"Birds are just as capable as we are," says award-winning scientist Onur Güntürkün

A pioneer in the field of Biological Psychology, Güntürkün says that the brains of birds may have a more efficient design than those of mammals. He presented a lecture at FAPESP headquarters.

By Karina Toledo

Agência FAPESP – For a long time, the prevailing opinion among neuroscientists was that the brain had developed in a linear fashion. According to the theory proposed by neurologist Ludwig Edinger (1855-1918) in the mid-19th century, fish had the most primitive brains, then came amphibians, then birds and, finally, mammals.

According to Edinger’s theory, the brains of mammals contained not only all of the structures found in the brains that had preceded them on the evolutionary scale but also something that gave them new and superior cognitive ability: the neocortex.

The neocortex, which is more developed in primates than in other species, is a type of coating that covers the outside of the brain. In humans, it is divided into six layers and has a large number of grooves filled with neurons that command complex functions such as sensory perception, motor coordination, spatial reasoning and language.

Edinger believed that because birds do not have a neocortex, they could never be trained like dogs and cats, nor could they develop complex cognitive abilities such as using tools. However, in the early 21st century, a group of scientists published an article in the Journal of Comparative Neurology demonstrating that this theory was incorrect.

One of its authors was Onur Güntürkün, a professor at the Ruhr-Universität Bochum in Germany. In another study published in the journal PLOS Biology, Güntürkün showed that crows can recognize themselves in the mirror, something that most mammals are not able to do and that requires a certain degree of self-awareness.

As a result of his pioneering efforts in the field of Biological Psychology, the Turkish-born Güntürkün received the Gottfried Wilheim Leibniz Prize, considered Germany’s Nobel, in 2013. In 2014, he earned the Communicator Award, presented each year by the Deutsche Forschungsgemeinschaft (DFG) and Stifterverband für die Deutsche Wissenschaft to scientists whose excellent communication skills enable them to communicate the findings of their research to the broader public, beyond the realm of academia.

On May 20, Güntürkün visited FAPESP headquarters to present a lecture, “Cognition without cortex: The convergent evolution of avian and mammalian forebrains,” in which he said that from his experiments with crows, he has been able to conclude that the brain structure of birds is comparable to the neocortex of mammals.

“Birds have a brain structure that has the same specificities as the neocortex, the same biochemistry and the same pattern of communication. The difference is that it is not divided into layers,” he said.

According to Güntürkün, it is as if nature created two different solutions to a single problem (advanced cognitive ability) in distinct occurrences and independent of evolutionary history.

“It’s possible that the brain design of birds is even more efficient than that of mammals because it enables complex cognitive abilities to occur in an even smaller volume. However, the brains of birds are too small to compete with ours,” he said.

In an interview granted to Agência FAPESP, Güntürkün explained more of the details surrounding his studies designed to understand the origins and evolution of thought. He also spoke about the importance of scientific communication and about his studies related to gender differences in the brain.
 

Agência FAPESP – What made you decide to visit Brazil?
Onur Güntürkün – I was invited by the DFG to present the “Leibniz Lecture” [a format designed for prize winners for the purpose of stimulating dialogue both with scientific communities abroad as well as with society in general] and talk to my fellow scientists in Brazil. Brazil is a very important country, not only in economic and political terms but also in terms of science. Germany has a long tradition in science, but it needs to plan its future appropriately, and in order to do this, it needs to think about what countries will be major science players in the future and to promote relationships between German scientists and those in the rest of the world. I think DFG’s notion is a very wise one: it is not the directors or the ministers who should be the ambassadors of science but rather the scientists themselves. The only way this can happen is by enabling interaction between them so they can determine shared interests. In this way it’s possible to discover that there is a great person on the other side of the Atlantic who is interested in the same subjects you are and can collaborate with you. That’s the idea anyway.

Agência FAPESP – How did you become interested in brain development and thought?
Güntürkün – We are only able to understand something when we know its history. I can only understand myself when I know something about my past. The same thing applies to the brain and to cognition. If we understand the evolutionary conditions under which cognition and thought arose, we can understand why we think the way we do. That’s the basic reason. I don’t remember any time in my life that I wasn’t interested in this subject, so there really is no exact starting point. As a child, I was already doing science and conducting experiments. Of course, they were simple and wrong, and I knew nothing about the literature. But it was science, and it was an important time in my life. Much of what I do today may also be wrong, and I’m still not aware of it.

Agência FAPESP – How are form and function related in the brain? Up to what point does brain structure determine cognitive ability?
Güntürkün – If the architecture of our brain were different, would our cognition be different? The answer is yes and no. If we lose a piece of our brain and our architecture is altered, our cognition would radically change. However, there are different types of brains, whose architectures, although completely different, are able to create the same type of cognition. It’s as if you are driving a car and you lose a piece of the engine and the car stops. But there are other types of engines that can propel a car. There are many solutions for a single problem. That’s why when they ask me if structure determines cognition, my answer is yes and no. Yes, there are many solutions, and no, within a specific solution, all the components need to be there for the system to work. This is an important issue in cognitive neuroscience. We can understand cognitive development by using this knowledge as a backdrop. There are different bodies and different types of brain. Do they think as we do or do they have completely different ways of thinking that we don’t even know? It’s enough stuff for a lifetime of research.

Agência FAPESP – In your lecture, you said that birds have cognitive abilities similar to those of mammals even though they do not have a neocortex. Does this hold true for all birds or just one particular group? And how is this possible?
Güntürkün – I don’t think that all birds are able to do this, just some, like crows and ravens, and we don’t know why the others do not have this ability. But the same goes for mammals. Dogs don’t recognize themselves in the mirror, nor do cats or even rhesus monkeys. Only some mammals and some birds are capable of this, and we still don’t know for sure why this is. What is special about the brain of a crow that makes it different from the brain of a pigeon? What’s special about the brain of a chimpanzee that gives it the ability to recognize itself in the mirror when a rhesus monkey cannot? We still do not know. It’s an important question because if self-awareness is an avenue towards our consciousness, we will be better able to understand it if we can understand how these differences among animals appear.

Agência FAPESP – Do birds have a type of primitive neocortex?
Güntürkün – No, it isn’t primitive. It’s as if nature had invented the wheel two times, each independent of the other. The brain of birds has an internal structure that is virtually identical to the pre-frontal cortex in humans. However, it is not divided into layers like our cortex. It appears that in two distinct periods of evolution, a group of animals had the need to develop higher cognitive ability and both ended up with the same basic solution to the problem. While one group developed a neocortex, the other developed a different type of brain structure. The inventions, however, are absolutely identical. It’s like going to Mars and discovering species that are completely different, from a completely different origin, but upon further analysis, you discover that some aspects of the brains of these creatures are virtually identical to yours. It’s a huge discovery because it suggests that there are two solutions to one important problem. You always end up re-inventing the wheel when what you really want to do is invent a new car.

Agência FAPESP – You suggested that the brain design of the birds is perhaps more efficient than that of mammals. Why is that?
Güntürkün – It’s possible that it is. Otherwise it would be hard to understand how small brains are able to be as powerful in cognitive terms as the large brains of mammals. However, the brain of birds was never able to grow as large as ours. There isn’t a single bird or reptile that has been able to develop a brain that weighs several kilos. There isn’t even one reptile whose brain weighs more than 100 grams. We don’t know why this is. For over 300 million years, reptiles and birds have had the chance to develop a large brain and have never managed to do so. The Argentinosaurus, discovered in Argentina, was probably the largest living thing that ever inhabited the planet. It was enormous, and its brain was the same size as that of a bird. The brains of these animals are limited in terms of absolute size, while our brain with its cortical architecture can become large. This was the evolutionary advantage we had. Otherwise, we’d be in cages as birds’ pets.

Agência FAPESP – Does the fact that the neocortex comprises 76% of human brain volume explain why we are the most intelligent animals?
Güntürkün – Yes. It’s possible that we just have a very large primate brain. We simply have more neurons in the neocortex than any other animal on earth. There are animals whose brains are larger, such as whales and elephants, but they have fewer neurons. Our superiority could be a result of quantitative reasons. It’s like computers. We put in more memory, improve other specifications, and suddenly, the computer works faster, is more powerful and can calculate more.

Agência FAPESP – So then we’re just primates with a big brain?
Güntürkün – Yes. I’m proud to be a primate.

Agência FAPESP – What do we already know about the neocortex and how it works?
Güntürkün – We know a lot about the neocortex. It’s one of the most well studied of the neurostructures. On the other hand, we understand very little about the brains of birds. Obviously, because we’re mammals, we’ve been thinking for hundreds of years that only by having a neocortex is it possible to have advanced cognitive ability, so there has been great interest in studying the neocortex. Now that we’ve discovered that birds are as capable as we are, we have to work hard to fill this knowledge gap about the brain structures of birds.

Agência FAPESP – Studying the brain is always a huge challenge because you can’t simply take a piece of tissue and examine it under a microscope without huge consequences. What methodologies do you use?
Güntürkün – Of course we cannot do invasive experiments in humans, but we can record an electroencephalogram or place our volunteers in an MRI and assess brain activity. When a patient has bad luck or bad genes that cause an alteration in the brain structure, there is always a corresponding alteration in cognitive ability that we can study. And obviously, we do behavioral experiments and things of that nature. In animals, such as pigeons, which I have used a lot in my laboratory, we can, with authorization, do invasive experiments such as implanting small electrodes in the brain to record activity.

Agência FAPESP – You have studies related to kissing and the tendency of couples to turn their heads to the right as they kiss. Why did you study this?
Güntürkün – I need to make it clear that I didn’t study kissing to understand the kiss itself, but rather to understand the asymmetry of the human brain. It all began with the discovery that the brains of birds are asymmetrically organized. That asymmetry appears even before they hatch, when they turn their heads to the right. This provides more light stimulation to the right eye of the embryo, which is up against the eggshell. Then, I discovered through the literature that humans also turn their heads before being born, most often to the right. And we continue to have this tendency for several months after birth. I have a crazy theory that this in some way modulates our brain circuits. If I’m a newborn, I almost always look to the right, I see my right hand and start to do things with my right hand. And I do fewer things with my left hand. So the fact that I am right-handed may have been influenced by my tendency to look to the right.

Agência FAPESP – Have you been able to prove this theory?
Güntürkün – I formulated this theory and my colleagues told me it was silly because babies stop looking to the right when they get to be 3-4 months old. And manual dexterity manifests itself several years later. There is a time interval between these two events. But I didn’t believe this and thought that perhaps the babies’ patterns of movement might just be too complex for us to clearly see the tendency to turn their head to the right. If this tendency really never disappears, as adults we would also be expected to manifest it in some way. One day, I was sitting on my couch at home and suddenly it occurred to me: the kiss. During the act of kissing, I cannot keep my head straight; I need to turn it to the right or left. I decided to observe couples in airports when they were waiting for their loved ones. The experiment was conducted in large international airports on three different continents to reduce the possibility of any cultural bias. I discovered that the human tendency to turn one’s head to the right appears at an absolutely identical rate between adults and newborns: two thirds of the time. This tendency does not change over the course of one’s life and possibly modulates manual dexterity in humans.

Agência FAPESP – In the case of birds, there is in some ways a relationship to stimulation of the right eye by light. Is the same true for humans?
Güntürkün – This doesn’t happen because our vision is frontal. My theory is that we turn our heads in order to see our own limbs. However, we still haven’t discovered what else is affected by this pattern of turning one’s head in addition to manual dexterity. It’s only one of the aspects of cerebral asymmetry that we’re currently studying in my laboratory.

Agência FAPESP – Is it true that one side of the brain controls emotions and musical ability and the other side is responsible for more analytical activities?
Güntürkün – This is a myth of psychology and neuroscience. We need the entire brain in order to play music or to reason. There are some relevant specializations. For music, for example, our ability to understand the rhythm is more dominant in the right hemisphere. So there is one aspect of music related more to the right side of the brain. After the famous composer [Maurice] Ravel had a stroke that affected the right hemisphere, although he was still capable of listening to music, he was not able to understand it because he had lost the ability to calculate the rhythm. Reasoning, however, is something that requires the entire brain. Many of these myths have some basis of truth, but not all the facts involved are true.

Agência FAPESP – Is it also a myth that men have more neurons than women?
Güntürkün – This is true. Men have between 10% and 15% more neurons, even if we calculate them in proportion to body size. The difference in practice, honestly, is something we still don’t know. The intelligence of men and women is quite possibly identical. There are some scientists who hold that IQ [intelligence quotient] is a little higher in men. If this were true, though, the effect would be small. There are other studies that were not able to show any difference. My theory is that men and women are identical in terms of intelligence. I assume this because most of the literature shows that, if there is any difference at all, it is very small and not important. However, there may be a difference in terms of knowledge. Men are apparently able to memorize 10% to 15% more facts than women are. It may just be that the cortex is a huge warehouse, and if you have a larger warehouse, you’re able to hold more. This is my preferred theory, and we’re developing studies to analyze it.

Agência FAPESP –Why would men need to have a larger warehouse?
Güntürkün – I have no idea. It makes no sense in evolutionary terms. Evolutionary selection pressure, with regard to knowledge, acts in equal measure on men and women. Why would men need to have more neurons? I really don’t know. We’ll go to our graves with many questions unanswered. But at least I’d like to discover whether there is, in fact, any relationship between having more neurons and being able to store more knowledge. And then an even more profound question would present itself: why? I worry when I think I may never know.

Agência FAPESP – You won the 2014 Communicator Award, which demonstrates your interest in communicating the findings of your research to the lay public as well as the scientific community. Why do you think science communication is important?
Güntürkün – I’m very honored to have been selected. According to the jury, I’m able to communicate very well with the media and the general public. I think this is something that all of us scientists have to do. We need to talk about our research with the media, with the lay public and with other scientists and students. And we have to do this in a way that everyone can understand. It’s something I consider to be my duty because I’m funded by taxpayer money. These taxes guarantee the best job on the planet to a very small number of people: scientists. We work at what we are interested in, with whom we want to work and using the techniques we choose. We’re free and can play with our ideas, and this is absolutely fantastic. At the same time, we’re surrounded by brilliant students and many interesting people all over the world. In exchange, the taxpayers have the right to know what we are doing. And when I talk to these workers, I don’t use words that make it hard to understand. It’s my duty.

Agência FAPESP – In general, do you think scientists do a good job of fulfilling this duty? How can they improve?
Güntürkün – I think that in general, scientists are aware of this duty and do a good job, but there are some limitations. The public is tremendously interested in science. On television, not only are there sports and soap operas, there are also programs about new discoveries, animals and many other aspects related to science. Journalists often come to me and my colleagues. They do this, obviously, because scientific journalism awakens the interests of people. But the responsibility goes both ways. Scientists can’t be shy about speaking clearly to the media. And the media have the responsibility to communicate science as it really is and not just report on scandals, fantastic inventions or that type of thing.

Agência FAPESP – Have you ever had problems with the media?
Güntürkün – I’ve learned a lot about dealing with the media over the course of my life, and I’ve had some difficult experiences. Most people in the media really try to do a good job. But sometimes, the internal mechanisms of the press cause the messages to be overly simplified. I think this is a problem that both scientists and journalists need to try to somehow resolve.