Time Perception and Slowing it Down?

Sapere_Aude__ · 4日前

Well, first of all, keep in mind that it's pretty dismissive to say that their data are worthless. The folks who ran that study have PhDs in their field (as do I -- my research does not concern this exact topic but it's pretty closely related) and have extensively studied the background literature. These studies take months, if not years, to run, during which everyone on the research team carefully considered every angle of the experiment. They discussed the design in lab meetings, they fought over many small details, they debated them with peers and with reviewers. Whereas I think I can conclude from the language you use that you don't have a PhD in this field and have not studied it anywhere extensively as we have. This doesn't mean your opinion is worthless, but it does make it highly unlikely that you have thought this problem through better than they have. You may well be a very smart person, but in all likelihood they are just as smart if not smarter -- and they have been thinking about this problem a LOT longer than you have. I don't want to be dismissive of you either, because good ideas can often come from people with less experience -- but a lot of bad ideas do too, and it usually takes experience to sort them out.

Now, onto the real topic. You say that the hypothesis is about time slowing down to "allow more time to solve the problem" -- but those are your words, not theirs. As a matter of fact, distortions in time perception happen in more focused contexts all over the place, both in stressful and non-stressful circumstances. That is already well-established. What this experiment set out to test was whether the GLOBAL subjective experience of "time slowing down" -- not just for the stress-provoking stimulus, but for everything around you, like slow-motion in a movie, which is how people tend to describe the feeling -- has any objective equivalent in terms of faster cognitive processing. This is all clearly stated in the Introduction section of the paper (just three paragraphs -- this is a very short and readable paper even if you're not a researcher by trade), which I have to assume you did not read.

I'm not trying to be snotty, because it's good to be skeptical -- that's what makes good scientists. But it's also good to be aware that it's a natural human tendency to think that you know everything and to go running off challenging the conclusions of experts before you've done any real learning and thinking on the topic. Experts can certainly be wrong -- we disagree with each other all the time, and of course two experts with opposing opinions can't both be right. And although I'm aware of all this, I myself will confess that I'm guilty of professing under-informed opinions all the time. But I try to keep it in check as much as I can, especially when talking to someone whose expertise is in a different field than mine. Studying something for years (or decades) is a real lesson in humility -- when I think about how much more I know now than I did pre-PhD, it makes me realize how impossible it would be to hold my own in a conversation with an astronomer about astronomy even if I've taken a few college classes and read some books, because I know how little OTHER non-experts know about psychology and neuroscience when they talk to me.

ombx · 4日前

I don't think anything you're saying here is too controversial, at least from the single-particle perspective. It's true that on the equation level, "antiparticle" is just shorthand for some values switching signs. And when you get to particles that are "their own antiparticles," as is sometimes said, it's basically semantics -- you could also just say that those are particles for which the matter/antimatter nomenclature simply isn't relevant.

I'd stop short of saying they are conceptually useless, though. The fact remains that on the macro scale, we care a lot about ordinary matter (i.e., that which is composed primarily of protons, neutrons, and electrons), insofar as it makes up everything that we interact with in daily life. So it's a useful distinction in that sense, especially for this question. In other words, if particles/antiparticles were equally common as theory predicts, we would expect to see this not only at the particle scale but at the macro scale -- so the universe would presumably contain anti-stars, anti-planets, perhaps even whole anti-galaxies, that behave just like ours, with the sole distinction that they would annihilate upon contact with our ordinary-matter stuff.

Granted, we have never observed antimatter on the atoms-and-bigger scale except for minute amounts that we have generated ourselves here on Earth -- you could argue that large-scale antimatter is thus a hypothetical concept (for now), but being hypothetical doesn't make it useless, in the sense of discussing what its properties would be if we ever got ahold of some.

Sapere_Aude__ · 4日前

Well, unfortunately I think you're going to be disappointed. I've seen some of the pharmacology stuff you're talking about, but I think that is mostly about how fast you feel like time is passing, not how fast your brain is actually working. (And, relatedly, how accurately you are able to judge the passage of time.)

It's highly unlikely we'd ever find a way to actually speed up mental processing in the way you're talking about. Essentially, your brain is a big sack of chemicals undergoing lots of reactions very rapidly, but those reactions are rate-limited in the way that all chemical reactions are, e.g. by factors such as the relative concentrations of the chemicals.

Interestingly, one way you can alter the speed of those reactions is with temperature. And there have been experiments in laboratory animals showing that you can decrease/slow activity in certain brain areas by cooling them down, because you're basically just making every reaction in those areas happen at a slightly lower rate. Conversely, you might expect that if you raised the temperature, everything would happen faster -- and that might be true, but it's not a practical solution for making people think faster. Being at the wrong temperature does more to just living tissue than speed up neural processing -- if you've ever had a high fever, you can probably see why this is not a good way to go and why temperature homeostasis is so important for warm-blooded creatures like ourselves.

Of course, there's always the old-fashioned way of speeding up processing -- by increasing efficiency, aka learning. Obviously you can read faster now than when you were first learning to read as a child, because you have managed to streamline those processes via experience. And there is certainly active research on creating "smart drugs" to help people learn faster by altering synaptic plasticity, and of course on creating better and more efficient teaching methods without any kind of drug intervention.

But in terms of developing a technology that allows us to just turn up the speed across the entire brain -- that's most likely impossible given the way biological systems work. (Now, when we get to the point that we can replace ourselves entirely with electronic artificial intelligences -- that's another matter...)

Sapere_Aude__ · 4日前

I see the point you're making, and there is some validity there, but I don't think it's correct to say that this experiment proves nothing.

Of course, it should go without saying that no single experiment proves anything. Maybe their measurement wasn't sensitive enough. Maybe someone made some kind of error designing the equipment. Maybe they just got really unlucky and had an unusually unrepresentative sample of the population. But that's true of everything. There's no way to definitively prove that the results of every experiment ever aren't just due to an amazing statistical coincidence -- it would just be incredibly unlikely. But I don't think that's what you're talking about.

I think this experiment tests the idea that subjective time-slowing relates to enhanced perceptual processing just about as well as anything could. The subjects knew about the free-fall ahead of time, and they weren't particularly height-phobic. They knew exactly what they had to do. They did report a subjective sense of time slowing down, so we know that the experiment didn't fail to create that sense. And their ability to identify the digits was almost exactly the same as it was on the ground, so we know the fall didn't distract them enough to make them WORSE -- they just didn't get any better either.

Of course, other alternatives remain. It's possible that their perceptual processing was enhanced by the fall, but that was offset by distraction... although if that were the case, the two effects would have to be almost exactly the same size to cancel out so nicely, which would be a pretty big coincidence. And it's possible that even though digit perception wasn't facilitated by the fall, some other cognitive process might be -- although this kind of perceptual process is, based on other literature, one of the most sensitive types of processing to temporal manipulations and thus among the most likely to succeed if the time-slowing effect is real.

You can't ever rule out every alternative in a single experiment, but that's not the same as claiming the experiment "proves nothing." It's always possible that there is a real effect, but the size is small enough that it fell within the measurement/statistical error bounds of the experiment and was thus undetectable. But experiments like this still help establish reasonable boundaries for what you can expect to be real. For example, these results do suggest that if there IS any kind of objective/measurable temporal-slowing effect, it is incredibly unlikely for it to be of a similar magnitude to the subjective feeling of time slowing down (Figure 2b of the paper).

So, what you can can conclude is that, barring extreme bad luck or a major goof-up by the research team somewhere in the process (always a possibility -- all our endeavors are prone to human error, though it is relatively rare for those errors not to be caught by the time a paper is published), the time-slowing people report during stressful events is probably mostly just a subjective feeling and not reflected in any objectively-measurable enhancement of cognitive processing.

TL;DR Yes, this one paper can't conclusively rule out ANY possibility of an objective temporal enhancement of cognitive processing during stressful events, but it is strongly suggestive that if such an effect does exist, it is small enough to be negligible.

JimKB · 5日前

... and I cannot lie.

ombx · 5日前

PS, that is also to say that most of the stuff you list would not be problematic for a universe with a perfect matter/antimatter balance. Antimatter doesn't have a whole different set of rules than matter. The equations are the same, it's just that some of the signs (e.g. on electric charge, for one) are flipped.

As noted in the Wikipedia article I linked, there is some conjecture that perhaps antimatter gravity is repulsive rather than attractive. It's hard to say for sure right now, because we never have enough of it in one place to observe its gravitational properties. Although (as the article also notes) the general thinking among most physicists is that antimatter does not exhibit antigravity, because that would conflict with relativity and some astronomical observations.

ombx · 5日前

I'm not a physicist by trade, but I know enough to say this: In a sense, you've sort of got it backwards. According to our best models of physics, the universe SHOULD have had equal amounts of matter and antimatter (and hence most of it would have annihilated early on, and there wouldn't be much matter or antimatter left at all).

So, in a sense, a universe with equal matter/antimatter wouldn't have laws of physics that are any different from our current ones. The real question is why our current laws/models don't fully explain OUR universe -- they work great in your hypothetical one!

Of course, there are various hypotheses out there to try to explain why (the observable part of) our universe is apparently mostly matter and not antimatter, but nothing super-solid. As usual, Wikipedia has a pretty decent summary.

Sapere_Aude__ · 8日前

Ha, looks like we started writing at about the same time and I got my reply submitted juuuust before you.

(Probably because I was typing it during a very stressful free-fall from the upper atmosphere.)

Sapere_Aude__ · 8日前

Yup, that's what I meant too, although maybe I was over-simplifying my terminology to the point where it was unclear. Not time LITERALLY slowing down in the relativistic sense, but a facilitation of faster mental processing.

Sapere_Aude__ · 8日前

This is mentioned briefly in the Wikipedia article, but it's such a cool study that I thought I'd elaborate. In one experiment, participants did a bungee jump while looking at a display strapped to their wrist that showed rapidly flashing numbers, which were difficult to perceive due to how quickly they went by.

The idea was that if time really does slow down in your brain during a stressful event like a bungee jump (as people report subjectively), people would be able to report the flashing number sequence better during the jump than they could on the ground, due to the numbers appearing to flash more slowly.

Sadly, this did not turn out to be the case -- so it looks like that sensation of "time slowing down" is merely an illusion, at least in that experimental setup. People did report feeling like time went slower during the jump, but they were no better at reading the numbers.

Here is a link to the paper, if you're interested. You might find some coverage on the Web that suggests that the bungee jump really DID make time slow down for people (if I remember correctly, at first it looked like the experiment might be working until they collected more data and the effect went away; I think there was a BBC show or something that covered them mid-experiment when they were more optimistic about the outcome). But the final result was not so exciting, even though the idea of the experiment is still pretty nifty if you ask me.

NowMoreEpic · 15日前

Well put -- you said a lot of the things here that I was trying to think how to say, but couldn't come up with a succinct way to do it in the time I had.

I think it is probably non-obvious to most people that most of the things we take for granted in the macroscopic world are dominated by electromagnetic interactions (and gravity, but that doesn't do too much for us on a day-to-day basis except keep us stuck to the ground). I suspect most people hear "electromagnetism" and think of electric power and magnets, and don't think of light (visible and otherwise), or the chemical bonds that hold matter together and dictate all biological processes, or any of that.

NowMoreEpic · 15日前

I am not a physicist by trade, but I think I can give you a quick answer. Your concept of a "quantum field" is a little mistaken. Our current understanding of physics has a place for four basic forces: Gravity, electromagnetic, and the strong and weak nuclear forces. All of these can be thought of as having associated fields, but there's not a single "quantum field" that is separate from those things.

In terms of what I think is the heart of your question (why we have such mastery over electromagnetism and not so much the others):

Gravity is not great for doing the kinds of things we use electromagnetism for because it's incredibly weak. Think of the amount of force that a handheld magnet can exert on a metal object. Now think about the same two objects if they aren't magnetic. Yes, they exert a gravitational attraction on each other, but it's so weak you'd never be able to tell by looking. So, gravity would be a worse way to move energy and objects around than electromagnetism, in general.
The weak nuclear force, though stronger than gravity, is also weaker than electromagnetism. Also, both the nuclear forces (strong and weak) work on a very limited spatial scale (e.g., on the order of an atom's nucleus, hence the name). Whereas the ranges of gravity and electromagnetism are theoretically infinite (though decreasing with distance). That's not to say we haven't "mastered" their power in some ways (think of nuclear fission for generating electricity, for example), but the way they work is not very conducive to doing the kinds of things we like to do with electromagnetism.
It's also a little tricky to even talk about this stuff, because everything we do requires a certain amount of understanding (or "mastery") of all the forces and their consequences, even if it's non-obvious. You charge your cell phone with electricity, but it works because of satellites that only stay up because of our "mastery" of gravity. We think of solar energy as being electromagnetic, but the sun wouldn't shine without the weak force allowing fusion to happen the way it does. Pretty much anything we do under the banner of "chemistry" (including cooking) is a consequence of electromagnetic and strong forces. Etc., etc.

TL; DR We use electricity the way we do because it has a good balance of being relatively strong and long-ranging, but really we use all the fundamental forces in ways that are hard to really separate out from each other.

subroutines · 1ヶ月前

Good point! I do use onCleanup() sometimes, but for other things. I guess sometimes I want to be left in the current directory if the script bugs out, as that might help me debug. And other times, I want to save the original working directory in a variable for other reasons (e.g., to change back to it mid-script or to extract some relevant metadata out of the filepath), so I've just gotten in the habit of doing it the way I posted. But this would be a good one-liner for me to keep in mind for the occasions where neither of those exceptions applies.

Talking about getting stuck in a directory due to an error reminded me of another tip, which you're probably aware of but I'll stick in for posterity. I try to remember to stick in a dbstop if error before running a script that needs debugging, so that it will pause in the debugger if any errors occur, and I can just check them out right then and there (as opposed to setting a breakpoint and re-running).

subroutines · 1ヶ月前

I have a bunch of quickie little tricks that I use. These are stupid-simple but they save me a bunch of time.

1) I have a function on my default Matlab path called caca.m. All it does is execute the code clear all; close all;. Super-fast to type whenever you want to zero out your workspace; has saved me millions of keystrokes, I'm sure. Plus "caca" means "poop" and is therefore automatically hilarious.

I also tried to make a script called crap.m (standing for Clear, Rehash, and Pack) that also calls rehash and pack, to also make sure that all of your functions are up-to-date and your memory is compacted, but apparently you can only do pack directly from the command-line. Sad.

2) I have another one-liner function on my path to make a beep. Code: sound(sin(1:1024)/4,8192); If I'm running some analysis that loops through a bunch of things that take a few seconds to a few minutes each, I stick a beep at the end of each loop iteration so I get a little progress update in the background while my attention is directed elsewhere. And I often stick multiple beeps at the very end of the function to catch my attention when the entire task is finished, so I can check on the results, start the next analysis, etc.

3) Also, more of a habit/tip: ALL of my .m files are functions, even if they don't really have to be. This is good practice in the same sense that avoiding global variables in a language like C is a good practice. It forces you to be explicit about the inputs and outputs of each script, and keeps your main workspace clear -- this way, each script doesn't barf out all of its internal variables all over the place. It also means that when you run multiple scripts, one after the other, you don't have to worry about accidentally using the same variable name to mean different things in each script, thus causing one script to overwrite a variable the other script is expecting to use in a different context.

I've seen some people's code that uses 5 or 6 non-function scripts that share a TON of variable names, and it's such a house of cards -- I find it horrifying. Keep your code chunks discrete, people! It feels like a time-waste for simple stuff at first, but once you get in the habit it takes almost no time at all, and it will save you tons of heartache in the end.

4) Last thing -- also more of a general programming practice. If you write a lot of Matlab code, develop your own conventions that will make it easier for you to read your own stuff. For example, my loop variables are always named i, j, k, m, n... (going from outermost to innermost loops). I skip 'l' because it looks too much like the number 1.

Also, if I make a variable that changes each time a loop executes, I preface it with "this", e.g. this_value = values(i); If I'm saving a result at the end of each loop iteration, I preface those variable names with "all", e.g. all_results(i) = this_result.

Finally, almost any function I write is prefaced by my initials, e.g. the beep function I mentioned above is mrj_beep.m. This isn't about egotism; it's to guard against name collisions in case Matlab adds a beep.m function in the future, or I download another person's toolbox that includes a beep.m function, or whatever.

One exception to that rule is for functions like caca.m, where the main point is to save keystrokes. I have to assume Matlab is never going to introduce that function in the future. Another exception is that if I have a bunch of scripts that are intended to be run in sequence, I preface them with arbitrary letters that make them show up in the right sequence when listed in alphabetical order, e.g. aaa_load_data.m, baa_preprocess_data.m, caa_main_analysis.m, daa_show_results.m. I use multiple letters in that example so that if I want to insert an intermediate step, I can do so without renaming everything else, e.g. aba_check_data_integrity.m between loading and preprocessing. The reasoning is that when I come back to this folder of scripts after some time away, and can't quite remember what I did or in what order, the naming conventions will make it abundantly clear, and it will be way easier for me to recreate my old workflow.

subroutines · 1ヶ月前

In any of my scripts that have to change around directories (e.g., to grab different data files in known directory hierarchy, which is a common thing for me), I've just gotten into the habit of always doing this as the first line in the script:

owd = pwd; %save original working directory

cd(owd); %restore original working directory

It's a simple habit to form, and it's so automatic for me now that it's not worth doing anything fancier...

DoctorPimpslap · 1ヶ月前

No, *you're* great! (big wet kiss)

Next time, I'll set so you can spike.

DoctorPimpslap · 1ヶ月前

It's The Gourds. You know, from the comment you originally replied to?

You linked to the exact same song.

BuddyLeetheB · 1ヶ月前

Thanks! Yours too! (Although I really need to stop commenting on these threads when they come up -- I love to talk about it, but it takes forever to properly frame the arguments...)

BuddyLeetheB · 1ヶ月前

I think this is an interesting discussion but unfortunately I have a ton of work to do, so I can't get TOO into it... but a couple of points:

1) I agree with your last paragraph, insofar as a big part of the problem is a sufficiently specific definition of what "free will" should be. If you want to define "free will" as "unpredictability" (as here, for example: http://en.wikipedia.org/wiki/Free_will#Free_will_as_unpredictability), then fine -- we have free will, insofar as our introspection capabilities can't always tell us what led us to make one decision versus another.

But I think most of us have a sense of what "free will" should be -- i.e., some kind of TRUE ability to choose, in the sense that if we ran the universe back a previous point in time, but with the EXACT same physical conditions, we would sometimes be capable of making a different choice than we did the first time. Obviously there is no way for us to verify that, but all the science we currently have points strongly toward the opposite view -- that a physical system in a given state will progress to the same conclusion every single time, if the starting conditions are identical.

2) Assuming that we are talking about that kind of free will, and not one of those weasel-wordy types -- I think from the words you are using, that you are maybe falling into the same trap as the philosophers I mentioned.

Take the two-identical-paths-in-the-woods scenario. Which, to simplify things further, is basically asking someone to choose heads or tails in a coin-flip scenario, if there are no environmental cues to suggest one is better than the other. It's true that there is no human-visible "reason" to choose one versus the other, and if you were asked to make that decision as fast as possible, you probably wouldn't be able to introspect about WHY you chose heads or tails either.

But nonetheless, although the choice feels "random" inside your head, from a cellular/biochemical perspective, it is still entirely deterministic. Imagine two neurons in your brain, one representing the "heads" decision, one representing the "tails" decision. Whichever neuron fires first will be what you say. (Of course this is highly simplified -- it takes a large ensemble of cells firing many times each to make even a simple action happen, but for the purposes of this example, we can abstract away all of that stuff and pretend it's just two cells.) Since a neuron fires when the sum of its inputs from other neurons reaches a certain threshold, what determines your "choice" is which cell gets more input inside of the given time window.

So, what determines THAT? Well, it could be all kinds of things, even in the absence of a conscious reasoning process. Maybe the last time you had to pick a coin flip, you picked heads, and the "heads" cell is now slightly depleted, making the "tails" cell a bit more likely to fire. Maybe you saw the tail of an animal more recently than you saw a head of one, which slightly primed the word "tail" in your memory. Maybe across the sum total of your lifespan, "tails" coin-flips worked out for you slightly better than "heads" coin-flips, so you got more reinforcement for "tails" and are now biased to choose that slightly more often. Maybe the capillary that delivers blood to your "tails" cell is slightly bigger than the one that serves your "heads" cell, so the "tails" cell is slightly more well-nourished and capable of firing just a bit faster.

And those are just examples of factors that are relatively easy to describe -- of course there are all kinds of more subtle cellular/chemical phenomena that could be playing a huge role in the "decision," but are difficult to describe in ordinary words. And since the brain is so complex, there is no way we could possibly predict what your decision would be, without having a nearly-perfect recording of where every single molecule in your brain is on a nanosecond timescale, plus an unimaginably huge computer to actually analyze the data. Since we don't have those things, in every observable sense the decision seems unpredictable and "random," and potentially due to some kind of "free will" thing -- but all the science we have so far suggests that this is just an illusion. If we DID have a perfect recording of your brain state and the computational ability to analyze it, it would turn out that your "free will" decision was exactly as determined as the trajectory of a ball thrown into the air -- in the case of the brain, it's simply harder to calculate.

Anyway, I've already gone longer than I have time for, but one final thought. Lest you think these are silly examples, it's worth noting that our "free will" is influenced ALL OVER the place by events we don't even notice, and would never expect to have an effect on our "conscious" "decisions." (Have I used enough "scare quotes" so far?) For example, consider the social priming literature in psychology -- one of my favorite examples.

(Note: That's not the best article to summarize the literature, but I'm in a hurry and it came up on my first page of search results -- I'm sure you can Google and find better summaries elsewhere if you care. And you may find articles talking about the "replication crisis" in that field of literature, which is a thing -- some of the effects are difficult to replicate, largely because the effects are pretty small/subtle. But there are SO MANY such effects that have been found in SO MANY different domains, that none of us in the field really doubt the overall existence of the phenomenon -- though individual findings may be iffy here and there.)

Anyway, what the social-priming people find is that incredibly subtle things can influence us -- for example, if you have recently been asked by one experimenter to briefly hold a cup of warm coffee (versus iced coffee), and then do an experiment where you are asked to rate the behavior of a different person, you will actually rate that person's attitude as friendlier (i.e., "warmer") if you held the hot coffee versus the cold coffee, due to the implicit association in your brain between physical warmth and emotional warmth. It's a small effect, but observable. In another study, people who saw words relating to aging in an experiment were then covertly observed as they left the lab, and were measured to walk more slowly (i.e., more like an old person) than control subjects who did not see any words relating to aging.

And one of my favorite effects ever -- in another study, subjects were asked to photocopy something, and for some of them a coin (it was a German study, but equivalent value to about $0.10 USD -- not very much) was placed near the copier for them to "find." Then when they later filled out a questionnaire involving their overall happiness with their lives, subjects who "found" a coin rated their overall life satisfaction as significantly higher than those who didn't! You would think that a question about your overall life satisfaction would be something you'd consider very carefully, and your decision about what to say would be a great example of "free will" -- you have no explicit motivation to choose any particular answer -- but it turns out that a single dime placed on a Xerox machine a few minutes earlier can be a substantial part of what "determines" your answer.

Anyway, now I've gone on way too long, but I think those are some cool examples of very subtle things that can unconsciously influence what we think of as our "free will" or "conscious" decisions -- and those, of course, are found with the relatively blunt tool of what we can easily manipulate in a psychology lab. In reality, all kinds of things -- the temperature in the room, something you see out of the corner of your eye but don't consciously register, something you read a week ago and have already forgotten about -- leave traces in your brain that influence your decisions in impossibly complex ways. Again, without being able to stop time, or having a perfect recording of every particle in the universe, there's no way we could ever measure and analyze all those interactions -- but they are still there nonetheless, determining what looks like "free will" to the casual observer.

matizzy · 1ヶ月前

OK -- yeah, I don't use audio stuff in Matlab enough to knock out a solution for you or tell you exactly what functions to use or how difficult it would be.

But if you do know Python already, my gut suspicion is that it would be easier to cobble something together from existing Python libraries -- it probably has a wider and more active open-source userbase than Matlab, plus you don't have to learn a new language.

Looks like there is already some discussion out there of how to do this in Python -- e.g.: http://stackoverflow.com/questions/1936828/how-get-sound-input-from-microphone-in-python-and-process-it-on-the-fly

(If you do want to go with Python and need to mathematical-type stuff that isn't covered in the audio libraries, check out NumPy -- it basically clones a lot of the core Matlab functionality and performance is similar. Looks like it has an FFT function too, although there might be better audio-specific ones in the audio libraries.)

matizzy · 1ヶ月前

Matlab is indeed a good tool for audio processing, although I'm not sure whether its hardware integration is tight enough to get microphone input in real time -- I've never tried that before.

But you haven't given us much to go on. This would not be an incredibly hard task for an experienced Matlab programmer, but what do you already know? Do you already know how to program in another language? If not, the first step, before you even start this project, is going to be to learn how to program.

You can learn programming in Matlab, but there aren't very many good resources for beginners. I think it's actually easier to learn another language first (e.g. Python, which I think is good for a first programming language and has many tutorials on the web), and then translate your general-purpose programming skills over to Matlab. Once you know one programming language and have the general concepts down, acquiring a second is much easier. (And the third is easier still, etc.)

If you already know Python or some other language -- hit the tutorials! See the links on the sidebar. And Mathworks has great documentation on all of Matlab's functions -- both on the web and built into the application. Plus, once you know the basics of programming and the Matlab language in particular, there are a million tutorials out there for specific tasks. So... start Googling. E.g., searches for "matlab audio processing" and "matlab microphone input" and "matlab fourier transform" will give you tons of relevant info.

BuddyLeetheB · 1ヶ月前

Agreed with everything said here, just tacking on a bit more re: compatibilism. There are various types of compatibilism, but for the moment I'll ignore the ones that just redefine "free will" in a way that is compatible with determinism but hence is no longer compatible with what we'd like "free will," intuitively, to mean. (In the opening paragraph of this article, it mentions that William James called compatibilism "a quagmire of evasion" and Kant called it "petty word-jugglery," and for those arguments that I think just boil down to semantics, I'm inclined to agree.)

The kind of compatibilism that SEEMS more reasonable, also discussed in that article, is the "alternative possibilities" version. I.e., maybe today I had a cheeseburger for lunch, and that was deterministic -- if we reset the universe to its pre-lunch state and ran it again, I would always have the same cheeseburger, and never a hot dog. Yet, one could argue, it is POSSIBLE in some sense that I COULD have chosen a hot dog -- as philosopher John Perry states in that article, having a hot dog for lunch is also well within what he calls my "repertoire of actions."

Perry's version of that example asks whether a person might stick a pen up their nose. As he says: "Assuming you're a relatively normal individual, I'm virtually certain that you're not going to do it. But there's a difference between you and someone who can't move their arms at all." So because sticking the pen up your nose is in your repertoire of actions, you have "free will" to perform the action in a way that a paralyzed person does not.

So the argument goes. But I think even that form of compatibilism rests on a poor understanding of the physics involved. On the macroscopic scale of everyday, visible-to-the-naked-eye objects, it seems like eating a hot dog is indeed in my action repertoire. And that's what our folk psychology suggests -- if you asked someone before lunch today if it was possible for me to eat a hot dog that day, they would say yes. They've seen me eat hot dogs before, they know I'll eat hot dogs again, I'm not paralyzed or anything, I even have hot dogs in my fridge right now -- sure, it's possible.

But if you consider the micro scale of my biochemistry and neural impulses (I agree with Lilyo and all the physicists who have already commented on other places that quantum physics doesn't have much to do with it -- quantum effects still occur on a scale that is too small to make much, if any, difference on things like neurons firing, and thus on behavior), it turns out that eating a hot dog is NOT within my repertoire of actions, at least not on this particular day of my life. The molecules in my brain are behaving in such a way that eating a cheeseburger is the ONLY physically possible action; if you consider the entire system in full detail, eating a hot dog is no more within my "repertoire of actions" than it is for a paralyzed person to lift up his arms, or me to pick up my feet and jump all the way to the moon.

Now, you could make a counter-argument that eating a hot dog is more plausible than jumping to the moon in some sense -- i.e., if you think about different parallel universes (each deterministic in itself) that might result from different starting conditions, it's true that the parallel universe in which I ate a hot dog looks much more similar to our own than the parallel universe in which I jumped to the moon. But that's just a difference of degree, not a categorical distinction.

I don't really want to hate on philosophers, but I think this branch of philosophy has kind of hit a dead-end, in the sense that most philosophers don't seem to take the laws of physics into account at the level of detail they would need to for their arguments to really hold water. Philosophical ideas are appealing when they make sense in terms of observable, everyday, human-scale objects and actions -- and many philosophical papers take this "intuitive appeal" aspect into account when weighing the strengths and weaknesses of different arguments. But our science has long since demonstrated that those intuitions, though appealing, are flat-out wrong (well, at least, imprecise) -- our human-scale (e.g. Newtonian) physics is only a rough approximation of a deeper, more detailed, more correct, and less intuitive (e.g. quantum) physics, and similarly that our folk psychology (e.g. our everyday definitions of people and actions) is only a rough approximation of a more correct but less intuitive biochemistry/biophysics/neuroscience. So, as a scientist myself, I find it difficult to entertain a philosophical argument that does not get down-and-dirty with the real science.

TL; DR I think even the "best" versions of compatibilism fall short because they fail to take into account all the implications of our current knowledge of physics, instead relying too heavily on our flawed human-scale conceptual models of the universe.

PS A lot of these ideas/arguments are sketched out nicely in the Stanford Encyclopedia entry on compatibilism: http://plato.stanford.edu/entries/compatibilism/

SuperAgonist · 1ヶ月前

Happy to shed some light on the subject.

FWIW, these questions are thorny for all of us -- when trying to understand the brain (or other biological systems), there is a great desire to ascribe "function" to things the same way you can talk about the functions of parts on a car. For artificial things, this is so easy -- the gas tank holds the fuel, the wheels rotate to move the car forward, the rear lights go on when the brake is depressed to signal braking, etc.

But natural systems are typically not so clean-and-simple in their design. We're a big bag of chemicals that are all constantly swimming around and interacting with each other in an impossibly complex manner. Some things are relatively easy to characterize on a fairly gross level -- e.g., the heart pumps blood, the lungs exchange oxygen for carbon dioxide, the brain thinks, etc. But when you try to get more granular, that 1:1 mapping of structure to function starts breaking down pretty quickly.

The analogy I like to use for understanding the brain is that it's like trying to understand the global economy. We can come up with some rules-of-thumb that work fairly well on various levels of analysis (e.g. supply-and-demand on the macro scale, predicting the general buying patterns of certain demographic groups, etc.). But we can't come up with a rule to tell us what a 34-year-old white American male's "function" is in the economy, because the environments of all those individuals are so different. Even on the macro scale, there would be no way to predict a nation's economy perfectly -- what if an earthquake wipes out Los Angeles tomorrow? That would certainly affect the economy, but no economic models contain precise geologic models within them. The only perfect economic model would be a perfect replica of the entire universe, so we have to settle for generalizations that work pretty well for a given level of analysis.

We struggle with this in research all the time. In my field, there is a desperate desire to ascribe functions to different brain regions -- we spent a good portion of our time from the mid-1990s (when fMRI became a thing) until today trying to "map" these functions. But unfortunately we quickly reached the limits of how useful a characterization we could make of certain areas. We can do a relatively good job with some areas -- e.g., we know that primary visual cortex mostly handles the initial processing of visual input, because it's a pretty straight shot from the retina to that area. But you get into an area like the prefrontal cortex, which is important for all kinds of vaguely-defined "higher-level" behaviors, and it gets harder and harder to say something that is both specific and accurate. (And even visual cortex, which we'd hope would be straightforward, is constantly getting feedback about our thoughts and memories and such from those "higher-level" areas, so things get messy pretty quickly there too.)

This is not to say the situation is hopeless -- we are making tons of good progress in neuroscience research all the time. But we have to be continually vigilant of our natural human tendency to categorize things into neat little logical packages, which unfortunately tend to make poor characterizations of the natural world, and try instead to come up with alternative characterizations that may be be imprecise and imperfect, but nonetheless do a decent job of explaining a certain phenomena at a certain level of analysis.

(If folks haven't heard it before, this would be a perfect time to reiterate George Box's perfect description of the problem: "All models are wrong, but some are useful." Pretty much sums it all up right there.)

SuperAgonist · 1ヶ月前

Neuroscience PhD to the rescue here. I am a cognitive neuroscientist by trade and not a dopamine expert, but I know enough to explain some of the issues behind the central premise of the question, and which are also problematic for most of the answers thus far.

Dopamine is a neurotransmitter. Neurotransmitters are frequently explained via a lock-and-key metaphor, where the transmitter is a key and the receptor is a lock. This is, of course, a simplification, but in this case it works very well for several important (one might say key) points:

Keys and locks need not have a 1:1 relationship. For example, my labmate's office key also opens my office, even though the locks are not identical. However, my key won't open her office door.
The shape of the key itself has no intrinsic meaning; any "function" that it has is determined by the lock it fits into and what that lock is attached to. For instance, most house keys look different from most car keys, to the extent that you can often look at a key and tell if it goes to a house or car. But there is nothing about the shape of a car key that means it could only be used in a car; if someone wanted to, they could install a car-type lock mechanism on a house door, and a "car key" could easily become a "house key."
Going even further -- we typically think that of keys as being things that OPEN doors, but of course keys can do lots of other things. They can lock doors even more (e.g., on a deadbolt). They can start cars. They can (help) launch nuclear missiles. In less conventional uses, they can be used to slice open envelopes or scratch someone's car if you don't like them.

All of these aspects of keys apply equally to neurotransmitters. Dopamine, like other neurotransmitters, doesn't DO anything particular; it's just a key that fits into different kinds of locks in different contexts. It so happens that some of those locks appear in neural circuits that seem to be important for reward and/or motivation, but they also appear in lots of other places.

I'll give you a more concrete example with a neurotransmitter I understand a bit better: Glutamate. Glutamate is typically called the major excitatory neurotransmitter in the brain. This is because its most common role is opening up "ionotropic" glutamate receptors, i.e. "doors" that only sodium ions can go through. When a glutamate key opens up a sodium-ions-only door, the sodium ions (Na+) flow into the cell, raise the voltage of the neuron, and make it more likely to fire an action potential.

But this isn't all glutamate can do; there are also metabotropic glutamate receptors that can do all kinds of other things. Think of glutamate's role here as like a key that starts a motor (or other mechanism), rather than opening a door. In other words, in a cell, attaching glutamate to a metabotropic receptor doesn't open a gate in the cell wall, but it does trigger a mechanism that causes a little chunk of a protein to break off inside the cell, which then triggers some other process. Those downstream processes can be complex, and some of them can even be effectively inhibitory -- the opposite effect of glutamate's usual role.

So, in summary -- although it's true that the same "keys" are sometimes reused in similar contexts across the nervous system, it's a mistake to see a "house key" and assume that its function is to open a house; it might instead be a key to a padlock or missile silo or old-fashioned car (back when car keys looked a lot more like house keys). There's nothing intrinsic to dopamine (or any other neurotransmitter) that "feels good"; dopamine does other things in other contexts (e.g., it appears to play an important role for cognitive function in the prefrontal cortex) that don't "feel" like anything at all.

Another couple of fun facts:

Different organisms can even use totally different neurotransmitters for the same(-ish) functions. For instance, where humans and many other animals have norepinephrine (adrenaline), insects use octopamine instead. Why one versus the other? It's probably just a fluke of evolution, but the exact chemical doesn't really make a difference per se, as long as it has a lock to fit into. (Think of two companies, one of which uses longer brass keys for all of its office doors and one which uses shorter aluminum keys. Both keys work fine to accomplish the same function in each company, even though they are totally mutually incompatible.)
Everyone's heard of serotonin, and you probably think of it as that neurotransmitter that makes you depressed if you don't have enough of it (although that characterization is at best oversimplified and at worst 100% invalid). But where is most of the body's serotonin actually located? In the gastrointestinal tract, where it regulates digestion! A fantastic example of a neurotransmitter having totally different functions in different places in the body.

too-kahjit-to-quit · 2ヶ月前

I bought a Butterball Electric Turkey Fryer (I'm on my phone, so it's a bit of a pain to find and insert a link, but it's easy enough to Google). They're about a hundred bucks in the USA. I love mine.

If you have no intention of ever frying a turkey, it might be overkill in terms of size and expense... but it's the only way to fry turkeys (up to 14 lbs or so) and works just fine as a general-purpose deep fryer. Way safer/easier than an outdoor fire-based fryer.

It is kind of huge compared to the other deep fryers linked... I think to fry a turkey you'd put in 2 gallons of oil. So less great if you're right on space. And draining/cleaning it is slightly annoying, but you can use the same oil for a long time so you don't have to do it THAT often.

If you have any questions, feel free to ask... I am a frying fiend with this thing. And frying turkeys (and Oreos, and Twinkies...) has been a huge hit at Thanksgiving and other parties over the past few years.

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