Researchers have found that archerfish is able to learn and recognize faces with a high degree of accuracy, which is an impressive feat given this task requires sophisticated visual recognition capabilities, according to a study published Tuesday in the journal Scientific Reports.
Being able to distinguish between a large number of human faces is a surprisingly difficult task, mainly due to the fact that all human faces share the same basic features.
"Fish have a simpler brain than humans and entirely lack the section of the brain that humans use for recognizing faces. Despite this, many fish demonstrate impressive visual behaviors and therefore make the perfect subjects to test whether simple brains can complete complicated tasks," said Dr. Cait Newport from University of Oxford, one of the authors of the study.
Researchers from University of Oxford and the University of Queensland tested this idea on fish, which has smaller and simpler brains, and with no evolutionary need to recognize human faces.
Archerfish is a species of tropical fish well known for its ability to spit jets of water to knock down aerial prey.
In the study, they were presented with two images of human faces and trained to choose one of them using their jets. The fish were then presented with the learned face and a series of new faces and were able to correctly choose the face they had initially learned to recognize. They were able to do this task even when more obvious features, such as head shape and color, were removed from the images.
The fish were highly accurate when selecting the correct face, reaching an average peak performance of 81 percent in the first experiment, as they picked the previously learned face from 44 new faces, and 86 percent in the second experiment, in which facial features such as brightness and color were standardized, according to the study.
The fact that archerfish can learn this task suggests that complicated brains are not necessarily needed to recognize human faces. "Humans may have special facial recognition brain structures so that they can process a large number of faces very quickly or under a wide range of viewing conditions," said Newport. (Xinhua)
