Interview with Rodolfo Llinás

This is a link to an interview with Rodolfo Llinás conducted by Sérgio Strejilevich in Brain & Mind electronic magazine on Neuroscience:

The body of the interview (excerpt from Brain & Mind electronic magazine number 6. June 1998) is also available below.

Continue reading “Interview with Rodolfo Llinás”

Consciousness and Cognition

Consciousness and Cognition: An International Journal provides a forum for a natural-science approach to the issues of consciousness, voluntary control, and self. The journal features empirical research (in the form of regular articles and short reports) and theoretical articles. Book reviews, integrative theoretical and critical literature reviews, and tutorial reviews are also published. The journal aims to be both scientifically rigorous and open to novel contributions.

Topics of interest include but are not limited to:

• Implicit memory
• Selective and directed attention
• Priming, subliminal or otherwise
• Neuroelectric correlates of awareness and decision-making
• Assessment of awareness; protocol analysis
• The properties of automaticity in perception and action
• Relations between awareness and attention
• Models of the thalamocortical complex
• Blindsight
• The neuropathology of consciousness and voluntary control
• Pathology of self and self-awareness
• The development of the self-concept in children

 Visit Elsevier Consciousness and Cognition description page.

Association for the Scientific Study of Consciousness

ASSC promotes research within cognitive science, neuroscience, philosophy, and other relevant disciplines in the sciences and humanities, directed toward understanding the nature, function, and underlying mechanisms of consciousness.

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.

References

(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.

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. 

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.