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Social Brain Hypothesis VS. Climatic Variability Hypothesis: Hominid Encephalization

Social Brain Hypothesis VS. The Climatic Variability hypothesis  

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  1. 1. Do you think the Social brain Hypothesis or the Climatic Variability hypothesis best explains the main pressures driving Hominid encephalization?

    • You believe the climatic variability hypothesis best explains human encephalization
    • You believe The social brain hypothesis best explains human encephalization
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@Lo

So are scientists, but they tend to have a disproportionately large affect on culture.

True true. how would autists have effected hunter gatherer populations? Don't you think mental defects would be selected against?

 

 

I was thinking about the idea that intelligence can be measured by brain volume or size. Given what we know about the larger volume of Neanderthal brains relative to early modern humans and if that larger brain idea is valid, our assumption should be that Neanderthals were likely smarter than their early modern competitors. Neanderthals were more dependent on their physicality and sensory experiences.

No, I said all else being equal a bigger brain comes out on top. Neanderthals were much stronger and fatter than us, not only that, but their brains were more primitively shaped.

 

We know from earlier links in our discussion that experience can and does influence brain size. Domesticated animals have smaller brains because their experiences are not as rich and varied as their wild cousins. We also know that Neanderthals brains were larger by volume but not as frontally large as ours relatively. These differences in brain growth suggest a distinction between the experiences of Neanderthals and modern humans producing that growth. We can assess the distinct and different experiences between the two species from the behaviors suggested by their differing areas of brain development--assuming, of course, that their brains were functionally configured similarly.

 

If Neanderthals brains were functionally configures as ours, there areas of superior parietal, temporal, and occipital growth suggest more sensory oriented behaviors and thought processes. Neanderthals had brains that favor their physical, sensory oriented lifestyle, which was a life of varied physical and sensory experiences. The superior frontal size of our ancestors brains suggests their greater dependency on thought processes such as problem solving, planning, and reasoning. This frontal cortical function favors a technology oriented and driven lifestyle. Evidence of this distinction between the two is suggested by their weaponry where Neanderthal favored close quarter weapons while early modern humans produced weapons that were lethal as a distance. Clearly, this suggests that early humans were more dependent on technology for their survival while the Neanderthals were more dependent on their physicality and sensory experiences.

I'll have to reread those links but yes this idea seem incredibly interesting. Are you suggesting that hominids evolved varying imbalances of g? It has long been my belief that the more globular/neotenous head shapes of our ancestors was an improvement upon homo sapien idaltu and neanderthalis. I would like sources for the frontal lobe's importance in technological advancement. I'm pretty sure the entirety of the brain is involved in problem solving tasks and not just a specific area.

 

Indeed it may be oversimplification, but that is the nature of evolution where a species proliferation is survival dependent. The species that evolve better survival attributes and strategies will likely thrives beyond its competitors as we have beyond the Neanderthal.

Still an oversimplification though, As I said plenty of times before innovation isn't intelligence and all animals have some kind of adaptation for acquiring resources but our intelligence is much too broad to be pigeonholed like this. The only thing that has more of an effect than natural selection is sexual selection and social interaction would have caused a major pressure for big brains through sexual selection.

 

http://www.davidbrin.com/neoteny1.html

Edited by HelloI'mmeLo

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@Lo

 

True true. how would autists have effected hunter gatherer populations? Don't you think mental defects would be selected against?

Autism has a broad spectrum of symptoms; some are able to survive without heroic efforts to help them. People have a desire to help others who are injured or disabled, that may have help them survive. Whatever the reasons, it is obvious genes survived that contribute or allow autism. It is a mystery that may one day be unraveled.

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No, I said all else being equal a bigger brain comes out on top.

 

Indeed you did, but I also recall the following:

 

Actually my question was in regards to encephalization not human intelligence but I do equate the two so I guess it doesn't matter. Neanderthals were more advanced than us technologically until a little bit before we left Africa. I give their enhanced spatial abilities credit for that one. I n my opinion the demise of neanderthals was probably their inefficient bodies, competition with our bigger groups and interbreeding with a more genetically diverse species, we were very close in intelligence.

 

All things being equal, as I understood, you do equate encephalization with intelligence and that a "bigger brain comes out on top." Hence, my thoughts on the idea of equating brain size or volume with intelligence.

 

Neanderthals were much stronger and fatter than us, not only that, but their brains were more primitively shaped.

 

Indeed, as I understand, Neanderthals had cold adapted bodies while our ancestors had warm adapted bodies when they arrived in Europe about 50,000 years ago. As you may know, within 10,000 years of our ancestors arrival, Neanderthals were extinct. Although I believe our early ancestors superior intelligence insured their survival, I also believe that other factors coupled with our ancestors arrival in Europe led to the extinction of the Neanderthals.

 

I'll have to reread those links but yes this idea seem incredibly interesting. Are you suggesting that hominids evolved varying imbalances of g? It has long been my belief that the more globular/neotenous head shapes of our ancestors was an improvement upon homo sapien idaltu and neanderthalis. I would like sources for the frontal lobe's importance in technological advancement. I'm pretty sure the entirety of the brain is involved in problem solving tasks and not just a specific area.

 

Along with previous comments, I inserted a Wiki-link on the prefrontal cortex in my comments in response to your posted link on the relative growth of our frontal cortex compared to earlier hominids. However, this Neurskills link discusses the effects of frontal cortical damage, which I offer as way of understanding how the frontal cortex contributes to our intelligence and innovative behaviors. From the link:

 

An interesting phenomenon of frontal lobe damage is the insignificant effect it can have on traditional IQ testing. Researchers believe that this may have to do with IQ tests typically assessing convergent rather than divergent thinking. Frontal lobe damage seems to have an impact on divergent thinking, or flexibility and problem solving ability. There is also evidence showing lingering interference with attention and memory even after good recovery from a TBI (Stuss et al., 1985).

 

Another area often associated with frontal damage is that of "behavioral sponteneity." Kolb & Milner (1981) found that individual with frontal damage displayed fewer spontaneous facial movements, spoke fewer words (left frontal lesions) or excessively (right frontal lesions).

One of the most common characteristics of frontal lobe damage is difficulty in interpreting feedback from the environment. Perseverating on a response (Milner, 1964), risk taking, and non-compliance with rules (Miller, 1985), and impaired associated learning (using external cues to help guide behavior) (Drewe, 1975) are a few examples of this type of deficit.

 

 

This Neurskill link and other frontal and prefrontal articles, provide functional insight into how this specific area of our brain contributes to our overall behaviors and capabilities. They describe how frontal function is critical to the thought processes and elements of behavior essential to invention, innovation, abstract thought, and associated learning. If brain size is experience dependent, then the larger size of our ancestors frontal brain relative to Neanderthals suggests that our ancestors were more frequently engaging in thoughts and behaviors associated frontal brain function. Admittedly, it is impossible to determine the details of Neanderthal brain function from their remains or endocranial casts but if the shape of those casts suggest their relative brain function, then the behaviors Neanderthals engaged were likely more physically and sensory oriented and not as analytical as our early modern ancestors. There's some evidence which suggests that Neanderthals brain were indeed more physically and sensory oriented.

 

Still an oversimplification though, As I said plenty of times before innovation isn't intelligence and all animals have some kind of adaptation for acquiring resources but our intelligence is much too broad to be pigeonholed like this. The only thing that has more of an effect than natural selection is sexual selection and social interaction would have caused a major pressure for big brains through sexual selection.

 

http://www.davidbrin.com/neoteny1.html

 

Although innovation isn't intelligence in your view, it is indicative of intelligence and a means by which we can measure and compare relative intelligence. Here's a link to innovation and intelligence research in orangutans, which appears to support my position. Even In sexual selection and social interaction, in my opinion, that selection and interaction process emerges from survival related pressures. In nature, animals select partners from displays that suggest survival fitness or dominance and there is, I believe, little disagreement that we are a tribal species because our ancestors understood the value of safety in numbers. If you accept the tenets of evolution, then you must accept that every form of persistent life does so because of natural selection shaped by survival pressures.

Edited by DrmDoc

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Indeed you did, but I also recall the following:

All things being equal, as I understood, you do equate encephalization with intelligence and that a "bigger brain comes out on top." Hence, my thoughts on the idea of equating brain size or volume with intelligence.

"Encephalization is defined as the amount of brain mass related to an animal's total body mass. Quantifying an animal's encephalization has been argued to be directly related to that animal's level of intelligence. "

https://en.wikipedia.org/wiki/Encephalization

 

Encephalization is not equivalent to absolute brain size.

 

This Neurskill link and other frontal and prefrontal articles, provide functional insight into how this specific area of our brain contributes to our overall behaviors and capabilities. They describe how frontal function is critical to the thought processes and elements of behavior essential to invention, innovation, abstract thought, and associated learning. If brain size is experience dependent, then the larger size of our ancestors frontal brain relative to Neanderthals suggests that our ancestors were more frequently engaging in thoughts and behaviors associated frontal brain function. Admittedly, it is impossible to determine the details of Neanderthal brain function from their remains or endocranial casts but if the shape of those casts suggest their relative brain function, then the behaviors Neanderthals engaged were likely more physically and sensory oriented and not as analytical as our early modern ancestors. There's some evidence which suggests that Neanderthals brain were indeed more physically and sensory oriented.

By "experience driven" I hope you don't mean something lamarkian in nature but instead that homo sapiens simply had more selection pressure against them for problem solving abilities. Yes it is true that the frontal lobe would have at least some functional control over technical solutions to everyday issues in the hominid world but it also has been shown to affect social abilities and your article even claims the same:

 

"There is no other part of the brain where lesions can cause such a wide variety of symptoms (Kolb & Wishaw, 1990). The frontal lobes are involved in motor function, problem solving, spontaneity, memory, language, initiation, judgement, impulse control, and social and sexual behavior."

A quote form wikipeia

 

"Common effects of damage to the frontal lobe are varied. Patients who have experienced frontal lobe trauma may know the appropriate response to a situation but display inappropriate responses to those same situations in "real life". Similarly, emotions that are felt may not be expressed in the face or voice. For example, someone who is feeling happy would not smile, and his or her voice would be devoid of emotion. Along the same lines, though, the person may also exhibit excessive, unwarranted displays of emotion. Depression is common in stroke patients; it affects a great number of those who have experienced one. Also common along with depression is a loss of or decrease in motivation. Someone might not want to carry out normal daily activities and would not feel "up to it". Those who are close to the person who has experienced the damage may notice that the person no longer behaves like him or herself. This personality change is characteristic of damage to the frontal lobe and was exemplified in the case of Phineas Gage. The frontal lobe is the same part of the brain that is responsible for executive functions such as planning for the future, judgment, decision-making skills, attention span, and inhibition. These functions can decrease drastically in someone whose frontal lobe is damaged."

 

https://en.wikipedia.org/wiki/Frontal_lobe#Damage

 

Although innovation isn't intelligence in your view, it is indicative of intelligence and a means by which we can measure and compare relative intelligence. Here's a link to innovation and intelligence research in orangutans, which appears to support my position. Even In sexual selection and social interaction, in my opinion, that selection and interaction process emerges from survival related pressures. In nature, animals select partners from displays that suggest survival fitness or dominance and there is, I believe, little disagreement that we are a tribal species because our ancestors understood the value of safety in numbers. If you accept the tenets of evolution, then you must accept that every form of persistent life does so because of natural selection shaped by survival pressures.

 

See but now your CVH has simply degenerated into a vague and dry version of itself. IT's no longer SBH vs CVH it's sexual selection vs natural selection and both were obviously intertwined tightly throughout any species' evolutionary history. it's far too simplified now. The CVH simply states that varying climates pushed our brain evolution. Which implies that our brain's evolution was driven more by who died than who had sex. This link here shows that orangutans who were more social had higher levels of problem solving skills. Hell even social isolation is worse for you than cigarettes. Your Orangutan link won't load for me.

 

http://www.evoanth.net/2016/09/29/social-isolation-unhealthy-smoking/

 

http://www.evoanth.net/2016/09/15/socialising-makes-smarter/

Edited by HelloI'mmeLo

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"Encephalization is defined as the amount of brain mass related to an animal's total body mass. Quantifying an animal's encephalization has been argued to be directly related to that animal's level of intelligence. "

https://en.wikipedia.org/wiki/Encephalization

 

Encephalization is not equivalent to absolute brain size.

 

Perhaps brain mass related to total body mass was not clearly inferred to you by my comments. I've reviewed my comments and believe I was indeed referring to the larger brain to body mass of Neanderthals relative to our ancestors.

 

By "experience driven" I hope you don't mean something lamarkian in nature but instead that homo sapiens simply had more selection pressure against them for problem solving abilities. Yes it is true that the frontal lobe would have at least some functional control over technical solutions to everyday issues in the hominid world but it also has been shown to affect social abilities and your article even claims the same:

 

No, not inherited experience but experience gained by a preponderance of survival pressures associated with the frontal area of brain function. Indeed, there is a social component in the frontal's functional contribution to our behaviors; however, that component is also technical in nature. Damage to the frontal lobe does not inhibit social behaviors or social elements of our thought process as it does those behaviors and thought processes associated with reasoning, planning, problem solving and host of other mental efforts associated with inventiveness and innovative behaviors. Frontal function refines our social behaviors and social elements of thought. In the case of Phineas Gage, one with which I am very familiar, his behavior is said to gone from one that was reasoned and discipline to one that was frequently inappropriate and prone to emotional outburst. He was able to engage other socially and did form friendships those his personality and disposition appeared to have changed considerably. I should add that the physician who treated Phineas, after that tamping rod virtually destroyed his frontal lobe, never provided a complete or detailed description of exactly how Phineas' behavior changed after the accident.

 

See but now your CVH has simply degenerated into a vague and dry version of itself. IT's no longer SBH vs CVH it's sexual selection vs natural selection and both were obviously intertwined tightly throughout any species' evolutionary history. it's far too simplified now. The CVH simply states that varying climates pushed our brain evolution. Which implies that our brain's evolution was driven more by who died than who had sex. This link here shows that orangutans who were more social had higher levels of problem solving skills. Hell even social isolation is worse for you than cigarettes. Your Orangutan link won't load for me.

 

http://www.evoanth.net/2016/09/29/social-isolation-unhealthy-smoking/

 

http://www.evoanth.net/2016/09/15/socialising-makes-smarter/

 

I agree, that CVH is incomplete and requires refinement but it is closest to my view of the forces compelling encephalization. Regarding problem solving, it remains my position that social groups may expound a skill but that skill likely originated from a solitary effort, which would not exist without a need compelled by some survival pressure or need.

Edited by DrmDoc

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Perhaps brain mass related to total body mass was not clearly inferred to you by my comments. I've reviewed my comments and believe I was indeed referring to the larger brain to body mass of Neanderthals relative to our ancestors.

I thought neanderthals were less encephalized than us? http://www.evoanth.net/2016/01/28/how-similar-were-neanderthals-and-humans/ In regards to an earlier comment you made I found that humans actually had a better sense of smell than neanderthals. http://www.evoanth.net/2012/01/02/neanderthals-had-differently-shaped-brains/

 

No, not inherited experience but experience gained by a preponderance of survival pressures associated with the frontal area of brain function. Indeed, there is a social component in the frontal's functional contribution to our behaviors; however, that component is also technical in nature. Damage to the frontal lobe does not inhibit social behaviors or social elements of our thought process as it does those behaviors and thought processes associated with reasoning, planning, problem solving and host of other mental efforts associated with inventiveness and innovative behaviors. Frontal function refines our social behaviors and social elements of thought. In the case of Phineas Gage, one with which I am very familiar, his behavior is said to gone from one that was reasoned and discipline to one that was frequently inappropriate and prone to emotional outburst. He was able to engage other socially and did form friendships those his personality and disposition appeared to have changed considerably. I should add that the physician who treated Phineas, after that tamping rod virtually destroyed his frontal lobe, never provided a complete or detailed description of exactly how Phineas' behavior changed after the accident

But the function of this experience is still inherited is it not? Sorry I'm getting confused here, this isn't a nature vs nurture question is it? Reasoning and planning are both useful in social settings and damage to the frontal lobe does in fact inhibit social behaviors I provided evidence above in my previous post. Phineas isn't the only case is he?

 

I agree, that CVH is incomplete and requires refinement but it is closest to my view of the forces compelling encephalization. Regarding problem solving, it remains my position that social groups may expound a skill but that skill likely originated from a solitary effort, which would not exist without a need compelled by some survival pressure or need.

We may just have to agree to disagree here all the evidence I have put forward has shown that wherever innovation or intelligence is, socialization is not far behind but neither is the survival needs for both. It is my belief that both the CVH and SBH have heavily influenced our brain and bodies evolution, but the CVH is simply the secondary mechanism, both in tandem. How are you sure that potential for the skill of innovation(which may have risen in solitary effort)did not originate from a social arms race?

@Lo

Autism has a broad spectrum of symptoms; some are able to survive without heroic efforts to help them. People have a desire to help others who are injured or disabled, that may have help them survive. Whatever the reasons, it is obvious genes survived that contribute or allow autism. It is a mystery that may one day be unraveled.

It is indeed interesting, I'll look more into it.

Edited by HelloI'mmeLo

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I thought neanderthals were less encephalized than us? http://www.evoanth.net/2016/01/28/how-similar-were-neanderthals-and-humans/ In regards to an earlier comment you made I found that humans actually had a better sense of smell than neanderthals. http://www.evoanth.net/2012/01/02/neanderthals-had-differently-shaped-brains/

 

Essentially, the idea I support is that "a greater percentage of the Neanderthal brain seems to have been devoted to vision and control of their larger bodies, leaving less mental real estate for higher thinking and social interactions" as suggested by recent research.

 

But the function of this experience is still inherited is it not? Sorry I'm getting confused here, this isn't a nature vs nurture question is it? Reasoning and planning are both useful in social settings and damage to the frontal lobe does in fact inhibit social behaviors I provided evidence above in my previous post. Phineas isn't the only case is he?

 

As I understood, you questioned whether an aspect of my previous comments was a reference to Lamarckism. Simply, it was not. The experiences I was referencing are those engaged directly rather than those pass on as a type of inherited or innate memory. I selected your links and reviewed your comments but could not find supporting evidence where frontal lobe damage inhibits social behaviors. At the very worse, frontal damage alters our social behaviors to something less refined but does not entirely inhibit us from engaging in those behaviors albeit sometimes crude in expression. The effects of lobotomies (ablation of the frontal/prefrontal lobe) provides an example of these personality alterations.

 

We may just have to agree to disagree here all the evidence I have put forward has shown that wherever innovation or intelligence is, socialization is not far behind but neither is the survival needs for both. It is my belief that both the CVH and SBH have heavily influenced our brain and bodies evolution, but the CVH is simply the secondary mechanism, both in tandem. How are you sure that potential for the skill of innovation(which may have risen in solitary effort)did not originate from a social arms race?

 

I'm not suggesting that innovation isn't a collaborative effort. What I am suggesting is that innovation overall emerges from a need set by survival conditions, which could be a umbrella for a variety of influences both environmental and social.

Edited by DrmDoc

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As I understood, you questioned whether an aspect of my previous comments was a reference to Lamarckism. Simply, it was not. The experiences I was referencing are those engaged directly rather than those pass on as a type of inherited or innate memory. I selected your links and reviewed your comments but could not find supporting evidence where frontal lobe damage inhibits social behaviors. At the very worse, frontal damage alters our social behaviors to something less refined but does not entirely inhibit us from engaging in those behaviors albeit sometimes crude in expression. The effects of lobotomies (ablation of the frontal/prefrontal lobe) provides an example of these personality alterations.

I'm still confused but that's probably my fault. I think you're just playing semantics I could provide a plethora of research showing that frontal lobe damage and other brain damage for that matter has enormous consequences on social cognition. The effects are obviously comparable to primitive social structures and so it becomes easy to see that the brain and sociality are heavily intertwined. This discussion may be going off the rails a bit.

 

http://www.tbicommunity.org/resources/publications/professional_education_social_comm.pdf

 

http://www.livestrong.com/article/24256-functions-frontal-lobe-brain/

 

http://memory.ucsf.edu/ftd/medical/anatomy/functional/single

 

 

 

 

I'm not suggesting that innovation isn't a collaborative effort. What I am suggesting is that innovation overall emerges from a need set by survival conditions, which could be a umbrella for a variety of influences both environmental and social.

 

You're misunderstanding me. How do you know that the potential, the ability to innovate and problem solve did not arise from evolutionary pressures regarding complex social units. What I am telling you is that it's a no brainer survival needs drove encephalization, because it drives all evolution! but that is a incomplete and oversimplified answer I think the SBH and the CVH fill in the gaps quite symmetrically, with the SBH being the main force of the two.

 

 

Here is a irrelevant/somewhat relevant link to our discussion http://www.evoanth.net/2016/10/12/brain-evolution-unique-bloodthirsty/

Edited by HelloI'mmeLo

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I believe we can resolve this debate with close examination of the examples and scenarios that have been presented so far.

 

Chimpanzees display what could be considered is the most basic interpretation of a tool; a stem used to withdraw termites from a mound. This activity along with other similar displays has not so far lead to a revolution in chimpanzee tool culture despite the chimpanzees having what would be the most important precursor to any tool making endeavor, a reasonably comparable brain to that of our earlier ancestors and two opposable thumbs. Although we don’t know when this termite extraction practice began for chimps, it did not lead to a series of extrapolations of the original idea, but merely the use of any suitable stem being stripped of obstructions. The first tool that the chimps originally utilized was most likely a found item and used as is and then copied through trial and error for generations after.

 

So, despite having what would seem as a good starting platform consisting of a brain of adequate intelligence to ascertain a possible use for a tool, and opposable thumbs to shape and use it, why haven’t they demonstrated what could be considered a measurable awareness of the fact that many of the materials and objects in their environment can be used and modified to their benefit? Does a bird building a nest garner their interest? Can they learn from their environment? Have they discovered what the sharp edge of a fractured stone can do? And then tried it in a multitude of situations?

 

The one very obvious attribute that they are missing is speech. And more importantly; what a speaking culture provides, a learning environment that enables and develops abstract thought processes. A sharp edge stone to a mind that is capable of abstract thought is the beginning of a cultural revolution.

 

What would initiate the early development of the physiology in chimps that would lead to a gradual and meaningful increase in vocalization like that which occurred in early human ancestors?

 

The apes all vocalize to some degree, no doubt like our early human ancestors must have, but at some point the resultant stimulation in cognitive intelligence of this activity in our ancestral groups lead to the greater survival and reproductive success of those involved. This feedback rewarded those that possessed the physiology of improved speech capabilities that then in turn spurred increased cognitive understanding and abstract thought capabilities. Even those within the group that evolution may not have chosen for this trait would have undoubtedly benefited from experiencing the results as a member. As the vocal physiology was passed down and selected by survival and reproduction the feedback cycle would assure this advantage would continue to strengthen though generations of successful reproduction.

 

This is why I believe tool development was not the driving agent for our ancestors’ unprecedented mental development. The chimpanzees’ meager advancements in this matter are rather hard to reconcile. They lack even the most basic level of abstract thought, tools can be found and/or modified to perform a task and this knowledge passed on through demonstration, but without the ability to imagine objects in different contexts and more importantly share that context verbally, the chances of a tool culture developing without speech would appear to be slim. But more importantly how would this tool making and use wire a child’s brain for creative thought? Are these tool utilization moments really numerous enough to provide the needed learning environment to the group’s offspring? We Know now how important stimulating and imaginative environments are for developing children and how much more capacity they have as adults if their environment growing up was filled with stimulating social contact.

 

This is why I believe the social model is so much more able to adequately explain this incredible anomaly that we undoubtedly are. There simply needs to be a feedback mechanism within this social group that promotes the use of abstract thought on an unprecedented level of circular reinforcement.

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I'm still confused but that's probably my fault. I think you're just playing semantics I could provide a plethora of research showing that frontal lobe damage and other brain damage for that matter has enormous consequences on social cognition. The effects are obviously comparable to primitive social structures and so it becomes easy to see that the brain and sociality are heavily intertwined. This discussion may be going off the rails a bit.

 

http://www.tbicommunity.org/resources/publications/professional_education_social_comm.pdf

 

http://www.livestrong.com/article/24256-functions-frontal-lobe-brain/

 

http://memory.ucsf.edu/ftd/medical/anatomy/functional/single

 

Perhaps you are confused, frontal function adds elements or components to our behaviors that disappear when severely damaged. The frontal also refines elements or components of our behavioral expression. To assess how essential or critical frontal function is to a particular element of our behavioral expression, we merely have to determine whether that element disappears entirely or whether its refinements disappear. Amid the latter (refinements), our affected behavioral elements still exist but are expressed in a coarse and clearly less refine state. The elements that most consistently and persistently disappear from our behaviors when the frontal is damage is our ability to independently problem solve, plan, and conceive the consequential effects of our experiences and behaviors. Those abilities are arguably vital components of our inventive and innovative behaviors. Conversely, frontal damage does not result in the disappearance of our ability to communicate, engage social groups, or engage our sexual interests--actually, our behaviors frequently become less socially inhibited. Clearly, the social elements of our behaviors do not emerge from frontal function as do those elements that make inventiveness and innovation possible.

 

You're misunderstanding me. How do you know that the potential, the ability to innovate and problem solve did not arise from evolutionary pressures regarding complex social units. What I am telling you is that it's a no brainer survival needs drove encephalization, because it drives all evolution! but that is a incomplete and oversimplified answer I think the SBH and the CVH fill in the gaps quite symmetrically, with the SBH being the main force of the two.

 

Here is a irrelevant/somewhat relevant link to our discussion http://www.evoanth.net/2016/10/12/brain-evolution-unique-bloodthirsty/

 

Maybe I have misunderstood; however, my opinion is shaped by a simple view of which likely had the greater impact on group survival--interactions within/among groups or the environment enveloping that group? I believe the environment is the dominant force because it sets the immersive conditions with which a group must contend to survive. Although I accept your certainty, I continue to believe that the social strategies our ancestors adapted would not have evolved without the survival demands of the enveloping conditions compelling those social strategies. By no means is the CVH complete but it seems closest to my view.

Edited by DrmDoc

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Perhaps you are confused, frontal function adds elements or components to our behaviors that disappear when severely damaged. The frontal also refines elements or components of our behavioral expression. To assess how essential or critical frontal function is to a particular element of our behavioral expression, we merely have to determine whether that element disappears entirely or whether its refinements disappear. Amid the latter (refinements), our affected behavioral elements still exist but are expressed in a coarse and clearly less refine state. The elements that most consistently and persistently disappear from our behaviors when the frontal is damage is our ability to independently problem solve, plan, and conceive the consequential effects of our experiences and behaviors. Those abilities are arguably vital components of our inventive and innovative behaviors. Conversely, frontal damage does not result in the disappearance of our ability to communicate, engage social groups, or engage our sexual interests--actually, our behaviors frequently become less socially inhibited. Clearly, the social elements of our behaviors do not emerge from frontal function as do those elements that make inventiveness and innovation possible.

Well from your link "Van Horn et al. concluded that damage to Gage's white matter (of which they made detailed estimates) was as or more significant to Gage's mental changes than cerebral cortex (gray matter) damage. Thiebaut de Schotten et al. estimated white-matter damage in Gage and two other famous patients ("Tan" and "H.M."), concluding that these three cases "suggest that social behavior, language, and memory depend on the coordinated activity of different [brain] regions rather than single areas in the frontal or temporal lobes.Gage displayed significant changes in behavior after his injury, but the nature, extent, and duration of these changes have been difficult to establish.Only a handful of sources give direct information on what Gage was like (either before or after the accident), the mental changes described after his death were much more dramatic than anything reported while he was alive, and few sources are explicit about the period of Gage's life to which each of their various descriptions of him (which vary widely in their implied level of functional impairment) is meant to apply. Harlow described the pre-accident Gage as hard-working, responsible, and "a great favorite" with the men in his charge, his employers having regarded him as "the most efficient and capable foreman in their employ"; he also took pains to note that Gage's memory and general intelligence seemed unimpaired after the accident (outside the periods of delirium). Nonetheless these same employers, after Gage's accident, "considered the change in his mind so marked that they could not give him his place again":"

 

 

Basically, like I had said before, the entire brain is needed for cognitive output, I have only found one source that says the frontal lobe has continuosly been growing. Not that it is wrong but I am skeptical, Some argued anecdotally that gage had kept his mental prowess but had lost his ability to control his impulsive social behaviors. All data on gage is near false though, so honestly using him as an example may be bad from the start and not entirely accurate. I actually have some links showing that the frontal lobe isn't as special in our evolution as we previously thought, We literally just have giant chimp brains. Even if we disregard all of that, none of your links show that he completely lost the ability to problem solve.

 

http://www.evoanth.net/2016/09/22/human-brain-not-special-thought/

 

 

 

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Well from your link "Van Horn et al. concluded that damage to Gage's white matter (of which they made detailed estimates) was as or more significant to Gage's mental changes than cerebral cortex (gray matter) damage. Thiebaut de Schotten et al. estimated white-matter damage in Gage and two other famous patients ("Tan" and "H.M."), concluding that these three cases "suggest that social behavior, language, and memory depend on the coordinated activity of different [brain] regions rather than single areas in the frontal or temporal lobes.Gage displayed significant changes in behavior after his injury, but the nature, extent, and duration of these changes have been difficult to establish.Only a handful of sources give direct information on what Gage was like (either before or after the accident), the mental changes described after his death were much more dramatic than anything reported while he was alive, and few sources are explicit about the period of Gage's life to which each of their various descriptions of him (which vary widely in their implied level of functional impairment) is meant to apply. Harlow described the pre-accident Gage as hard-working, responsible, and "a great favorite" with the men in his charge, his employers having regarded him as "the most efficient and capable foreman in their employ"; he also took pains to note that Gage's memory and general intelligence seemed unimpaired after the accident (outside the periods of delirium). Nonetheless these same employers, after Gage's accident, "considered the change in his mind so marked that they could not give him his place again":"

 

Again, I believe there remains some misunderstand. There are behaviors that disappear when our brain is damaged and there are behaviors that are altered when the brain is damaged. The behaviors that disappear when the brain is damage suggest an area of the brain where those behaviors originate. Damage to the frontal does not result in the disappearance of our social behaviors but does alter those behaviors considerably, which suggests that the frontal merely mediates those behaviors rather than originate those behaviors. Altered behaviors after frontal damage are mediated by executive functions that primarily originate from the frontal cortex. Damage to the frontal creates a loss of executive functions, critical to the mediation of all our behavioral expressions, which do not completely return. Phineas was never able to hold a position of leadership and responsibility as he had held before his injury and didn't manage to sustain stabile employment until much later in his life which, arguably, was likely a result of his brain plasticity.

 

Basically, like I had said before, the entire brain is needed for cognitive output, I have only found one source that says the frontal lobe has continuosly been growing. Not that it is wrong but I am skeptical, Some argued anecdotally that gage had kept his mental prowess but had lost his ability to control his impulsive social behaviors. All data on gage is near false though, so honestly using him as an example may be bad from the start and not entirely accurate. I actually have some links showing that the frontal lobe isn't as special in our evolution as we previously thought, We literally just have giant chimp brains. Even if we disregard all of that, none of your links show that he completely lost the ability to problem solve.

 

http://www.evoanth.net/2016/09/22/human-brain-not-special-thought/

 

Perhaps Phineas Gage isn't the best example; however, there is little disagreement on the functional contributions of our frontal cortex. Indeed, you initially introduced both Phineas and the growing frontal lobe to our discussion. No doubt there may be a majority who believes as you do about the predominant hypothesis relative to encephalization and all else is merely superfluous. I continue to hold a different view but have, admittedly, become more informed than prior because of your perspective and our discussion.

Edited by DrmDoc

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Again, I believe there remains some misunderstand. There are behaviors that disappear when our brain is damaged and there are behaviors that are altered when the brain is damaged. The behaviors that disappear when the brain is damage suggest an area of the brain where those behaviors originate. Damage to the frontal does not result in the disappearance of our social behaviors but does alter those behaviors considerably, which suggests that the frontal merely mediates those behaviors rather than originate those behaviors. Altered behaviors after frontal damage are mediated by executive functions that primarily originate from the frontal cortex. Damage to the frontal creates a loss of executive functions, critical to the mediation of all our behavioral expressions, which do not completely return. Phineas was never able to hold a position of leadership and responsibility as he had held before his injury and didn't manage to sustain stabile employment until much later in his life which, arguably, was likely a result of his brain plasticity.

 

 

Perhaps Phineas Gage isn't the best example; however, there is little disagreement on the functional contributions of our frontal cortex. Indeed, you initially introduced both Phineas and the growing frontal lobe to our discussion. No doubt there may be a majority who believes as you do about the predominant hypothesis relative to encephalization and all else is merely superfluous. I continue to hold a different view but have, admittedly, become more informed than prior because of your perspective and our discussion.

I concede to you, Yes it seems that executive function is inhibited after frontal lobe damage but it still is irrelevant to my main point. That maybe executive function and innovative problem solving may have been induced from socializing. But I don't want this to turn to ad nauseam for you or me. I have multiple other debates and discussions I am currently a part of So for now I will agree with you and simply look more into it later, But yes I did originally show that post until it started biting me in the ass, but in retrospect the link it's derived from mentions nothing of the frontal lobe still increasing but like I said that doesn't mean it's wrong. You have definitely showed me another side to our brain's evolutionary story, and truth be told I am starting to come around to the CVH a little more.

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As an epilogue to my comments regarding brain size or volume as experience dependent. I failed to mention--that's if you remain interested--what happens to our brain cells when we sleep. Sleep is perhaps the least physically engaging and activity intensive experience influencing brain function. Consequently, recent evidence suggests that our brain cells shrink by as much as 60% whenever we sleep. That shrinkage facilitates the efficient removal of extracellular, interstitial waste through the recently discovered glymphatic system. This system involves the removal of brain cell waste that is not removed when the brain is actively engaged. Essentially, this process infers how a brain's active experiences builds volume that diminishes when the brain disengages experience.

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As an epilogue to my comments regarding brain size or volume as experience dependent. I failed to mention--that's if you remain interested--what happens to our brain cells when we sleep. Sleep is perhaps the least physically engaging and activity intensive experience influencing brain function. Consequently, recent evidence suggests that our brain cells shrink by as much as 60% whenever we sleep. That shrinkage facilitates the efficient removal of extracellular, interstitial waste through the recently discovered glymphatic system. This system involves the removal of brain cell waste that is not removed when the brain is actively engaged. Essentially, this process infers how a brain's active experiences builds volume that diminishes when the brain disengages experience.

So in a very simplified sense the glymphatic system basically is the reset button on your brain? Does this have anything to do with neural plasticity?

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So in a very simplified sense the glymphatic system basically is the reset button on your brain? Does this have anything to do with neural plasticity?

 

It's not necessarily a reset system but a sanitation system--a means by which brain cells can eliminate waste and prepare for renewed activity. Active brain cells swell as they consumes energy (adenosine triphosphate)--some 20% of the body's total intake while being no more than 5% of body mass--and accumulate waste. As you may know, neural plasticity regards our brain's ability to rewire itself, adapt and/or rebound after trauma. That process is certainly supported by our brain's capacity to efficiently remove cell waste that may cause neurodegeneration. Glymphatic processes essentially explains why sleep is so important to a healthy brain.

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It's not necessarily a reset system but a sanitation system--a means by which brain cells can eliminate waste and prepare for renewed activity. Active brain cells swell as they consumes energy (adenosine triphosphate)--some 20% of the body's total intake while being no more than 5% of body mass--and accumulate waste. As you may know, neural plasticity regards our brain's ability to rewire itself, adapt and/or rebound after trauma. That process is certainly supported by our brain's capacity to efficiently remove cell waste that may cause neurodegeneration. Glymphatic processes essentially explains why sleep is so important to a healthy brain.

That's what I basically meant. I've never gotten much sleep, that has probably caused plenty of side effects on my mental performance. Do you think the shrinkage of our brain cells has any effect or influence on our subconsciousness and to maybe a lesser extent our dreams? This talk of sleeping has me probing ground I haven't in a while. I heard our brains are actually more active when we are asleep, or at least certain parts.

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That's what I basically meant. I've never gotten much sleep, that has probably caused plenty of side effects on my mental performance. Do you think the shrinkage of our brain cells has any effect or influence on our subconsciousness and to maybe a lesser extent our dreams? This talk of sleeping has me probing ground I haven't in a while. I heard our brains are actually more active when we are asleep, or at least certain parts.

 

Sleep is as essential as the nutrients we intake for optimum brain function. Insufficient sleep causes an accumulation of extracellular toxins that may contribute to the early onset of neurodegenerative conditions such as Alzheimer. There is also some evidence suggesting our brain doesn't recover from sleep deprivation as quickly as previously thought. As I've learned, every aspect of the sleep process evolved to serve the metabolic needs of brain and body, but particularly the brain. The different stages of sleep serve distinctly different aspects of the brain's metabolic processes. Indeed, brain activity amid REM does routinely exceeds conscious levels particularly in those extrastriate visual areas of the cortex. REM (Rapid Eye Movement), as you may know, is that stage of sleep where dreaming primarily occurs. Dreaming occurs when our brain activates to restore its glycogen reserves. Shrinkage and waste removal occurs during the initial stages of sleep where dreaming does not occur. The glymphatic process actually promotes our brain's ability to uptake energy in sleep. Dreaming is an active unconscious state of brain function that increases circulation to the brain, which brings adenosine triphosphate (ATP) into brain structure for storage and subsequent use. The glymphatic process more efficiently remove the waste byproducts of this energy uptake process in sleep. The imagery and scenarios we recall as dreams upon arousal are actually how our waking brain synthesis or interpret the lingering effects of its mid-sleep activations. The term subconscious isn't an accurate reference for the source of those brain activations because subconscious isn't a state of brain function. There are two states of normal brain function: Conscious and unconscious. Dreaming arises from an unconscious state and, therefore, unconscious is more descriptive of that attribute of mind and brain function from which dreaming arises. If interested, here's a link to prior a discussion on the subject of subconscious vs. unconscious.

Edited by DrmDoc

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Sleep is as essential as the nutrients we intake for optimum brain function. Insufficient sleep causes an accumulation of extracellular toxins that may contribute to the early onset of neurodegenerative conditions such as Alzheimer. There is also some evidence suggesting our brain doesn't recover from sleep deprivation as quickly as previously thought. As I've learned, every aspect of the sleep process evolved to serve the metabolic needs of brain and body, but particularly the brain. The different stages of sleep serve distinctly different aspects of the brain's metabolic processes. Indeed, brain activity amid REM does routinely exceeds conscious levels particularly in those extrastriate visual areas of the cortex. REM (Rapid Eye Movement), as you may know, is that stage of sleep where dreaming primarily occurs. Dreaming occurs when our brain activates to restore its glycogen reserves. Shrinkage and waste removal occurs during the initial stages of sleep where dreaming does not occur. The glymphatic process actually promotes our brain's ability to uptake energy in sleep. Dreaming is an active unconscious state of brain function that increases circulation to the brain, which brings adenosine triphosphate (ATP) into brain structure for storage and subsequent use. The glymphatic process more efficiently remove the waste byproducts of this energy uptake process in sleep. The imagery and scenarios we recall as dreams upon arousal are actually how our waking brain synthesis or interpret the lingering effects of its mid-sleep activations. The term subconscious isn't an accurate reference for the source of those brain activations because subconscious isn't a state of brain function. There are two states of normal brain function: Conscious and unconscious. Dreaming arises from an unconscious state and, therefore, unconscious is more descriptive of that attribute of mind and brain function from which dreaming arises. If interested, here's a link to prior a discussion on the subject of subconscious vs. unconscious.

 

Sorry, I'm pretty ignorant of these things. So these glymphatic systems will basically induce dreams and when these dreams occur it makes the visual system in your brain fire connections like crazy which in turn creates visual stimuli that probably correlate with your everyday back of the head thoughts, in this sense is the term subconsciousness accurate from where the content of your dreams originate?? You're incredibly smart and have pointed me to some very interesting discussions, I will explore them soon. Thank you for taking the time to humor my anthro debate and provide me with more materials to further my intellectual endeavors. Truth be told I don't get much of this kind of stimulation in my normal social life so I've enjoyed this quite a bit. On a completely unrelated and maybe even weird note I like your avatar, it looks "trippy". :)

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Sorry, I'm pretty ignorant of these things. So these glymphatic systems will basically induce dreams and when these dreams occur it makes the visual system in your brain fire connections like crazy which in turn creates visual stimuli that probably correlate with your everyday back of the head thoughts, in this sense is the term subconsciousness accurate from where the content of your dreams originate?? You're incredibly smart and have pointed me to some very interesting discussions, I will explore them soon. Thank you for taking the time to humor my anthro debate and provide me with more materials to further my intellectual endeavors. Truth be told I don't get much of this kind of stimulation in my normal social life so I've enjoyed this quite a bit. On a completely unrelated and maybe even weird note I like your avatar, it looks "trippy". :)

 

Dreaming is an involved process that even some experts really don't understand very well. I think of the glymphatic system as our brain's janitor who cleans after work hours in preparation for the following work day. The removal of waste enables the intake of nutrients, which our brain cells convert to glycogen. The process is thought to begin with impulses from a brainstem structure called the Pons. That is not my view; however, our brain activates for metabolic reasons and dreaming piggybacks on that process. The imagery and scenarios in our dreams emerge from an unconscious process of brain function. There are many who construe unconscious and subconscious to be synonymous terms. To be precise, they are not synonymous. Unconscious describes a state of brain function while subconscious references an influence emerging from or affecting brain function. In clearer terms, unconscious describes the producer of influence, while subconscious describes how that influence is packaged and delivered. Dreams are how our brain synthesize the subconscious influences emerging from the unconscious metabolic activations our brain engages. Those activations can go beyond those involving our visual field of brain function. How dreams emerge is something I've studied for a number of years and still have few solid answers. I enjoy these discussions as well and I credit much of what I now know and understand to discussions like this. My avatar--yes, it's trippy ^_^

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That is not my view; however, our brain activates for metabolic reasons and dreaming piggybacks on that process. The imagery and scenarios in our dreams emerge from an unconscious process of brain function. There are many who construe unconscious and subconscious to be synonymous terms. To be precise, they are not synonymous. Unconscious describes a state of brain function while subconscious references an influence emerging from or affecting brain function. In clearer terms, unconscious describes the producer of influence, while subconscious describes how that influence is packaged and delivered. Dreams are how our brain synthesize the subconscious influences emerging from the unconscious metabolic activations our brain engages.

Dreams are incredibly interesting to me. Do you think you could dumb down those sentences I quoted form you a little bit? I'm having trouble understanding what you mean. Do other animals have dreams?

 

EDIT: Sorry for the late response*

Edited by meLothedestroyerofworlds

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Dreams are incredibly interesting to me. Do you think you could dumb down those sentences I quoted form you a little bit? I'm having trouble understanding what you mean. Do other animals have dreams?

 

EDIT: Sorry for the late response*

 

You quoted quite a bit there, but I shall try to be brief. Many researchers believe we dream for reasons associated with memory and better mental acuity. I do not because that is not what the evidence in brain evolution suggests to me. Remarkably, our brain structure contiguously reflects its various stages of evolution. From spinal cord to neocortex, our central nervous system (CNS) functionally suggests how it evolved, as well as, the survival advantages compelling each stage of its functional evolution. What these stages suggest is that brain evolution and function were driven by its metabolic needs. We don't dream for better memory or mental acuity, we dream because of our brain's energy requirements. Conscious mental activity drains the reserve energy (glycogen), which our brain tries to restore by becoming active when our body is at rest in sleep. Dream imagery arise from this brain activity in sleep. There are some who believe that dreams emerge from a part of the mind some call the subconscious. The subconscious, ​in my view, does not exist and is not a part of the mind because it is not a mental state. Both conscious and unconscious are mental states because they can be directly observed as functional states of the brain. Subconscious can only be observed as an influence or by its effects rather than as an actual state of brain activity. Dreams and dreaming emerge from the unconscious active state of brain function. Indeed, there is sufficient evidence that other animals do dream. Since we have moved on from the original subject of this discussion thread, you may want to open a separate thread to continue our discussion of the dreaming brain. I'm sure others here would like to participate as well.

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You quoted quite a bit there, but I shall try to be brief. Many researchers believe we dream for reasons associated with memory and better mental acuity. I do not because that is not what the evidence in brain evolution suggests to me. Remarkably, our brain structure contiguously reflects its various stages of evolution. From spinal cord to neocortex, our central nervous system (CNS) functionally suggests how it evolved, as well as, the survival advantages compelling each stage of its functional evolution. What these stages suggest is that brain evolution and function were driven by its metabolic needs. We don't dream for better memory or mental acuity, we dream because of our brain's energy requirements. Conscious mental activity drains the reserve energy (glycogen), which our brain tries to restore by becoming active when our body is at rest in sleep. Dream imagery arise from this brain activity in sleep. There are some who believe that dreams emerge from a part of the mind some call the subconscious. The subconscious, ​in my view, does not exist and is not a part of the mind because it is not a mental state. Both conscious and unconscious are mental states because they can be directly observed as functional states of the brain. Subconscious can only be observed as an influence or by its effects rather than as an actual state of brain activity. Dreams and dreaming emerge from the unconscious active state of brain function. Indeed, there is sufficient evidence that other animals do dream. Since we have moved on from the original subject of this discussion thread, you may want to open a separate thread to continue our discussion of the dreaming brain. I'm sure others here would like to participate as well.

Sorry, I have been preoccupied lately. I always thought the subconscious was just a combination of instinctual reaction and long term memory. ill make a new thread but I don't know how soon. it is interesting but I am involved in a lot of other debates at the moment.

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It happened in stages. First the brain gathered statistical data about very random environments. This increased brain size greatly because the data needed was massive. In the next stage socialization further accelerated the adaptation by adding the social factor.

 

 

Usually resources come before function. You can't have functionality when resources aren't present. The resource needed for social adaptation to occur is behaviors.

Edited by nimae

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It happened in stages. First the brain gathered statistical data about very random environments. This increased brain size greatly because the data needed was massive. In the next stage socialization further accelerated the adaptation by adding the social factor.

 

 

Usually resources come before function. You can't have functionality when resources aren't present. The resource needed for social adaptation to occur is behaviors.

I know that now. I was mistaking differing functional causation with differing levels of importance. Survival needs like, shelter and resource allocation are the base influence of all evolution. Our socialization is simply the specializer.

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