Author
|
Topic: The mirror test for self-awareness (Read 5595 times) |
|
rhinoceros
Archon
Gender: 
Posts: 1318
Reputation: 8.40
Rate rhinoceros
My point is ...
  
|
 |
The mirror test for self-awareness
« on: 2002-09-03 19:44:01 » |
 |
Hey! good looking
by Gretel H. Schueller
New Scientist vol 166 issue 2243 - 17 June 2000, page 30
http://archive.newscientist.com/secure/article/article.jsp?rp=1&id=mg16622434.600
(subscription required)
To know your reflection is to know yourself, or so the theory goes. But is an animal that recognises itself in a mirror really self-aware, asks Gretel H. Schueller
ONCE upon a time, the evil queen was "the fairest of them all"--her mirror told her so. Then a new beauty came on the scene. Even the mirror could not resist her milky skin, blood-red lips and hair as black as ebony. When the evil queen asked her mirror who was the fairest in the kingdom, it now responded "Snow White". And the mirror never lies.
In another land, far, far away, some clever people in white coats are also consulting their mirrors. But they want to know about intelligence, not beauty. Confident in their standing as members of the smartest species in the animal kingdom, they are using mirrors to delve into the minds of other creatures. By testing how animals react to their reflections, scientists hope to discover how they think. The problem is, they can't agree about what it means to recognise your reflection. Some say it's the true test of self-awareness--the ability to understand one's own existence--but others argue that the mirror's message has been misunderstood.
The tale begins one morning in the 1960s, about 100 years after Charles Darwin first put two orang-utans in front of a mirror and watched them kiss their reflections. Graduate student Gordon Gallup was shaving and as he stared back at his own reflection, he had an idea. "It dawned on me--gee, wouldn't it be interesting to try to determine whether there were other species that could recognise themselves in mirrors?"
Chimpanzees seemed the obvious first subjects, being our closest living relatives. Gallup found that, confronted with their mirror image, chimps soon realise that the reflection is their own. He followed up this finding with a simple but elegant experiment that was published in 1970. After administering a general anaesthetic, he painted brightly coloured marks on the chimps' eyebrows or near their eyes--places they couldn't see without looking in a mirror. On awakening, the chimps noticed the change in their reflection right away, touching the dyed areas, then smelling and looking at their fingertips.
Since then, researchers have subjected dozens of species to Gallup's mirror test--including dogs, cats, birds, elephants, and more than 20 species of monkey. So far, the only ones that have conclusively passed are the great apes: chimpanzees, orang-utans, and one gorilla (Koko, the human-reared ape that has learned sign language). But this elite club may include more members than just our close cousins.
In the early 1990s, Gallup and his colleagues Laurie Marino from Emory University in Atlanta and Diana Reiss from the New York Aquarium found that bottlenose dolphins reacted to mirrors. "It turned out to be suggestive but inconclusive," says Reiss. One difficulty is interpreting the mark test in an animal that lacks arms or hands to explore its body. But a study soon to be published by Reiss and Marino may provide a definitive answer to the dolphin question.
Mirror studies have also identified many animals that "understand" what mirrors do, yet cannot solve the riddle of their own reflection. They react to their image as if it's another member of their species. Monkeys, pigeons, parrots, elephants, ducks, chickens and even fish can use mirrored information to find hidden objects or to solve a puzzle. In one of the most extreme cases, Gallup reared a pair of rhesus monkeys from two months old, exposing them to a mirror 14 hours a day, 7 days a week, for 18 years. "They had to have been the most mirror-experienced creatures in the cosmos," he says. "But when it came to responding to themselves they were at a complete and total loss."
Animals that do pass the mirror test behave in a stereotypical way towards their reflection. First, they act as if they are seeing another individual. But very quickly--in as little as five minutes--they begin to engage in unusual body movements. Mesmerised by this mimic in the mirror, they slowly, deliberately and repetitively move their arms, legs or head. Then they do the same sort of thing with their face, making wild contortions. When they grasp the equivalence between themselves and their mirror image, they begin to explore their body, using their hands or feet to systematically inspect those parts they couldn't otherwise see. "It's really something to see," says Daniel Povinelli, an anthropologist from the University of Southwestern Louisiana in Lafayette. "They'll get into these exaggerated postures in front of the mirror, from the most studied, serious explorations of their teeth and eyes to hilarious body contortions to look at their anogenital region."
Gallup, now at the State University of New York in Albany, believes that passing the mirror test is good evidence that an animal has a concept of self. "If you didn't know who you were," he says, "how could you possibly know who it was that you were seeing in a mirror?" He also believes that recognising a mirror image, in principle, allows an individual to do three things. First, to think about itself in relationship to past, present and future events. "In other words, you can begin to engage in mental time travel," he says. Secondly, to contemplate the inevitability of its own demise. And thirdly, to use your experiences to make inferences about the psychological state of others. So a chimp can make the leap from feeling pain when hit by a rock, to knowing that another chimp will feel pain when pummelled.
Gallup acknowledges that these three traits have been tricky to test. There have, however, been experiments that suggest that animals who pass the mirror test are capable of "mind reading". These tests look for signs of what Gallup calls "introspectively based social strategies", such as empathy, gratitude, deception, role-playing and pretending. "All of those capacities require the ability to track mental states in other individuals," he says. In one test, for example, chimps had to choose one of two humans to help them find some hidden food. While the animals themselves could not see where the food was being hidden, they could see that only one of the humans had a full view of the process. When asked to choose a helper, the chimps overwhelmingly chose the human who knew where the food was hidden. Monkeys fail these sorts of tests. But even chimps don't pass them all.
According to Gallup, the best support for his mind-reading idea comes from mirror studies with human infants. At about six months, children begin to react to their mirror image as if it were another child. They start to show evidence of mirror self-recognition at 18 months, and by 24 months about 65 per cent recognise themselves. At the same stage in their development they begin to use the words I, you and me, and exchange roles in play. Most compelling, says Gallup, is the finding that as children start to recognise themselves, they also begin to infer the mental state of others. Before about 18 months, a child who sees another child crying will join in. But after 18 months, that child will get help from an adult or try to comfort the distressed child.
Gallup is working with his colleagues to pinpoint the area of the human brain that mediates self-awareness and mental states such as gratitude and deception. He says both seem to reside in the same region: the right prefrontal cortex. "And it turns out that the part of the human brain that's growing the most rapidly at 18 to 24 months is the prefrontal cortex. We haven't proven any of this, but the data is very consistent with the proposition that self-awareness paves the way for the ability to make inferences about others."
But not everyone agrees with Gallup's conclusions. "On the surface, such findings seem to imply that chimps can understand the mental state of others," says Povinelli. "Because the chimp at some superficial level engages in a similar behaviour to us, we force our human interpretation upon them. It's the ultimate anthropocentric conceit." In fact, says Povinelli, even mirror studies with our humans show how little we know about what self-recognition means. Take a look at your reflection. When you say, "Ah, that's me," what pops into your head? A lot of baggage: your desires and wants, your past, your personality traits, aspects of your body, and much more. "Are all of those captured when an animal or child exhibits the kinds of behaviours in front of mirrors that have been called self-recognition?" asks Povinelli. "I don't think so."
Povinelli describes experiments that he and his colleagues are conducting to unravel the mysteries of self-perception in young children. These involve secretly hiding a sticker on top of a child's head and then playing back the event on video. If young children really have the same self-recognition as adults you would expect them to say: "That's me and you put a sticker on my head." What the researchers found, however, was that two-year-olds reach up for the sticker if they watch the video in real time--the equivalent of seeing themselves in a mirror. But if you introduce even a brief delay, they say the most bizarre things. You ask them who it is and they say: "That's me. But why is he wearing my shirt?" You point to the sticker on the monitor and ask them what it is, and they say: "That's a sticker on his head." It's not until they're about four years old that children pass a delayed test. "If we find those kind of surprises in members of our own species, imagine what we're going to find when we seriously look at others," Povinelli reported in 1998.
What's more, human infant mirror studies reveal no correlation between whether they pass the mark test and whether they understand what mirrors do. If, for example, they face a mirror and an entertaining toy is silently suspended by a string behind them, every infant smiles at the mirror image. About half of them will turn around to see the real toy. And on a mark test, about half will touch the mark. But it is not the same half. "Now, for most traditional intuitive theories of what's going on, that's almost incomprehensible," says Povinelli.
It does make sense, he argues, if you abandon the assumption that infants or chimps understand anything at all about what mirrors actually do. As they stand in front of a mirror, what they say is, "That out there in space, whatever that is, is equivalent to me." "In other words," says Povinelli, "they have a concept of their own body and what it's doing--called a kinaesthetic self-concept." He believes orang-utans hold the key to understanding the origins of this self-concept. They are unexpectedly good at the mirror test, given that they are more distantly related to humans than are gorillas. What's more, unlike other primates, orang-utans do not live in large social groups, challenging the common argument that self-awareness evolved to allow social interactions that involve predicting and gauging the behaviour of others. "You have these lonely orang-utans who are masters of self-recognition, but who are pretty much living solitary lives. They are oddballs," says Povinelli. He thinks he knows why.
Like our earliest ancestors, orang-utans are almost exclusively tree dwellers. What's more, unlike monkeys, they are big: males weigh up to 80 kilograms. They have to be acutely aware of their own bodies if they are to move safely through the forest canopy. Povinelli speculates that arboreal acrobatics just like those performed by orang-utans led early apes to evolve a more explicit understanding of the position and movements of their body. This enabled them to plan the effects of their actions on the environment around them. Self-recognition in mirrors, he says, is an "incidental by-product" of this ability.
Povinelli may be going out on a limb, but other researchers also question traditional interpretations of the mirror test. Many believe that it underestimates the mental capacities of animals that fail it. "We have to stop saying that this is the test for self-awareness," says Marc Hauser from Harvard University. After all, he adds, animals don't have to be self-aware to behave in a way that suggests--incorrectly--the ability to infer the thoughts of others. Look at the birdbrained plover, which fakes an injured wing to lure a potential predator away from its nest. On the other hand, even among humans, self-recognition is not synonymous with self-awareness. Blind people obviously can't see themselves in a mirror, and some people with a type of brain damage called prosopagnosia can't recognise their own faces. Yet both are self-aware.
Hauser believes that some animals may fail the mark test not because they lack a concept of self, but because they are not interested in their new coloured splodges. A few years ago, he painted bright green marks on the arms of cotton-top tamarins under anaesthetic. When they awoke, the primates didn't even bother to touch their new markings. But in another experiment Hauser dyed the white tufts of fur on the tamarin's heads flamingo pink, apple green or lagoon blue, and this time they did appear interested in their reflections. No one has been able to replicate the results of the second experiment, however.
Other researchers point out that monkeys may fail the mirror test partly because they find their image too threatening. "It's like the gunfight at the OK Corral," says James Anderson from Stirling University, who has been trying for 20 years to get monkeys to recognise themselves. "They're too fixated on the eyes to understand that they're looking at themselves." Anderson tried to get around that by fixing the mirrors at 60° angles so that the monkeys could only see their profile. "The monkeys did spend a lot more time looking at their reflection, bobbing their heads from side to side." Yet they still did not seem to recognise themselves.
The fact that animals never encounter mirrors in the wild has led some researchers to suggest alternative tests of self-awareness. In a recent study, Robert Seyfarth and Dorothy Cheney from the University of Pennsylvania looked at social recognition in baboons. They examined how pairs of females reacted to the recorded sounds of other adults in a fight. If the adults were not their own kin, they didn't react. If the cries came from one of the female's relatives, however, the other female would look at her. And if both were related to the brawlers, the two females looked at each other. The researchers concluded that baboons know individuals and their calls, and also the family relationships of each individual. This knowledge of their social selves, says Seyfarth, raises the possibility that they have a sophisticated sense of self.
Other animals may be failing the mirror test because they are not as visually attuned as primates. Cats and dogs, for example, are largely dependent on their sense of smell, which could explain why they tend to show little interest in their reflection.
Some researchers are now looking for alternative tests of self-awareness for the many animals that may recognise themselves through the smell of their own pheromones or the sound of their calls. In one study birds did seem to react differently to recordings of their own songs than to those of neighbours or strangers. Though, as Hauser points out, a recording of your voice sounds quite different from what you hear when you are speaking.
Gallup admits that it should be possible to design olfactory or auditory tests that are analogous to the mirror test. But he still believes his original test is valid in most animals. "If I close my eyes, cover my ears, or hold my nose, my sense of self doesn't fade or disappear," he says. "My concept of self is not tied to the visual, auditory or olfactory modality."
Others, including Povinelli, are more sceptical about what mirrors reveal. Unlike the wicked queen in Snow White and the Seven Dwarfs, they are not prepared to take a mirror too seriously.
Mirror, mirror
a letter from ake@mira.net
New Scientist vol 166 issue 2232 - 01 April 2000, page 53
http://archive.newscientist.com/secure/article/article.jsp?rp=1&id=mg16622326.500
(subscription required)
The mirror test for self-awareness of animals--which assumes that if animals recognise themselves in a mirror they are self-aware--rears its head yet again (4 March, p 27).
Unfortunately, human bias means there are serious flaws in the usefulness of this test. A better design would be to use the animal's primary sense instead of our own. Imagine a group of canine scientists inventing a device that reflects scent and holding it up to humans to see if they recognise their own smell. I seriously doubt that a single human would pass the test. The dogs would be forced to conclude that we aren't self-aware, no matter how cute our antics.
Visual tests for self-awareness have been applied throughout animal cognition research. For instance, the results of the mirror test on dolphins have been inconclusive, but I bet clearer results would have been obtained had mechanisms for reflecting "sonar images" been used instead.
|
|
|
|
|
Hermit
Archon
Posts: 4287
Reputation: 8.94
Rate Hermit
Prime example of a practically perfect person
|
|
Re:The mirror test for self-awareness
« Reply #1 on: 2006-10-31 13:27:52 » |
|
Elephants' jumbo mirror ability
External Links: BBC Video
Source: BBC
Authors: Not Credited
Dated: 2006-10-31
Elephants can recognise their own reflection, showing self-awareness seen before only in humans, great apes and bottlenose dolphins, scientists say.
US researchers made the discovery by studying the behaviour of Asian elephants in front of a tall mirror.
One of the animals repeatedly touched a white cross painted on her forehead - a classic test used to assess mirror self-recognition in children and apes.
The study is reported in Proceedings of the National Academy of Sciences.
"We see highly complex behaviours such as self awareness and self-other distinction in intelligent animals with well-established social systems," said Joshua Plotnik, from the Yerkes National Primate Research Center, Emory University, Atlanta, Georgia.
"The social complexity of the elephant, its well-known altruistic behaviour and, of course, its huge brain, made the elephant a logical candidate species for testing in front of a mirror."
'X' marks the spot
Many animals will respond to a mirror but very few show any evidence that they recognise themselves in the reflection.
Canines, for example, will react to the "other dog" and will even look behind the mirror to try to find it.
'Happy' passed the 'X' test
The Asian elephants in this study also displayed this type of behaviour when standing in front of a 2.5m-by-2.5m mirror - they inspected the rear and brought food close to the mirror for consumption.
But one of the elephants, called "Happy", went to the next level: she began repeatedly touching a painted "X" on her head with her trunk.
The mark could only be seen in the mirror, and the elephant ignored another mark made with colourless paint that was also on her forehead to ensure she was not merely reacting to a smell or feeling.
While only one elephant passed the mark-touching test, the researchers note that fewer than half of chimpanzees tested typically pass this test.
A clever club
"Elephants have been tested in front of mirrors before but previous studies used relatively small mirrors kept out of the elephants' reach," said Plotnik.
"This study is the first to test the animals in front of a huge mirror they could touch, rub against and try to look behind."
Few animals show self-awareness
Co-researcher Frans de Waal said: "As a result of this study, the elephant now joins a cognitive elite among animals commensurate with its well-known complex social life and high level of intelligence.
"Although elephants are far more distantly related to us than the great apes, they seem to have evolved similar social and cognitive capacities, making complex social systems and intelligence part of this picture.
"These parallels between humans and elephants suggest a convergent cognitive evolution possibly related to complex sociality and cooperation."
The study, conducted with the Wildlife Conservation Society (WCS), used elephants housed at the Bronx Zoo in New York.
|
With or without religion, you would have good people doing good things and evil people doing evil things. But for good people to do evil things, that takes religion. - Steven Weinberg, 1999
|
|
|
|
Logged
