The Dolphin in the Mirror (14 page)

In addition to the intellectual relationship that was established that day at lunch, a more practical relationship began as well. Barney generously donated some of his personal HP stock, which allowed me to get my lab up and running and was sufficient to keep it operating for several years. Despite this, I was still on a very tight budget, but I was lucky with my subject of research; it made raising funds easier than it would have been if I were studying, say, the digestive system of liver flukes. I was frequently on the phone saying something like "Hello. I am doing research on dolphin communication here at Marine World, just down the road from you. We have very limited funds and I was hoping you might consider donating [some piece of equipment] in support of the research program." The answer was usually "Yes, willingly." For instance, I was given a generous supply of audiotapes from Ampex Corporation, a neighbor in Redwood City. With the bounteous support of Ampex, several other Silicon Valley companies, and the U.S. Geological Survey, I was now ready to embark on my research program proper.

***

Terry, Circe, Pan, and Delphi were the first dolphins with whom I tried keyboard studies. The experimental setup was fairly simple, too simple probably to allow the dolphins to show us what they were really capable of, but I was constrained by engineering issues. I was lucky to have a terrific engineering student, Bill Baldwin, who helped me construct my equipment, a twenty-one-by-twenty-four-inch underwater keyboard with nine positions on it in a three-by-three matrix.
^*
Designing an underwater keyboard for dolphins is not a trivial engineering task, given the need for safety, sensitivity, and speed of switching in a corrosive, saltwater environment; water is a hazardous environment for most electronic equipment. Our solution was to power the keyboard by light, via fiber-optic cables, so that when a key was pressed by the dolphins, a light beam was broken behind the key. Since my lab was generously supported by Barney Oliver, the founder and director of Hewlett-Packard laboratories, he paved the way for his company to donate the fiber-optic cables.

When I began the study, I had only three labeled keys: a circle, which represented "fish"; a triangle, which represented "ball"; and an H, which represented "rub"—that is, one of us would rub the dolphin. Bill had cleverly engineered the keyboard system and software in such a way that if a dolphin touched, say, the triangle key, a specific computer-generated whistle would sound in an underwater speaker for the dolphins, and in my headphones I would hear the word
ball
produced by a computer-generated voice. My job would then be to give the dolphin the ball. The same thing happened for the fish key and the rub key. I would give a fish or a rub, depending on what I heard in my headphones.

In another laboratory I had heard examples of computer-generated sounds that were supposed to be akin to dolphin whistles, and for the most part, they sounded exactly that, computer-generated and tinny. I wanted something that at least sounded biological. A sound engineer from Mountain Music Systems in Silicon Valley, not far from the lab, helped me to create synthesized dolphin whistles. The computer whistles needed to be similar to natural dolphin whistles in frequency and time so they could easily be reproduced by the dolphins, yet they also needed to be different from the dolphins' own signals to show us that the dolphins could acquire new sounds. Through trial and error we found waveforms that generated sounds rich in harmonics that had the timbre of dolphin signals. But, of course, what sounded "dolphinish" to our ears might not have sounded the least bit so to dolphins. Could we create a shared code for humans and dolphins? Could we discover anything about dolphin learning?

Dolphins are adept at mimicking sounds. I therefore expected these dolphins to imitate our artificial whistles in some way, and I hoped to learn more about the process by which they learned these whistles. Dolphins produce a wide variety of whistle types and little was understood of their structure and function. I grandly hoped my keyboard could be a Rosetta stone for helping our decoding efforts.

I began the keyboard study on July 13, 1984, when Pan and Delphi were eleven months old, by simply lowering the keyboard into the pool and recording what happened. Terry and Circe were swimming with their respective offspring, as usual. Each dyad was in what I called a P2 swim formation—side by side within inches of each other. Eventually Terry and Pan approached the keyboard, apparently curious to investigate it. They got very close, and then Terry touched the triangle key with her rostrum. The ball whistle immediately sounded in the underwater speaker right next to them. But they turned and fled at high speed before I had a chance to give her the ball. They continued to swim rapidly around the pool for a while. This novel sound had obviously freaked them out, and they didn't come near the keyboard again during the rest of the half-hour session.

A few minutes after I put the keyboard in the pool the following day, Terry and Pan again approached it, this time much more cautiously. Then Terry pec-rubbed Pan, an act of reassurance, as if to say, Don't worry. It's okay. You try this time. He moved forward and touched a key, and it was like a light bulb went on for him; he quickly got into pressing the keys, hearing the whistles, and getting the objects or rubs. I had designed the protocol so that the positions of the keys changed every minute. The keyboard would be deactivated, and I'd hear in my headphones a mechanical voice saying, "Ball—position one; fish—position three; rub—position four," or whatever the preassigned pseudo-random set was. We changed the positions of the symbols from key to key at the end of each minute so the dolphins would have to learn which symbol was associated with what object or activity rather than erroneously thinking that the position of the key was the critical factor in obtaining what they wanted.

Delphi had been watching what Pan was up to with the keyboard, and two days after Pan's first tentative touch, he joined in too. (Pan was always first to do new things, and Delphi generally followed suit shortly thereafter.) Very soon we had the two boys enthusiastically using the keyboard, just as we had hoped. Terry and Circe, meanwhile, had no interest in it. Why, I'm not sure, but they seemed to be happy to use it as a baby-sitting device. Both mothers were constantly on the go with their calves, always attending closely to them, always swimming with them. Before the calves were born, Terry and Circe regularly rested or slept for ten-minute intervals. They would lie stationary at the surface or swim slowly with one eye closed; remember, dolphins are "specialized" sleepers. But once the boys were on the scene, there were no more breaks, which any human mother can understand. The only time Terry or Circe got to rest after that was when one of them took care of both calves for a while. This form of baby-sitting is called allomothering, and it is observed in both wild dolphins and dolphins in aquariums. Now that the keyboard was in the pool half an hour each day and the boys were enthusiastically using it, both mothers could get some rest. I empathized with them.

Both Pan and Delphi were still nursing at this point, as they would continue to do for another year or two, at least. Dolphins usually nurse for about three years, and sometimes longer, even though they are eating fish as well. Pan had already started to take an interest in fish; at first he'd simply mangled them and generally seemed to be playing at or practicing eating fish, but now he had started to actually eat them. It soon became clear that our inclusion of a fish key, with the promise of a real fish when it was touched, had been a mistake. In each session, Pan spent most of his time requesting and getting fish—small silver smelt—and used the other keys for ball and rub less frequently. (Rub was the least-favorite request throughout the study—perhaps, we thought, because they could get rubs from each other, while they depended on us for balls and fish.) We decided to remove the fish key after thirteen sessions and replace it with a symbol meaning "ring," a category of toy that the dolphins played with often.

At the beginning of the fourteenth session, Pan was the first to come to the keyboard, as usual. He normally pressed the fish key as soon as he got to the keyboard. This time he paused for a few seconds, scanning the keyboard. It was as if he were thinking,
Okay, where's the fish key?
He didn't try any of the other keys. Instead, he swam to the bottom of the pool, apparently looking for something. I had no idea what. He swam back to the keyboard with a silver smelt in his mouth, left over from the morning's feed. He held the fish up to a blank key and looked me in the eye expectantly. I could almost hear him asking for the fish. Both Pan and Delphi had hit blank keys a couple of times in the early sessions, but they'd quickly learned that those keys produced nothing, not a whistle, not an object, and they hadn't touched them since. The fact that Pan was using a blank key in the way he did was quite remarkable, an obviously deliberate act of attempted communication.

I was suddenly in an awful position. I knew in my heart and in my mind that he was trying to communicate with me in a very innovative way, and I would have loved to give him the fish. But that would have been against the rules of the game. The rules of the game were that he got objects when he touched the appropriate keys. And there was no fish key on the keyboard. I had no choice but to ignore him. He continued to look at me for a few seconds, as if he were thinking,
What don't you understand about my message? Can't you get what I'm asking for?
He soon gave up. A good example of scientific rigor working against fundamental decency and perhaps discovery. I
really
wanted to give him a fish.

***

On the nineteenth occasion that Pan hit the ball key, a few weeks into the project, I heard something in my headphones that made me start. I heard the computer-generated ball whistle, of course. But there was something else.
Did Pan make something like a ball sound?
I thought to myself. I couldn't tell. As I said earlier, unlike dolphins, we humans are not superb acoustic detectors, especially in these circumstances. Pan was pushing his newly acquired ball around. He pushed it against the wall near the hydrophone to my right, and I heard another very clear ball signal, repeated twice. He came back to the keyboard, and this time he clearly produced the ball whistle and then pressed the ball key; again I heard something in my headphones that sounded a lot like Pan making the ball whistle. The same thing happened a third and fourth time. I couldn't wait to get to the lab to print out a spectrograph (a sound picture) of what I'd been hearing. Then I would know if my ears had been fooling me, if it had been nothing but wishful thinking.

What I saw set my heart pounding. It was one of those moments a scientist sometimes experiences, when you know you have seen something new, something that no one has ever seen before. It was a delicious moment. The ball whistle is quite simple: it's a sinusoidal waveform with flat ends, an initial rise, followed by a fall, then ending with a rise, all of which takes about a second. What the spectrograph showed me was that on the first occasion I thought I'd heard Pan make a ball sound, he had in fact produced just the end of the whistle, the final fall and rise, a U-shaped component with a flat tone at the end. On the second occasion he had made the beginning of the sound, a rise and fall. On the third occasion he had matched the timbre, the overall resonant quality of the model sound, by adding harmonics, and in his forth rendition, he'd brought it all together in a beautiful facsimile of the entire ball whistle. In each case, he matched the exact duration of the model sound, but he transposed the frequency a bit, whistling just a little higher. Pan had spontaneously mimicked a new sound, with no teaching, no training, no food reward. No reward at all, except what pleasure he might have derived from learning something new in an interactive, social environment. This was entirely novel.
^*

By repeating the last part, then the first part, then putting it all together, Pan had done what young children do when they learn new words. It's called segmentation. Kids often imitate the last part of a new word first, such as saying
nana
after hearing
banana.
In psychological terms, this is called the recency effect; it refers to the tendency to best recall what has been perceived most recently. Conversely, repeating the first part of a word is called the primacy effect. Then kids begin to put the two parts together.

When a child is able to put a whole word together, he or she often practices it. For instance, a child who has learned the word
dolly
can often be heard repeating to herself "Dolly, dolly, dolly" while playing with the doll. And this is what we saw with Pan and, subsequently, with Delphi too.

Both Pan and Delphi learned to produce the ball whistle after about nineteen or so exposures to the sound. They subsequently learned the rub sound, the ring sound, and the disk and float sounds that we later added, each one after fewer and fewer exposures. At first, Pan and Delphi imitated the sound immediately after hitting the key and hearing the computer-generated sound; we call this mimicry. But they made the sound at other times too, such as before pressing the key or later or while playing with the ball or being rubbed; we call this production. The difference between mimicry and production is that production is an indication that the dolphin has made a strong association between the sound and the object or activity it's associated with. When Pan or Delphi repeated the ball whistle when playing with a ball, it was the equivalent of the young girl saying "Dolly, dolly, dolly" when playing with the doll. Repetition serves to reinforce the word in the utterer's mind and perhaps forms associations in the dolphin's mind.

Whether these sounds represent to the dolphins what we might call a label, or even a word, is hard to say. And I was very cautious in my interpretation. I stressed that while the dolphins' productive and contextual use of their facsimiles clearly indicated that they had formed close learned associations among the sounds, visual symbols, and objects and activities, I couldn't conclude that the symbols or sounds represented words or labels to the dolphins. But it looks that way. Neither Pan nor Delphi ever whistled the sound for, say, "ball" and then hit the rub key or some other inappropriate key. They were 100 percent consistent in associating the appropriate sounds with the visual symbols.