I had been thinking about doing work on optical illusions with Alex ever since I was at the MIT Media Lab. In the summer of 2005, I teamed up with Patrick Cavanagh, a psychology professor at Harvard, to put the idea into practice. The human brain plays many tricks on us, so we sometimes see things not as they are. Patrick and I planned to ask a simple but profound question: Does Alex literally see the world as we do? That is, does his brain experience the optical illusions just as our brains do?
I envisaged this work as the next horizon in my journey with Alex, beyond naming objects or categories or numbers. Bird and human brains diverged evolutionarily some 280 million years ago. Does that mean that bird and mammalian brains are so different structurally that they operate very differently, too?
Until a landmark paper [pdf] by Erich Jarvis and colleagues in 2005, the answer to this question had been a resounding yes! Look at a mammalian brain and you are struck by the multiple folds of the massive cerebral cortex. Bird brains, it was said, don’t have such a cortex. Hence, their cognitive capacity should be extremely limited. This, essentially, was the argument I had faced through three decades of work with Alex. He was not supposed to be able to name objects and categories, understand “bigger” and “smaller,” “same” and “different,” because his was a bird brain. But, of course, Alex did do such things. I knew that Alex was proving a profound truth: brains may look different, and there may be a spectrum of ability that is determined by anatomical details, but brains and intelligence are a universally shared trait in nature—the capacity varies, but the building blocks are the same.
By the turn of the millennium, my argument was beginning to gain ground. It wasn’t just my work with Alex but others’ work, too. Animals were being granted a greater degree of intelligence than had been previously allowed. One sign of this was that I was asked to co-chair a symposium at the 2002 annual meeting of the American Association for the Advancement of Science, called “Avian Cognition: When Being Called ‘Bird Brain’ Is a Compliment.” The preamble read as follows: “This symposium demonstrates that many avian species, despite brain architectures that lack much cortical structure and evolutionary histories and that differ so greatly from those of humans, equal and sometimes surpass humans with respect to various cognitive tasks.” Even five years earlier, such a symposium would have been a difficult sell. That was progress. Jarvis’s paper three years later effectively said that bird and mammalian brains are not so very structurally different after all. More progress.
