What is Brain: Definition and 737 Discussions

A brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as vision. It is the most complex organ in a vertebrate's body. In a human, the cerebral cortex contains approximately 14–16 billion neurons, and the estimated number of neurons in the cerebellum is 55–70 billion. Each neuron is connected by synapses to several thousand other neurons. These neurons typically communicate with one another by means of long fibers called axons, which carry trains of signal pulses called action potentials to distant parts of the brain or body targeting specific recipient cells.
Physiologically, brains exert centralized control over a body's other organs. They act on the rest of the body both by generating patterns of muscle activity and by driving the secretion of chemicals called hormones. This centralized control allows rapid and coordinated responses to changes in the environment. Some basic types of responsiveness such as reflexes can be mediated by the spinal cord or peripheral ganglia, but sophisticated purposeful control of behavior based on complex sensory input requires the information integrating capabilities of a centralized brain.
The operations of individual brain cells are now understood in considerable detail but the way they cooperate in ensembles of millions is yet to be solved. Recent models in modern neuroscience treat the brain as a biological computer, very different in mechanism from an electronic computer, but similar in the sense that it acquires information from the surrounding world, stores it, and processes it in a variety of ways.
This article compares the properties of brains across the entire range of animal species, with the greatest attention to vertebrates. It deals with the human brain insofar as it shares the properties of other brains. The ways in which the human brain differs from other brains are covered in the human brain article. Several topics that might be covered here are instead covered there because much more can be said about them in a human context. The most important is brain disease and the effects of brain damage, that are covered in the human brain article.

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  1. gleem

    Studying Handwritten Notes Improve Learning

    More research is confirming that taking handwritten notes improves learning. The discussion of this research appeared in https://www.newsweek.com/neuroscientists-reveal-trick-help-study-1863968.
  2. jedishrfu

    Medical A First of Its Kind: A Calcium-based signal in the Human Brain

  3. T

    I How does our brain differentiate between a source of light and a painted circle?

    I approach a traffic light. It is red. I know it is a light. What is happening in my brain to inform me that I am looking at a red light, and not a brightly colored red circle on the canvas of my perceptions of the physical world? If my eyes are moist and I squint, I see radiating red lines...
  4. C

    How a-priori intelligence is even possible?

    By a-priori intelligence I mean for example: 1. when a human toddler is born he's born with the intelligence to seek for a breast to feed on. 2. sea turtles - the moment they are born on the beach they know that they must immediately to run into the ocean. 3. baby ducks - the first duck they see...
  5. M

    Medical Does the human brain really have a limit for memory storage?

    I recently read that the “functional information content of human memory" as 10^9 bits at midlife based on testing of text and image retention” It makes sense that anything biological would have a limit but memory is such a strange thing that I can’t see how it would be like storing bytes on a...
  6. Ahmedbadr132

    Do all bactriophages cross the blood brain barrier?

    Hi Bactriophages can cross the blood brain barrier but do all of them cross? They are very diverse.
  7. L

    Medical Derealization parts of brain? (schizophrenia)

    I have read people with schizophrenia and DID may experience thinking that the world has become less real. Are certain parts of the brain acting up that could be making reality seem less real?
  8. Strato Incendus

    Modern Sci-Fi Books and Their Apparent Obsession with Brain Implants

    Semi-rant incoming: In both of the two science-fiction novels I’ve touched most recently (“Braking Day” by Adam Oyebanji and “The Forever Watch” by David Ramirez), all the characters having a bunch of implants was simply the default. Now I came across a story named K3+ (by Erasmo Acosta) that...
  9. Bolzmann_brain

    I Does Memorizing 70,000 Digits Increase the Chance of Being a Bolzmann Brain?

    Assuming that all of my brain states are equally likely to be BBs, and that BBs may exist somewhere outside the event horizon and I won't know about this аnd also the fact that I am either BB or OO, by memorizing 70,000 digits in this way, it is expected that I have increased my chance that I...
  10. nomadreid

    Medical Brain Death: Tests & Secondary Reactions

    Looking at the site https://emcrit.org/ibcc/brain-death/ and similar sites, I see that there are a series of tests of secondary reactions for brain death. Isn't the lack of brain activity sufficient?
  11. A

    I Electromagnetic effects in the brain

    good evening gentlemen, for some months I have a problem and maybe it depends on the wind turbines. I live in the countryside and there is a wind farm near my house, and when I am out gardening, when there is strong wind and the blades are spinning fast, I feel strange, as if I fall into a...
  12. T

    Psychopaths have Bigger Striatum area in Brain

    Popular article: https://scitechdaily.com/scientists-have-established-a-key-biological-difference-between-psychopaths-and-normal-people/ Research article (paywall): https://dx.doi.org/10.1016/j.jpsychires.2022.03.006 Cheers, Tom
  13. K

    Brain blocked on recalling this formula

    Trying to build a mixing fluid calculator and cannot for the life of me figure out how to solve for m2 rather then Tf Got an answer to question 1, but bonus question: is there anyway to solve for m2 and m1 if mt is known? IE given a total volume of mixture IE 99ml, at 20 deg. I know T1 is 25...
  14. BillTre

    Sex Differences in Adolescent Brain Development & Depression Risk

    Here is a study on the sexual differences in development of certain parts of the brain of human adolescents who may become depressed. I am not an expert on this stuff, so comments would be interesting to me...
  15. Jarvis323

    Mild Covid-19 Linked to Brain Damage

    We've been hearing about brain damage caused by moderate and severe covid. A new study suggests even mild Covid causes brain damage. Pretty scary. https://www.nbcnews.com/health/health-news/long-covid-even-mild-covid-linked-damage-brain-months-infection-rcna18959...
  16. shivajikobardan

    Need to revise, nothing entering my brain after studying for few hrs

    I am studying artificial intelligence for exam and came to a point where I need to revise everything I stuided. It ofc takes more effort in brain than learning the concept watching tutorials and reading blog posts as you need to memorize it(for exam). Any guidance, on how to crack this position...
  17. T

    COVID Hospitalized COVID-19 Brain Damage greater than in Alzheimers....

    ...And even higher in deceased patients. Popular version: https://www.news10.com/news/covid-19-patients-show-more-signs-of-brain-damage-than-people-with-alzheimers-disease/ Research article: https://doi.org/10.1002/alz.12556
  18. T

    COVID COVID-19 in Brain (and rest of body) up to 8 months (so far)

    It's a pre-print from a bunch of researchers at the NIH. https://assets.researchsquare.com/files/rs-1139035/v1_covered.pdf?c=1640020576 No wonder Long Covid exists! ?:)
  19. shivajikobardan

    How do I level up my brain? (Studying AI for college exam)

    I am studying AI for college exam. https://www.ioenotes.edu.np/ioe-syllabus/ioe-syllabus-artificial-intelligence-ai-378 The thing is here I am totally on my own as I don't have teacher due to some random reason. Even if I had, they were worst so it doesn't matter I have teacher or not. I have...
  20. EFech

    What are the implications of quantum biology on cognitive computational models?

    I am a student and researcher interested in the mind, brain, related biological processes and emerging "mental" processes. I am interested in cognitive computational models, implementing new computational paradigms.
  21. W

    I Just for fun: math brain teaser

    My answer looks like this (translating from my pen+paper notepad): a+b = a+a*b 1+1*4=5 2+2*5=12 3+3*6=21 8+8*11=96 my friend got 40, which I can also see. I am not sure who is correct. Please let me know and let’s put our heads together and have fun.
  22. gleem

    Unlocking Speech Through Brain Implant & Machine Learning

    In a collaboration of several institutions researchers have been able to record the thoughts of a person with a brain stem stroke resulting in anarthria (an inability to articulate speech) by mplanting network of electrodes in the brain and using a machine learning algorithm to decode the...
  23. Ygggdrasil

    COVID COVID-19's Impact on the Brain: New Evidence Emerges

    Here's a nice news piece from Nature summarizing various studies to find the underlying causes behind the neurological symptoms associated with COVID-19. In particular, the article highlights studies suggesting that SARS-CoV-2 can infect astrocytes in the brain, that SARS-CoV-2 can affect blood...
  24. T

    Brain health/brain exercises? (part 2) Moved

    What parts of the brain and/or mind do you use and/or stimulate when doing these activities? If you know. 1. rubix cube? 2.indian finger touching.? 3.playing minecraft.? 4. playing the classic pc game exiled?. 5. playing tetris?. 6 interpreting irrationality or irrational language?. 7.drawing or...
  25. T

    COVID Significant Loss of Brain Grey Matter after COVID-19

    https://www.medrxiv.org/content/10.1101/2021.06.11.21258690v1 doi: https://doi.org/10.1101/2021.06.11.21258690 Full PDF (32 pages) at: https://www.medrxiv.org/content/10.1101/2021.06.11.21258690v1.full.pdf
  26. BillTre

    A Brain Shrinking Domestication Event

    Domesticated cattle (cows or steers) evolved, under domestication, into a variety of different lines (or strains), from aurochs (Bos primigenius,, now extinct) about 10,000 years ago. Science mag news article here. Ana Balcarcel of the University of Zurich and colleagues scanned the skulls of...
  27. pinball1970

    Human Brain Evolution: 2 Studies Examined

    Two studies on human brain evolution/development. FIRST A new study is the first to identify how human brains grow much larger, with three times as many neurons, compared with chimpanzee and gorilla brains. The study identified a key molecular switch that can make ape brain organoids grow more...
  28. M

    Medical Memory: Do some people have more “space” or just better retrieval?

    I’ve read that the human brain capacity has 2.5 petabytes worth of memory storage. I have an excellent memory for details; even super obscure things that happened decades ago. I only have an average IQ but my recall is very good especially when my memory is jogged or if I had read something...
  29. Eagle9

    Can we move the brain cortex up and down?

    Hello people :oldsmile: I guess that this is quite fantastic question/idea, but perhaps some day it will be possible to do it :oldeyes: So, in brain we have got the cortex and the axons that leave one certain area in cortex and enter another area: cortico-cortical afferents/efferents. Some...
  30. T

    What is the role of immune function in age-related cognitive decline?

    Seems to be partially a reversible auto-immune situation. So far it is in mice and in-vitro for Humans; no Human-use-approved compounds exist. :cry: https://med.stanford.edu/news/all-news/2021/01/study-reveals-immune-driver-of-brain-aging.html
  31. PainterGuy

    Human body growth in the absence of a brain

    Hi, Does the brain control the physical growth of a human baby? I think if, for some unfortunate reason, the brain is absent, the growth would still take place normally but more like a vegetable. I don't think if the brain is absent, one can even blink the eye or move a finger. But the...
  32. Snoopy1234

    Sound transmission to the brain

    Water antenna Humantenna
  33. J

    I How Does Touch Occur in the Brain in a Vat Hypothesis?

    If the brain in a vat hypothesis is correct, it means that we cannot touch another person or object. My only concern is how touch occurs, if in the real world it is the interaction of atoms (in particular, electrons). Thanks
  34. entropy1

    B Will brain-computer interfaces reveal more about QM?

    Will brain-computer interfaces that are hooked up to quantum measurement devices reveal more about quantum mechanics?
  35. kyphysics

    Paralyzed Man w/ Chip in Brain Controls Computer with Thoughts

    This is pretty amazing. Could this point to a future where we all can do this and much more with implanted brain chips?
  36. T

    What are all the ways to grow grey matter in the human brain?

    Hi, forgot to say a thanks for all the info provided in my previous thread to everyone who posted. So what is the answer or answers to this threads question or what works?
  37. BillTre

    Interesting Brain Scanning/Stimulating Backpack Allows Mobile Brain Studies

    This new technology will make monitoring outside of labs possible. It requires a brain implant. Kind of reminds me of the Borg.
  38. T

    Do strategy games and real time strategy games improve brain function?

    Hi, just wanting to know the answer to this. What parts of the brain do playing these games stimulate? What effects do playing these games have on the brain? what brain functions do they improve or strengthen? more specifically I mean the games call to power 1 and/or empire Earth 1. Note that i...
  39. notaphysicsmajor79

    Brain function & bipolar: fluid volume & speed of information in tubes

    This is a long post with limited amount of physics in it (but it is a physics question, so hopefully it is allowed). I am a scientist but trained as an ecologist (PhD) and despite my long interest in physics, my knowledge of it remains rather rudimentary. Apologies for that, in advance. I am...
  40. .Scott

    Is Brain Connectivity the Same among All Mammals?

    This paper was published in Nature: Mammal Brain Connectivity And was described by the University in this press release: https://www.aftau.org/press-release---brain-connectivity---july-20-2020 What interests my is the editorial spin: From the press release: From the Abstract: Cajal and...
  41. T

    What brain exercises improve brain functions based on facts

    Hi, there. I couldn't find much information about this on the net so I came here to ask if anyone here knows as I thought it would be the right forum or maybe I just wasn't looking hard enough. Please not that I don't mean skills but rather what actually works that improves brain functions like...
  42. S

    I Do all mental states really exist in some universe in Many-Minds?

    According to the Many Minds interpretation of quantum mechanics (https://en.wikipedia.org/wiki/Many-minds_interpretation), the distinction between worlds in the Many Worlds interpretation should be made at the level of the mind of an individual observer. I have read that, in this case, each...
  43. T

    [Neural Networks] Classification of a sick brain

    Hi, i have a dataset with MRI of patients with a specific disease that affects the brain and another dataset with MRI of healthy patients. I want to create a classifier (using neural networks) to classify if the MRI of a new patient show the presence of the ill or not. First of all, i...
  44. kolleamm

    What happens in the brain when we feel pleasure or pain?

    From what I understand dopamine is released when we feel pleasure but how exactly does it interact with the brain? Does it spread to only a small space or a much bigger one? I wonder the same for pain too.
  45. A

    Medical Text about higher cognitive functions of the brain?

    I'm looking for a document (possibly online) which describes the higher cognitive functions (such as thinking, planning, creativity, comprehension, reasoning, etc.) from the neuroscientific point of view. I found only texts of brain anatomy or other describing senso-motoric and metabolic aspects...
  46. Frigus

    On what basis are parts of the brain classified?

    On the basis of what brain is classified,like we say on the basis of function the neurons are of 3 types.
  47. S

    Does the brain play a part in Magno and Parvo channel creation

    Regarding human vision and the retina: Where are these channels produced? To put it simply, is it produced in the eye or in the brain. For example; does light enter the eye, hits the retina and it applies a series of filters to produce these 2 different channels (the parvo and magno) and it...
  48. C

    B How do we resolve the Boltzmann Brain problem

    I think this refutes the standard picture since if ylour universe would just keep expanding we should be a Boltzmann brain. https://en.wikipedia.org/wiki/Boltzmann_brain https://arxiv.org/pdf/0802.0233 I would bet on the "big rip" (dark energy getting stronger) since that would also resolve...
  49. M

    What does a good memory mean about the brain?

    My question on neurons and memory.
  50. O

    I Efficiency of computers vs. brains

    Hi, I’m an undergraduate student interested in cognitive processes. I’m about to ask a very interdisciplinary question, and so hopefully I can find a physicists that can take on the challenge. What is the fundamental reason behind why modern electronic computers (transistor computers) are...