lundi 18 décembre 2017

Evolution of Consciousness

“Thinking”: The Evolutionary Catalyst for “Consciousness”

Introduction


I believe that many human traits as we know them, such as consciousness and language, are results of evolutionary adaptations that resulted in the first "thought". I believe that “thinking” sparked the incredibly rapid evolution of the human brain, relatively speaking, by means of an intra-species evolutionary arms race. As new and better forms of “thinking” became more important for the survival and fitness of the individuals within and between communities, traits that mutated which allowed individuals to express, understand, monitor and control the “thinking” of themselves and the “thinking” of others would be selected for and allowed to propagate through the gene pool. Twisted mirror neurons were crucial in this evolutionary arms race and I suspect the first “thought” was the result of a twisted mirror neuron creating an internal referential gesture. I will explain, and this has many implications.

Evolutionary Setting


Evolution is driven by selection pressures, with the biggest threats to survival and reproduction driving the natural selection of favorable traits from random mutations. Our most recent evolutionary ancestors were bipeds, nomadic, omnivorous, self-aware, capable of simple problem solving, referential gestures and vocalizations, lived in communities, etc. As our ancestors reached this stage of evolution, they became more reliant on their community to provide insulation via food, child rearing, protection, etc. The community allowed each individual to become more and more resistant to external selection pressures; due to both their relative dominance over other species/nature and the fact that the greatest threat to the survival of their genes would be the destruction of or disbarment from their community (1).

This means that mutations with adaptive value to the social cooperation both within and between communities would be strongly selected and propagate through the population. Meanwhile, if a cheater mutation occurred that enhanced an individual’s fitness while threatening the social cooperation of the community, both the damage to this social cooperation and the damage to every other individuals genetic fitness would act as selection pressures for natural selection of traits that counter the evolutionary advantage of the cheater. These two groups would have children together that possessed both traits, and the arms race would continue and intensify as cheaters had selection pressures to cheat better, anti-cheaters had selection pressures to police better, and individuals with both traits had selection pressures to monitor their own cheating and anti-cheating behavior (2). I believe these evolutionary conditions allowed such an intra-species evolutionary arm race to occur, sparked by the first “thought”, which led to the relatively rapid expansion in the size and capabilities of the human brain (1,3).

References


(1) Ecological dominance, social competition, and coalitionary arms races: Why humans evolved extraordinary intelligence. Mark Flinn, David Geary, Carol Ward. 2005. Evolution and Human Behavior 26 10-46
“He argued that as our hominin ancestors became increasing able to master the traditional hostile forces of nature, selective pressures resulting from competition among conspecifics became increasingly important, particularly in regard to social competencies. Given the precondition of competition among kin- and reciprocity-based coalitions (shared with chimpanzees), an autocatalytic social arms race was initiated, which eventually resulted in the unusual collection of traits characteristic of the human species, such as concealed ovulation, extensive biparental care, complex sociality, and an extraordinary collection of cognitive abilities.

(2) Manhes P, Velicer GJ. Experimental evolution of selfish policing in social bacteria. Proceedings of the National Academy of Sciences of the United States of America. 2011;108(20):8357-8362. doi:10.1073/pnas.1014695108.
"In nature, evolution within cheater-infected lineage groups may proceed faster than the rate at which cheaters are passively lost from a population due to kin selection operating at the group level. Thus, local cheater frequencies might often be shaped by complex coevolutionary arms races in which diverse cooperators, cheaters, and policers cycle through phases of exploitation and resistance among socially cotransmitted lineages."

(3) Literary Darwinism: Evolution, Human Nature, and Literature, By Joseph Carroll
"In cheating and the detection of cheating, some Darwinian social thinkers see an evolutionary arms race that is in large measure responsible for the development of human intelligence

Thoughts: Internal Referential Communication

What is a “thought”? According to google dictionary: "an idea or opinion produced by thinking or occurring suddenly in the mind." I believe a “thought” can best be described as an internal referential communication, which makes “thinking” the active processing of internal referential communications. Let me explain.

A referential communication, as documented in science, is when gestures or vocalizations are produced for the purpose of attracting the attention of another to a particular aspect of the environment for the purpose of eliciting a specific behavior. Two examples include the shouting of alarm calls, which alert others to run from a predator, and pointing at an itchy spot on one's body for another to scratch. Referential communication is considered by some to be the closest animal communication system to human language, though it falls short in many ways, as it is displayed in some of the most intelligent non-human species such as apes and corvids (4).

With this definition of a referential communication in mind, a hypothetical internal referential communication is thus an internal gesture or vocalization, or simply the memory of a gesture or vocalization, activated for the purpose of attracting the attention of only oneself to a particular aspect of the environment for the purpose of eliciting a specific behavior.

I believe the internalization of referential communications sparked the “arms race” as described above because internal referential communications are a form of cheating which threatens both social cooperation and the reproductive success of the other individuals in the community. To use an example, consider a hypothetical evolutionary path of mutations on referential vocalizations; in particular, alarm calls. The idea of an alarm call is that an organism draws attention to himself by shouting an alarm and pointing out a predator, hurting his chances of survival but increasing the chances of survival of his community.

Imagine one individual had a mutation such that he heard his own alarm call while he was calling and processed it and reacted to it as though it had come from someone else - by hearing it, experiencing intense fear and running - involuntarily altering his behavior, but increasing his chances of survival and thus passing on his genes. In this scenario, he has not associated fear with the predator, but with his own alarm calling behavior, essentially “learning” that it is not a wise thing.

The next time our individual was in a similar situation to call he would no longer react to the predator, but to this newly formed fear associated with the memory of his own alarm calling behavior, and to avoid that fear he would run. In this sense, the memory of his own alarm call became an internal referential vocalization, as the memory of the alarm call directed only the attention of the individual to the predator and the need to run away. This allowed the individual to “cheat”, creating a selection pressure for the evolution of policing behavior and igniting the arms race, as described above (5).
While hypothetical, this example is comparable beyond alarm calls to many situations where it would be favorable for an individual to internalize a referential communication and, once the system became further evolved, to alter many behaviors - by reexperiencing the effects of that behavior before actually behaving; by thinking before acting.

References

(4) https :// www . psychologytoday. com/blog/animal-emotions/201305/fish-use-referential-gesture-communicate-during-hunting

I don’t know of anyone who writes about internal referential communication. But there is evidence to support the concept the way I have described it. For example,

(5) Language Evolution: The Origin of Meaning in Primates. School of Psychology, University of St Andrews, St Andrews KY16 9JP, UK.
"These findings were interpreted as evidence of the males’ ability to keep track and remember which group members had and had not given alarm calls."

This is a perfect example of a “policing" trait that could be selected for in the intra-species arms race were "cheaters" to emerge who were able to repress their alarm calls.

Further, to quote myself, “consider if one individual had a mutation such that he heard his own alarm call while he was calling and processed it and reacted to it as though it had come from someone else”

Now consider mirror neurons. From Wikipedia: A mirror neuron is a motor neuron that fires both when an animal acts and when the animal observes the same action performed by another. These neurons are suspected to have been important in the evolution of human empathy, language, awareness, and consciousness by modern academia. I think it is likely that mirror neurons allowed the evolution of the system I am describing.

A “thought”, when defined as an internal referential gesture, can be described similarly to mirror neurons as neurons that fires both when an individual acts and when an he observes his own action - as was the case when the individual both gave his alarm call and heard himself giving his alarm call.

Since it is different, I had thought to call this an “internal” mirror neuron until I ran across the work of David McNeill, so I will stick to his and George Herbert Mead’s title: “twisted” mirror neurons. Here is a quote from his David McNeill’s Wikipedia on the evolution of the speech-gesture-thought unity of language.

“According to Mead's Loop, mirror neurons underwent a "twist" whereby they came to respond to one’s own gestures as if they came from someone else: this is what evolved. The "twist" works because it brings the significance of one’s own gestures into the same areas of the brain where speech is being orchestrated.”

Note that this is talking about gestures, and not vocalizations such as the alarm call. I’ll get into how the two might become connected in the next section.

V.S. Ramachandran also writes about concepts that are similar to this. For example, here is a quote from his article https :// www . edge. org/conversation/vilayanur_ramachandran-self-awareness-the-last-frontier

“I also speculated that these neurons (mirror neurons) can not only help simulate other people's behavior but can be turned "inward"—as it were—to create second-order representations or metarepresentations of your own earlier brain processes. This could be the neural basis of introspection, and of the reciprocity of self awareness and other awareness.”

This seems to fit the description of these twisted mirror neuron "thoughts".

From Thoughts to Consciousness
From google dictionary, Consciousness is defined as the fact of awareness by the mind of itself and the world. This is a very complex topic that it is beyond me academically, but I think most people would agree consciousness is what separates humans from animals, and that human consciousness is built from many traits, such as awareness, inner speech, theory of mind, language, a conscience, etc. I believe this system of involuntary thoughts-before-behavior led to many of these human traits, and will attempt to explain a few.

How could thoughts lead to language? In this model, language is a result of selection pressures for individuals to be able to express and understand the thoughts and behavior of themselves and others better. Expressing and understanding thoughts became a form of interpersonal information exchange. By this logic language and consciousness would evolve simultaneously, since an individual could only understand the world better as it gained the evolutionary hardware to explain the world better to others and to himself.

I believe a key step in this process, the mechanism that would most strongly drive both language and consciousness, was the onset and internalization of interrogative behavior; questions and answers, in a manner similar to the initial alarm call repression. Interrogative behavior (Who, What, When, Where, Why, How) are questions and answers that allow an interpersonal information exchange of specific information via evolutionarily linked vocalizations and gestures. Interrogative behavior likely evolved both as a way to enhance social cooperation and as a “policing” mechanism to regulate cheating within themselves and others.

Gestures would become linked with question-answers to add communicative push and so communication could transcend learned speech differences. For example, “I mean you no harm” has the same gesture regardless of what vocalization is associated with “friend”. By linking gestures and vocalizations in this way, the motor-visual system became linked with the vocal-auditory system.

Consider how twisted mirror neurons would interact with these speech-hand linked questions and answers. To quote David McNeill’s Wiki again,
“While “straight” mirror neurons reproduce the actions ofanother, with meanings that are those of the other’sactions, the Mead’s Loop “twist” responds to one’s owngestures as if from another, and brings into the actionorchestration areas of the brain different meanings thatintrinsically have a social, public, outgoing orientation.”

As an individual answered a question, he would hear and see himself answering the question as though he were someone else. By bringing questions into the action orchestration areas of the brain, I believe those questions activated the “straight” mirror neurons. Thus, as the individual heard and saw himself answering a question as though he were someone else, he activated the mirror neurons as if he had heard himself answer the question as though he were someone else. In other words, he became aware via inner speech.

This inner speech to an intrapersonal transfer of information similar to the interpersonal transfer of information allowed by interrogative behavior; allowing awareness of thoughts, and directly leading to other aspects of consciousness and language to evolve.

For example,
a. Who are you? Became Who am I? - Answers form identity, self-esteem
b. What are you doing? Became What am I doing? - Answers allow awareness of behavior, voluntary motor control?
c. When did you do this? Became When did I do this? - Answers allow awareness of time.
d. Where is it? Became Where am I? Answers create mental construction of external reality
e. Why did you do that? Became Why did I do that? Answers allow awareness of motivations, goals
f. How are you doing this? Became How am I doing this? Answers allow logic; rational thought process, ability to learn and teach

There are other questions that the brain would evolve to ask itself. For example, what do I see? Hear? Taste? Feel? Smell? Would allow conscious awareness of senses. The answers to all of these questions, because they are processed as though someone else had answered them, are how the brain began to use thoughts to guide it’s own behavior and not just it’s own vocalizations.

For example, if an individual was about to do something that he would hate another person for, the brain would respond to “What am I doing?” with angry feelings and thoughts and likely avoid the behavior. In other words, this was also an evolutionary mechanism for The Golden Rule and an individual’s conscience.

I even suspect the questions that were most important for the individual to internally aware of evolved in localized or permanently connected areas of the brain. For example, with quotes from www . neuroskills . com

a) What do I look like? “Right Superior Lobule: (partly) responsible for constructing your “body image” - the vivid mental awareness you have of your body’s configuration and movement in space. (RamachandranTTB, 20)”
b) How do I do that? “Left Supramarginal Gyrus: conjures up a vivid image of intended skilled actions and executes them. Injury (here) hinders you from orchestrating skilled movements. (RamachandranTTB, 20).”
c) Where am I? “Right Angular Gyrus: A brain region which gives you the sense of being localized within your own body. Zap it (with an electrode) and you may have an ‘out-of-body experience.’ (Blakeslee, 205)”
d) What am I seeing? “Dorsal stream of Occiptal Lobe: ventral stream is known for the processing the "what" in vision” (Wikipedia on occipital lobe)

Does it Add Up?

If this is “how” the brain evolved, the proof should be in the pudding, in our perception and behavior. I believe it is. Consider a few of the illnesses Ramachandran studies to examine mirror neurons. These quotes are from https :// www . newyorker. com/magazine/2009/05/11/brain-games

“Apotemnophilia: An otherwise completely normal person develops an intense desire to have his arm or leg amputated. The right parietal (a part of it known a SPL) normally contains a complete internal image of the body. We showed recently that in these patients the part of the map corresponding to the affected limb is congenitally missing, leading to alienation of the limb.”

According to our model, this individual is asking himself What do I look like? The answer is located in the SPL, which is missing the visual representation of “arm”. Without the visual representation, the question cannot activate the “straight” mirror neurons in the speech orchestrating parts of the brain, and the individual suffers a disconnect between how they feel and what is real. They know that they have an arm, but feel as though they do not, and the resulting cognitive dissonance is why they desire to lose the arm.

The opposite is true in the case of phantom limbs, another illness that Ramachandran has done a great deal of research on.

“ In the majority of cases where people have lost limbs, they continue to vividly feel the presence of the missing limb. Chronic phantom pain — which strikes roughly two-thirds of patients who have had a limb removed — can become so severe that patients seriously contemplate suicide.”

According to our model, this individual is asking himself “What do I look like?” and the visual representation still exists despite the arm being gone. Thus, the “straight” mirror neurons will still kick in in the speech orchestrating parts of the brain, causing the individual to be aware of the feelings of an arm that no longer exists.

The method that Ramachandran uses to “amputate” the phantom limbs is particularly striking when thought about in terms of this theory. To quote the article,

“His first test subject was a young man who a decade earlier had crashed his motorcycle and torn from his spinal column the nerves supplying his left arm. After keeping the useless arm in a sling for a year, the man had the arm amputated above the elbow. Ever since, he had felt unremitting cramping in the phantom limb, as though it were immobilized in an awkward position.
In his office in Mandler Hall, Ramachandran positioned a twenty-inch-by-twenty-inch drugstore mirror upright, and perpendicular to the man’s body, and told him to place his intact right arm on one side of the mirror and his stump on the other. He told the man to arrange the mirror so that the reflection created the illusion that his intact arm was the continuation of the amputated one. Then Ramachandran asked the man to move his right and left arms simultaneously, in synchronous motions—like a conductor—while keeping his eyes on the reflection of his intact arm. “Oh, my God!” the man began to shout. “Oh, my God, Doctor, this is unbelievable.” For the first time in ten years, the patient could feel his phantom limb “moving,” and the cramping pain was instantly relieved. After the man had used the mirror therapy ten minutes a day for a month, his phantom limb shrank—“the first example in medical history,” Ramachandran later wrote, “of a successful ‘amputation’ of a phantom limb.””

According to our model, why does this work? Because the mirror allows the individual to see the “answer” to “what do I look like” in the exact same way a twisted mirror neuron does – by seeing the hand as though it were someone else’s hand. This allows the mirror to “hijack” the internal visual representation’s link to “straight” mirror neurons that control how the phantom limb “feels”.

Conclusions
I believe this logic suggests by understanding how internal referential communication evolved we may begin to grasp a top down approach of understanding the brain and ourselves – a way of performing what Ramachandran believes is missing from consciousness and “self” research: "psycho-anatomy"; whose goal is to explain specific details of certain complex mental capacities in terms of equally specific activity of specialized neural structures.

To summarize this model: “twisted” mirror neurons allowed the repression of alarm call behavior, allowing an individual to learn from his own behavior and sparking the “arms race” by allowing the individual to “cheat” social cooperation. The arms race would allow the evolution of simple questions and answers for interpersonal information transfer. The meaning of vocalizations and gestures would evolve together, becoming “linked” and bringing “twisted” mirror neurons into the part of the brain where speech is orchestrated – activating mirror neurons. The result was that as an individual answered a question, he would see himself answering the question as though he were someone else and actually answer the question to himself as though he were someone else (with inner speech). This allowed an intrapersonal information transfer that became the basis for awareness and the evolution of other aspects of consciousness.

Thank you for reading. I have tried to keep the focus of this post narrow, believe it or not, as there are a lot of different directions I think this can go and a lot of questions left to be asked. That means I almost certainly overlooked stuff in my editing. Feedback would be appreciated. What makes sense? What makes no sense? What can I explain better?

Sorry that my references don’t follow a consistent format.


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