The magic of cognition

I would like to tell you about the most powerful computers on the face of earth, maybe in the entire universe. Those who know me can guess that I am referring to the humid, squishy, pinky, convoluted material apparently messy and not very elegant, that most of us wear hanging in between our shoulders and above our noses. Our brains. The famous British writer Oscar Wilde sentenced: “The great events of the world take place in the brain”. Our brains allow us to communicate, to think, to feel, they enabled our ancestors with the ability to distinguish friend from foe, to search for food, they allowed us to develop mathematics and prove Fermat’s theorem among many others, to synthesize antibiotics, to go to the moon and to explore other planets and also to fabricate those artificial and rudimentary computers that are so entertaining to us. Our brains have changed the course of natural evolution.

How is it possible that a soft biological tissue, composed of nothing more and nothing less than moving organic and inorganic molecules, can give rise to the magic of cognition? The fundamental basis for the study of the brain was established by a Spaniard, Ramon y Cajal. A giant. He wanted to become an artist. His parents told him “no way” and forced him to study medicine. He combined tradition and passion by devoting his life to observing and drawing the main cells of the brain: the neurons. The secret of the brain is hidden within the complex neural networks that connect millions of neurons. Our memories, our decisions, our feelings are codified in the patterns of connection and communication among neurons.

Let us consider an example. What does it mean to see and recognize the face of a friend? Light is reflected in that face and reaches our eyes, our retinae, and is converted into electrical signals, almost like pixels in a digital camera. From there, those electrical signals travel, in a binary format, essentially fancy sequences of zeros and ones, moving at enormous speeds, passing from one neuron to another, extracting relevant features from that face, and transforming those pixels into new codes, new formats and thus building a reality, an interpretation of the world. What we perceive is nothing more and nothing less than our interpretation, our own way of building our internal world in a code formed by zeros and ones. In a small fraction of a second, in less time than it takes to blink, we can compare those electrical pulse sequences with our memories and recognize the person in front of us.

This may not seem too surprising. After all, any kid can recognize his family and friends without having to study advanced calculus. And yet, those other computers, the artificial ones, still cannot do this very well. In fact, those tasks that seem difficult to us, such as computing the square root of 7 are very easy to execute for artificial computers. In contrast, those common sense tasks that are so intuitive to us such as identifying a friend and understanding their jokes, can be extremely difficult to teach to an artificial computer.

During the last couple of years, we have developed new tools that enable us to interrogate the brain at unprecedented resolution. We are beginning to characterize and describe the neural circuits within our brains in a large scale. Maybe in the not too distant future we may have brain diagrams similar to the ones used by electrical engineers to design computers. We are also beginning to listen how ensembles of neurons converse with each other. Elucidating how the brain works is changing history. Understanding neural circuits will enable us to alleviate the devastating conditions that afflict the brain. Imagine a world without Parkinson’s disease and without Alzheimer’s disease. Deciphering the biological codes in neuronal circuits will also enable us to build robots that are smarter than us, with tremendous consequences in almost every domain. Imagine a world where robots can paint better than Picasso, compose more beautiful music than Bach and develop theories better than Einstein. The first ultra-intelligent machine is the last invention that man need ever make. Because that machine will be able to make the rest. And perhaps more importantly, decoding the magic of cognition will allow us to understand who we are.