Questions tagged [brain]

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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26
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2answers
1k 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 ...
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1answer
294 views

What really is color and how do we perceive it?

How do our brains actually transform the information that the cones in our eyes receive into the different colors that we can see and imagine?
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50 views

Is it comfirmed that Alzheimer's is a diabetes of the brain?

I read in this New Scientist report, that the mental decline during diabetes may be an early stage of Alzheimer's. The hypothesis was based on a study with 20 rats. Has there been any follow up ...
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1answer
44 views

Physical activity in fasted state: Glucose for brain vs muscles [closed]

Let's consider this scenario: You do sports in the morning in a fasted state (i.e. without consuming any calories after waking). Your brain of course needs glucose and your liver probably still has ...
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0answers
51 views

Can sleep be replaced by chemical supliments? [closed]

If adenosine makes a person sleepy to rebuild chemicals in the brain, than is it possible to inhibit adenosine and externally produce and inject the needed chemicals?
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1answer
142 views

What happens to the human brain when unconscious?

What part of the brain gets affected and does it harm the brain? Thank you I just needed some extra info for a video I'm making.
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140 views

What happens to the brain during sleep versus unconsciousness?

How does being unconsciousness differ from being asleep and whether it causes breaks in consciousness?
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1answer
697 views

Why doesn't the rest of the body have something like the “blood-brain” barrier to protect itself from pathogens?

According to Wikipedia: "The blood–brain barrier acts very effectively to protect the brain from most pathogens". This is because the pathogens cannot pass through the tight junctions of the ...
7
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1answer
639 views

How can neurons divide without centrioles?

I have read in my studies that neurons lack centrioles. If that is so, then how is it possible that new neurons are added to our brain? Does this have anything to do with memory loss?
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1answer
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Brain capacity of Cro-magnon man vs Modern man

Cranial capacity of Cromagnon man was about 1650cc whereas average cranial capacity in modern human is 1450cc. My question is, why during the course of evolution, a reduction in cranial capacity is ...
5
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1answer
165 views

How were (many) dinosaurs' brains so small?

Brain size (or its proxy, encephalization quotient) usually varies allometrically with mass -- larger creatures need larger brains to control their larger bodies, apparently. Dinosaurs are popularly ...
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1answer
67 views

the evolution of the human brain size [closed]

I was thinking, as I know, sometimes the process of producing DNA did not work well(correct me if I'm wrong), so it gives us some changes in the object we gonna ...
4
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1answer
36 views

“Next generation” brain scanners, can they detect CTE?

I've just read the news that a "new generation" brain scanner is under development. I wonder whether they can detect chronic traumatic encephalopathy. I haven't been able to find the paper about these ...
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0answers
111 views

Is there an equivalent to a refresh rate for the brain and consciousness?

Computers have a clock rate that synchronizes their processors. In spite of tempting analogies, the brain is clearly not simply an organic computer. It is constantly changing, rewiring and pruning its ...
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2answers
6k views

Headshot = instant kill? [closed]

While whatching a film, I've been thinking about how does a headshot kill someone, and how long does it take? For example let's say you've beeing shot by a normal (police) handfired weapon - no ...
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0answers
48 views

Transcranial Magnetic Stimulation on science fair [closed]

My friends and I would love to make a TMS machine and apply it to make famous "god helmet". We know that magnetic stimulation may cause visions of angels, gods etc. My question is: what are the ...
5
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1answer
64 views

Does Alzheimer affect more than day-to-day memory?

I know that Alzheimer's damages a part of the brain called the hippocampus, which has a central role in day-to-day memory. But, could it affect also on things in other memory centers, things such as ...
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2answers
117 views

How long does a spiking signal last?

It is surprisingly hard to find information about the timing of neurons, in particular how long an action potential can contribute to the summation of a neuron. Is it on the order of milliseconds or ...
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0answers
218 views

What are the dangers related to keeping a human brain alive outside of a human body? [closed]

I am interested in learning about the feasibility of keeping a human brain alive outside of a human body. The question: What obstacles do we need to overcome to be able to keep a human brain alive ...
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1answer
156 views

What were the main discoveries in Biology? [closed]

What were the greatest achievements in Biology? Can you please provide a short list of discoveries that you would consider as being the most important discoveries of the history of Biology.
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0answers
34 views

How is the brain kickstarted during development [closed]

The brain is a complicated beast, that operates (generally) by electrical activity. During development, all cells originate from the a single "cell": the zygote. At some point during development, the ...
4
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2answers
2k views

Brain wave and motor movement correlation

I am trying to better understand which brain waves are generated when the motor system (arms, legs, muscles of any kind) are activated. According to Wikipedia, several types (Beta, Gamma, Mu) appear ...
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0answers
51 views

why does brain produces noise? [duplicate]

when i look at a white wall i see little colored dots moving in circles filling my whole visual view, just like the static on a tv but then in color. I thought everybody had this but recently i ...
4
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2answers
2k views

How does the mechanism which controls blood pressure in the brain work?

I know that pressure is sensed in the skin by mechanoreception mediated by skin receptors. Static pressure stimuli are mainly sensed by slow-adapting fibers connected to receptors like the Merkel ...
5
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1answer
151 views

What physical or mental actions can be picked up by EEGs?

There certainly seem to be a lot of gadgets and gizmos leveraging EEG technologies to the control of devices. This makes me wonder: what intentions/thoughts can be captured by EEG technology, and ...
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1answer
1k views

Synaptic pruning and selective elimination during adolescence

How does Synaptic pruning occur during pre-adolescence, adolescence and post-adolescence, after there is blooming overproduction of synaptic connections until the years of late childhood, and how does ...
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1answer
535 views

Examples of seeking behavior by brainless animals

Are there any examples of brainless animals (e.g. jellyfish) exhibiting seeking behavior, such as following smell or light gradients towards food, or following hormones towards mates?
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0answers
90 views

Atlas from human brain structures to 3D coordinates?

I would like to visualize specific human brain structures in the three dimensional space and compute specific geometric properties of these brain structures (size, centroid, etc). Therefore, I am ...
4
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2answers
297 views

How can binaural beats change mental state?

Can anyone tell me how binaural beats of 10 Hz can cause a person to calm down and one of 40 Hz to cause someone to heighten their attention. All I know is that they work on the principal of Brainwave ...
3
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0answers
925 views

Why do we have two brain hemispheres? [closed]

Is there any explanation why we have two brain hemispheres? Is there any advantage of having two in contrast to having one (or three / four)? From what I've read so far (not too much; I'm not a ...
5
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1answer
652 views

How does the brain train its neural network?

One question that came up learning how artificial neural networks are working was how the brain can train its neural network? When we say we have an artificial neural network, the problem behind it ...
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0answers
122 views

How much should one smoke in order to prevent Parkinson's? [closed]

There are studies who claim that nicotine has a neuroprotective effect against Parkinson's(such as this: http://www.ncbi.nlm.nih.gov/pubmed/11772120) What would be the minimum amount of nicotine(...
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0answers
55 views

Of people who develop Alzheimer disease, are those people genetically predisposed to it?

I have read a lot lately about microbiological pathogens that are found in blood vessels in the brain of patient's with Alzheimer disease (positive association). So, I am confused whether there are ...
2
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1answer
5k views

How does waking up from an alarm clock work?

During sleep, one's brain is shut down. All it can do is to see some dreams from the semi-conscious mind. Then how does it hear when the alarm clock rings?
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1answer
103 views

Are all tastes just a combination of sour, sweet, bitter, etc.?

For example, can the taste of pineapple be isolated to just a certain amount of "salty-taste-triggering-molecules" and "sweet-taste-triggering-molecules" etc.? Can our current understanding of the ...
11
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2answers
308 views

Understanding the brain: how are neurotransmitters released in the brain?

I have a basic knowledge of how neural networks work. A potential difference is created that forces sodium, potassium, chloride, and calcium ions to flow which carries an electrical signal to the end ...
2
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2answers
333 views

How can neuronal signals faithfully be reproduced by scalp electrodes?

There is a skull barrier (and possibly other layers too) between the brain and the scalp. I have seen people trying to extract EEG signals from the scalp by connecting electrodes and interface it to ...
2
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0answers
34 views

Synapse formation [closed]

I am trying to learn about neuronal synapse formation, but the literature is intimidating to someone with little background knowledge. I am interested in synapse formation in both human adults as ...
8
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1answer
263 views

Can brain damage caused by physical injury affect the social behaviour of a person?

Can a physical injury to the brain, resulting from an accident, and not the result of a diagnosed mental illness, affect a person's social behavior?
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1answer
722 views

Why does our mouth “water”?

Whenever we see something delicious, rapid salivation starts in our mouth. Also, it doesn't happen for all other food, which we eat regularly. So, Is there any particular use of "rapid salivation"? ...
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1answer
11k views

Dreaming after passing out [closed]

I'll have few questions about passing out and dreaming. English is not my native language, and my biology knowledge is very limited. So bear with me. What exactly is blackout? (in a really simple way)...
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1answer
403 views

How does the brain recall information?

In computers, finding a single word is realized through serial attempts across all available connections to find a specified target. How does the brain solve this? How does the whole process, from ...
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2answers
710 views

Is there a difference between visual sensation and imagination in the brain?

How substantial is the difference between the neural signal associated with seeing an image and the imagination of that image? Surely, it can not entirely copy the pathway from the sensory organs to ...
2
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0answers
28 views

Is there an evolutionary reason why so many white matter tracts decussate in the brainstem and spinal chord?

From a developmental perspective, I would tend to assume that it would be much simpler for the fibers descending from (for instance) the pyramidal tracts, superior cerebellar peduncles, or ascending ...
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0answers
40 views

Is there any evidence to suggest that exercise reduces the side effects of caffeine?

I heard a friend say: I'm not drinking coffee this week. My body can only process the caffeine if I run at least 15km a week. I found this claim fascinating - that exercise temporarily increases ...
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0answers
708 views

Acetylcholine and muscles- excitatory or inhibitory? (muscle atonia and myasthenia gravis)

I have heard that acetylcholine can be excitatory or inhibitory, but I am confused as to which it is when it comes to muscles. On the one hand, I believe that muscle atonia during REM sleep is ...
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0answers
350 views

“synapses grow closer together in order to decrease the distance”, is it true?

Is there a source? That synapses get physically get close as their interaction increases. I have also read that where neurons crosses each other they create new neuron, is that true?
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1answer
172 views

How does the brain manifest and realize the intention to resist sleep?

The question title says it all. What happens in my brain when I resist sleep? I would appreciate explanations on neurotransmitter changes, what areas of the brain activate to resist sleep, what can an ...
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1answer
1k views

Nernst equation?

I keep seeing the Nernst equation in two different forms, one using the natural log and the other using log base 10. Could someone explain why there are two different versions, and which should be ...
3
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1answer
2k views

Loss of appetite during fever

It is a well-known phenomenon that sickness like the common flu is often accompanied by reduced appetite. Why do sick people stop eating?