[HN Gopher] Why the Human Brain Perceives Small Numbers Better
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       Why the Human Brain Perceives Small Numbers Better
        
       Author : digital55
       Score  : 86 points
       Date   : 2023-11-11 01:56 UTC (1 days ago)
        
 (HTM) web link (www.quantamagazine.org)
 (TXT) w3m dump (www.quantamagazine.org)
        
       | jojojaf wrote:
       | I didn't read the article but, small numbers are more immediately
       | useful. Larger numbers are needed for describing more complex
       | phenomena, and their construction relies on smaller numbers. So I
       | find the explanation to the title of this article to be
       | intuitively obvious; I don't see how it could be possible for a
       | brain to evolve to perceive large numbers better than smaller
       | ones
        
         | atleastoptimal wrote:
         | I didn't read the headline, but I agree.
        
           | willio58 wrote:
           | I didn't read either of your comments but I agree as well
        
             | dd36 wrote:
             | Where am I?
        
               | notmuchserious wrote:
               | Maybe
        
               | adhesive_wombat wrote:
               | Why?
        
               | sethammons wrote:
               | Not reddit; the thread should expect downvotes
        
               | layer8 wrote:
               | Sunday
        
             | ilayn wrote:
             | I'm scraping the web. You are right by the way.
        
         | Swenrekcah wrote:
         | Perhaps a fish or an insect might benefit more from knowing an
         | accurate approximation of their or another school/swarm, than
         | it would from knowing if there are 2 or 4 of them somewhere
         | (since there seldom are so few).
        
         | passion__desire wrote:
         | Brain systems do handle order of magnitude changes. E.g. going
         | from dimly lit room [1-3] to bright sunlight. [1000-2000]
        
       | kzrdude wrote:
       | What's the number of things that we can count instataneously and
       | intuitively. What's your number in your opinion?
       | 
       | It would appear as though it's three or four. I look over to some
       | series of things, if it's exactly two or three, I know that
       | pattern, if it's more, I have to make out groupings of two or
       | three. I think even for four or five we might do this habitually?
        
         | Drakim wrote:
         | For me it's four, my brain just instantly recognizes that there
         | are four things, that instant pairing of pairings: oooo
         | 
         | Five is a bit more iffy, I can obviously tell quickly that
         | there are five things, but then it feels like it's my 3 and 2
         | pattern recognition kicking in plus some addition math: ooo oo.
         | If you spread the objects out in a weird way where I don't see
         | that 3+2 grouping then I have to count em.
        
         | arketyp wrote:
         | Many years ago at a LAN party at my friend's house his father
         | came in with a news article saying studies showed that gamers
         | could develop a better sense for instantaneous assessment of
         | count, up to 6 I vaguely recall. Anyhow I do remember
         | reconsidering my aptitude, since for me it gets confusing with
         | >= 5.
        
         | ooterness wrote:
         | For what it's worth, the upper limit for subitization varies
         | quite a bit.
         | 
         | The neurotypical limit is usually four, but can be raised with
         | practice. Children with Down's Syndrome may not be able to
         | subitize at all. Autistic savants can subitize up to thirty or
         | more, with unconfirmed cases up to several hundred.
        
       | apienx wrote:
       | These guys claim to see distinct "neural signatures" depending on
       | whether n is >4 or =<4. They can see neurons misfiring for the
       | larger numbers.
       | 
       | Is it hard-coded in our brains? My guess is no. You can probably
       | train brains to instantly recognise patterns for numbers larger
       | than 4, and I'd expect the observed effect would disappear for
       | then trained individuals.
        
         | tgv wrote:
         | It's a visual count. The visual system probably isn't optimized
         | for counting. It identifies and tracks objects, but not many.
         | I'm not surprised 4 is a common boundary, and I also wouldn't
         | be surprised if it were somewhat hard-coded. It could well be
         | limited by a "lower" layer.
         | 
         | The experiment is artificial, so it might not represent
         | counting in a more natural setting, where e.g. the objects
         | might have features that distinguish them better. The article
         | brushes over that.
        
         | monocasa wrote:
         | There's a lot of evidence from other studies of being able to
         | track about 4 simultaneous objects. It looks like (but we don't
         | have concrete evidence quite yet) that somewhere (maybe higher
         | level parts of the visual cortex, maybe something higher level
         | like state scratch pads, maybe something else we haven't
         | thought of) there's a four wide logical pathway. When we
         | overload it, it seems that we sort of time slice whatever it
         | is, jumping between the objects at roughly four at a time. In
         | addition to performance tests, there's also the data point that
         | there's a surprising amount of languages in pre agricultural
         | societies that have words for 'one' through 'four', but
         | anything else is some degree of 'many'.
         | 
         | And yeah, you can train your brain to see larger sets if
         | they're in a pattern that the middle parts of the visual cortex
         | can train on, but the limit does seem to be around 4 visual
         | symbols/tokens concurrently.
         | 
         | Another place you see an interesting bandwidth limitation is
         | that pretty much all languages have a pretty fixed semantic
         | bits per secondnwhen spoken. Specifically around 39 bits per
         | second. We can listen and hear faster but rates, but it's very
         | difficult to speak faster. Similar to the above discussion the
         | cute hack to go faster is to essentially give a single internal
         | symbol to a larger sequence of syllables through training, not
         | casting off the limitation but sort of hacking around it.
         | https://www.science.org/doi/10.1126/sciadv.aaw2594
        
           | dboreham wrote:
           | PCI lanes
        
         | pixl97 wrote:
         | Not sure if it's hard coded, but the brain is taking a lot of
         | visual shortcuts because of the limited visual bandwidth you
         | have.
         | 
         | https://youtu.be/HU6LfXNeQM4?si=PRdZP_hdwdyJQkdP&t=521
         | 
         | Your Brain: Perception Deception
         | 
         | This section is interesting on how little we see in high
         | definition, and how much mental processing it takes.
        
       | hiAndrewQuinn wrote:
       | The rule of four comes in handy across all kinds of places. A
       | command line argument that can be run with 4 or fewer distinct
       | words/flags/etc is one I'm much more likely to try running than
       | one with more.
        
         | bee_rider wrote:
         | It even kinda works for something like tar.
         | 
         | tar czvf output files
         | 
         | The czvf is really four arguments I guess, but it expresses a
         | single concept in some sense.
        
       | cheschire wrote:
       | There are four lights.
        
       | neoneye2 wrote:
       | Tetris games with 4 cells, is that easier that Tetris games with
       | 5 or more cells?
        
       | Someone wrote:
       | I find this unconvincing. FTA:
       | 
       |  _"More than 150 years ago, the economist and philosopher William
       | Stanley Jevons discovered something curious about the number 4.
       | While musing about how the mind conceives of numbers, he tossed a
       | handful of black beans into a cardboard box. Then, after a
       | fleeting glance, he guessed how many there were, before counting
       | them to record the true value. After more than 1,000 trials, he
       | saw a clear pattern. When there were four or fewer beans in the
       | box, he always guessed the right number. But for five beans or
       | more, his quick estimations were often incorrect."_
       | 
       | and
       | 
       |  _"For example, some neurons are tuned to the number 3. When
       | they're presented with three objects, they fire more. Other
       | neurons are tuned to the number 5 and fire when presented with
       | five objects, and so on. These neurons aren't exclusively
       | committed to their favorites: They also fire for numbers adjacent
       | to it. (So the neuron tuned to 5 also fires for four and six
       | objects.) But they don't do it as often, and as the presented
       | number gets farther away from the preferred number, the neurons'
       | firing rate decreases"_
       | 
       | So, the experiment was about integers, not numbers in general,
       | and the neurons don't necessarily encode integers, but also could
       | encode reals with noise/uncertainty.
       | 
       | I think the latter decently describes the experimental data if
       | the noise/uncertainty is around 20% of the value. Rounding such a
       | signal to integers will be faultless for n < 4, and get
       | increasingly worse the larger _n_ is.
       | 
       | In pseudocode:                   Round(n * (1 +
       | gaussianRandom())) == n
       | 
       | for small _n_ , but not for larger _n_.
       | 
       | To support a claim that we're better at smaller integers, I think
       | you'd have to show that the standard deviation for larger _n_
       | goes up superlinearly.
       | 
       | (An alternative way to phrase this is by claiming that these
       | cells encode logarithms of numbers)
        
         | ahoho wrote:
         | This was exactly my undergrad research topic! My knowledge is a
         | bit out of date (perhaps this is in TFA), but the running
         | theory is that there are two number systems. The first operates
         | noiselessly and immediately for numbers under 4. The second
         | works in the exact way you are describing, where the magnitude
         | of errors are linear in the size of the set (the "analog
         | magnitude" system). As I recall, there is substantial evidence
         | supporting the idea of two separate systems rather than one.
         | 
         | I don't really follow your point about integers. We know the
         | brain does object detection at a low level, so it makes sense
         | that the number systems will operate over countable elements.
        
           | pixl97 wrote:
           | I was watching a NOVA episode about the human mind recently,
           | and in the episode they were showing that the eyes only have
           | a very limited 'high bandwidth' optical viewing area.
           | Anything outside of this high bandwidth area has to be
           | committed to memory. I wonder if anyone has researched if
           | that corresponds with our ability to count.
        
         | bee_rider wrote:
         | I think this is a near-universal experience among people who've
         | played a lot of Risk, but did everyone else collect their
         | little dudes into units of 5, and then collect those up into
         | further collections of five five-unit-squads? After that, 125
         | units is too many to really be necessary at once.
        
         | Aerbil313 wrote:
         | There are arena in the brain which encode integers up to <small
         | number I forgot>. Alex's Adventures In Numberland was a
         | fascinating book.
        
       | jacobgorm wrote:
       | And yet GitHub still send me six digit one time codes, with no
       | spaces to help my brain with chunking.
        
       | aragonite wrote:
       | Relevant: https://en.wikipedia.org/wiki/Subitizing
       | 
       | Also, technically it's not that we perceive small number
       | "better". We only _perceive_ (i.e. subitize) the size of a small
       | collection. We find out the size of a large collection by
       | counting, but counting is not a kind of perception, any more than
       | inference, computation, etc are kinds of perception.
        
         | ooterness wrote:
         | For what it's worth, the upper limit for subitization varies
         | quite a bit.
         | 
         | The neurotypical limit is usually four, but can be raised with
         | practice. Children with Down's Syndrome may not be able to
         | subitize at all. Autistic savants can subitize up to thirty or
         | more, with unconfirmed cases up to several hundred.
        
           | mike_hock wrote:
           | _Monkeys_ can fucking subitize double-digit numbers, which
           | makes you question whether we are actually the smartest
           | species on the planet.
        
             | cscurmudgeon wrote:
             | No, it doesn't. Why?
             | 
             | No monkeys are discussing of subitization as a concept and
             | how their species compares with others.
             | 
             | Just because a kangaroo can jump higher than humans doesn't
             | mean it can go to the moon before humans.
             | 
             | And, g factor.
             | 
             | https://en.m.wikipedia.org/wiki/G_factor
             | 
             | Even savants can have low IQ.
        
             | pixl97 wrote:
             | Eh, we're doing that smartest/most intelligent thing that
             | always has lead to problems in human perception.
             | 
             | An adult Chimpanzee can rip your arms off. Pretty much all
             | it's muscles are fast twitch. Of course you're going to
             | have far better dexterity than the chimp, because you have
             | a much better balance of muscle fibers.
             | 
             | That's the thing about intelligence, it's about
             | generalization, not specific ability. A CPU can count to a
             | billion in a second, nothing about that speed means it's
             | 'smarter' than you.
             | 
             | This is also why we're going to have to come up with new
             | metrics on abilities as we develop more general
             | intelligence software to see how and where said software
             | differs from humans.
        
             | bee_rider wrote:
             | Humans just "do it in software."
        
           | falsaberN1 wrote:
           | Is it really four? Could have sworn it was five, since you
           | got a "middle" to help managing the group or subgroup. At
           | least I immediately bunch things in groups of five, so I
           | always thought it was the correct one.
        
             | _a_a_a_ wrote:
             | It's deffo 4 for me. I can see 4 in one shot, if it's say 5
             | or 6 or a bit higher I have to split the group and subitise
             | each then sum them. YMMV and your mileage beats mine :)
        
               | falsaberN1 wrote:
               | Huh. Interesting. I thought it was one of those things
               | like how we ended up with base 10 numbers because we have
               | 5x2 fingers and that kinda stuff, but interesting to know
               | I was off.
        
             | Modified3019 wrote:
             | I had a warehouse job for a while, essentially being my own
             | independent mini-factory within a larger factory, cutting
             | conduit and packaging things up for shipping out.
             | 
             | Part of the job involved accurately counting hundreds or
             | thousand of screws. I quickly found that visually grouping
             | screws into groups of 4 on a large table was the fastest
             | way to be 100% accurate. If I tried to do 5, sometimes I'd
             | get a sort of confusion/uncertainty, not being quite clear
             | if it was really 5, or 4 or 6, forcing me to check. I'd go
             | on to group these little piles of 4, into larger groups of
             | 4. So I got really good at counting in 4 and it's
             | multiples, 16, 64, 256.
             | 
             | I can definitely see 4 being generally optimal, unless one
             | can expect perfect visual ordering, which is possible with
             | text, but rare in the real world.
        
       | hun3 wrote:
       | Maybe it could also explain why we decided on hexadecimal radix
       | e.g., each digit has 2^4 possible values.
        
       | trebligdivad wrote:
       | I'd love if these guys spoke to the Allen institute guys doing
       | genetics of individual neurons; what is it that makes these
       | neurons count particular values. Also, does anyone understand
       | what the 'interface' is? Is this 'n' spikes within a given time,
       | or spikes on different inputs?
        
       | layer8 wrote:
       | So the brain uses floating-point with only two bits for the
       | mantissa. ;)
        
       | nayuki wrote:
       | The headline would be fuel for anti-metric advocates.
       | 
       | "Look! 1 pound is easier to mentally process than 454 grams."
       | 
       | "3 cups is better than 710 mL."
        
         | softg wrote:
         | Except here in the metric land when we want to buy a pound of
         | something (or thereabouts) we ask for half a kilo. And the
         | second can easily be 3/4 liters.
        
           | gumby wrote:
           | In northern Germany it's fairly common to hear _Pfund_ used
           | in the market to mean 500 g.
        
         | gumby wrote:
         | I don't know if you intended this as a joke, but this is true
         | and a good UX insight.
         | 
         | For day to day activities, the US customary units are more
         | humane. Foot, pound, cup, are simply common sizes that one
         | encounters. Foot and cup break into convenient units (powers of
         | two in small scale volume, convenient rationals like a half,
         | two thirds, etc for both). A standard stair riser is 2/3 of a
         | foot -- 8 inches -- for example. The US system is better in
         | this way than the imperial system as the former's pint, quart
         | etc are more conveniently sized with better fractions.
         | 
         | And, to your point: all this breaks down when the sizes get
         | bigger (or tinier!) than you can physically "handle". A
         | yard/meter is pretty big (people don't usually measure areas
         | for rooms etc in yards) and beyond that metric becomes as good
         | and most of the time easier. If only it hadn't been designed
         | around powers of 10!
         | 
         | But this principle extends to other special case units. For
         | example while I prefer to use metric screws technical reasons,
         | the fractions of 2 in drill threads are much more intuitive.
         | 
         | And you can see this principle breaks down for non-"intuitive"
         | units: temperature is abstract, foot-pounds are not better than
         | newton-meters etc.
         | 
         | But use the right tool for the job. I mostly write Lisp and C++
         | code but it doesn't mean I won't sometimes reach for Python.
         | 
         | Note: I was born in a (then) non-metric country and currently
         | live in the remaining one, but have lived in metric land for a
         | lot of my life and use them both all day long. So no bias.
        
           | FunkyDuckling wrote:
           | For room temperature I do like Fahrenheit, and feel it's
           | pretty intuitive ... 100 is Hot, 0 is cold. 75 is pretty
           | warm, 25 is pretty cold.
           | 
           | It doesn't match the small number scale, but still feels
           | better.
        
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