The primary component of the central nervous system, which, along with the spinal cord, controls the body of bilaterally symmetrical beings.

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3answers
19k views

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 ...
17
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5answers
3k 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 ...
13
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2answers
267 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 ...
12
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1answer
459 views

Supercomputer Vs Human Brain

With supercomputers doing calculation in petaflops ($10^{15}$ Calculations per Second), have we crossed the speed of Human Brain?
9
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1answer
365 views

Why does this illusion work?

This is another image I found on Google+ All lines are absolutely straight, parallel and perpendicular but why does it appear to have a curvature? Related: How does this illusion work?
9
votes
1answer
364 views

Is it possible to lose synapses over time?

I mean, what if a person is for a long time submitted to conditions in which his mental capacities are not explored, are the synapses undone? I've heard that drugs may cause such an effect, but what ...
9
votes
2answers
590 views

What happens once a brain is full?

I just read the answer to this question, and it got me thinking... If the human brain (or any other brain) has a finite amount of storage, what would happen once the brain has taken in its maximum ...
8
votes
2answers
422 views

Do memories have mass?

If it were possible to live forever, would our brains grow infinitely with the number of memories that we store? Or would we remove old memories as we create new ones?
8
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1answer
975 views

How does this illusion work?

I found this image on Google+ If you shake your head you can see a portrait of a person. Can anyone explain how the image is constructed in the brain?
8
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2answers
52 views

Is mammalian vision processed as a sequence of frames?

I often read that people believe that human vision has an inherent frames-per-second rate (FPS) that causes stroboscopic effects - such as seeing the spokes of a rotating wheel apparently rotating at ...
8
votes
1answer
136 views

Is it a limitation of the eyes, or the brain, that we can't see a moving bullet?

Are the photoreceptors in our eyes not fast enough to register the fast moving bullet, or is the brain not powerful enough to make sense of something happening that fast?
8
votes
2answers
249 views

How long does it take for memory to disperse after death?

1: There seem to be cases where coma patients with a non-active brain (i.e. flat EEG) have regained full consciousness. => Apparently memory and knowledge are stored independent of brain activity. 2: ...
8
votes
1answer
940 views

Disadvantages of unihemispheric sleep

Is is well known fact that marine mammals and some birds can sleep with one brain hemisphere at a time, since it's essential for their survival. However, at least in my opinion, such mechanism would ...
7
votes
1answer
100 views

What happens when we know that there is something that we forgot but we can't remember what it was?

I think it happens for everyone that sometimes we go to a room and forget why we went there. Is there any research or article on this?
7
votes
2answers
153 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 ...
6
votes
1answer
265 views

Influence of alcohol on brain cells

As I am not related to biology, I would appreciate if you can keep your answers as simple as possible. My question is about the influence of alcohol on the brain. As far as I know, drinking alcohol ...
6
votes
3answers
153 views

Why are males more likely than females to have autism spectrum disorder?

The male to female ratio in autism spectrum disorder is around 4:1. However it seems ASD is not a simple X-linked disorder. Then how is it possible males are more susceptible than females, if the ...
6
votes
2answers
42 views

Neuronal Architecture of the Brain

To what extent do brains (e.g. of humans) contain recurrent connections? I am studying artificial neuronal networks and frequently encountered the statement, that recurrent neural networks are ...
6
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2answers
141 views

How would the human body adjust to sleep times if we were to live in a place with different day lengths?

You sleep at night and are active during the day that's how things work for humans, but theoretically if a human whose parents lived on earth were to be born in another planet resembling earth but the ...
6
votes
2answers
1k views

How are babies born without a brain?

In the United States, anencephaly occurs in about 1 out of every 10,000 births. There are several forms of this condition, wherein the forebrain is absent. The forebrain is host to most of the higher ...
6
votes
1answer
111 views

What is meant by “neurotransmitters flooding the brain”?

I frequently hear expressions like "Dopamine flooding the brain" or "X neurotransmitter flooding the brain" used to communicate with general audiences. For example: "Following [orgasm]? oxytocin ...
4
votes
1answer
252 views

Why do humans alone have the capability to have religious/spiritual experiences?

What is it in our brain that makes having such experiences possible? I assume other species don't have these. Sure there are instances in the natural world where you can see individuals of the species ...
4
votes
4answers
150 views

Why has evolution made neurons use spiking?

I'm going to be forward and say that I'm not a biologist. I don't claim to fully understand the functionality of a neuron from an electrical/chemical perspective... I'm curiously gazing from the ...
4
votes
2answers
37 views

What is the biological principle of this “holotropic breathwork” technique?

Holotropic breathwork is a non-drug technique developed by Stanislav Grof used in psychotherapy. The therapy as a whole is usually called holotropic breathwork (at least by Grof himself) and will most ...
4
votes
2answers
89 views

Which part of the brain needs to be shut down to lose conciousness?

Whether it is mechanical (trauma), chemical (anaesthesia) or electrical - which part of the brain is shut down to cause loss of consciousness?
4
votes
3answers
136 views

What is the difference between different brain regions

The brain is separated into different regions, and different regions perform different tasks. Well, what are the differences between these regions on the cellular/systemic level. The brain is made up ...
4
votes
1answer
144 views

Why does strenous exercise cause vision of “lights”?

I had a hard climb a week ago. I got so tired then any time I closed my eyes I saw these lights inside my head. I see these lights almost every time that I run fast or some thing like that. What are ...
4
votes
3answers
157 views

Can children restore brain cells?

By "children" I mean young people at the age of 10 or lower. I know that the adult brain cannot restore brain cells, but what about children? I mean, the brain must develop from a few cells to a 90 ...
4
votes
1answer
289 views

What are the advantages and disadvantages of being ambidextrous?

What are the advantages and disadvantages of being ambidextrous? We have two hands and we nearly can't use one and this seems like a weakness, and a stupid one when you first think about it. But ...
4
votes
1answer
455 views

What is the average volume of the hippocampus?

I'm trying to find any information on sizes of the hippocampus? Ideally in the average adult male & female brain
4
votes
1answer
155 views

How is consciousness linked to the brain?

Could the brain be working without consciousness? Does the brain interact with consciousness? Alternately, is it that consciousness can't really control the brain, and you only have the impression ...
4
votes
1answer
1k views

3D models of adult male brain in the Blender software? Any open-sourced version for research?

I am trying to find 3D model of brains. I am particularly interested in adult-male -brains in Blender-model. I could find such 3D models of brains for sale here but because I am researching I would ...
4
votes
1answer
107 views

Does playing music during sleep actually suppress rather than rouse the brain?

I've long been interested in the effect of music/sound on dreaming, and even built 2 apps that play music during REM period. Now I'm looking at this article about FMRI studies of a sleeping brain, and ...
4
votes
1answer
39 views

Can the negative afterimage appear only if there is light or is it possible in darkness?

Reading the following paragraph: After staring at the red and blue shamrock, you saw a green and yellow afterimage. Opponent-process theory proposes that as you stared at the red and blue ...
4
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0answers
36 views

How does the frequency of a visual stimulus affect the steady-state visually evoked potential?

I want to make a project for EEG signal processing, and in my research I found the concept of SSVEP, which means that if you have a stimulus with low frequency applied to the eye, the electrical ...
4
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0answers
71 views

Does Lucid Dreaming decrease the regenerative effect of sleep?

After watching this SciShow video on sleep, I wonder about lucid dreaming. Specifically: Does lucid dreaming and associated directed agency within Lucid Dreaming decrease the regenerative effect of ...
3
votes
4answers
110 views

Is there a correlation between total neurons and intelligence?

Thanks for looking. First off, I am not a biologist, just a curious layman, so I apologize in advance if this isn't a "good" question. Please don't downvote me into oblivion. I read today that the ...
3
votes
1answer
74 views

How do we memorize something?

When we see something, how and where in the brain do we remember it and are able to recognize it later? What happens in the brain that makes this possible?
3
votes
2answers
41 views

EM Brainwaves VS Brain Wave (EEG) [closed]

The brain purportedly produces very weak EM waves. EEG is a method of measuring electrical brain activity, it has classifications for the types of brain wave it can detect: Theta, Alpha, Beta, Gamma ...
3
votes
2answers
107 views

What are the factors that control the speed of propagation of neuronal signals?

If we consider an analogy between a wire and a neuron there may be some resemblance between the factors controlling the data flow rate. For example the increased width of wire leads to decreased ...
3
votes
1answer
284 views

Is there any size limit to the amount of information a human (or other) brain can hold

Im not sure how this would ever be tested but is there a limit to how much the brain can 'hold' before it reaches capacity ? I guess this could also be interpreted in terms of memory, as how well ...
3
votes
2answers
136 views

How is information sent from limbs to the brain exactly?

Say you have a needle, and you poke a very specific area on your left thumb. A signal gets sent from that nerve up your spine and into your brain. How does the brain know exactly where this signal ...
3
votes
1answer
43 views

Is there a hormone combination that makes humans grumpy?

Imagine a typical situation that is likely to give rise to a bad temper within an individual: a person is awoken very early in the morning by a sound of a lawn being mowed next door. Unlike expected ...
3
votes
1answer
44 views

Do people who have been blind all their lives dream?

Do the people who have been blind all their lives dream and do they experience or report "imagery" in the dreams?
3
votes
1answer
53 views

How Behind is the Human Mind (Latency of the Senses)

I would like to know if there is any research into the latency of human perception. Particulary: What is the minimum time for various inputs (vision, touch, sound) to be recognized by the conscious ...
3
votes
1answer
173 views

Ventral stream pathway and architecture proposed by Poggio's group

Please can you give me a very brief explanation about all functions in the ventral stream architecture summarized in this figure: This figure is from Serre et al.'s A quantitative theory of ...
3
votes
1answer
536 views

Why Do Nerve Signals Get Crossed?

First off, I don't know if this is a normal healthy thing to occur. There have been many times where I have an itch on say my arm and I scratch it, only to feel the scratching elsewhere on my body. I ...
3
votes
1answer
182 views

Are there any types of cancer that cause neurons to divide?

After birth neurons generally do not divide. But is there any specific type of rare cancer or tumour where neurons divide? And if there is such a cancer, then how is it possible for a neuron to regain ...
3
votes
1answer
59 views

Brain response frequencies while sleeping

I'm not sure if this is the right place to ask this but Biology seemed to fit best. I'm trying to find out what frequencies the brain responds to best while sleeping. The reason for this is recently ...
3
votes
1answer
32 views

Do human neurons in a petri dish do different things from chimpanzee neurons

I want to know if qualitative experiments have been done growing chimpanzee neurons and human neurons in vitro and have any differences emerged, such as the amount of connections per neuron or ...