Information is typically packaged. The smallest unit of information (something like a bit) (see August 23, 2009 and August 17, 2009 posts) has limited meaning (information value) on its own. Aggregating, absorbing, connecting, colliding, and communicating with other units of information expands the information value associated with the package of bits. These packages of information include small subatomic units, electrons, atoms, chemical compounds, photons, waves of sound and light, proteins, genotypes, cells, organs, phenotypes, letters, words, songs, books, and culture. (See November 27, 2010 post).
Information migrates. (See May 20, 2012 post) It is in nearly constant motion. And when it is in motion, information can be altered and its meaning changed. (See August 15, 2011 and August 23, 2009 posts). Sometimes information is degraded by change; sometimes information is enhanced. Information moves with its package; the package migrates, and information moves along. Genes, Peoples and Languages is about the movement of genetic information in the package of a phenotype and the scientific quest to track the movement and transformation of modern human genes over the course of roughly one hundred thousand years. And along the way, as a result of natural selection, and in some geographic areas, genetic drift, the information in this genetic package was edited and revised from the general population that preceded it: hair texture and color changed, skin color changed, small genetic changes enabled humans to digest milk, immunized them from diseases such as malaria in certain areas, morphologies changed, and so on.
This research supports the Out of Africa hypothesis: that modern human origins begin on the African continent approximately 100,000 years ago, likely in southern Africa; that intra-continental African migration ensued northward along East Africa in the thousands of years afterward; and the first migration of homo sapiens out of Africa occurred roughly 50-60,000 years ago to the Arabian peninsula and the Levant, likely along the coast, and ultimately to southern Asia (India), southeast Asia, and Oceania (Australia) about 45,000 years ago. And about the same time that modern humans were reaching Oceania, migrations out of the Levant northward in the direction of Europe, and later in the direction of central Asia and ultimately to North America roughly 15,000 years ago. What should not be forgotten in this focus on modern human migration is that a similar migratory path may have been taken over a million years earlier by homo erectus.
Cavalli-Sforza sees a parallel between genetic evolution and cultural evolution. The units and type of information as well as the means of information transmission in these two circumstances, however, are radically different. Speech acts (including rituals) and language are the means of transmitting cultural information, and Cavalli-Sforza treats linguistic evolution as a type of cultural evolution. But genes and culture do not co-evolve. As mentioned in an earlier post, "Language is a social institution, and social institutions and culture evolve, albeit at a different and faster pace than biological evolution." (August 31, 2009 post). Language changes can occur as a result of migration and conquest of another's territory. Cavalli-Sforza documents this in a number of cases. Religion is another attribute of culture that likewise can change as a result of migration and conquest. (See May 12, 2010 post). And ideas can change as a result of migration and conquest. (See May 20, 2012 post). "There is a fundamental difference between biological and cultural mutation," writes Cavalli-Sforza. "Cultural mutations may result from random events, and thus be very similar to genetic mutations, but cultural changes are more often intentional or directed to a very specific goal, while biological mutations are blind to their potential benefit. At the level of mutation, cultural evolution can be directed while genetic change cannot." Later he adds, "We must note a significant difference between biological and linguistic mutation. A genetic mutant is generally very similar to the original gene, since one gives rise to another with only a small change. Words vary in more complicated ways. The same root can change meaning. One word can have may unrelated senses. One could try to establish greater similarities between genes and words taking into account all of the peculiarities, but it is not clear that would be useful." The curious aspect of Cavalli-Sforza's discussion of biological and cultural evolution and transmission is the absence of any discussion of the evolutionary debate about whether evolution operates on genes, phenotypes, or groups that has laced this subject for several decades now. (See November 4, 2009, November 30, 2009, September 12, 2012, and September 17, 2012 posts). References to Richard Dawkins, memes, and Edward Wilson are not to be found. Cavalli-Sforza's discussion on this subject is disjointed, and one wonders how he would treat the subject of the unit of information on which evolution operates.
Showing posts with label language evolution. Show all posts
Showing posts with label language evolution. Show all posts
Wednesday, September 25, 2013
Tuesday, October 25, 2011
V.S. Ramachandran, The Tell-Tale Brain (2011)
My original expectations for this book never materialized, but still there was much learned . From my cursory examination in the bookstore, I was expecting to learn something about the role of the brain in creating art, particularly storytelling, works of fiction and imagination. I noticed a couple of chapters on art and aesthetics, but these turned out to be ruminations and speculation on the role of the brain in appreciating visual arts. That is not to say these ruminations were without value, but only that I was expecting a different treatment of the subject.
Second, I knew that V.S. Ramachandran , one of the world's leading neuroscientists, promoted research findings about mirror neurons, a subject that was covered in the September 18, 2009 post discussing Marco Iacoboni's book, Mirroring People. Ramachandran, however, despite his disclaimer that mirror neurons do not explain everything about the brain, seems to suggest that they explain an awful lot: certainly a lot more than the subtitle of Iacoboni's book suggests --- empathy for others and how we are able to comprehend the actions and perhaps the intentions of others from their body movements. Ramachandran suggests that mirror neurons may also be key to understanding our own self-awareness: awareness of what our own mind is thinking. Regrettably, the proof is not yet there to support his surmises in this regard; too often Ramachandran says that this area of the brain is involved in such and such, and that area of the brain is known to be rich in mirror neurons, and with that association it might be the case that mirror neurons explain such and such. That is not to say he is wrong, but he may be more right than wrong when he says that mirror neurons do not explain everything.
Here is an example of what I just said. Ramachandran strongly believes that mirror neurons, while initially identified in monkeys, are an important piece in understanding human evolution. "[O]nly in humans do they seem to have developed to the point of being able to model aspects of others' minds rather than merely their actions. Inevitably this would have required the development of additional connections to allow a more sophisticated deployment of such circuits in complex social situations. . . It is difficult to overstate the importance of understanding mirror neurons and their function. They may well be central to social learning, imitation, and the cultural transmission of skills and attitudes --- perhaps even of the pressed-together sound clusters we call 'words.' By hyperdeveloping the mirror-neuron system, evolution in effect turned culture into the new genome. Armed with culture, humans could adapt to hostile new environments and figure out how to exploit formerly inaccessible or poisonous food sources in just one or two generations --- instead of the hundreds or thousands of generations such adaptations would have taken to accomplish through genetic evolution." This is an astonishing hypothesis, to borrow a phrase from Francis Crick. But Ramachandran strongly believes he is on to something because of the presence of mirror neurons located in certain parts of the human brain that are relatively unique to humans, in contrast to the apes, our nearest relative. Ramachandran is referring to Wernicke's area in the left temporal lobe (the area of the brain that is responsible for our comprehension of language -- where speech acquires meaning), the prefrontal cortex (an area responsible for decision-making and cognition, which includes the motor cortex where commands are sent to muscles for movement, and it includes Broca's area, which is responsible for speech), and the inferior parietal lobe (IPL). In humans, Ramachandran notes, the IPL evolved into two parts not found in apes --- the supramarginal gyrus (an area responsible for our ability to "visualize" words and action) and the angular gyrus (an area of the brain that Ramachandran says is connected to metaphor comprehension, but also finding a common denominator between two superficially dissimilar things). The genetic change that created these areas of the brain "rich in mirror neurons," surmises Ramachandran, "freed us from genetics by enhancing our ability to learn from one another" --- "liberat[ing] our brain from its Darwinian shackles, allowing the rapid spread of unique inventions" (tools, new words, constructing shelter, creating communities) that are at the foundation of culture. "Instead, increased sophistication of a single mechanism --- such as imitation and intention reading --- could explain the huge behavior gap between us and apes."
Ramachandran is a neuroscientist who has a wealth of clinical research observations about damage to specific areas of the brain and the consequences of that damage. And with that wealth, my appreciation for the role of specific areas of the brain and their connections to other areas of the brain during normal operations continued to grow. Other books, some of which are discussed in previous posts, have contributed to my appreciation, but Ramachandran's presentation in this book, including his drawings of the regions of the brain together with his glossary and specific case studies begins to put it all together. From a big picture point of view, with this book Ramachandran is pursuing the same subjects that Michael Gazzaniga pursued in examining what makes us "human" (see September 27, 2009 post) and that Antonio Damasio pursued in examining what creates our sense of self (see April 8, 2011 post). And Ramachandran contributes his own views on the origin of human language, a subject that was extensively reviewed in Christine Kenneally's The First Word (see August 31, 2009 post).
Let's discuss Ramanchandran on the evolution of language, because this is really the part of The Tell-Tale Brain that demonstrates what I have just said about this book. In discussing the evolution of language, Christine Kenneally reviews the views of Noam Chomsky (language is not the outcome of evolution, but is simply a built-in property of the brain), Stephen J. Gould (language initially evolved as a way to represent the world --- namely thinking about the world, and only later became a means of communication), and Steven Pinker (language is an instinct, an adaptation that is unique to humans that evolved specifically for communications purposes). Ramachandran does likewise, dismisses Chomsky quickly (his thesis cannot be tested), and then says that there is a grain of truth to both Gould and Pinker, but they just did not go far enough. For Ramanchandran, language did not evolve from some general mechanism for thinking, but neither did it evolve specifically for purposes of communication. What is innate and what evolved, says Ramachandran, is the competence to acquire rules of language. The actual acquisition of language occurs as a result of social interaction. Ramachandran believes that language was enabled by cross linkages in the brain between different motor maps (e.g. the area responsible for manual gestures and the area responsible for orafacial movements). Ramachandran calls this synkinesia ("together" "movement"), but he is borrowing from research on synesthesia, a brain phenomenon where senses are joined by cross-activation of two sensory maps. Thus what humans have is a built-in capacity to for translating gestures (movement) into words. The original "words," if you will, may have been grunts or other noises that accompanied a gesture (a proto-language). Synkinesia alone probably does not explain speech and language, but the human capacity for mimicry is critical as well, and hence the subject of mirror neurons enters the discussion of speech development, and again we return to the linkages between Broca's area, Wernicke's area, and the supramarginal gyrus and the angular gyrus in the IPL that enable what Ramachandran labels "cross-modal abstraction."
Ramachandran borrows from Gould the latter's concept of exaptation. An adaptation is an evolutionary response to natural selection. An exaptation is a refinement of an adaptation whereby a function is borrowed and used for a different function. Ramachandran believes that the IPL did not evolve for higher forms of abstraction such as giving names (words) to something, but evolved to provide hominids for refined interaction between vision and muscle and joint position while negotiating branches on tree top, a type of cross-modal abstraction. A subsequent exaptation was the development of these areas of the brain --- and their capacity for abstraction --- to develop tools and subassemblies of tools (e.g. an axehead and a suitably designed handle), says Ramachandran. He sees "a tantalizing resemblance" between the wielding of a tool made from composite parts and a full blown sentence including noun phrases and verbs. Speech, including syntax, emerged from the area of the brain that was key to tool manufacture, he speculates, and this became Broca's area. Add to that the areas of the parietal lobe (Wernicke's area and the IPL) and the human brain now has a language acquisition device. By the end of his discourse, Ramachandran concedes that he has been speculating on the evolution of language and thought, and he still has not resolved it, but he believes that it is not inconsistent with what neurologists know about patients who are damaged in these areas of the brain, and what we know about the evolution of other body parts. The problem is that language and abstraction are "software," and they can't be found in the fossil record that is all we have to understand what happened tens and hundreds of thousands of years ago. Unlike Christine Kenneally, Ramachandran does not discuss the debate over the FOXP2 gene and its possible connection to human language. Ramachandran asks, why were genes for language competence selected, but he does not illuminate what those genes might be., and perhaps that is because he recognizes that language is the outcome a several different modules in the brain, and there can be no single gene that would explain that fact.
There is much more to this book than just mirror neurons and the evolution of language, but there are discussions of memory, brain plasticity, the self, and free-will. Marco Iacoboni believes that, in view of research on mirror neurons and social behavior, the concepts of the self and free-will are blurred --- at least our Western sense of the individual is not as real as we sometimes think. (See September 18, 2009 post). Just how "free" and unique are we? he asks: Self and other are inextricably blended, says Iacoboni, and our behavior is subtly influenced by mirror neurons which produce automatic imitative influences based on what others are doing or saying. Iacoboni believes we have only "limited autonomy." Ramachandran does not touch this subject, but he does profess that humans have a sense of agency --- a desire to act and our belief in our ability to perform that act. Ramachandran says that there is evidence that the anterior cingulate in the frontal lobe is involved with wanting and intention. Damage to this area leads to apathy. The anterior cingulate, says Ramachandran, receives inputs from the parietal lobe, including the supramarginal gyrus, which as noted above, is involved with our ability to conjure up images of action (movement). These connections lead Ramachandran to believe there may be a neurological basis for free-will, signifying that it is not just a philosophical problem.
Ramachandran summarizes the current state of neuroscience with a comparison to chemistry: neuroscience is now at about the same stage that chemistry was in the 19th century, discovering the basic elements, grouping them into categories, and studying their interactions. As neuroscientists "map" the brain, they are "grouping their way toward the periodic table" of elements, but are not anywhere near atomic theory. As I noted in a previous post (see January 21, 2011 post and April 8, 2011 post), this is not fatal to the proposition that the era of skepticism is over. Ramachandran notes numerous experiments that remain to be started that would confirm one hypothesis or another.
And a final note. While Ramachandran failed to provide specific insight into how the brain creates art or fiction, on reflection, the elements of that mechanism may very well have been covered. We are, after all, talking about imagination, and the parts of the brain that enable abstraction, when combined with the parts of the brain that enable language (not just speech, but semantic content as well), when combined with the parts of the brain that enable us assemble things and to mimic what others do, must be involved in the creation of fiction and other forms of art that are the production of imagination.
Second, I knew that V.S. Ramachandran , one of the world's leading neuroscientists, promoted research findings about mirror neurons, a subject that was covered in the September 18, 2009 post discussing Marco Iacoboni's book, Mirroring People. Ramachandran, however, despite his disclaimer that mirror neurons do not explain everything about the brain, seems to suggest that they explain an awful lot: certainly a lot more than the subtitle of Iacoboni's book suggests --- empathy for others and how we are able to comprehend the actions and perhaps the intentions of others from their body movements. Ramachandran suggests that mirror neurons may also be key to understanding our own self-awareness: awareness of what our own mind is thinking. Regrettably, the proof is not yet there to support his surmises in this regard; too often Ramachandran says that this area of the brain is involved in such and such, and that area of the brain is known to be rich in mirror neurons, and with that association it might be the case that mirror neurons explain such and such. That is not to say he is wrong, but he may be more right than wrong when he says that mirror neurons do not explain everything.
Here is an example of what I just said. Ramachandran strongly believes that mirror neurons, while initially identified in monkeys, are an important piece in understanding human evolution. "[O]nly in humans do they seem to have developed to the point of being able to model aspects of others' minds rather than merely their actions. Inevitably this would have required the development of additional connections to allow a more sophisticated deployment of such circuits in complex social situations. . . It is difficult to overstate the importance of understanding mirror neurons and their function. They may well be central to social learning, imitation, and the cultural transmission of skills and attitudes --- perhaps even of the pressed-together sound clusters we call 'words.' By hyperdeveloping the mirror-neuron system, evolution in effect turned culture into the new genome. Armed with culture, humans could adapt to hostile new environments and figure out how to exploit formerly inaccessible or poisonous food sources in just one or two generations --- instead of the hundreds or thousands of generations such adaptations would have taken to accomplish through genetic evolution." This is an astonishing hypothesis, to borrow a phrase from Francis Crick. But Ramachandran strongly believes he is on to something because of the presence of mirror neurons located in certain parts of the human brain that are relatively unique to humans, in contrast to the apes, our nearest relative. Ramachandran is referring to Wernicke's area in the left temporal lobe (the area of the brain that is responsible for our comprehension of language -- where speech acquires meaning), the prefrontal cortex (an area responsible for decision-making and cognition, which includes the motor cortex where commands are sent to muscles for movement, and it includes Broca's area, which is responsible for speech), and the inferior parietal lobe (IPL). In humans, Ramachandran notes, the IPL evolved into two parts not found in apes --- the supramarginal gyrus (an area responsible for our ability to "visualize" words and action) and the angular gyrus (an area of the brain that Ramachandran says is connected to metaphor comprehension, but also finding a common denominator between two superficially dissimilar things). The genetic change that created these areas of the brain "rich in mirror neurons," surmises Ramachandran, "freed us from genetics by enhancing our ability to learn from one another" --- "liberat[ing] our brain from its Darwinian shackles, allowing the rapid spread of unique inventions" (tools, new words, constructing shelter, creating communities) that are at the foundation of culture. "Instead, increased sophistication of a single mechanism --- such as imitation and intention reading --- could explain the huge behavior gap between us and apes."
Ramachandran is a neuroscientist who has a wealth of clinical research observations about damage to specific areas of the brain and the consequences of that damage. And with that wealth, my appreciation for the role of specific areas of the brain and their connections to other areas of the brain during normal operations continued to grow. Other books, some of which are discussed in previous posts, have contributed to my appreciation, but Ramachandran's presentation in this book, including his drawings of the regions of the brain together with his glossary and specific case studies begins to put it all together. From a big picture point of view, with this book Ramachandran is pursuing the same subjects that Michael Gazzaniga pursued in examining what makes us "human" (see September 27, 2009 post) and that Antonio Damasio pursued in examining what creates our sense of self (see April 8, 2011 post). And Ramachandran contributes his own views on the origin of human language, a subject that was extensively reviewed in Christine Kenneally's The First Word (see August 31, 2009 post).
Let's discuss Ramanchandran on the evolution of language, because this is really the part of The Tell-Tale Brain that demonstrates what I have just said about this book. In discussing the evolution of language, Christine Kenneally reviews the views of Noam Chomsky (language is not the outcome of evolution, but is simply a built-in property of the brain), Stephen J. Gould (language initially evolved as a way to represent the world --- namely thinking about the world, and only later became a means of communication), and Steven Pinker (language is an instinct, an adaptation that is unique to humans that evolved specifically for communications purposes). Ramachandran does likewise, dismisses Chomsky quickly (his thesis cannot be tested), and then says that there is a grain of truth to both Gould and Pinker, but they just did not go far enough. For Ramanchandran, language did not evolve from some general mechanism for thinking, but neither did it evolve specifically for purposes of communication. What is innate and what evolved, says Ramachandran, is the competence to acquire rules of language. The actual acquisition of language occurs as a result of social interaction. Ramachandran believes that language was enabled by cross linkages in the brain between different motor maps (e.g. the area responsible for manual gestures and the area responsible for orafacial movements). Ramachandran calls this synkinesia ("together" "movement"), but he is borrowing from research on synesthesia, a brain phenomenon where senses are joined by cross-activation of two sensory maps. Thus what humans have is a built-in capacity to for translating gestures (movement) into words. The original "words," if you will, may have been grunts or other noises that accompanied a gesture (a proto-language). Synkinesia alone probably does not explain speech and language, but the human capacity for mimicry is critical as well, and hence the subject of mirror neurons enters the discussion of speech development, and again we return to the linkages between Broca's area, Wernicke's area, and the supramarginal gyrus and the angular gyrus in the IPL that enable what Ramachandran labels "cross-modal abstraction."
Ramachandran borrows from Gould the latter's concept of exaptation. An adaptation is an evolutionary response to natural selection. An exaptation is a refinement of an adaptation whereby a function is borrowed and used for a different function. Ramachandran believes that the IPL did not evolve for higher forms of abstraction such as giving names (words) to something, but evolved to provide hominids for refined interaction between vision and muscle and joint position while negotiating branches on tree top, a type of cross-modal abstraction. A subsequent exaptation was the development of these areas of the brain --- and their capacity for abstraction --- to develop tools and subassemblies of tools (e.g. an axehead and a suitably designed handle), says Ramachandran. He sees "a tantalizing resemblance" between the wielding of a tool made from composite parts and a full blown sentence including noun phrases and verbs. Speech, including syntax, emerged from the area of the brain that was key to tool manufacture, he speculates, and this became Broca's area. Add to that the areas of the parietal lobe (Wernicke's area and the IPL) and the human brain now has a language acquisition device. By the end of his discourse, Ramachandran concedes that he has been speculating on the evolution of language and thought, and he still has not resolved it, but he believes that it is not inconsistent with what neurologists know about patients who are damaged in these areas of the brain, and what we know about the evolution of other body parts. The problem is that language and abstraction are "software," and they can't be found in the fossil record that is all we have to understand what happened tens and hundreds of thousands of years ago. Unlike Christine Kenneally, Ramachandran does not discuss the debate over the FOXP2 gene and its possible connection to human language. Ramachandran asks, why were genes for language competence selected, but he does not illuminate what those genes might be., and perhaps that is because he recognizes that language is the outcome a several different modules in the brain, and there can be no single gene that would explain that fact.
There is much more to this book than just mirror neurons and the evolution of language, but there are discussions of memory, brain plasticity, the self, and free-will. Marco Iacoboni believes that, in view of research on mirror neurons and social behavior, the concepts of the self and free-will are blurred --- at least our Western sense of the individual is not as real as we sometimes think. (See September 18, 2009 post). Just how "free" and unique are we? he asks: Self and other are inextricably blended, says Iacoboni, and our behavior is subtly influenced by mirror neurons which produce automatic imitative influences based on what others are doing or saying. Iacoboni believes we have only "limited autonomy." Ramachandran does not touch this subject, but he does profess that humans have a sense of agency --- a desire to act and our belief in our ability to perform that act. Ramachandran says that there is evidence that the anterior cingulate in the frontal lobe is involved with wanting and intention. Damage to this area leads to apathy. The anterior cingulate, says Ramachandran, receives inputs from the parietal lobe, including the supramarginal gyrus, which as noted above, is involved with our ability to conjure up images of action (movement). These connections lead Ramachandran to believe there may be a neurological basis for free-will, signifying that it is not just a philosophical problem.
Ramachandran summarizes the current state of neuroscience with a comparison to chemistry: neuroscience is now at about the same stage that chemistry was in the 19th century, discovering the basic elements, grouping them into categories, and studying their interactions. As neuroscientists "map" the brain, they are "grouping their way toward the periodic table" of elements, but are not anywhere near atomic theory. As I noted in a previous post (see January 21, 2011 post and April 8, 2011 post), this is not fatal to the proposition that the era of skepticism is over. Ramachandran notes numerous experiments that remain to be started that would confirm one hypothesis or another.
And a final note. While Ramachandran failed to provide specific insight into how the brain creates art or fiction, on reflection, the elements of that mechanism may very well have been covered. We are, after all, talking about imagination, and the parts of the brain that enable abstraction, when combined with the parts of the brain that enable language (not just speech, but semantic content as well), when combined with the parts of the brain that enable us assemble things and to mimic what others do, must be involved in the creation of fiction and other forms of art that are the production of imagination.
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