June 13th, 2008
Pigeons are as clever as 3-year-old children
Japanese scientists from Keio University have found that pigeons have self-cognitive abilities higher than 3-year-old humans. They have ‘trained pigeons to discriminate real-time self-image using mirrors as well as videotaped self-image, and proved that pigeons can recognize video images that reflect their movements as self-image.’ Until recently, it was widely admitted that only humans and primates such as chimpanzees could recognize images of themselves. Now, researchers have found that dolphins or elephants also could do it. But these Japanese scientists have proven that pigeons also were able to do it — and even discriminate paintings of Van Gogh from Chagall. But read more…
This research project has been led by Professor Shigeru Watanabe of the Graduate School of Human Relations of Keio University at his Laboratory of Comparative Cognitive Neuroscience. You can see above Shigeru Watanabe with a pigeon he trained. (Credit: Keio University) Tsukuba University graduate student Kohji Toda collaborated with him.
On the left is a picture of a pigeon looking at a painting. (Credit: Keio University)
So how this pigeon was trained? “The pigeon was trained to discriminate two types of video images in the following method. First, live video images of the present self (A) and recorded video images of the pigeon that moves differently from the present self (B) are shown. When the pigeon learns to discriminate these two images, the video image of (A) is shown with a temporal delay, so that the monitor shows the image of the pigeon a few seconds before. If the pigeon remembers its own movements, it can recognize it as self-image even with the delay.”
But how these Japanese researchers were able to compare the self-cognitive abilities of pigeons and those of 3-year olds? “Through various experiments, it is known that pigeons have great visual cognitive abilities. For example, a research at Harvard University proved that pigeons could discriminate people photographs from others. At Prof. Shigeru Watanabe’s laboratory, pigeons could discriminate paintings of a certain painter (such as Van Gogh) from another painter (such as Chagall). Furthermore, pigeons could discriminate other pigeons individually, and also discriminate stimulated pigeons that were given stimulant drugs from none. In this experiment, pigeons could discriminate video images that reflect their movements even with a 5-7 second delay from video images that don’t reflect their movements. This ability is higher than an average 3-year-olds of humans. According to a research by Prof. Hiraki of the University of Tokyo, 3-year-olds have difficulty recognizing their self-image with only a 2 second delay.”
For more information, this research work has been published online in Animal Cognition, an interdisciplinary journal published by Springer, under the title “Discrimination of moving video images of self by pigeons (Columba livia)” (June 3, 2008).
Here is the beginning of the abstract. “The ability to recognize self has been known to be limited to some animal species, but previous research has focused almost exclusively on the animal’s reaction to a mirror. Recent studies suggest that the temporal contingency between a subject’s action and the corresponding visual scene reflected in a mirror plays an important role in self-recognition. To assess the roles of visual-proprioceptive contiguity in self-recognition, we explored whether pigeons are able to discriminate videos of themselves with various temporal properties.”
So how did the scientists proceed? “We trained five pigeons to respond to live video images of themselves (live self-movies) and not to video filmed during previous training sessions (pre-recorded self-movies). Pigeons learned to peck trial-unique live self-movies more frequently than pre-recorded self-movies. We conducted two generalization tests after pigeons learned to discriminate between the two conditions. First, discrimination acquired during training sessions was transferred to a test session involving live self-movies and new pre-recorded self-movies. Second, the same pigeons were tested in extinction procedure using delayed live self-movies and new pre-recorded self-movies.”
You have to pay $32 to read the full article, but Naomi Mizuno, from the Office of Communications and Public Relations Keio University, sent me a copy. She also sent me the photos featured above. Here is an excerpt from the conclusions of the article. “The pigeons were able to learn to discriminate live from pre-recorded self-movies. Because the pre-recorded stimuli used during test sessions were the live self-movies used during training sessions, responses to these stimuli had been reinforced previously. Despite this, pigeons discriminated between live and new pre-recorded self-movies during test sessions. This suggests that pigeons’ discrimination was not dependent on the memory of the pre-recorded selfmovies. Additionally, the relative response rates to live self-movies with delayed presentation gradually decreased with increased temporal discrepancy between the subject’s own behavior and the corresponding video feedback. The diVerence between the live, delayed and pre-recorded selfmovies, respectively, was the contiguity of a subject’s own movement and the corresponding video. Therefore, our results demonstrate that pigeons can learn to discriminate self-movies based on the temporal contiguity of visual-proprioceptive information.”
And here is another quote about future work. “Three-year-old human children are unable to identify video of themselves with a 2-s delay (Miyazaki and Hiraki, 2006). Although a direct comparison of these results with our Wndings is diYcult because of several procedural diVerences, it is interesting that pigeons appeared to perform better than human children. It would be important to conduct the experiment using human children to allow a direct comparison.”
Sources: Keio University news release, via ResearchSEA - Asia Research News, UK, June 11, 2008; and various websites
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