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The language here is weird. He's talking about doing more than one thing at a time. If you're talking about multi-threading in the context of the brain, the obv
by frereubu 7y ago
The language here is weird. He's talking about doing more than one thing at a time. If you're talking about multi-threading in the context of the brain, the obvious comparison is with neural architecture. The brain does a massive amount of parallel processing and it very much is multi-threaded. But "multi-threading" sounds a bit cooler than "doing more than one thing at a time" I guess.
- rhombocombus 7y agoThere is a big difference between multitasking and parallel processing. As a former neuroscientist I get rankled when I read gross conflations like this, it doesn't help anyone understand how the brain actually works, nor does it effectively underscore the attentional drawbacks of trying to multitask.
- bwb 7y agoTrue, but from a big-picture view he might be doing a better job explaining the concepts to laypeople. And in that it might help them improve how they work / live :)
- pathseeker 7y agoSure, the layperson knows what multi-threading is.
- bonoboTP 7y agoThe lay hacker.
- rm_-rf_slash 7y agoI think a better analogy is the way GPU calculations are done, as the calculations are done in parallel but the process is ultimately sequential: move data from CPU RAM to GPU RAM, calculate in parallel on GPU, move results data back to CPU RAM, operate on the results data on the CPU serially.
- frereubu 7y agoFellow former neuroscientist here! The proliferation of pseudo-neuro explanations and analogies is infuriating. I envy people like theoretical physicists who work in a field where laypeople don't feel like they have an intuitive understanding of their subject area.
- deleted 7y ago[deleted]
- nprincigalli 7y agoMaybe you haven't noticed how "quantum" is being thrown around these days, check https://en.wikipedia.org/wiki/Quantum_healing https://en.wikipedia.org/wiki/Quantum_healing and https://en.wikipedia.org/wiki/Quantum_mysticism https://en.wikipedia.org/wiki/Quantum_mysticism
- posterboy 7y agoI for one am a specialist on quantum mechanics since I read Steven Hawking. It's all bonkers, I can tell you that, but because of the uncertainty principle, I'm not really sure. That's OK because there is some parallel world in the multiverse in which it isn't. And please don't ask me to explain, I've read enough to know that by Hoffstadter's Incompleteness theorems I cannot prove it.
- Jd 7y agoI know that dog created the universe with a pair of parentheses and after that it was pretty much backwards and uphill. ok maybe not: https://xkcd.com/224/ https://xkcd.com/224/
- perl4ever 7y agoI remember Richard Feynman (a theoretical physicist) explaining how you could deduce things about the human mind by observing behavior and self-reported internal states.
- muzani 7y agoI really wish there were more books for laypeople by neuroscientists. I don't care much for theoretical physics personally, but a lot of people want to understand their own brains.
- a1369209993 7y agoThe brain is more like SIMD than multicore processing, but I think a better analogy is a FPGA; it can do heterogenous instructions, but switching from one task to another is a crushingly expensive stop-the-world affair.
- perl4ever 7y agoPossibly people assume that they are conscious of all the tasks that their brain does? Can they walk and chew gum?
- EamonnMR 7y agoYou are conscious of most things your brain does. Background tasks like walking and chewing gum tend to be very rote and decision light. Try and write while listening to someone speak, fold a paper airplane while navigating a new city, or program while watching a film.
- spiralx 7y agoWriting, listening, watching a film and navigating a new place all require attention as they're novel activities. But I could easily make a shit paper aeroplane while navigating, and I've coded through pure muscle memory plenty of times. Almost any activity can be internalised.
- AstralStorm 7y agoI'd call it more similar to a computer system with multiple specialized processors working in parallel and limited buffers between them. Parallel system, really, not multithreaded.
- blattimwind 7y agoBut isn't the brain massively multitasking? It controls and keeps track of an awful lot of stuff. The "can't do multiple things [well] at once" really just applies to conscious efforts.
- Filligree 7y agoIt is, but that's not what the article is about.
- alexanderdmitri 7y agoMaybe he meant the conscious mind we experience abstractly and is somehow hosted in / by the brain. In which case, sure, it makes sense that each thought blocks the main thread and that's why thought-loops are particularly annoying. In terms of I/O though, I certainly try to optimize the main thread with concurrent patterns when the input queue gets hit with high traffic. Even if I'm recurrently mulling over something for days, hoping for a break-through or insight or whatever, it's not like I'm incapacitated and can't perform / prioritize other thoughtful tasks on the event loop.
- nvrspyx 7y agoThe keyword in the previous person's comment is attention. It's attention that is incapable of multi-tasking. It really just bounces from one thing to the other and attention is sort of what drives consciousness and directs it where to go. But the rest of the brain is doing a ton, such as memory encoding to both working and long-term memory. It's also doing things like language, motor, emotional processing, etc. as well as all the things more peripheral to consciousness like senses, time, vitals, etc. If we look at the brain like a computer that interacts with the world as well as interacted with, I like to imagine that the brain is very complex and running many parallel processes. Like a computer, it has many parts of the interface to the world. Eyes are the screen, ears are the speakers, muscles are the mouse and keyboard, etc. I like to think of attention as the cursor; sort of a single process that directs what the user is interacting with. I'm positive that is much too simple of an analogy because it still leaves the question: why can't consciousness control multiple attention cursors simultaneously? In many ways, it does in which consciousness can pass things off to automatic processing, like triggering muscle memory and other previously strengthened pathways. But, I think the why there's not multiple attention processes running is still a big question yet to be answered. I think neuroscience still has a lot to be understood before we'll be able to answer it sufficiently.
- ken 7y agoYes, the title is rather poor. From reading the post, it seems what he really means is: "Mental Context Switches are Really Expensive". That's far less exciting, and probably also kind of obvious to most knowledge workers.
- nvrspyx 7y agoI think the title should be "Attention is not multi-threaded", which I believe is pretty well known in psychology and where the expensiveness of context switching stems from.
- no_wizard 7y agoI wish more places and people understood this! I am of the opinion that this for instance might be the biggest singular reason nodejs has been successful without people even realizing it. Since “full stack” development is so in demand/popular this really limits the context overhead of switching languages and semantics between front end and back end in such a way that it can keep productivity high. (Yes nodejs has other strengths too and to be fair weaknesses but I wouldn’t discredit this as A much factor off hand at least)
- Aloha 7y agoI have ADD, and I've been using a context switch for years to explain why it's so hard for me to change between two totally different tasks, but I can change pretty rapidly (with no penalty) between multiple similar tasks. I've likened it has having to pack up one set of tools, before I can unpack the other one.
- spiralx 7y agoI find that when doing something less interesting I tend to switch back and forth between two tasks quite a lot while working - each switch acts to regain attention before it starts dropping off again. As long as nothing external forces me to context switch this both keeps me focused and drives my boss nuts.
- djsumdog 7y ago
- posterboy 7y agoThreading has a rather specific meaning in cpus, no? Synapses are parallel, but so are various operations in a single threaded CPU, even just the ALU (carry look ahead addition e.g.). Vice versa, hyperthreading switches context when the single threaded cpu is stalled by memory look-ups. While its notable how many ideas can converge, or how you remember that name out of the blue that you couldn't figure out minutes or days before is surely interesting. But attention is pretty much directed, so to speak. Just doing a different motion with each hand at the same time requires a certain ammount of orchestration. This requires planning and training. The brain is a super scalar architecture, sure, but you cant do taxes with one hand, paint a picture with the other, and explain quick sort to your mom over the phone while you get your ... nippeles pinched (the classic Password Swordfish situation). Or more simply speaking, you can't be angry (at the taxes), elated (because of the forms and colors) and aroused (the nipple pinching throws various interrupts, whether arrousel or panic) at the same time while remaining pleasently calm towards your mum. Well, that does not sound like a good study design, but because of the health hazzard. Come on, if you stress a metaphor, I want too.
- frereubu 7y agoNo metaphor is perfect - my claim is that this is quite a bad one compared to many others that he could have chosen.
- posterboy 7y agowe agree that the choice of words is bad, we agree that the metaphor is appealing, and we can probably agree that we don't know how the brain works. Mixing behavioral ideas and whatever-else-accurately-describes knowledge of cpus (systemic?) is a bad idea, over all. That's not reductive and breaks the deductive argument.
- deleted 7y ago[deleted]
- rokhayakebe 7y ago"In the context of the brain" what is the difference between multi-thread and multi-task? Can you give examples?
- ben_w 7y agoI can simultaneously walk and listen to a podcast; but when I hear two overlapping voices I can only parse[1] one of them at a time even though I can easily choose which one of the two to listen to[1]. [1] listen to? Parse? Hear? I’m not sure what the right word is in this context.
- gerbilly 7y agoIt would appear that the prefrontal cortex is much less parallel than the rest of the brain. This is why we often get much better task performance when we allow our gut feelings (which come from subconscious parts of the brain) to inform our reasoning. Deliberative reasoning in the human brain has a very limited capacity. See: https://en.wikipedia.org/wiki/Working_memory https://en.wikipedia.org/wiki/Working_memory and https://en.wikipedia.org/wiki/The_Magical_Number_Seven,_Plus_or_Minus_Two https://en.wikipedia.org/wiki/The_Magical_Number_Seven,_Plus...
- zbentley 7y agoPerhaps a better analogue would be a largely single- (or few-) threaded main processor with a truly astounding number of single-purpose coprocessors? I.e. physics units (motion vector approximation), graphics units (optical processing), management engines (parasympathetic nervous system) etc.