 If I ask you, what do you think that is happening? There is a group of people talking in a park probably having a good time. And in principle, there is nothing surprising about the image. Let's hear a bit what they might be saying. Some of you have a smile because it is surprising. What it is surprising is that we made some expectations about the language that they would be speaking or at least a group of languages that they might be speaking, Chinese not being one of them. And then what we heard was people at the bar that were speaking in Chinese. To be able to do this, we have had to perform a series of very complicated computations. On the one hand, we have had to analyse the visual image and to recognise that there are human beings and that these human beings are of a Caucasian origin. On the other hand, we have had to perform another set of very complicated computations too, this time over the language, over the speech stream, to recognise that there was a particular language or at least a language that didn't sound familiar to some, and to the others it sounded like a familiar language, namely Chinese. All these computations are extremely complicated and as a matter of fact, we are having difficulties and it's really difficult to have a machine to perform these computations. However, it is very easy for a human to perform them. Today, what I'm going to present to you are a series of evidence that shows that humans were able to do this from the very first days of our lives. That all what I'm going to talk to you today is what happens between zero and six months of age, not years, six months of age. One of the things that surprised us was recognising that this language was not the language that we were expecting. Let's see how good you are at differentiating languages. Let's imagine that we see that there are people in the distance, that we have a microphone and that we can hear what they are saying. I'm going to play you two different groups of sentences and my question to you is, do you think that the two groups of sentences belong to the same or to a different language? Do you think that the two groups of sentences belong to the same or to a different language? Different. This is easy. Let's see the two. If the two groups of sentences belong to the same or to a different language, I'm ready to take that decision. The two groups of sentences belong to the same or to a different language. The two groups of sentences belong to the same or to a different language. Sometimes it's easy and sometimes it's different. And as a matter of fact, infants as young as four hours to four days of life, they can also differentiate between some languages but not all. They can differentiate between Japanese and Dutch. They can differentiate between Russian and French, but they cannot differentiate between English and Dutch and they cannot differentiate between Italian and Spanish. This is something that, as a matter of fact, we don't know exactly is being done, but what we know is that it's also shared with other animals. For instance, some monkeys and laboratory rats. So our species evolves. I don't know if it's the same or not, but we share with other animals some properties that allows us to perform relatively complex computations of the speech signal. But speech is not only something that comes through our ear. We also see speech. When we are in a very noisy environment, we tend not to look to the eyes to the person, but if we're having difficulties in understanding what's being said, we will look to the mouth. So the mouth also conveys very important information about what's being said. And now I'm going to test you on another different capacity. That is, how good you are at noticing that the articulation of two languages they belong to the same or they belong to a different language. And this is the other. The question is, is she speaking the same or is she speaking different languages? Different languages? For those of you who say, well, I have no idea. This is really difficult. I'm going to give you a last chance. Now I'm playing the two together. These are English and French. And actually, they are very, very distinguishable from a visible point of view. If you could not, the problem is that they were different. And the problem is that you are too old. If you had four and six months of age, they would be a piece of cake. Four and six months of age, they had no difficulties noticing that that speaker was speaking two different languages. However, too old is already eight months. At eight months, the babies, they no longer show the capacity to differentiate these languages. If the babies are monolingual. If the babies, they are bilinguals, namely they are learning French and English, then at eight months, they can still make it. And it is not because they are learning French and English, because Spanish and Catalan bilingual infants, and these are the two languages that are being spoken in Barcelona, my hometown, they behave just those babies who are learning French and English. So it's the mere fact of being bilingual that makes you better in these type of tasks. Why is it, around six to eight months, monolingual infants, they leave, they start looking to the mouth much more than to the eyes when they are interacting with their parents, and then they are getting a lot of the information from the mouth, and then from eight months on, they will go back to look to the eyes. The bilinguals, on the other hand, they stay on the mouth for longer. So, and this is true also for the case of babies when they are looking to emotional faces, faces of other babies that are not speaking. So in this case, what we see is that in blue you have the monolinguals, and as you can see as compared to the orange ones, they tend to look more to the eyes. Bilinguals, they look much more to the mouth. That allows them to pick up more information from what the language is being spoken. We presented babies with videos where there was an actor who was introducing herself in a particular language. The language could be the language of the babies, namely Spanish, or it could be a different language that they don't know. In our case, it was German. Then they saw a series of videos where repeatedly they saw things like this. That is, they saw that the actress observed a ball getting into a box, and when the ball was inside the box, the actress picked up the ball. When the ball got out of the box, the actress did nothing. So we present that to the baby so that they know that this is what the actress wants to do. And finally, they saw these videos. In these videos, what happens is that the box goes inside, the ball goes inside, and then it goes out. Then, just at the moment when the curtain goes up, what happened is that we measured the brain activity of the babies. If the babies knew, we're going to act in a way that when we were mind reading the actor, then they would think that she would go and pick up the ball because she didn't see that the ball went out of the box. So this is called the mind reading capacity of humans. We know that humans behave because of the things that they have in their head, not because of how reality is. If, on the contrary, the babies think that whenever the ball is not in the box, you should not look for the ball because the ball is no longer there, then what happened is that the babies should not care. They should expect that the actor should not move. What we observed was that the patterns of brain activity were consistent with the fact that the babies were mind reading the actor. So they really did not expect, in the video that you saw, they did not expect the actor to go and pick up the ball. But this was only when the actor introduced herself in the native language. When the actor introduced herself in the non-native language, they did not care. So they used the language to make a social decision about the importance of this particular actor. So, just to wrap up, I have presented you evidence showing on the first hand that already at birth humans are able to compute extremely complicated operations over the speech signal. Second, that these operations are not only on the auditory information but also on the visual information and that they will adjust the behavior to what is in the signal and what is in the input. And finally, the language is a very, very powerful social guru that will help them to decide in which social group they are. And thank you very much.