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Thick-Brained People Are Smarter By Charles Q. Choi, Special to LiveScience
posted: 31 March 2009 10:07 am ET
Areas in the brain where there is an association between general cognitive ability and cortical thickness. Credit: Montreal Neurological Institute Full Size 1 of 1
Areas in the brain where there is an association between general cognitive ability and cortical thickness. Credit: Montreal Neurological Institute Although being called "thick-headed" means one is dumb, it turns out being literally thick-brained suggests one is smart, new findings reveal.
In the past decade, scientists across the world have unearthed conflicting evidence regarding where the seat of intelligence lies in the brain. For instance, in 2000, researchers in England and Germany discovered that intelligence seemed to depend exclusively on the frontal lobes of the brain.
"That was a bit surprising," said neuroscientist and psychiatrist Sherif Karama at the Montreal Neurological Institute. "It was hard to understand why something as complex as intelligence was restricted to just a few places in the brain."
In the following years, other teams of investigators found signs that intelligence was based in other parts of the brain. One problem with all these experiments was they each looked at relatively small numbers of children.
To help settle the argument, Karama and his colleagues used MRI to scan the brains of 216 healthy boys and girls ages 6 to 18 from a range of ethnic groups and socioeconomic statuses, mirroring the 2000 census. These children also took intelligence exams testing analogies, vocabulary, reasoning and visual-spatial skills.
The scientists discovered that intelligence was linked in general to the thickness of the "grey matter" the cerebral cortex of the brain, which plays a key role in memory, thought, language and consciousness. "It's not just a few regions. It's dispersed all throughout, in the areas associated with integrating information coming from diverse areas of the brain, which makes sense," Karama said.
If one looked at the average thickness of the cortex in these children, the differences between the lowest and highest IQs is on the order of a half-millimeter, Karama explained. That's roughly a third as thick as a penny.
Karama stressed these findings do not mean that cortex thickness or intelligence is based solely on genetics. "Environment plays a role, to be sure," he said.
By finding out which genes affect thickness of the cortex, one could potentially help treat mental disorders such as Alzheimer's, depression and schizophrenia. "You could help treat a lot of cognitive decline," Karama said.
Future research could instead focus on what role, if any, the "white matter" of the brain the insulation for the grey matter plays in intelligence.
"Perhaps those with higher IQs have better white matter that allows for faster or better connections through disparate areas," Karama told LiveScience. "We can also look at gender differences if men have different regions of the brain associated with intelligence than women. The possibilities are endless."
Karama and his colleagues detailed their findings this week in the March-April issue of the journal Intelligence.
Posts: 2007 | From: Washington State | Registered: Oct 2006
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An MRI study of increased cortical thickness in autism.
Hardan et. al. Stanford University, Department of Psychiatry and Behavioral Sciences, 401 Quarry Rd., Stanford, CA 94305, USA. hardanay@stanford.edu OBJECTIVE: The purpose of this study was to examine cortical thickness in autism in light of the postmortem evidence of cortical abnormalities of the disorder. METHOD: Magnetic resonance imaging (MRI) scans were acquired from 17 children with autism and 14 healthy comparison subjects, and sulcal and gyral thickness were measured for the total brain and for all lobes. RESULTS: Increases in total cerebral sulcal and gyral thickness were observed in children with autism relative to comparison subjects. Similar findings were noted in the temporal and parietal lobes but not in the frontal and occipital lobes. CONCLUSIONS: These preliminary findings indicate that increased cortical thickness may contribute to the increased gray matter volume and total brain size that have been observed in autism and may also be related to anomalies in cortical connectivity.
-------------------- Black Roots. Posts: 2007 | From: Washington State | Registered: Oct 2006
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JJ Cannell Atascadero State Hospital, Psychiatry, 10333 El Camino Real, Atascadero, CA 93423, United States. jjcannell@charterinternet.com Any theory of autism's etiology must take into account its strong genetic basis while explaining its striking epidemiology. The apparent increase in the prevalence of autism over the last 20 years corresponds with increasing medical advice to avoid the sun, advice that has probably lowered vitamin D levels and would theoretically greatly lower activated vitamin D (calcitriol) levels in developing brains. Animal data has repeatedly shown that severe vitamin D deficiency during gestation dysregulates dozens of proteins involved in brain development and leads to rat pups with increased brain size and enlarged ventricles, abnormalities similar to those found in autistic children. Children with the Williams Syndrome, who can have greatly elevated calcitriol levels in early infancy, usually have phenotypes that are the opposite of autism. Children with vitamin D deficient rickets have several autistic markers that apparently disappear with high-dose vitamin D treatment. Estrogen and testosterone have very different effects on calcitriol's metabolism, differences that may explain the striking male/female sex ratios in autism. Calcitriol down-regulates production of inflammatory cytokines in the brain, cytokines that have been associated with autism. Consumption of vitamin D containing fish during pregnancy reduces autistic symptoms in offspring. Autism is more common in areas of impaired UVB penetration such as poleward latitudes , urban areas, areas with high air pollution, and areas of high precipitation. Autism is more common in dark-skinned persons and severe maternal vitamin D deficiency is exceptionally common the dark-skinned. Conclusion: simple Gaussian distributions of the enzyme that activates neural calcitriol combined with widespread gestational and/or early childhood vitamin D deficiency may explain both the genetics and epidemiology of autism. If so, much of the disease is iatrogenic, brought on by medical advice to avoid the sun. Several types of studies could easily test the theory.
Posts: 2007 | From: Washington State | Registered: Oct 2006
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^ I've heard an hypothesis out there that autistic people are descended from Neanderthals. If autism is indeed more common in tropically-adapted populations, that would refute the argument that autism is of cold-adapted Neanderthal origin.
quote:Increases in total cerebral sulcal and gyral thickness were observed in children with autism relative to comparison subjects. Similar findings were noted in the temporal and parietal lobes but not in the frontal and occipital lobes. CONCLUSIONS: These preliminary findings indicate that increased cortical thickness may contribute to the increased gray matter volume and total brain size that have been observed in autism and may also be related to anomalies in cortical connectivity.
Is this implying that autistic people are more intelligent? If so I have to take issue with that argument. We with autism probably have better systematizing intelligence than neurotypical people, but they score better than we do on social intelligence. It's hard to say who is more intelligent overall.
^ I've heard an hypothesis out there that autistic people are descended from Neanderthals. If autism is indeed more common in tropically-adapted populations, that would refute the argument that autism is of cold-adapted Neanderthal origin.
Why would autism in tropically-adapted populations be necessary to dispel the "Neanderthal origin" dogma, when molecular genetics is already at our disposal to do that?
Posts: 7516 | From: Somewhere on Earth | Registered: Jan 2008
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quote:Originally posted by T. Rex: ^ I've heard an hypothesis out there that autistic people are descended from Neanderthals.
Evergreen Writes:
The only possible correlation between autism and Neanderthals is vitamin D deficiancy in cold climates. Autistic humans do not descend from Neanderthals.
Posts: 2007 | From: Washington State | Registered: Oct 2006
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quote:Originally posted by T. Rex: If autism is indeed more common in tropically-adapted populations, that would refute the argument that autism is of cold-adapted Neanderthal origin.
Evergreen Writes: It is more common in tropically-adapted populations because of melanin and the inability to synthesize of vitamin D in northern latitudes.
Posts: 2007 | From: Washington State | Registered: Oct 2006
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quote:Originally posted by T. Rex: Is this implying that autistic people are more intelligent? If so I have to take issue with that argument. We with autism probably have better systematizing intelligence than neurotypical people, but they score better than we do on social intelligence. It's hard to say who is more intelligent overall.
Evergreen Writes: Hence, your real question should be "how is intelligence measured?". IQ tests are biased toward systemizing and not syncrenyzing (i.e., interhemispheric transfer) cultures.
Posts: 2007 | From: Washington State | Registered: Oct 2006
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quote:Originally posted by T. Rex: Is this implying that autistic people are more intelligent? If so I have to take issue with that argument. We with autism probably have better systematizing intelligence than neurotypical people, but they score better than we do on social intelligence. It's hard to say who is more intelligent overall.
Evergreen Writes: Hence, your real question should be "how is intelligence measured?". IQ tests are biased toward systemizing and not syncrenyzing (i.e., interhemispheric transfer) cultures.
Can you explain wha tyou mean by the difference between systemizing and syncrenizing and what is "interhemispheric" transfer BTW?
Posts: 70 | Registered: May 2009
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If the topic of this thread is true then the trolls in this forum must have transulent brains.
Posts: 26238 | From: Atlanta, Georgia, USA | Registered: Feb 2005
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quote:Originally posted by T. Rex: ^ I've heard an hypothesis out there that autistic people are descended from Neanderthals. If autism is indeed more common in tropically-adapted populations, that would refute the argument that autism is of cold-adapted Neanderthal origin.
Boy, you just might be retarded.
Posts: 113 | From: Dayr al-Barsha | Registered: May 2007
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