120
votes
Accepted
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 ...
- 51k
90
votes
Accepted
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) ...
- 51k
63
votes
Accepted
Can brain cells move?
The question is relatively broad and one should take into account that the brain not only consists of neurons, but also glial cells (supportive cells) and pre-mitotic neuronal stem cells. Furthermore, ...
- 51k
53
votes
Accepted
Why is the brain white?
The brain is indeed stacked with blood vessels, as shown in a 3D model in Fig. 1.
Fig. 1. 3D-printed model of blood vaculature. Source: Biobots.
The blood supply on the surface of a live brain is ...
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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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23
votes
Accepted
How long does it take for memory to disperse after death?
There are multiple levels of memory, some of which would die immediately, some of which would take some time. So the answer is: it depends; some immediately, some only very slowly.
At the highest ...
- 424
22
votes
Supercomputer Vs Human Brain
I will just show the statistics of last attempt to mimic the brain process.
In 2011 fastest computer in Japan was launched:
K computer OR SPARC64 VIIIfx 2.0GHz
Features:
Manufacturer: Fujitsu
...
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21
votes
Accepted
Can a human acquire a memory of an animal?
No, it can't be done for a lot of reasons. Here are just a few.
1) Memories are stored in electrical pathways, not the the cells themselves. You don't have 1000 memories in a chunk of brain that ...
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21
votes
Accepted
Can the human brain be reduced to a binary system?
First of all, I would like to point out that making analogy between digital computers and the brain is often very misleading.
That being said, my answer is, some scientists believe so, some don't.
...
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18
votes
Accepted
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 ...
- 34.7k
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 ...
- 939
15
votes
Accepted
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 ...
- 1,152
14
votes
Accepted
Supercomputer Vs Human Brain
There's a very big difference between doing the calculations needed to simulate the human brain (or any animal brain - we can do a fairly decent job on C. elegans), and doing computations. While a ...
- 3,603
14
votes
Accepted
Is there a significant difference in sedentary calorie-burn between a thinker and non-thinker?
Is there a significant difference in calorie burn?
No.
The brain, while only making up 2% of our body weight, accounts for ~20% of our energy use at rest. That's because the brain, being critical ...
- 24.2k
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 ...
- 67.5k
12
votes
Accepted
Is mammalian vision processed as a sequence of frames?
Short answer: no, there is no fixed frame rate or frame-based processing in mammalian vision.
Photons arriving at the photoreceptors at the back of the human retina interact with photo-sensitive ...
12
votes
Accepted
What is the mechanism behind tinnitus?
Short answer
The exact mechanism behind tinnitus (ringing in the ear) is unknown.
Background
Of the two theories you pose here, to the best of my knowledge the second one is the most widely ...
- 51k
12
votes
Accepted
Are Whales More Intelligent Than Humans?
The "wiring" of the brain is more important than the actual size. If only size would matter that basically humans would be rather unintelligent beings ( many many animals have larger head and brain ...
- 3,068
12
votes
Accepted
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 ...
12
votes
Accepted
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 ...
12
votes
Accepted
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 ...
- 34.7k
11
votes
Can brain cells move?
To add to Christiaan's answer, I'll mention one striking example of long-distance neuronal migration in the adult mammalian brain: the so-called Rostral Migratory Stream found in rodents, in rabbits ...
- 1,277
10
votes
Can human brain memory be removed by EMP?
http://en.wikipedia.org/wiki/Electromagnetic_pulse mentions the following natural sources of EMP, which I have ordered by frequency / period, from the shortest to the longest:
Electrostatic discharge ...
- 409
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 ...
- 201
10
votes
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 ...
- 474
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 ...
- 34.7k
9
votes
What are the advantages and disadvantages of being ambidextrous?
I think that the advantages of using both hands with equal ease is quite evident whether it be sports, at your work or while you are doing your household chores.
An obvious advantage is using both ...
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