Do More Brain Wrinkles Lead to Increased Intelligence?
Well first off, I would like to start by showing how a person with no brain wrinkles (Lissencephaly) is negatively affected. It is almost always accompanied by microcephaly (tiny head), difficulty swallowing, muscle spasms, seizures, and severe mental and motor skills retardation. Lissencephaly is caused during embryonic development by defective neuronal migration (the process in which nerve cells move from their place of origin to their permanent location.) Currently there is no treatment, and most people that develop it die before the age of two, and the ones that don’t die are severely retarded, not developing past the intelligence of a 3-5 month old baby.
Cortex- Structure Cerebral and Function.
The Cerebral Cortex or “Gray Matter” as it is commonly referred to, encompasses about 2/3rds of the brain’s mass. It is here where the brains 100 billion neurons reside. They are all jam-packed into a thin layer with the thickness of an orange peel. The Cortex is divided into the left and right hemispheres, and into four lobes; The Parietal Lobe – Involved in the reception and processing of sensory information in the brain, Frontal Lobe – Involved with decision making, problem solving, and planning. Occipital Lobe – Involved with vision. Temporal Lobe – Involved with memory, emotion, hearing, and language. Most of the informational processing actually takes place here in the Cerebral Cortex. It also makes possible unique abilities such as thinking, learning, remembering, and creating. It is worth noting that Chimpanzee’s cortex is 1/3rd the size of ours.
Brain Development
When we are born our brains are nice and smooth, just like our baby bottoms! But, within a few short months the brains wrinkles are fully developed, and the brain resembles a tiny adult brain. This happens because as neurons continue to grow, divide, and migrate, the cortex folds in on its self forming sulci and gyri. The sulci and gyri (brain wrinkles) allow a much larger surface area of the cerebral cortex (and therefore neurons). This is why we can have a brain that has the surface area of a pillow in our skull, yet not look like we have watermelons for heads. Cortical development is the result of the division of neural precursor cells, some of which divide into 2 dividing daughter cells and others which turn into neurons. Unlike other cells in the body, brain cells stop dividing, and become fully formed right before birth. Studies also show that brain wrinkles protect the brain from trauma by giving it the ability to compress during an accident to absorb energy from the impact. (“Journal of Biomechanics”)
Beta Catenin: An Amazing Protein
Beta Catenin is a protein which acts like a switch during cell growth, it tells the cell whether to keep dividing and making more of itself, or to go on and do something with its little cell life. (Neural Precursor cell --> Neuron) When Beta Catenin is over expressed it slows down the rate at which the precursor cells turn into neurons, and increases the dividing of the precursors, causing much more precursor cells to be developed, which eventually will turn into neurons. The increase is about 3-4 fold over a normal cerebral cortex. A man by the name of Christopher A. Walsh conducted a study on transgenic mice that over expressed Beta Catenin. What he found is that these mice (which normally have smooth brains) had very wrinkly brains, similar to that of a human. The first mice in his experiment grew heads so large that they actually weren’t able to survive very long after birth because their heads were so tremendously larger than they should have been. He toned down the amount of B-Catenin and is now testing his second version of the mice with brains 40% larger than normal. So far he hasn’t been able to get a definite answer on whether intelligence was significantly affected. There was however, a notable increase in aggression.
What it All Means
So, the question still remaining is: Does a bigger brain/more brain wrinkles lead to increased intelligence? Well… It appears from recent studies by Michael McDaniel, that within a given species, a bigger brain scores more IQ points than a smaller brain. One such study was: Given that males have brains larger than females; they should have a slightly higher IQ. Tests over 100,000 SAT scores of 17-18 year olds were converted to IQ scores, and it showed that males scored about an average of 4 IQ points higher than females.
Well first off, I would like to start by showing how a person with no brain wrinkles (Lissencephaly) is negatively affected. It is almost always accompanied by microcephaly (tiny head), difficulty swallowing, muscle spasms, seizures, and severe mental and motor skills retardation. Lissencephaly is caused during embryonic development by defective neuronal migration (the process in which nerve cells move from their place of origin to their permanent location.) Currently there is no treatment, and most people that develop it die before the age of two, and the ones that don’t die are severely retarded, not developing past the intelligence of a 3-5 month old baby.
Cortex- Structure Cerebral and Function.
The Cerebral Cortex or “Gray Matter” as it is commonly referred to, encompasses about 2/3rds of the brain’s mass. It is here where the brains 100 billion neurons reside. They are all jam-packed into a thin layer with the thickness of an orange peel. The Cortex is divided into the left and right hemispheres, and into four lobes; The Parietal Lobe – Involved in the reception and processing of sensory information in the brain, Frontal Lobe – Involved with decision making, problem solving, and planning. Occipital Lobe – Involved with vision. Temporal Lobe – Involved with memory, emotion, hearing, and language. Most of the informational processing actually takes place here in the Cerebral Cortex. It also makes possible unique abilities such as thinking, learning, remembering, and creating. It is worth noting that Chimpanzee’s cortex is 1/3rd the size of ours.
Brain Development
When we are born our brains are nice and smooth, just like our baby bottoms! But, within a few short months the brains wrinkles are fully developed, and the brain resembles a tiny adult brain. This happens because as neurons continue to grow, divide, and migrate, the cortex folds in on its self forming sulci and gyri. The sulci and gyri (brain wrinkles) allow a much larger surface area of the cerebral cortex (and therefore neurons). This is why we can have a brain that has the surface area of a pillow in our skull, yet not look like we have watermelons for heads. Cortical development is the result of the division of neural precursor cells, some of which divide into 2 dividing daughter cells and others which turn into neurons. Unlike other cells in the body, brain cells stop dividing, and become fully formed right before birth. Studies also show that brain wrinkles protect the brain from trauma by giving it the ability to compress during an accident to absorb energy from the impact. (“Journal of Biomechanics”)
Beta Catenin: An Amazing Protein
Beta Catenin is a protein which acts like a switch during cell growth, it tells the cell whether to keep dividing and making more of itself, or to go on and do something with its little cell life. (Neural Precursor cell --> Neuron) When Beta Catenin is over expressed it slows down the rate at which the precursor cells turn into neurons, and increases the dividing of the precursors, causing much more precursor cells to be developed, which eventually will turn into neurons. The increase is about 3-4 fold over a normal cerebral cortex. A man by the name of Christopher A. Walsh conducted a study on transgenic mice that over expressed Beta Catenin. What he found is that these mice (which normally have smooth brains) had very wrinkly brains, similar to that of a human. The first mice in his experiment grew heads so large that they actually weren’t able to survive very long after birth because their heads were so tremendously larger than they should have been. He toned down the amount of B-Catenin and is now testing his second version of the mice with brains 40% larger than normal. So far he hasn’t been able to get a definite answer on whether intelligence was significantly affected. There was however, a notable increase in aggression.
What it All Means
So, the question still remaining is: Does a bigger brain/more brain wrinkles lead to increased intelligence? Well… It appears from recent studies by Michael McDaniel, that within a given species, a bigger brain scores more IQ points than a smaller brain. One such study was: Given that males have brains larger than females; they should have a slightly higher IQ. Tests over 100,000 SAT scores of 17-18 year olds were converted to IQ scores, and it showed that males scored about an average of 4 IQ points higher than females.
Another example is Einstein, his brain as a whole was perfectly normal sized, but certain parts of it were bigger than normal, like his inferior parietal region (responsible for mathematical thought, visuospatial cognition, and imagery of movement). However, his language was lacking, due to a smaller region of the Broca’s area that controls speech, because his oversized mathematical region took up some of the space for language. (He didn’t learn to talk till he was 3 years old.)
Also, certain activities seem to increase the size of individual aspects of the brain. Scientists have found that the brains of London's cab drivers enlarge and change as they learn complicated routes. Cab drivers who have been navigating the streets for years had significant structural changes, as they exhibited a larger posterior hippocampus and a slightly smaller front hippocampus.
As for B-Catenin, my hypothesis is that an extra 200 billion neurons added to our only 100 billion will have an amazing impact on cognitive abilities in humans, or any animal for that matter. Take the monkey for example; if his little monkey brain was increased in surface area by a factor of 3, then it would roughly equal that of a human. What would be the result? The monkey, (now having a cortex the size of ours) could very possibly be able to comprehend aspects of human language, be able to think, and plan, and further develop creativity.
So modern studies have shown that, Yes – Larger brain structure when coupled with high organization does in fact most often lead to increased cognitive abilities. Unless of course, your just a 17 pound whale brain on the hunt for nothing other than krill! :)
- Tyler Martin.
As for B-Catenin, my hypothesis is that an extra 200 billion neurons added to our only 100 billion will have an amazing impact on cognitive abilities in humans, or any animal for that matter. Take the monkey for example; if his little monkey brain was increased in surface area by a factor of 3, then it would roughly equal that of a human. What would be the result? The monkey, (now having a cortex the size of ours) could very possibly be able to comprehend aspects of human language, be able to think, and plan, and further develop creativity.
So modern studies have shown that, Yes – Larger brain structure when coupled with high organization does in fact most often lead to increased cognitive abilities. Unless of course, your just a 17 pound whale brain on the hunt for nothing other than krill! :)
- Tyler Martin.
