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Everything posted by Speldosa
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Yes, I admit I took it a little far there. Could you specify what you mean with a control or processing function?
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Can you explain love with science?
Speldosa replied to WendyK's topic in Anatomy, Physiology and Neuroscience
Ok. But still. Is this the question we are supposed to debate in this thread? I seriously don't understand what TS is meaning when s/he states that s/he thinks there is "some spirituality that cant be explain in science". That is, what the heck are we debating? -
So according to your definition, 90% of the brain would have to be totaly silent (that is, without any activity going on at all) for someone to say that you're only using 10% of your brain?
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Can you explain love with science?
Speldosa replied to WendyK's topic in Anatomy, Physiology and Neuroscience
I still don't understand the question. What are we supposed to debate? Whether the brain operates in such a way that its output can be predicted? -
@insane_alien: I'm still waiting for a definition of what it means when a part of the brain, or when a specific neuron, is in use. What does it mean to be using (over a certain quite long time interval) the whole brain? That activity above baseline flows through each area at some point in time? What if that activity isn't manifested in any overt behavior or conscious thoughts? Was it still being used then? What I have problems is that when you're saying that you use 100% of the brain, you're just throwing in a number, just as when you're saying that you only use 10% of the brain, without really defining what the heck you mean by that number. The problem with the 10% statement isn't, in my opinion, the number itself, but rather that it's a nonsense statement from the beginning unless you're really specifying what you're talking about. You can't debunk it by replacing it with some other number. @omgwyther: The uploader, jlvincent, who appears to be the author of the papers associated with this video states as an answer to the very first comment to that video that it is based on fMRI (Q: "where data come from? electroencephalography? fnmr?" A: "fMRI"). Further, the papers being referred to in the description of the video are both on BOLD-signals, that is, fMRI. Also, since the activity is mapped on an actual model (although flattened out) of the cortex, rather than on a model of a head, one can be pretty sure that the data comes from fMRI because of the spatial uncertainty that comes inherent with the EEG-method. That is, if this data would have been acquired through the use of EEG, it would have been bullshit. You can't specify where the signal comes from with this much accuracy (in the movie, you can even see how activity disappears behind some sulci from time to time). In an fMRI measurement you usually get voxel not more than a couple of millimeters wide.
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I don't think the argument will get any better by me looking at the other links. Note, that I do not defend the 10% hypothesis, however, I think that the 100% hypothesis is equally dumb.
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From the first link iNow posted: What data were used to come up with the number - 10%? Does this mean that you would be just fine if 90% of your brain was removed? If the average human brain weighs 1,400 grams (about 3 lb) and 90% of it was removed, that would leave 140 grams (about 0.3 lb) of brain tissue. That's about the size of a sheep's brain. It is well known that damage to a relatively small area of the brain, such as that caused by a stroke, may cause devastating disabilities. Certain neurological disorders, such as Parkinson's Disease, also affect only specific areas of the brain. The damage caused by these conditions is far less than damage to 90% of the brain. I find this to be a terrible argument. If one says that you're only using 10% of the brain (a statement that clearly needs more clarification; c.f. my earlier post) that doesn't imply that all brain matter being used is concentrated in only one part of the brain. Therefore, it could be fully consistent to say that you only use 10% of your brain and still that you would be handicapped if you removed any specific part of it. Further, the author states: Perhaps when people use the 10% brain statement, they mean that only one out of every ten nerve cells is essential or used at any one time? How would such a measurement be made? Even if neurons are not firing action potentials, they may still be receiving signals from other neurons. I find it funny that the author questions the possibility of measuring this, yet he concludes his article with "We use 100% of our brains". Well, how the heck did you measure that?
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Well, since this sequence is created from a fMRI scan, it is really the concentration of oxygen from the blood we are looking at, which has not been shown to be directly correlated with electrical activity. Further, what we are looking at is where the amount of oxygen is significantly higher than in the rest of the brain. That is, even if we assume a direct correlation between brain activity and blood flow, this visual presentation only shows where the strength of the activity deviates from the baseline. That an area of the brain is blue doesn't mean that nothing is going on there. We could for example in theory have a brain with uniform activity everywhere. This brain wouldn't show any activation in the fMRI at all (unless you have two conditions, in which one of them, the brain is much more quiet than in the other...Then you could light up the whole freakin brain. However, that would only show that the activity was higher in one of the conditions.). Also, I don't see where you get that 10% to 30% number from. It isn't obvious to me.
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Could you please provide some good source to how the moon behaviorally affects behavior in some animals?
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Well, first of all. I wouldn't place the brain in a pool of blood, but rather in something equivalent to cerebrospinal fluid which the brain normally is surrounded by. As you can see in the Wikipedia-article I linked to, the cerebrospinal fluid has four functions: 1. Buoyancy: The actual mass of the human brain is about 1400 grams; however the net weight of the brain suspended in the CSF is equivalent to a mass of 25 grams.[7] The brain therefore exists in neutral buoyancy, which allows the brain to maintain its density without being impaired by its own weight, which would cut off blood supply and kill neurons in the lower sections without CSF.[8] 2. Protection: CSF protects the brain tissue from injury when jolted or hit. In certain situations such as auto accidents or sports injuries, the CSF cannot protect the brain from forced contact with the skull case, causing hemorrhaging, brain damage, and sometimes death.[9] 3. Chemical stability: CSF flows throughout the inner ventricular system in the brain and is absorbed back into the bloodstream, rinsing the metabolic waste from the central nervous system through the blood-brain barrier. This allows for homeostatic regulation of the distribution of neuroendocrine factors, to which slight changes can cause problems or damage to the nervous system. For example, high glycine concentration disrupts temperature and blood pressure control, and high CSF pH causes dizziness and syncope.[10] 4. Prevention of brain ischemia: The prevention of brain ischemia is made by decreasing the amount of CSF in the limited space inside the skull. This decreases total intracranial pressure and facilitates blood perfusion. Now, we can do without point number 2 since the brain is going to lay still in a jar, but we really need to fulfill all the other criteria's. Also, the fluid have to be renewed somehow and go through the usual cycle inside the brain. Also, we need some form of replacement for the heart and the lungs to pump oxygenated blood into the brain and to take care of blood coming back from the brain. Without these actions, the brain would certainty die pretty much immediately. Now, let's say that we could fulfill these basic things. Would the brain be able to survive? Well, not necessarily, if we with survival mean ongoing meaningful activity, which is a pretty good definition. First of all, the brain wouldn't get any stimulation from outside. That is, the eyes, the ears, the tounge, yeah, all of your senses, wouldn't generate any kind of structural input at all, but rather some kind of noisy input, if any input at all would be generated. Further, the brain wouldn't get it's usual chemical input from the body, making it go all out of balance. All this would probably create havoc inside the brain and even if you in the end would be able to maintain some kind of activity, which isn't certain, the activity would probably not represent anything meaningful.
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I guess you're referring to the following paragraph in the Scientific American article (if not, please correct me): The myth's durability, Gordon says, stems from people's conceptions about their own brains: they see their own shortcomings as evidence of the existence of untapped gray matter. This is a false assumption. What is correct, however, is that at certain moments in anyone's life, such as when we are simply at rest and thinking, we may be using only 10 percent of our brains. Now. There are two problems with using this as a source that we're using 10 percent of our brain at any given time. First of all, it's just at statement by some guy. There is no further reference to any scientific study. Second, he's not stating that it's correct that we're using ten percent of our brain at any given time, but rather that it's correct that we may use ten percent of our brain at any given time. That is a huge difference. That's like saying that at any given time point lightning might strike somewhere on the earth rather than at any given time point lightning does strike somewhere on the earth. This would be true both in a world where lightning only struck once and a world where lightning struck several times a second (as I believe is the case in our world). Merged post follows: Consecutive posts mergedIf we're going to talk about this, we really have to define what we mean by usage. All the neurons in the brain are spontaneously firing all the time, so by that means, given a sufficient time window, we're using all of our brain all the time. Would you define usage as activity above a certain threshold in a certain neuronal population? We could do that, but then you would have to specify a specific amount before saying anything about any percentages of the brain being in use at any given time point.
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Could you please provide a source supporting this claim?
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electromyography (EMG)
Speldosa replied to Myelinated-Man's topic in Anatomy, Physiology and Neuroscience
Then I have a question. What's the difference between EEG and EMG? Both just measures electrical activity, right? -
Can you explain love with science?
Speldosa replied to WendyK's topic in Anatomy, Physiology and Neuroscience
Well, are you a monist or a dualist when it comes to the question of consciousness? If you are the former, science should be able to explain the whole shabang, both behavior and experience. If you are the latter, depending on what form of dualism you prefer, science could explain degrees of the behavior (in the case of epiphenomenalism, all of the behavior) but not the experience. The way I see it, your question is not tied to love in any way. You could pose the same question regarding for example hunger. -
I remember that I've heard of cases with stroke affected (I guess) patients who could see color but not form, and others who could see form but not color. However, I can't remember where I read it and my searches in several different databases have all comed up empty. Is there someone here who recognize what I'm talking about and could point me in the right direction? I need references which I in the end can put in a scientific paper.
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What you're referring to actually has its own name: "The grandfather paradox". I'm not in the mood to contributing to the discussion right now since I have some papers to write but start by checking out its entry in the Stanford Encyclopedia of Philosophy.
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What is meant by this example?
Speldosa replied to Speldosa's topic in Modern and Theoretical Physics
Hi again, After looking at your suggestions I also think that it's quantum entanglement Block is talking about, although in a quite strange way. However, ydoaPs suggestion is interesting. It makes the quoted section less strange. However, it doesn't fit that well into the general argument Block makes. Block argues that the neural correlate of phenomenal consciousness can be studied empirically. He means that there is no kind of gold standard of evidence in any scientific area and that the science of consciousness should be no different. Therefore, we should be able to use indirect proof to detect conscious experiences in the same way indirect evidence is accepted in, for example, physics. This is what Block is trying to convey with his example. Since it is about correlations and what kind of knowledge you can draw from them, the quantum entanglement theory seems most likely. -
Hello! Sorry if this question is to basic but since I'm no physicist, this confuses me. I'm reading an article by Ned Block about consciousness ("Two neural correlates of consciousness"). In it, he tries to draw parallels to physics in how to find a criteria for consciousness. He writes: "...observed electrons can provide evidence about electrons that cannot in principle be observed, for example electrons that are too distant in space and time (e.g. outside our light cone) to be observed." I have pretty good understanding of high school physics but this I can't really understand. Can even something outside our light cone affect us? Could someone explain what phenomena he's referring to?
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Start with checking out Helen Fisher but keep a healthy dose of sceptiscism. Sometimes she makes claims that haven't really been confirmed in humans, especially when it comes to oxytocin.
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I'm still confused by your description. It was "multidimensional"?
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Hi! This is my first post here on SFN. I'm wondering about the evolution of the female breast. The reason why I'm thinking about this is because my field is psychology, and I'm trying to form an opinion regarding if the sexual appeal of breasts for men is more a cultural thing than an inherent preference. For example, its quite obvious that men should be drawn to younger females since they, among other things, are less likely to have a miscarriage. But what about the preference for big, up-pointing breasts? Some initial questions: Does breast size has anything to do with milk production capacity? Why does women's breast swell during pregnancy? I assume this has something to do with the feeding of the baby? I've "heard" that humans are the only mammal where the women's breasts swells at puberty and then stays swollen, in contrast to other mammals where the breasts only swell when it's time for a baby? What about this flat-face-theory which says that infants need larger breast to be able to suck without risking to suffocate? I'd be grateful for any answers!