Researchers from Australia have proved that fish can recognize human faces with favorable rates. Up to know, humans were the truest expert species when distinguishing faces. On Tuesday, researchers from Australia published a study in which it has been demonstrated that archerfish (Toxotes chatareus) can recognize human faces.

The study, titled Discrimination of human faces by archerfish, has shown remarkable evidence of fish discriminating human faces. Researchers have said that even if archerfish do not have neocortex in their brain structure (a part in mammalian brains) they could still accurately identify a human face from another.

Archerfish or spinner fish bodies are deep and laterally compressed, with the dorsal fin, and the profile a straight line from dorsal fin to mouth. Credits: Fish wallpapers/Wikipedia

Researchers at the University of Queensland carried out the study in two different experiments. In the first one, archerfish were trained, using operant conditioning, to discriminate between two images of human faces. Researchers displayed some pictures on a computer monitor, which was suspended over a tank containing archerfish and the fish were trained to spit at one of the faces. When fish learned to recognize a face, researchers mingled dozen of new faces with the one spat by the fish, and it showed an average of 81 percent in the first phase.

In the second experiment, researchers eliminated different clues, such as brightness, head shape, and color, and they trained a new shoal of archerfish with standardized human faces. The new fish got and 86 percent of accuracy to discriminate face during the second experiment.

According to the lead author of the study, Dr. Cait Newport, the findings point out that simple brains, such as those of archerfish, bees and birds, can carry out human facial recognition. “We show that archerfish (Toxotes chat areas) can learn to discriminate a large number of human face images, even after controlling for color, head shape, and brightness,” researchers said.

This is the first time researchers have tested this type of skill in fish, and successfully, the experiment showed unusual visual behaviors in archerfish. Further, scientists have affirmed that there must be some distinctive natural features in human face to explain the findings. It is not a matter of having or not facial recognition brain structures because in this case, archerfish do not have the same brain structure than humans, and they still can recognize with favorable rates.

After testing fish behavior in front of human faces, researchers also concluded that it seems like there are some aspects of facial recognition that can be learned, even in the absence of the neocortex, the brain structure associated with face processing.

Findings were published in the journal Scientific Reports.

Source: Nature