Animals in Translation (10 page)

Take the cat who knows when its owner is coming home.
⁹
My friend Jane, who lives in a city apartment, has a cat who always
knows when she's on her way home. Jane's husband works at home, and five minutes before Jane comes home he'll see the cat go to the door, sit down, and wait. Since Jane doesn't come home at the same time every day, the cat isn't going by its sense of time, although animals also have an incredible sense of time. Sigmund Freud used to have his dog with him every time he saw a patient, and he never had to look at his watch to tell when the session was over. The dog always let him know. Parents tell me autistic kids do the same thing. The only explanation Jane and her husband could come up with was ESP. The cat must have been picking up Jane's I'm-coming-home-now thoughts.

Jane asked me to figure out how her cat could predict her arrival. Since I've never seen Jane's apartment I used my mother's New York City apartment as a model for solving the mystery. In my imagination I watched my mother's gray Persian cat walk around the apartment and look out the window. Possibly the cat could see Jane walking down the street. Even though he would not be able to see Jane's face from the twelfth floor he would probably be able to recognize her body language. Animals are very sensitive to body language. The cat would probably be able to recognize Jane's walk.

Next I thought about sound cues. Since I am a visual thinker I used “videos” in my imagination to move the cat around in the apartment to determine how it could be getting sound cues that Jane would be arriving a few minutes later. In my mind's eye I positioned the cat with its ear next to the crack between the door and the door frame. I thought maybe he could hear Jane's voice on the elevator. But as I played a tape of my mother getting onto the elevator in the lobby, I realized that there would be many days when Mother would ride the elevator alone and silent. She would speak on the elevator for only some of the trips—when there were other people in the elevator car with her—but not all of them.

So I asked Jane, “Is the cat always at the door, or is he at the door only sometimes?”

She said the cat is always at the door.

That meant the cat had to be hearing Jane's voice on the elevator every day. After I questioned her some more, Jane finally gave me the crucial piece of information that solved the cat mystery: her
building does not have a push-button elevator. The elevator is operated by a person. So when Jane got on the elevator she probably said “Hi” to the operator.

A new image flashed into my head. I created an elevator with an operator for my mother's building. To make the image I used the same method people use in computer graphics. I pulled an image of my mother's elevator out of memory and combined it with an image of the elevator operator I saw one time at the Ritz in Boston. He had white gloves and a black tuxedo. I lifted the brass elevator control panel and its tuxedoed operator from my Ritz memory file and placed them inside my mother's elevator.

That was the answer. The fact that Jane's building had an elevator operator provided the cat with the sound of Jane's voice while Jane was still down on the first floor. That's why the cat went to the door to wait. The cat wasn't
predicting
Jane's arrival; for the cat Jane was already home.

D
IFFERENT
S
ENSE
O
RGANS

Cats have really good hearing, so Jane's cat was using a sensory capacity we humans don't have. Animals have all kinds of sensory abilities we don't have, and vice versa. (Our color vision is a good example of a sensory capacity we have that a lot of animals don't.) Dogs can hear dog whistles; bats and dolphins can use sonar to “see” a moving object at a distance (a flying bat can actually spot and classify a flying beetle from thirty feet away); dung beetles can perceive the polarization of moonlight. I know dung beetles are insects, not animals, but an insect's brain is so tiny it makes the things their sensory system can handle even more miraculous.

There are two things going on with extreme perception in animals: one is the different set of sense
organs
animals have, and the other is a different way of
processing
sense data in the brain. With Jane's cat, I'm talking mostly about a different physical capacity to hear sounds humans can't.

There are hundreds or maybe even thousands of examples of this in the animal world, lots of which we probably still don't know about. A good example is the
silent thunder
of elephants. It wasn't
until the 1980s that a researcher named Katy Payne, of Cornell University, figured out that elephants communicate with one another using infrasonic sound waves too low for humans to hear.
¹⁰
People who studied elephants had always wondered how elephant families managed to coordinate their movements with family members miles away. An elephant family could be split up for
weeks,
and then meet up at the same place at the same time. They had to be communicating with one another somehow, but they were way out of the range any human could either see or shout across.

Katy Payne made a lucky guess about infrasonic sound when she felt “a throbbing in the air” next to the elephant cages at the Portland Zoo in Oregon. She'd had the same feeling as a child when the organ played in church. She started to think maybe the elephants were communicating with each other in a super-low range humans don't hear. That would solve the problem of the long-distance communication, because infrasonic sound travels a lot farther than sound waves in the register humans do hear.

She turned out to be right. Elephants “roar” out to each other below our level of hearing. During the daytime an elephant can hear another elephant calling him from at least as far away as two and a half miles. At nighttime, because of temperature inversions, that distance can go up by an order of magnitude to as much as twenty-five miles. It's a huge distance.

Now it turns out that elephants may be talking to one another through the ground, not just the air. Caitlin O'Connell-Rodwell, a biologist at Stanford, is working on this. She believes elephants can probably use
seismic communication
—making the ground rumble by stomping on it—to communicate with other elephants as far away as twenty miles.

She figured this out by watching the elephants in the Etosha National Park in Namibia. Right before another herd of elephants arrived, the elephants she was watching would start to “pay a lot of attention to the ground with their feet.”
¹¹
They'd do things like shift their weight or lean forward, or lift a foot off the ground. They were listening.

Dr. O'Connell-Rodwell thinks the animals are probably using the pads of their feet like the head of a drum. She and her team are also
dissecting elephant feet to see whether they have
pascinian
and
meissner corpuscles
, which are special sensors elephants have in their trunks to detect vibrations. If they find them in the feet, too, that's pretty good evidence elephants use seismic waves to communicate. A lot of animals communicate by thumping on the ground, including skunks and rabbits, so it won't surprise me if we find out elephants are talking to one another that way.

If elephants do have special corpuscles to detect vibrations that would be an example of an animal species having extreme perception because they're built differently and have different sense organs. Animals have all kinds of sense receptors we don't. Another example: dolphins have an oil-filled sac in their foreheads, underneath their forehead bumps, that they use for sonar. The dolphin sends a sound through the oil (which “focuses” the sound) and out to objects in the water. The sound bounces back to the dolphin and his brain forms a sound picture of what's out there. Humans can't use sonar because humans don't have any of the necessary sense structures.

Humans also have sensory receptors animals don't, like the huge number of cones in our retina for seeing color.

I've been talking mostly about vision, but all the other senses are different in different animals, too. There's some fascinating new research about the relationship between vision and smell in New World versus Old World primates. Old World primates are the famous ones everyone knows about: gorillas, chimpanzees, baboons, orangutans, macaques, humans. New World primates are the smaller animals we call monkeys. New World primates usually live in trees in Central and South America; they have long prehensile tails and flat noses. Tamarins, squirrel monkeys, sakis, and marmosets are all New World monkeys.

Old World primates, like baboons, chimpanzees, and macaques, have trichromatic, three-color vision, but most of the New World monkeys (spider monkeys, marmosets, capuchins) only have dichromatic, two-color vision. (Some New World females have trichromatic vision, but not all.)

What's interesting about this is that Old World primates and humans also have very poor ability to smell pheromones, which are chemical signals animals emit as a form of communication. (Most peo
ple think of pheromones as sexual signals, like the pheromones a female in heat emits, but a pheromone is
any
chemical used for communication. Ants, for instance, leave trails of scents behind them for other ants to follow.) About a year ago researchers found that Old World primates and humans both have so many mutations in a gene called TRP2, which is part of the
pheromone signaling pathway,
that it's not working anymore. In the course of evolution, the pheromone system in Old World primates, including humans, broke down.

It turns out that when we gained three-color vision we probably lost pheromone signaling. Jianzhi George Zhang, an evolutionary biologist at the University of Michigan, ran a computer simulation to find out
when
the TRP2 gene started to deteriorate, and discovered that TRP2 went into decline at the same time Old World primates were developing trichromatic color vision, around 23 million years ago.
¹²

Probably what happened was that once Old World primates could see in three colors they started using their vision to find a mate, instead of their sense of smell. That theory fits with the fact that a lot of Old World primate females have bright red sexual swellings when they're fertile, while New World monkeys do not. Once monkeys no longer needed a good sense of smell to reproduce successfully, their ability to smell probably went into decline as a direct result.

That would have happened because
use it or lose it
is a principle in evolution. If monkeys with a poor sense of smell can reproduce just as well as monkeys with an excellent sense of smell, the monkeys with the poor ability pass all of their weak or defective smell genes on to their offspring, and any spontaneous new mutations in the smell genes don't get winnowed out. It looks like that's what happened to Old World primates. The normal mutations that happen in the process of reproduction just kept accumulating until no primates had a working copy of TRP2 anymore. Improved vision came at a cost to their sense of smell.

S
AME
B
RAIN
C
ELLS
, D
IFFERENT
P
ROCESSING

So far I've been talking about the sense organ or sense receptor part of animal perception: animals have different sensory organs than we
do, organs that let them see, hear, and smell things we can't. But the other half of the story is where things get interesting, and that is the differences in brain processing.

All sensory data, in any creature, has to be processed by the brain. And when you get down to the level of brain cells, or neurons, humans have the same neurons animals do. We're using them differently, but the cells are the same.

That means that theoretically we
could
have extreme perceptions the way animals do if we figured out how to use the sensory processing cells in our brains the way animals do. I think this is more than a theory; I think there are people who already do use their sense neurons the way animals do. My student Holly, who is severely dyslexic, has such acute auditory perception that she can actually hear radios that aren't turned on. All appliances that are plugged in continue to draw power, even when they're turned off. Holly can hear the tiny little transmissions a turned-off radio is receiving. She'll say, “NPR is doing a show on lions,” and we'll turn the radio on and sure enough: NPR is doing a show on lions. Holly can hear it. She can hear the hum of electric wires in the wall. And she's incredible with animals. She can tell what they're feeling from the tiniest variations in their breathing; she can hear changes the rest of us can't.

Autistic people almost always have excruciating sound sensitivities. The only way I can describe how a lot of sounds affect me is to compare it to staring straight into the sun. I get overwhelmed by normal sounds in the environment, and it's painful. Most autism professionals talk about this as just being super-
sensitive,
which is true as far as it goes. But I think autistic people are also super-
perceptive.
They're hearing things normal people aren't, like a piece of candy being unwrapped in the next room.

It happens with vision, too; a lot of autistic people have told me they can
see
the flicker in fluorescent lighting. Holly's the same way. She can barely function in fluorescent lighting because of it. Our whole environment is built to the specifications and limitations of a normal human perceptual system—and that's not the same thing as a normal animal perceptual system, or as a
normal-abnormal
human system like a dyslexic person's system, or an autistic person's. There are probably huge numbers of people who don't fit the normal envi
ronment. Even worse, half the time they probably don't even realize they don't fit, because this is the only environment they've ever been in, so they don't have a point of comparison.