Optical illusions are things that make us see something that isn’t actually real. In many cases, visual signals, such as color, movement, shape, and size, among other things, can prompt us to perceive falsehood, and it turns out this quality isn’t unique to just humans.
Scientists from the University of Queensland in Australia studying the effects of optical illusions on lagoon triggerfish (Rhinecanthus aculeatus) have found that even fish are capable of bring tricked by optical illusions. Their findings are noted in Scientific Reports.
Image Credit: University of Queensland, Australia
Researchers trained fish to recognize orange and brown colors on a cube. When they would select the right color, they would be prompted with a reward.
Using shading as a primary form of illusion, scientists were able to make orange squares look like brown ones.
“In the test phase, the fish were then presented with the illusion in which the ‘orange' and brown are actually the same color (but we perceive them to be different), and the fish preferentially chose the square that was most similar to their trained color,” Dr Cheney said.
The fish that were trained to select brown would then select the shaded orange, which meant they were being tricked into thinking the color was brown when it was really just orange with darker shading.
Although the illusion itself is still misunderstood, it’s widely documented to be confusing for humans.
The results of this study suggest that even coral reef fish can be tricked by optical illusions based on color shading, like this one. This kind of activity has been recorded previously in butterflies and guppies as well in previous experiments.
So relax, silly humans! If you get confused by an optical illusion, chances are you’re not the only species on Earth that would be fooled.
Source: University of Queensland, Australia