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Brain structure of intellingent humans?


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Structurally, there probably isn't much difference, but I suspect one might see a difference in the number (or density) of neural connections and synapses, and maybe differences in the the myelin sheathing.

 

Really where the struggle happens is when you're asked to define what you mean by "intelligence." It's a really difficult word to pin down and there are different types of intelligence. Depending upon which you're asking about you could explore many alternative versions of "brain differences."

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Structurally, there probably isn't much difference, but I suspect one might see a difference in the number (or density) of neural connections and synapses, and maybe differences in the the myelin sheathing.

 

Really where the struggle happens is when you're asked to define what you mean by "intelligence." It's a really difficult word to pin down and there are different types of intelligence. Depending upon which you're asking about you could explore many alternative versions of "brain differences."

I mean just intelligence in general

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I would actually be surprised if there are any structural differences. On the extreme ends of the spectrum (of whatever parameter we are testing) I would expect maybe slight differences in the activation patterns (e.g. due to the way a problem is being perceived and subsequently solved) but I am not certain that there would be anything detectable on the (sub-)cellular level, for instance.

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Right. Intelligence is a subjective matter.

If you're interested in altering intelligence, you would have to quantify what you want to change in relation to some other measured quantity.

I think, however, I've mentioned that intelligence relates to AMPA receptors. It seems to be a feature of "learning."

There are a lot of nitty-gritty aspects of cognition and intelligence that have biological "correlates."

 

So, it's a subjective issue that can be mathematically quantified, thus making it an objective matter. So, intelligence can be objectified.

It's one of those exchanges between "psychology" and science, whereby what is subjectively observed then becomes quantified into a mathematical measure.

 

So, when talking about intelligence, consider what aspect/aspects of behavior is/are being measured (mathematically quantified) and how it/they is/are being measured.

 

To answer your question, as I believe you have a novice education, I would say differentiating levels of neural regeneration, AMPA receptors, LTP, mitochondrial count, etc. etc. You may want to further study neural plasticity. Long-term potentiation has historically held a large involvement in intelligence. Maybe follow up some Wikilinks on various pages to get a broad view of the issue.

Edited by Genecks
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The amount of cortical convolution might be a factor (due to the increased surface area and density of connections it allows, especially in some important regions), but that's still somewhat speculative and results are mixed.

 

http://white.stanford.edu/teach/index.php/Brain_Gyrification_and_its_Significance

 

Gyrification in the brain, also known as convolution, is a process of cortical folding that leads to the wrinkle like appearance of mammal brains. It is the basis for the presence of gyri and sulci (hills and valleys) in cerebral cortex. The extent of gyrification of brains is highly implicated as being positively related to species intelligence. The basic idea is that gyrification allows for (or is a result of) greater surface area of cortical neurons within the same skull volume. However the exact mechanism by which this occurs, its true significance, and the implications of differences within species is not conclusively known or explored.

 

<snip>

 

Luders (2007) showed that intelligence scores were positively associated with the degree of folding in the temporo-occiptal lobe. Furthermore, greater gyrification in the frontal cortex of females was correlated with higher IQ, while less convolution in frontal cortex of males was associated with lower IQ [11]. See Figure 5. These mixed results might make any official statement about whether greater gyrification in normal humans can be positively correlated to intelligence invalid due to the gender differences. However, it at least appears to be implicated in females and in the temporo-occiptal lobe for both genders.

 

<snip>

 

The notable differences in gyrification across species (more cognitively able mammals having greater gyrification), as well as the reality that many mental and developmental disorders in humans are known to have phenotypes of cortical smoothing, all point to the argument that gyrification is positively related to cognitive ability. The mechanistic model by which gyrification is said to occur suggests that the more cortical neurons present, the more likely gyrification is to occur due to increased tension and crowding of neurons, forcing neurons to fold in a manner that increases surface area. It is most likely fair to assume that more cortical neurons equate a greater capacity for cognition (though pruning processes are important in normal development).

 

However whether somehow increasing the gyrification or surface area of a cortex within a species would be related to increased intelligence is still up for debate. Though higher IQ was correlated with greater convolution in females, an opposite effect was found in males. No genes have been associated with increasing gyrification; only loss of function in certain genes has been shown to exhibit negative and abnormal convulutions (Lissencephaly). The studies on meditation and autism could be further explored to more conclusively answer the question of whether positive modulation of gyrification within the human species could equate higher intelligence.

To see the above referenced Luder's study yourself, follow this link. It's important to recall the limitations imposed by the gender differences noted, but they shared: "Intelligence scores were positively associated with the degree of folding in the temporo-occipital lobe, particularly in the outermost section of the posterior cingulate gyrus (retrosplenial areas)," so perhaps there is something to that.

Edited by iNow
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There are two very large misconceptions in the OP. First is that we know what the entire structure of the average person's brain is, and second is that we know enough about intelligence to define what differences in that structure are meaningful. The first one is fairly self explanatory, but I feel I may need to discuss the second.

 

Intelligence is not a well defined concept, I believe the current consensus is that there are differences in types of intelligence. There is the concept of general intelligence, but even that is ill defined. Ignoring those problems we still have the major problem of what the structural differences would be DUE to the differences in intelligence. It would be difficult to say whether a structural difference in, for example, the occipital temporal fissure is due to a better ability to recognize patterns (something this brain area is believed to play a large part in) or because the person does things that use that brain area more than average. So it may just be a correlated structural difference and not a causal structural difference. And because of neuronal plasticity there can be large structural differences in the brain of a single person when they are 30 when comparing it to when they are 40.

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Adding to Ringer's post above, we also don't often know whether the structure of certain brain regions are formed as they are due to genetics and that's why the person is intelligent, or if instead the person is intelligent and through experience and education those brain regions became shaped that way. Is intelligence the result of the brain infrastructure or is the brain infrastructure the result of intelligence. It's the classic nature/nurture problem, and that's all before you even delve into the challenges of defining intelligence in a meaningful way.

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There are two very large misconceptions in the OP. First is that we know what the entire structure of the average person's brain is, and second is that we know enough about intelligence to define what differences in that structure are meaningful. The first one is fairly self explanatory, but I feel I may need to discuss the second.

 

Intelligence is not a well defined concept, I believe the current consensus is that there are differences in types of intelligence. There is the concept of general intelligence, but even that is ill defined. Ignoring those problems we still have the major problem of what the structural differences would be DUE to the differences in intelligence. It would be difficult to say whether a structural difference in, for example, the occipital temporal fissure is due to a better ability to recognize patterns (something this brain area is believed to play a large part in) or because the person does things that use that brain area more than average. So it may just be a correlated structural difference and not a causal structural difference. And because of neuronal plasticity there can be large structural differences in the brain of a single person when they are 30 when comparing it to when they are 40.

By intelligence I mean their cognotive abilities

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Honestly the only answer that we can give you is that we don't know enough about brain activity and structure to give you a satisfactory answer. This answer works for virtually any cognitive ability and structure correlation, with the exception of what happens when some specific areas are completely removed.

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  • 1 month later...

What you have in one aspect you loose in another, its a simple trade off. The greatest scientific minds might work brilliantly at storing facts and linking related subject matter but be aweful at spelling, articulation or sporting ability. Same aplies to savants, what they have in cognition they loose in social capabilities. The list goes on, the trade offs are sometimes not so obvious, it all fades into some sociological equalibrium really. Just swollow what you can, your subconscious usually gives you what you need, unless you've overloaded it.

 

Subconscious and Intelligence are very closely related, the strength of communication between your subconscious and conscious mind gives rise to your intellect i believe.

 

Unfortunately what your conscious mind actually is in the physical realm makes this scientifically sticky. A NASTY BUG.

Edited by DevilSolution
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  • 4 weeks later...

The short answer: there must a connection between physical brain structure and intelligence (and personality), but today's science doesn't know what that is.

 

 

Our knowledge of the brain and the mechanisms of thought are much too primitive to answer this.

 

It's an extremely important question, lots of people are working on various steps in this direction.

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