that you and your neighbor can accurately estimate the size and distance of a tree, a ball, or a dog and that your two fields of vision are identical?
You’re wrong. This was the conclusion reached by researchers at the University of California at Berkeley in a study published in the Proceedings of the Royal Society. “We assume that our perceptions perfectly reflect the physical world around us, but this study shows that each of us has a unique visual imprint,” says the study’s lead author, Zixuan Wang, also a doctoral student in psychology at the University of California, Berkeley.
A Unique Visual Footprint
To reach this conclusion, the researchers first examined whether we see all objects in our environment in the same way. “For example, if you look at a coffee cup on a table, can two people agree on its exact position and whether its handle is big enough to hold it,” they wrote in a news release.
The results of a series of experiments conducted by scientists with volunteers suggest that this is not the case. “We may reach for a coffee mug thousands of times in our life, and through practice, we reach our target,” says Prof. Wang. “That’s the behavioral aspect of how we train ourselves to coordinate how we act in relation to what we see.”
The volunteers’ first experiment was to locate a target on a computer screen to test their visual accuracy. In another experiment, which examined the variations in visual acuity in each person’s field of vision, the participants observed two lines that were at a minimum distance from each other and determined whether one line was clockwise or counterclockwise with respect to the other.
Large differences in visual performance
Finally, in a final experiment, participants observed a series of arches of different lengths and were asked to estimate their length. Surprisingly, people found that the same arches were larger in some parts of the visual field and smaller in others.
Another lesson learned from the experiments was that there were significant differences in visual performance between the participants and, even more surprisingly, within each individual’s field of vision. So the mapped data show that each participant has a unique visual footprint and that no one is immune to perceptual distortions.
“Although our study suggests that the source of our visual impairment may be in our brain, more research is needed to discover the neural basis,” said Prof Wang.
According to the researchers, such differences in perception have important implications for the practice of medicine, engineering, driving, and sports, among other areas where accurate visual location is essential. “The important thing is how we adapt to these deficiencies and compensate for our mistakes,” the researcher concluded.
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