Summary: Researchers have discovered new variations of the visual saltation illusion, where rapid flashes of light in peripheral vision create perceptual errors. Their study shows that our brain misplaces the second flash near the midpoint, regardless of its actual position.
This finding challenges our understanding of visual processing and calls into question the reliability of eyewitness accounts. The research opens the door to further studies on visual perception and attention.
Highlights:
- Rapid flashes of light in peripheral vision create misperceived positions.
- The brain places the second lightning bolt near the midpoint, regardless of its true location.
- These findings call into question the reliability of eyewitness accounts.
Source: University of Kyushu
Researchers at Kyushu University have discovered new variations of a traditional illusion, based on how we perceive the movement of flashing lights.
Published on May 21 in i-PerceptionThe results show that when three flashes of light occur in rapid succession in our side vision, our brain tends to perceive them in a straight line, with the second flash located around the midpoint, regardless of the actual location of the second flash.
This research, which won the journal’s Best Early Career Paper award this year, offers new insights into perceptual errors and the reliability of eyewitness testimony.
For people without severe visual impairment, sight is the most vital sense. However, the information provided by our eyes is not always an accurate representation of reality. A fascinating phenomenon that highlights this phenomenon is the visual illusion of saltation.
When a series of points of light flicker rapidly in peripheral vision, we may misunderstand their true position, thinking that the flash is jumping from its original location to another location. It appears as if a rabbit is jumping from one place to another, which is why it is also called the “visual rabbit illusion.”
In traditional experiments, this illusion is studied using three flashes that appear in two places: the first two flashes in exactly the same place on the left and the third flash on the right. Under these conditions, an illusion is created since the second flash is perceived approximately halfway between the two points.
But is this the only condition for the illusion to occur? Researchers at Kyushu University decided to experiment by changing the location of the second lightning bolt to see if it had any impact on the illusion.
They corrected the first and third flashes in peripheral vision, changed the duration and intervals of the flashes to ensure the illusion occurred, and then conducted three experiments.
Their results indicate that participants misperceived the second flash, placing it halfway between the first and last flashes. This illusion occurred regardless of whether the second lightning bolt was in the same location as the third lightning bolt or even further to the right of the third lightning bolt.
“It’s like a rabbit that returns to the middle after the brain has processed it,” comments Sheryl Anne Manaligod de Jesus, first author of the study and a doctoral student at the Graduate School of Design at Kyushu University.
Additionally, the researchers found that the flashes do not need to be presented online for the illusion to occur. Even when the second flash appeared above or below the midpoint, its perceived location still tended to be near the center.
This happens because when our visual system receives flashes in rapid succession, the brain processes them as a whole, leading to a perceptual reorganization of the flashes into a simpler, more coherent pattern.
One way to further study the mechanisms of the visual saltation illusion is to provide the experimental results to artificial intelligence. Comparing human and AI responses could reveal whether our visual pathways are simpler or more complex than we imagine.
What we “see” does not depend solely on our vision, it is often a construct of our brain, influenced by attention and memory. This calls into question the reliability of eyewitness accounts.
“Our brains sometimes use future events to interpret the past,” says de Jesus. “This is called postdiction, meaning that the way we perceive a past event, like the second flash, is influenced by what happens next. This gives the fascinating illusion of the Flash appearing in a place where it never really existed.
As the study suggests, our peripheral vision, especially with fast-moving objects, is not completely reliable. Further research into visual saltation illusions is needed to help us better understand visual processing and potentially improve our peripheral vision. After studying how position changes affected the perception of the “rabbit,” the team’s next step is to explore the impact of attention on the illusion.
Where does the rabbit jump? Or do we see a rabbit or a duck? To what extent does our brain mislead our perception of the visual world? Although more research is needed to fully understand these illusions, their power to enrich our lives with unique and enjoyable experiences is clear.
As Professor Hiroyuki Ito, De Jesus’ supervisor and second author from the Faculty of Design at Kyushu University, notes, “The most important thing is to enjoy the illusions.” »
About this news from research in visual neuroscience
Author: Qinln Wu
Source: University of Kyushu
Contact: Qinln Wu – Kyushu University
Picture: Image is credited to Neuroscience News
Original research: Free access.
“Retracing the Rabbit’s Path: Effects of Changing the Position of the Second Flash in the Visual Saltation Illusion” by Sheryl Anne Manaligod de Jesus et al. i-Perception
Abstract
Retracing the rabbit’s path: effects of changing the position of the second flash in the visual illusion of saltation
Two dots displayed in rapid succession at one point and a third at a distance on the same linear path create an illusion of intermediate flashes across a visual field, a phenomenon known as the reduced visual rabbit illusion or visual saltation illusion.
This study presents this illusion in a novel way by changing the position of the second flash, which is usually only presented in the same position as the first flash.
A series of experiments were conducted to observe whether saltation would occur if the second flash was presented in the same position as the third flash, in sequential order relative to the first and last flash, or out of linear alignment in the middle between the first flash. and the last flash.
When the three flashes were presented in rapid succession, participants misperceived the second flash as occurring near the midpoint between the first and last flashes.
Saltation was obtained in all three new conditions, suggesting that a particular neurological process may be responsible for shared results.