February 16, 2006

Consciousness, evolution, language and social behavior

A History of Knowledge Piero Scaruffi Editor of
Wilson-Edward Osborne, the founder of "sociobiology", applied the principles of Darwinian evolution to behavior, believing that the social behavior of animals and humans can be explained from the viewpoint of evolution.
Richard Dawkins pointed out that one can imagine a Darwinian scenario also for the evolution of ideas, which he called "memes". A meme is something that infects a mind (a tune, a slogan, an ideology, a religion) in such a way that the mind feels the urge to communicate it to other minds, thus contributing to spreading it. As memes migrate from mind to mind, they replicate, mutate and evolve. Meme are the cultural counterpart of genes. A meme is the unit of cultural evolution, just like a gene is the unit of biological evolutionJust like genes use bodies as vehicles to spread, so memes use minds as vehicles to spread. The mind is a machine for copying memes, just like the body is a machine for copying genes. Memes have created the mind, not the other way around.
Dawkins held the view that Darwinian evolution was driven by genes, not by bodies. It is genes that want to live forever, and that use bodies for that purpose. To Dawkins, evolution is nothing but a very sophisticated strategy for genes to survive. What survives is not my body but my genes. Dawkins also called attention to the fact that the border of a "body" (or, better, phenotype) is not so obvious: a spider would not exist without its cobweb. Dawkins' "extended phenotype" includes the world that an organism interacts with. The organism alone is an oversimplification, and does not really have biological relevance.
Stuart Kauffman and others saw "self-organization" as a general property of the universe. Both living beings and brains are examples of self-organizing systems. Evolution is a process of self-organization. The spontaneous emergence of order, or self-organization of complex systems, is ubiquitous in nature. Kauffman argued that self-organization is the fundamental force that counteracts the universal drift towards disorder. Life was not only possible and probable, but almost inevitable.
Linguistics focused on metaphor as more than a poetic tool. George Lakoff argued that language is grounded in our bodily experience, that language is "embodied". Our bodily experience creates our concepts. Syntax is created by our bodily experience. The "universal" grammar shared by all humans is due to the fact that we all share roughly the same bodily experience. The process by which we create concepts out of bodily experience is metaphor, the process of experiencing something in terms of something else. The entire human conceptual system is metaphorical, because a concepts can always be understood in terms of less abstract concepts, all the way down to our bodily experience. No surprise that we understand the world through metaphors, and we do so without any effort, automatically and unconsciously. Lakoff held that language was created to deal with physical objects, and later extended to non-physical objects by means of metaphors. Thus metaphor is biological: our brains are built for metaphorical thought.
Dreams continued to fascinate neurologists such as Allan Hobson and Jonathan Winson, as new data showed that the brain was "using" sleep to consolidate memories. Dreams are a window on the processing that goes on in the brain while we sleep. The brain is rapidly processing a huge amount of information, and our consciousness sees flashes of the bits that are being processed. The brain tries to interpret these bits as narratives, but, inevitably, they look "weird". In reality, there is no story in a dream: it is just a parade of information that is being processed. During REM sleep the brain processes information that accumulated during the day. Dreams represent "practice sessions" in which animals refine their survival skills. Early mammals had to perform all their "reasoning" on the spot. Modern brains have invented a way to "postpone" processing sensory information.
Colin McGinn was skeptic that any of this could lead to an explanation of what consciousness is and how it is produced by the brain. He argued that we are not omnipotent: like any other organisms, there may be things that we just can't conceive. Maybe consciousness just does not belong to the "cognitive closure" of our organism. In other words, understanding our consciousness is beyond our cognitive capacities. The search for consciousness inside the brain took an unexpected turn when a mysterious biorhythm of about 40 Hertz was detected inside the brain. The traditional model for consciousness was "space-based binding": there must be a place inside the brain where perceptions, sensations, memories and so forth get integrated into the "feeling" of my consciousness.
Thus Gerald Edelman and Antonio Damasio hypothesized mechanisms by which regions of the brain could synthesize degrees of consciousness. Damasio realized that the "movie in the mind" consciousness caused by the flow of sensory inputs was not enough to explain self-awareness. He believed that "Self" consciousness reqired a topography of the body and a topography of the environment, that ultimately the "self" originated from its juxtaposition against the "non-self". An "owner" and "observer" of the movie is created within a second-order narrative of the self interacting with the non-self. The self is continuously reconstructed via this interaction. The "I" is not telling the story: the "I" is created by stories told in the mind.
Francis Crick launched the opposite paradigm ("time-based binding") when he speculated that synchronized firing (the 40 Hertz biorhythm) in the region connecting the thalamus and the cortex might "be" a person's consciousness. Instead of looking for a "place" where the integration occurs, Crick and others started looking for integration in "time". Maybe consciousness arises from the continuous dialogue between regions of the brain.
Rodolfo Llinas noticed a possible implication of this viewpoint. It looks like neurons are active all the time. We do not control our neurons, no more than we control our blood circulation. In fact, neurons are always active, even when there are no inputs. Neurons operate at their own pace, regardless of the pace of information. A rhythmic system controls their activity, just like rhythmic systems control heartbeat or breathing. It seems that neurons are telling the body to move even when the body is not moving. Neurons generate behavior all the time, but only some behavior actually takes place. It sounds like Jerne's model all over again: it is the environment that selects which movement the body will actually perform. Consciousness is a side-effect: the thalamus calls out all cortex cells that are active, and the response "is" consciousness.
How consciousness was produced by evolution was a fascinating mystery in itself. Graham Cairns-Smith turned the conventional model upside down when he claimed that emotions came first. A rudimentary system of feelings was born by accident during evolution. That system proved to be useful for survival, and therefore evolved. The organism was progressively flooded with emotions until a "stream of consciousness" appeared. Language allowed to express it in sounds and thoughts instead of mere facial expressions. Then the conscious "I" was born.

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