Global Workspace Theory (GWT)

Baars uses the theater metaphor in order to give an intuitive idea of his theory of consciousness known as Global Workspace Theory.

Baars tell us about a “theater” in which the spotlight on the scene represents the focus of consciousness directed by attention. The complete scene corresponds to the working memory, which is the memory system that stores the conscious contents of the mind. The information retrieved under the spotlight is globally broadcasted throughout the theater to two different types of unconscious processors: the audience and the ones behind the scene. The latter are unconscious contextual systems that create the events taking place in the scene.

The spotlight metaphor is also used by Crick (1994) when he argues that the visual information processing in the brain takes place centered in a spotlight, whereas in other regions of the visual field the information is less processed or not processed at all.

The theater metaphor used by Baars is essentially opposed to other metaphor known as “Cartesian theater”. Even thought both ideas sound similar they are actually divergent. The idea of a Cartesian theater refers to the existence of a concrete point in the brain, the pineal gland, where Descartes thought the link to the soul was located (Finger, 1995). Theories that pretend to localize consciousness in a central concrete point of the brain are broadly rejected by scientific community. However, scientists are looking for the neural correlates of consciousness (NCC), although they are not believed to be in a concrete point, but formed from neural coalitions (Crick and Koch, 2003).

Coming back to the theater metaphor developed by Baars, it is important to remark that the scene is composed by the working memory. This is the place where the actors compete for the spotlight space of attention. When they get there, they appear as conscious contents of the mind. The selection of the spotlight position is to a great extend done behind the scene. Unconscious processors select the conscious contents (the play in the scene) using contexts and beliefs. Baars indicates that the “director” can take decisions in the field of working memory driven by goal accomplishment. The play director also works behind the scene; this means that usually we have no access to the reasons why we do things. This conception resembles to the ideas of other authors who argue that the conscious self confabulates in order to deduce the reasons why the subject perform the actions (Ronsenthal, 2000; Morin, 2002).

According to Baars, consciousness is the key to access to the vast domain of unconscious knowledge. Consciousness is used for rapid learning and accurate recognition. It also activates a great number of unconscious routines providing coordination and control. Conscious experiences activate unconscious contexts which help to interpret future conscious events. In sum, consciousness provides a framework for global access to the vast unconscious contents of the mind. It seems that recent advances using brain imaging techniques (fMRI, PET, etc.) confirm Baars’ hypothesis. (Baars, 2002, Baars et al. 2003). Anyhow, more neurological insight is needed to completely confirm Baars’ assumptions.


(Baars, 1988) BAARS, B.J. 1988. A Cognitive Theory of Consciousness: Cambridge University Press.

(Baars, 1997) BAARS, B.J. (1997). In the Theater of Consciousness. Global Workspace Theory, A Rigorous Scientific Theory of Consciousness. Journal of Consciousness Studies, 4, pp. 292-309.

(Baars, 2002) BAARS, B.J. (2002). The conscious access hypothesis: Origins and recent evidence. Trends in Cognitive Science, 6, pp. 47-52.

(Baars et al., 2003) BAARS, B.J. RAMSOY, T.Z. y LAUREYS, S. (2003). Brain, conscious experience and the observing self. Trends in Neurosciences. Vol. 26, No. 12, pp. 671-675.

(Crick and Koch, 2003) CRICK, F. y KOCH, C. (2003). A framework for consciousness. Nature Neuroscience, 6. pp. 119-126.

(Crick, 1994) CRICK, Francis. (1994). Astonishing Hypothesis: The Scientific Search for the Soul. Scribner Book Company.

(Morin, 2002) MORIN, A. (2002). Do you “self-reflect” or “self-ruminate”? Science and Consciousness Review. Dec. No. 1.

(Rosenthal, 2000) ROSENTHAL,  D.M. (2000). Metacognition and Higher-Order Thoughts. Consciousness and Cognition 9, pp. 231-242.

The “Machiavellian intelligence” hypothesis

The most popular theory that tries to account for the extremely fast evolution of human brain is the “Machiavellian intelligence” hypothesis (also known as “social brain” hypothesis).

Human brain has evolved much faster than other mammals. In only 25 million years lots of mutations have taken place in many human genes. The Machiavellian intelligence hypothesis might explain this phenomenon, and could give us the reason why we have such a big and complex brain. According to this theory, the intense social competition was (and still is) the main reason why the human brain evolved to a highly complex organ consuming 20% of our energy. Natural selection supported those individuals whose social strategies provided them with social and reproductive success. Sophisticated “Machiavellian” strategies, involving social behaviors like lying, cunning or leadership were the means to be successful in the emerging complex society.

Sergey Gavrilets and Aaron Vose, from the University of Tenesse, have provided data that supports this hypothesis. They have designed a mathematical model to simulate the development of human brain according to the Machiavellian intelligence theory. In their model, the genes control brains that invent and learn social strategies (memes). These strategies are used by males in their competition for mates. The model suggests that cerebral capacity evolves faster that learning capacity, and the advantage of having a large brain decreases as the exposure to memes increase in modern societies.

Source: The dynamics of Machiavellian intelligence . Proc. Natl. Acad. Sci. USA, 10.1073/pnas.0601428103. Abstract.

What is Machine Consciousness?

First of all, I would say that the concept of machine consciousness is not really new. What I think is new is the application of the latest scientific or philosophic models of consciousness in the Artificial Intelligence arena. Basically, machine consciousness central objective is to produce consciousness in an artificial system, and one of the greatest challenges here is to understand what actually a conscious process is. What we currently have is plenty of hypotheses which could be somehow applied to engineered artifacts. However, we don’t know to what extend these hypotheses correlate with the reality of human mind. This is the reason why we always keep a closer look to the latest advances in neuroscience. As the brain and cognitive sciences develop, more insight in the mind processes is gained.

There is no doubt that machine consciousness field has to be related to human consciousness studies (I’d better say scientific consciousness studies in general, as there are proofs of conscious behaviors in other mammals). Therefore, as part of the AI discipline, machine consciousness has to follow a multidisciplinary approach, where neuroscience, philosophy, psychology, physics, etc. All play a significant contribution role to the matter. Obviously, engineering play its central role here as well; at the end of the day, we are talking about machines.

Elephants recognize themselves in the mirror

We already knew that humans, great apes, and dolphins are able to recognize themselves in the mirror. Usually, the rest of higher mammals or other animals think the image in the glass belongs to another individual (if they understand the concept of individual at all). According to the research work done at the Yerkes National Primate Research Center at Emory University, elephants have joined this small group of species able to recognize themselves in the mirror. Scientists exposed elephants to 8’x8′ mirrors and the pachyderms responded with behavior of self-awareness, including touching marks painted on their foreheads, and inspecting their own body.

Scientists say that animals express this ability in four phases. The first one is a social response to the image in the mirror. Secondly, a physical inspection of their own body is performed. And the final recognition of themselves comes after some imitating behaviors. Animals with this ability are self-conscious and generally evolve to more complex social abilities (like empathy). Nevertheless, only one of the elephants participating in the experiment touched the mark painted on his forehead. If the elephant’s self-awareness hypothesis is true, we should expect more experiment results in this way.

More information: Yerkes Primate Research Center

We know the brain as much as Galileo knew the universe

The knowledge we currently have about the human brain is comparable to the knowledge about the Universe we had in Galileo’s time, said the Novel Prize Torsten Wiesel during a meeting in Santiago de Compostela (Spain). Mr. Wiesel argues that plasticity is a key factor in human brain development as many regions of it need stimuli for their development. Wiesel received the Nobel Prize jointly with Hubel thanks to their work on brain visual processing. They demonstrated that the brain needs to configure itself after birth. i.e., even though no physical problem exists, without stimuli there is no brain development.
Within the framework of ConCiencia program, coordinated by the professor Jorge Mira, Mr. Wiesel talked about the challenges of human brain understanding. When he was asked about the percentage of human brain that we currently understand, he answered that our knowledge of human brain is more or less the same as the knowledge we had about the universe in Galileo’s time. Probably, 90% of the mechanisms in the brain are still unknown. Brain imaging techniques are the main advance in the knowledge of the brain. These techniques allow us to study not only isolated cells but brain processes in general, Wiesel said. 

The Complete Work of Charles Darwin Online

In the context of evolutionary computing it is very interesting to know that from October 2006 the University of Cambridge offers the complete work of Charles Darwin online at

The site contains more than 50,000 searchable text pages and 40,000 images of both publications and handwritten manuscripts. There is also the most comprehensive Darwin bibliography ever published and the largest manuscript catalogue ever assembled. More than 150 ancillary texts are also included, ranging from secondary reference works to contemporary reviews, obituaries, published descriptions of Darwin’s Beagle specimens and important related works for understanding Darwin’s context.

There are other two websites referenced in Darwin-Online home providing complementary Darwin materials:


Press release (Oct. 2006)
The largest collection of Darwin’s writings ever published will appear on the website The Complete Work of Charles Darwin Online ( on 19 October 2006. Never before has so much Darwin material, and so many rare and widely dispersed items, been brought together in one place and made available free of charge. This site currently offers more than 50,000 pages of searchable text and 40,000 images of both publications and transcribed manuscripts. Most of the materials are available both as fully formatted electronic text and colour images of the originals. Darwin’s works are also available as free machine-read audio mp3 files. The project, designed and directed by Dr John van Wyhe of Christ’s College, Cambridge, is hosted by the Centre for Research in the Arts, Social Sciences, and Humanities at the University of Cambridge. The launch marks the end of the first year of the three-year’s funding awarded by the Arts and Humanities Research Council.

The website also includes the largest Darwin bibliography ever produced, based on the work of R. B. Freeman, and the largest catalogue of manuscripts (with over 30,000 entries) ever published. More than 150 supplementary documents are also provided, from secondary reference works to contemporary reviews, obituaries, published descriptions of Darwin’s Beagle specimens and important related works for studying and understanding Darwin and his work. Each work containing illustrations or maps is provided with an overview page of thumbnail images allowing readers to see in seconds all the illustrations which are scattered throughout hundreds of pages. The thumbnails take readers directly to the larger version of the image in its context within the original work.

Most of the materials provided are appearing online for the first time such as the first edition of the Journal of Researches (1839) (or Voyage of the</I> Beagle), The descent of Man (1871), The Zoology of the Voyage of H.M.S. Beagle (1838-43) and the 2nd, 3rd, 4th and 5th editions of the Origin of species. There are also many newly transcribed and never before published manuscripts such as Darwin’s Beagle field notebooks. One of these, the notebook in which Darwin recorded his immediate thoughts on the Galapagos, was stolen in the early 1980s and is still missing, but the text has been transcribed from microfilm. The many contributors and benefactors who have kindly helped to create this milestone in Darwin studies can be found on the website’s acknowledgements.
As vast as the collection now is, there is much still to come. The site currently contains about 50% of the materials that will be provided by 2009, the bicentenary of Darwin’s birth and the 150th anniversary of the publication of the Origin of species. Forthcoming materials include further editions and translations, images of the majority of the Darwin Archive at Cambridge University Library, more editorial introductions, notes, transcriptions and technical facilities for printing and larger images. New content is continually being added.

For more information contact:
The Director, Dr John van Wyhe
Centre for Research in the Arts, Social Sciences and Humanities
University of Cambridge

Consciousness in Vegetative State?

As reported last week in Science, a team of researchers in Cambridge have demonstrated that a patient in vegetative state preserved conscious awareness. Using a fMRI scanner the patient showed same activation patterns as healthy volunteers when she was asked to imagine playing tennis. Dr. Adrian Owen, the leader of this research, claim that the vegetative diagnosed brain was able to understand the meaning of sentences and respond consciously. For a detailed description of the research visit the Medical Research Council website. This specific research work is published in Science, 8th September 2006 under the title Detecting Awareness in the Vegetative State.

If these research conclusions are confirmed, it means that current techniques to assess the level of consciousness of humans are not fully valid. One might be unable to move or speak, however that does not neccesarily means that the subject is unable to experience some level of consciousness.

Taking this idea about consciousness level assesment to the field of machine consciousness, one could think about the best way to determine the level of awareness of a robot. Obviously, the first reference is always the Turing test. However, as demonstrated in humans, a purely external evaluation could not be valid in terms of assessing the real level of consciousness of an artificial entity. Anyway, from a strictly engineering point of view this question is irrelevant.

What is is an Internet portal dedicated to the scientific research in Machine Consciousness. This field of artificial intelligence is very much related to cognitive robotics, and the following terms are often used as synonyms: Artificial Consciousness, Synthetic Consciousness and Robot Consciousness. Although much more detailed definitions can be found in these web pages, we could briefly define Machine Consciousness as the research on producing consciousness in an artificial device (like a robot) using engineering techniques. Understanding human consciousness is a great challenge, hence Machine Consciousness problem is even harder. There is no doubt that these problems have to be addressed from multiple disciplines. This site aim to follow this multidisciplinary approach including information and resources from many fields, from philosophy to genetic programming. offers the following content:
  • Resources, publications and information about Machine Consciousness research and related AI techniques.
  • Latest news and reviews about conscious software, conscious machines and robots used for research in machine consciosness.
  • Discussion Forums about Machine consciousness and related fields (Forums section).
  • Almost real time news feeds from many sources related to machine consciousness, AI and neuroscience (News feeds section).
  • Microsoft Robotics Studio Developer 2008 Pages.