Consciousness: Confessions of a Romantic Reductionist

Christoph Koch, the author of “Consciousness: Confessions of a Romantic Reductionist”  is not only a renowned researcher in brain science but also the president of the Allen Institute for Brain Science, one of the foremost institutions in brain research. What he has to tell us about consciousness, and how he believes it is produced by the brain is certainly of great interest for anyone interested in these topics.

However, the book is more that just another philosophical treatise on the issue of consciousness, as it is also a bit of an autobiography and an open window on Koch’s own consciousness.

With less than 200 pages (in the paperback edition), this book is indeed a good start for those interested in the centuries-old problem of the mind-body duality and how a physical object (the brain) creates such an ethereal thing as a mind. He describes and addresses clearly the central issue of why there is such a thing as consciousness in humans, and how it creates self-awareness, free-will (maybe) and the qualia that characterize the subjective experiences each and (almost) every human has.

In Koch’s view, consciousness is not a thing that can be either on or off. He ascribes different levels of consciousness to animals and even to less complex creatures and systems. Consciousness, he argues, is created by the fact that very complex systems have a high dimensional state space, creating a subjective experience that corresponds to each configuration of this state space. In this view, computers and other complex systems can also exhibit some degree of consciousness, although much smaller than living entities, since they are much less complex.

He goes on to describe several approaches that have aimed at elucidating the complex feedback loops existing in brains, which have to exist in order to create these complex state spaces. Modern experimental techniques can analyze the differences between awake (conscious) and asleep (unconscious) brains, and learn from these differentes what exactly does create consciousness in a brain.

Parts of the book are more autobiographical, however. He describes not only his life-long efforts to address these questions, many of them developed together with Francis Crick, who remains a reference to him, as a scientist and as a person. The final chapter is more philosophical, and addresses other questions for which we have no answer yet, and may never have, such as “Why there is something instead of nothing?” or “Did an all powerful God create the universe, 14 billions year ago, complete with the laws of physics, matter and energy, or is this God simply a creation of man?”.

All in all, excellent reading, accessible to anyone interested in the topic but still deep and scientifically exact.


AlphaZero masters the game of Chess

DeepMind, a company that was acquired by Google, made headlines when the program AlphaGo Zero managed to become the best Go player in the world, without using any human knowledge, a feat reported in this blog less than two months ago.

Now, just a few weeks after that result, DeepMind reports, in an article posted in, that the program AlphaZero obtained a similar result for the game of chess.

Computer programs have been the world’s best players for a long time now, basically since Deep Blue defeated the reigning world champion, Garry Kasparov, in 1997. Deep Blue, as almost all the other top chess programs, was deeply specialized in chess, and played the game using handcrafted position evaluation functions (based on grand-master games) coupled with deep search methods. Deep Blue evaluated more than 200 million positions per second, using a very deep search (between 6 and 8 moves, sometimes more) to identify the best possible move.

Modern computer programs use a similar approach, and have attained super-human levels, with the best programs (Komodo and Stockfish) reaching a Elo Rating higher than 3300. The best human players have Elo Ratings between 2800 and 2900. This difference implies that they have less than a one in ten chance of beating the top chess programs, since a difference of 366 points in Elo Rating (anywhere in the scale) mean a probability of winning of 90%, for the most ranked player.

In contrast, AlphaZero learned the game without using any human generated knowledge, by simply playing against another copy of itself, the same approach used by AlphaGo Zero. As the authors describe, AlphaZero learned to play at super-human level, systematically beating the best existing chess program (Stockfish), and in the process rediscovering centuries of human-generated knowledge, such as common opening moves (Ruy Lopez, Sicilian, French and Reti, among others).

The flexibility of AlphaZero (which also learned to play Go and Shogi) provides convincing evidence that general purpose learners are within the reach of the technology. As a side note, the author of this blog, who was a fairly decent chess player in his youth, reached an Elo Rating of 2000. This means that he has less than a one in ten chance of beating someone with a rating of 2400 who has less than a one in ten chance of beating the world champion who has less than a one in ten chance of beating AlphaZero. Quite humbling…

Image by David Lapetina, available at Wikimedia Commons.

Portuguese Edition of The Digital Mind

IST Press, the publisher of Instituto Superior Técnico, just published the Portuguese edition of The Digital Mind, originally published by MIT Press.

The Portuguese edition, translated by Jorge Pereirinha Pires, follow the same organization and has been reviewed by a number of sources. The back-cover reviews are by Pedro Domingos, Srinivas Devadas, Pedro Guedes de Oliveira and Francisco Veloso.

A pre-publication was made by the Público newspaper, under the title Até que mundos digitais nos levará o efeito da Rainha Vermelha, making the first chapter of the book publicly available.

There are also some publicly available reviews and pieces about this edition, including an episode of a podcast and a review in the radio.