托福official28听力lecture2 Mirror Self-Recognition原文解析+翻译音频

[00:00.00]NARRATOR: Listen to part of a lecture in an animal behavior class.[00:04.54]FEMALE PROFESSOR: As you know, researchers have long been interested in discovering exactly how intelligent animals are.[00:18.09]Today we are going to talk about a particular cognitive ability some animals seem to have—the ability to recognize themselves in a mirror.[00:25.62]FEMALE STUDENT: Oh. I've heard about that. [00:27.05]Chimpanzees have it...[00:28.54]FEMALE PROFESSOR: Right. Chimpanzees and other primates,—chimps, gorillas, orangutans,..and of course, humans. [00:34.32]But it's also been found in elephants and bottlenose dolphins, a bit of a surprise. [00:39.01]It's very rare. [00:40.50]Most animals don't have it. [00:41.90]And it's called mirror self-recognition, or MSR.[00:45.63]FEMALE STUDENT: Well, how does it work?I-I mean...how do researchers know if elephants or chimps recognize themselves?[01:00.25]FEMALE PROFESSOR: Researchers give them a mirror mark test.[01:03.69]In the mirror mark test, researchers put a mark on the animal where the animal is unable to see it or smell it or feel it, like on the side of their head, without looking in the mirror.
[01:20.32]Now, typically, when animals first see themselves in the mirror, they think they are seeing another animal. [01:25.89]Often they will look for this animal behind the mirror. [01:28.68]They may even exhibit aggressive behavior.
[01:31.32]But some animals, after this period of exploration, exhibit behaviors that show they know they are looking at themselves. [01:38.59]For instance, elephants will touch the mark on their heads with their trunks.[01:43.09]Now, it's been assumed that primates and some other mammals stood alone at the top of the hierarchy of cognitive evolution. [01:57.23]But recently, birds have been found to possess some of the same cognitive abilities![02:02.70]In particular, researchers have discovered these abilities in corvids, birds of the corvidae family.[02:08.18]Corvids include ravens, jays, crows and magpies among others. [02:20.53]And what kinds of cognitive abilities are we talking about? [02:23.96]Well, corvids and some mammals have the ability to plan for the future, to store food for instance, in places where they can find it later. [02:32.59]It's been suggested in fact that jays—corvids known for stealing each other's food, may hide their food precisely because they are projecting their own tendency to steal onto other jays.[02:43.79]So let's talk about a study recently conducted with magpies.[02:47.72]As I said, magpies are corvids.[02:57.53] And because corvids have these other cognitive skills, researchers wanted to see if they were also capable of mirror self-recognition. [03:05.40]So they gave them the mirror mark test, placing yellow sticker on the birds...black throat feathers.
[03:11.22]At first, the magpies all engage in the same social behaviors that other animals do—looking behind the mirror, etc.[03:19.21]But eventually, some of the birds, while looking in the mirror, kept scratching at the mark until they got rid of it. [03:25.69]And they didn't scratch at it when there was no mirror around.[03:29.27] So they passed the test.[03:31.42]MALE STUDENT: Wow! Do any other birds have this ability?[03:43.02]FEMALE PROFESSOR: Well, not that we know of. [03:45.00]There was a study using pigeons, where researchers attempted to reduce MSR to a matter of conditioning, that is, they claimed that the ability to recognize oneself in a mirror could be learned. [03:56.15]So these researchers basically trained some pigeons to pass the mirror mark test.
[04:01.19]But two things are noteworthy here. [04:03.18]One, no one's ever replicated the study. [04:06.21]But more importantly, it misses the point. [04:09.06]The issue isn't whether some behavior can be learned. [04:12.14]It's whether a species has developed this ability spontaneously.[04:15.73]MALE STUDENT: So what does the test tell us about corvids or chimpanzees?[04:19.16]FEMALE PROFESSOR: Good question. [04:20.21]For one thing, it is important because it sets animals with a sense of self apart from those without a sense of self. [04:27.60]But more importantly, many researchers believe that MSR is indicative of other advanced cognitive abilities.
[04:34.08]Self-awareness, even in its earliest stages, might entail an awareness of others, the ability to see their perspective, to look at the world from another's point of view. [04:43.74]This is crucial, because it implies a high level of cognitive development.[04:48.28] It's perhaps the first stage toward the development of empathy.[04:51.71]MALE STUDENT: But birds...brains are so small, compared to primates...[04:55.34]FEMALE PROFESSOR: True. Though corvids do have unusually large brains for birds. [04:59.43]But size isn't the whole story. [05:01.67]It's thought that primates are so intelligent because of a certain part of their brains, which birds simply don't have.
[05:08.84]But there is an area in birds' brains that researchers believe governs similar cognitive functions.[05:15.06]So primates' and birds' brains have evolved along different tracks, but ended up with similar abilities.