Questions tagged [neuroscience]

The study of the structure and function of the nervous system and its components.

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Are male and female brains physically different from birth?

Male and female brains are wired differently according to this article: Maps of neural circuitry showed that on average women's brains were highly connected across the left and right hemispheres, ...
Pablo's user avatar
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84 votes
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Is there an RGB equivalent for smells?

Millions of colors in the visible spectrum can be generated by mixing red, green and blue - the RGB color system. Is there a basic set of smells that, when mixed, can yield all, or nearly all ...
Spartacus9's user avatar
73 votes
3 answers
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How does the brain's energy consumption depend on mental activity?

What is the impact of mental activity on the energy consumption of the human brain? I am most interested in intellectually demanding tasks (e.g., chess matches, solving a puzzle, taking a difficult ...
Piotr Migdal's user avatar
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63 votes
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Are there organisms with fewer than 1000 neurons?

I'm developing neural networks comprised of just 3 to 10 layers of virtual neurons and I'm curious to know if there are any insect brains out there with fewer than a thousand neurons? Are there any ...
J.Todd's user avatar
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62 votes
3 answers
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Why do smaller mammals move intermittently?

I was watching a nice little video on youtube but couldn't help but notice how snappy smaller animals such as rats and chipmunks move. By snappy I mean how the animal moves in almost discrete states ...
Fraïssé's user avatar
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54 votes
5 answers
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Human perception of time depending on age

From what I can tell and what thus far all people with whom I discussed this subject confirmed is that time appears to "accelerate" as we age. Digging a little, most explanations I found basically ...
back2dos's user avatar
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52 votes
1 answer
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Do large animals experience a meaningful delay when moving their most distant appendages?

According to the Physics Factbook, nerve impulses travel at speeds anywhere from 1 meter per second up to around 100 meters per second. Blue whales reach up to around 30 meters long. For a full-size ...
Tal's user avatar
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47 votes
2 answers
52k views

Why can't we kill ourselves by holding our breath?

Is it possible to kill yourself by holding your breath? This question is obviously copied from Quora, but I had heard it as a fact that we cannot kill ourselves by holding our breath and I'm looking ...
Abhishek Choudhary's user avatar
45 votes
3 answers
14k views

Are humans more adapted to "light mode" or "dark mode"?

I was discussing with a colleague about using dark-mode vs. light mode and remembered an article arguing that humans vision is more adapted to light-mode rather than dark-mode: I know that the trend “...
Alexei's user avatar
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43 votes
2 answers
4k views

Can brain cells move?

I was discussing this with my brother. I'm pretty sure I read somewhere that they can move. Thanks EDIT: By movement I mean long distance migration (preferably within the brain only).
DLV's user avatar
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43 votes
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If the brain has no pain receptors, how come you can get a headache?

I've read many years ago in books, that the brain has no nerves on it, and if someone was touching your brain, you couldn't feel a thing. Just two days before now, I had a very bad migraine, due to a ...
Zerium's user avatar
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40 votes
2 answers
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What actually happens when my leg 'falls asleep'?

Most people have experienced the temporary loss of feeling and tingling in their leg resulting from sitting in an abnormal position for a short while. Usually you get a loss of feeling in your leg ...
Gordon Gustafson's user avatar
38 votes
6 answers
45k views

Why do the two hemispheres of the brain control the opposite sides of the body?

Why does the left hemisphere control the right and the right hemisphere control the left? I googled it but didn't find a good answer regarding this. Could someone explain? Does this adaptation help ...
lmathl's user avatar
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36 votes
2 answers
3k views

Is C. elegans always observed with precisely 302 neurons? Are there ever individual viable exceptions?

This answer mentions that the C. elegans hermaphrodite has exactly 302 distinct neurons. This has made it a very effective model for a variety of types of biological research, including neurology and ...
uhoh's user avatar
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34 votes
3 answers
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How and where, in the human brain, are memories stored?

Background I am a computer programmer who is fascinated by artificial intelligence and artificial neural networks, and I am becoming more curious about how biological neural networks work. Context &...
Matt Cashatt's user avatar
33 votes
1 answer
22k views

What do you see when your eyes are closed?

If you are in pitch black and you close your eyes, you sometimes can see strange shapes of various colors. A lot of the time these shapes and colors change as you observe them. This phenomenon still ...
JonHerman's user avatar
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32 votes
3 answers
35k views

Why is saltatory conduction in myelinated axons faster than continuous conduction in unmyelinated axons?

How does spacing apart sodium and potassium channels allow the action potential to travel faster down the axon? This is the reason always cited for saltatory conduction and myelination, but my mental ...
user7924's user avatar
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32 votes
4 answers
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How does cerebrospinal fluid circulate in the central nervous system?

Cerebrospinal fluid (CSF) is produced in the choroid plexus of the lateral ventricles and in the 4th ventricle of the brain. CSF then circulates through the ventricles of the brain and the ...
DQdlM's user avatar
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32 votes
4 answers
6k views

Do men have more extreme variations than women?

This question was considered unsuitable for Skeptics and I think it is more suited to BIology than Cognitive Sciences I was reading this article which I found interesting. It is not supported with ...
Sonny Ordell's user avatar
31 votes
3 answers
9k views

Can humans ever directly see a few photons at a time? Can a human see a single photon?

I am not asking the following question: Can humans ever see a photon in the same way we see a chair? My question is: Can a human retina respond to a single photon? If so, how does this happen and why ...
Daniel Mera's user avatar
30 votes
3 answers
10k views

Can one see flickering of a light bulb at 50 Hz?

Yesterday I had a BBQ with some friends. The sun had already set and the only light source left (besides some ambient light from the world around) was a low energy light bulb. After a while I started ...
Timo's user avatar
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28 votes
5 answers
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What are the advantages of forgetting?

How forgetting things is helpful for the brain or the human body biologically? This web page After some moment of being rude, selfish, or weak, either we are able to put it behind us, or the person ...
Mesentery's user avatar
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26 votes
3 answers
20k views

Do oysters feel pain?

Do oysters feel pain when you bite into the inside, or when you crack open the shell? I tried google searching it to no avail. When you bite inside the oyster or when you break the shell to open the ...
Sweet_Cherry's user avatar
26 votes
2 answers
2k views

What's the mechanism for being mentally tired?

I notice that after long tests, or long periods of critical thinking, my body and mind feel noticeably tired. Why does this happen? Are the neurons in my head not firing as quickly, or is there just a ...
Dupontrocks11's user avatar
25 votes
7 answers
7k views

Why can't we see in low light if staring long enough?

For me it seems reasonable that if I kept my gaze on a fixed point in a room with low light, a progressively brighter and better picture would appear before my eyes, just like a camera can see in the ...
filip's user avatar
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25 votes
2 answers
38k views

How do the brain and nerves create electrical pulses?

The information between the brain and peripheral nerves is sent via electrical pulses or signals, How then does a non-metallic human cell manage to conduct an electrical signal?
johnny1bucket's user avatar
25 votes
2 answers
2k views

How is temperature sensed?

Can anyone summarize the mechanism by which when an object of a given temperature is placed in contact with, say, the skin on a human fingertip, the average speed of the particles of the object is ...
mring's user avatar
  • 1,963
24 votes
9 answers
23k views

Why have humans evolved much more quickly than other animals?

Humans have, in a relatively short amount of time, evolved from apes on the African plains to upright brainiacs with nukes, computers, and space travel. Meanwhile, a lion is still a lion and a ...
Matt Cashatt's user avatar
23 votes
1 answer
456 views

What is the mechanism responsible for the periodicity of hiccups?

Hiccups (singultus) are caused by involuntary spasm of the intercostal muscles and diaphragm, producing a sudden inspiration with associated glottic closure. It seems the neurobiology of the reflex ...
Susan's user avatar
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22 votes
3 answers
1k views

When did vision evolve for the first time?

Today I wondered what the first organism to evolve vision would have been. I assume that it would have been kind of primitive and basic, but of course extremely innovative and eventually useful to a ...
magnetar's user avatar
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22 votes
3 answers
63k views

Why can't neurons undergo cell division?

Many cells in the human body can divide and reproduce, making healing possible. Neurons, however, cannot reproduce, which makes diseases affecting the brain particularly crippling. Why can't neurons ...
HDE 226868's user avatar
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22 votes
2 answers
2k views

Does human brain store duplicate data?

There are several answers and articles about how the brain stores data, but none specifically cover whether a human's brain stores duplicate data. I was reading in this article that a human brain can ...
Johansson's user avatar
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22 votes
1 answer
787 views

Why does regular exercise increase brain volume?

It has been shown in several studies that regular aerobic exercise increases brain volume in aging humans. The changes were observed in hippocampus and were correlated with dramatic reduction of age-...
Aleksandra Zalcman's user avatar
21 votes
1 answer
1k views

Why do we feel tired if we sleep excessively?

When we eat, finally we feel full. I know which mechanism causes the sensation of being full. But when we sleep excessively we often still want more sleep. Why does this happen? Is there a mechanism ...
MySky's user avatar
  • 2,264
20 votes
1 answer
632 views

Why are fearful stimuli more powerful at night?

For example, horror movies appear to be scarier when viewed at night than during broad day light. Does light have any role in this phenomenon? Are there changes in hormones at night versus during ...
Mesentery's user avatar
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20 votes
2 answers
4k views

What causes the range of severity of neurological deficits in Down's syndrome?

It's known that the severity of symptoms caused by a trisomy 21 varies from individual to individual. Part of the explanation for this range of severity is the finding that 94% of Down's syndrome ...
AliceD's user avatar
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19 votes
2 answers
4k views

What makes learning more difficult as we age?

Why is it harder to adapt yourself to different cultures, places, and languages as you age? What makes breaking up with emotional patterns or ideas after years of habit more difficult? Is there a ...
PbxMan's user avatar
  • 311
19 votes
2 answers
895 views

Can parts of a human brain be asleep independently of each other, or vary in the times required for them to fall asleep?

I know that some birds and marine animals can continue complicated activity (swimming, flying?) while one hemisphere of their brain is asleep. I'm interested if human brain has some parts of it that ...
Alex Stone's user avatar
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19 votes
1 answer
13k views

Is it correct that the body only responds to the most painful stimulus?

I'm rather ashamed to say that this question is partly based on an episode of House. I have previously heard that, if there are multiple simultaneous painful stimuli, the mind will only feel the ...
Rory M's user avatar
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19 votes
1 answer
3k views

How does Sodium Valproate cause neural plasticity

I have been reading a fascinating paper: Valproate reopens critical-period learning of absolute pitch 18 individuals were given Sodium Valproate (VPA) for a fortnight during which they trained on a ...
P i's user avatar
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18 votes
1 answer
560 views

The human brain in numbers I: neurons

Even though knowing the number of neurons in a functional unit or with the same function is not of main importance, it may be interesting to know their orders of magnitude, especially in the human ...
Hans-Peter Stricker's user avatar
17 votes
3 answers
563 views

Under what conditions do dendritic spines form?

I'm looking for resources or any information about the formation of dendritic spines and synaptogenesis, especially in relation to how new connections are formed on a daily basis. Does the ...
hiddensunset4's user avatar
17 votes
2 answers
12k views

Why do neurons have only one axon?

I have just learnt about neurons. I wonder why neurons have only one axon. Can they transmit nerve impulses faster and more rapidly when they have more axons? Does having more axons help in ...
lmathl's user avatar
  • 739
17 votes
2 answers
365 views

What are the main mechanisms of interaction between the nervous and immune systems?

We know from pop science that our psychological states have an effect on our immune systems ("worrying ourselves sick", etc.), but what are the actual mechanisms through which our nervous systems pass ...
jonsca's user avatar
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17 votes
3 answers
2k views

Are two eyes necessary for 3D vision?

It has always been my understanding that humans have two eyes so that we can have 3D vision: the left eye sees more of the left side of an object than the right eye and vice versa. This helps us to ...
Héctor van den Boorn's user avatar
16 votes
2 answers
2k views

Do humans learn to distinguish different senses?

Does a human being learn to differentiate between its senses at some stage in their development? Is there a time when it, for example, cannot tell if an input is a taste or a visual image? The ...
B.Swan's user avatar
  • 283
16 votes
2 answers
3k views

Do human beings have pheromone receptors?

What is the current consensus on whether or not humans have receptors that detect pheromones? If there are purported receptors, in what anatomical areas are they located? With what organ systems do ...
jonsca's user avatar
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16 votes
2 answers
818 views

How does an axon "know" it's not connecting to its own neuron?

I recently read about an experiment where they removed the dendrites and axons from rat neurons and placed them on a grid. After a while they started reconnecting and were able to learn things. Since ...
Lennart_96's user avatar
16 votes
1 answer
3k views

What limits the maximum spacing of Nodes of Ranvier and which organisms tend to have the widest gaps?

Assuming that a longer distance between gaps in the myelin sheath is beneficial for an organism due to the increased propagation speed, what is the limiting factor in determining the maximum spacing ...
Rory M's user avatar
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16 votes
1 answer
2k views

Why do neurons die so quickly (relative to other cells) when deprived of oxygen?

This question could be considered a follow-up question to Why is a lack of oxygen fatal to cells?, although the top answer there does not address why damage starts to pop in. The answer says this: ...
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