122
votes
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Are male and female brains physically different from birth?
Short answer
Yes, men and women's brains are different before birth.
Background
First off, learning effects versus genetic differences is the familiar nature versus nurture issue. Several genes on ...
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91
votes
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Do animals exhibit handedness (paw-ness?) preference?
Short Answer
Yes. handedness (or Behavioral Lateralization) has been documented in numerous vertebrates (mammals, reptiles and birds) as well as invertebrates.
This includes domestic cats (see Wells ...
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82
votes
Are there organisms with fewer than 1000 neurons?
Short answer
As far as I know, a complete neural map (a connectome) is only available for the roundworm C. elegens, a nematode with only 302 neurons (fig. 1).
Fig. 1. C. elegans (left, size: ~1 mm) ...
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25
votes
Are there organisms with fewer than 1000 neurons?
The organism you are looking for is the nematode C. elegans, which always has the same number of neurons, 302, and has been fully mapped, see WormWeb or you can chase original publications from there. ...
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18
votes
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Does human brain store duplicate data?
The way neuroscientists currently think about storage in the brain, it doesn't make any sense to think about "duplicate" data but rather about the "robustness" of a given memory to interference or ...
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16
votes
Are there organisms with fewer than 1000 neurons?
I believe there are types of water snail with 8 distinct neurons in a ganglia, there's a bit of information here: molluscs.at.
The cell bodies of the neurons are massive, visible under a standard ...
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16
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Do the foldings in the brain vary person to person?
The major structure is consistent but there is a lot of variation in the details, including the presence and absence of certain gyri:
Kennedy, D. N., Lange, N., Makris, N., Bates, J., Meyer, J., &...
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15
votes
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Do we use 100% of our cerebral capacity?
The idea that we only use 10% of our brain capacity is a myth. There is a great article at wired.com that discusses the myth and it's history.
There is really no reason to evolve an entire brain ...
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14
votes
Is it theoretically possible to create two humans by splitting one human in two?
If you split a human early enough (in the first weeks after fertilization), you can get monozygotic twins.
Other than that, you are in the field of science fiction and we cannot safely answer such ...
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12
votes
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What's the mechanism for being mentally tired?
There is ongoing research on this topic, but there is a theory known as inhibition theory. It has been defined as:
Inhibition theory is based on the basic assumption that during the performance of ...
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12
votes
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The human brain in numbers I: neurons
First of all, let me clear out that these numbers are calculated, not observed (obviously, nobody has counted the number of neurons in any part of brain). So, take these with a grain of salt.
I was ...
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12
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Do self-exciting neurons exist?
Short Answer
Yes, autapses exist, though the role of excitatory autapses in particular is unclear.
Long Answer
A lot of your assumptions are wrong for biological neurons (I'm suspecting you have a ...
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10
votes
Is hunting animals, crafting and attacking/defending from enemies intellectually equivalent to learning quantum physics?
Addressing some assumptions/presumptions apparently present in the question (this might be too long for a comment):
First, natural selection has not stopped. The sexual selection might be more active ...
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What is the brain's preferred energy source? Glucose or ketones?
First of all, for those readers with less knowledge of the general principles of biology, I want to state an important, even if obvious, point: The brain doesn't
"prefer" anything. Despite ...
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10
votes
Is it theoretically possible to create two humans by splitting one human in two?
Given how some parts of the brain control the opposite hemisphere of the body, and how this is not consistent throughout the entire brain, you would have to do a lot more than split someone in half ...
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9
votes
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What does +60mm mean in MRI scans?
Short Answer
They are marking distance from a reference plane.
Longer Answer
In the images you provided, you are looking at horizontal slices through a brain. The legends are indicating that each ...
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9
votes
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Why does music give you emotions?
The evolutionary origin is alleged to be recent: Other animals do not have a preference for dissonance and consonance. (McDermott & Hauser, 2004).
Humans have new auditory regions in the brain ...
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9
votes
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What structures does our brain use for a quick indexing of all the data we store in our heads?
Brains are not computers, and do not process information like computers.
The trees from CS you are talking about are ways to run linear information stores through a central processing unit. Even with ...
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8
votes
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Why doesn't the rest of the body have something like the "blood-brain" barrier to protect itself from pathogens?
There can be many reasons to why BBB-like barrier is not present in all the capillaries of the body. Let's talk about them one at a time.
Source
Blood-brain barrier has its own side effects. Some ...
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8
votes
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How do neurons find each other?
Q: We know neurons can organize into very complex networks, but how?
The answer is your first guess: Neurons find other target neurons with specific chemical signals.
Q: What are the names of said ...
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8
votes
Are there organisms with fewer than 1000 neurons?
Re: insect brain size
Following article has a good summary — in short insects' nervous systems range from 7400 to 850000 neurons:
http://blogs.discovermagazine.com/notrocketscience/2011/11/30/how-...
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8
votes
Cerebral activity during exposure to non - visible light
Vision is based on a protein interaction with a molecule called retinal from vitamin A.
Wavelengths of light in the visual range cause a photoisomerization of retinal (a cis- to trans- change), which ...
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8
votes
Are male and female brains physically different from birth?
One point of view you rarely see is the perspective of sex differences from an evolutionary standpoint. Never mind that this is the reason why the differences exist in the first place if they do at ...
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8
votes
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Why Is Gray Matter Gray?
The terms gray and white matter relate to their color in gross specimens (i.e., not microscopic specimens) that have been formalin fixed. Nissl granules describe a microscopic structure, the rough ...
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8
votes
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Biological Neural Network Training for Babies
Biological neurons function in a very different way, as compared to the simplistic artificial neural networks of machine learning. For example, see how real neurons work and how they connect with each ...
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7
votes
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Can brain damage caused by physical injury affect the social behaviour of a person?
Socialization is a cognitive and executive brain based function that requires higher level thinking mechanisms usually dependent on the prefrontal coretex. A lot of social cues we obtain from our ...
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7
votes
How can neurons divide without centrioles?
You talk about memory loss. The hippocampus is involved in the formation and storage of memories and indeed one of the few places in the brain where new neurons are formed. The formation of new ...
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7
votes
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What are the factors that contribute to genetically identical individuals behaving differently?
Your question has actually more to do with developmental biology and the origin of phenotypic variance in populations than with neuroscience.
Here is a list of factors which variance explain observed ...
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