[HN Gopher] ML model can classify sex from retinal photograph, c...
       ___________________________________________________________________
        
       ML model can classify sex from retinal photograph, clinicians can't
        
       Author : jeffbee
       Score  : 113 points
       Date   : 2021-05-15 13:59 UTC (9 hours ago)
        
 (HTM) web link (rdcu.be)
 (TXT) w3m dump (rdcu.be)
        
       | p1esk wrote:
       | How long did they train humans to perform this task?
        
         | dkarras wrote:
         | I don't think we even know what to look for yet.
         | 
         | >Clinicians are currently unaware of distinct retinal feature
         | variations between males and females, highlighting the
         | importance of model explainability for this task.
        
         | NoPie wrote:
         | Do we even need clinicians be able to distinguish male and
         | female retinas?
         | 
         | The task is meaningless. Yes, there might be some interesting
         | facts in discovery how male and female retinas are different.
         | It could even lead to differentiated treatments. But ML hasn't
         | provided any clues regarding this and therefore it is not that
         | deep.
        
       | stewbrew wrote:
       | "model was trained on 84,743 retinal fundus photos from the UK
       | Biobank dataset. External validation was performed on 252 fundus
       | photos"
       | 
       | Is it common practice in this field to test an overfitted model's
       | performance with such a small data set so that the test could
       | yield random results?
        
         | hervature wrote:
         | The probability of a 50% guess getting 75% accuracy (I believe
         | the paper is something like 77.2%) on 252 trials is 1 in 10^15.
        
         | drdeca wrote:
         | Are you asserting that it is overfit?
         | 
         | Also, before they tested on the other smaller dataset from a
         | different source, aiui, they also trained only on the earlier
         | subset of the first source, and used the later portion from the
         | first source (with no overlap in patients) for the testing.
         | 
         | (also, I'm not sure that 252 is really all that small?)
        
         | make3 wrote:
         | Why do you say that the model is overfitted? You have no way of
         | knowing that. Plus, 84 743 is a very reasonable size for a
         | vision dataset with a binary prediction
        
         | avalys wrote:
         | That was not the only validation set they used.
        
       | kevingadd wrote:
       | I would be curious whether this is actually classifying something
       | that typically corresponds with sex, like hormone levels. In that
       | case people with hormonal disorders would potentially be mis-
       | classified, and someone photographed pre/during puberty might
       | also be mis-classified. Since the paper mentions both neural and
       | vascular tissue being represented in retinal photos, it seems
       | like the levels of various hormones in the individual's blood
       | could potentially also generate a mis-classification if they (for
       | example) cause blood vessels in the eye to expand or contract.
       | The mention that foveal pathology causes the model to mispredict
       | suggests it would probably have issues in these cases too, I
       | think.
       | 
       | I wonder what actual values they were trying to predict with this
       | analysis? Based on the paper, I get the impression they were
       | trying to do something more interesting and they got the best
       | data for sex.
        
         | spuz wrote:
         | They were specifically trying to classify sex because it is
         | something that experts cannot already do:
         | 
         | > While our deep learning model was specifcally designed for
         | the task of sex prediction, we emphasize that this task has no
         | inherent clinical utility. Instead, we aimed to demonstrate
         | that AutoML could classify these images independent of salient
         | retinal features being known to domain experts, that is, retina
         | specialists cannot readily perform this task.
        
         | cassonmars wrote:
         | I wonder this too, and they could get a pretty solid answer if
         | they incorporated transgender folks' data into the set since
         | they're actively keeping their hormones in the desired ranges
         | of their gender identity.
        
           | esyir wrote:
           | Generally you'd start with the common, easier problem before
           | you delve into the abnormal cases. There are probably better
           | ways to do that, like looking at bloodwork.
        
             | lukeschlather wrote:
             | That's fine for training, but for testing the model delving
             | into abnormal cases seems required. If there's noticeable
             | difference on abnormal cases that gives a lot of insight
             | into what your model is actually testing.
        
               | cassonmars wrote:
               | All observations about the use of the term "abnormal"
               | aside, I agree the idea of specifically isolating the
               | hormone variable by using groups of people who naturally
               | fit that range and groups of people that use medication
               | to mirror that range would at least indicate whether this
               | classifier is picking up on sexual dimorphism or vascular
               | effects from hormonal differences (which also would
               | potentially impact not only transgender people, but
               | intersex people -- who make up around 3% of the
               | population)
        
       | chx wrote:
       | They claim they are able to detect _gender_ which according to
       | the relevant Canadian government website https://cihr-
       | irsc.gc.ca/e/48642.html
       | 
       | > Gender refers to the socially constructed roles, behaviours,
       | expressions and identities of girls, women, boys, men, and gender
       | diverse people
       | 
       | First it's not some hamfisted mixup of sex and gender:
       | 
       | > Terefore, this feld may contain a mixture of NHS recorded
       | gender and self-reported gender. Genetic sex in the UK Biobank
       | was determined
       | 
       | And yet:
       | 
       | > Predicting gender from fundus photos, previously inconceivable
       | to those who spent their careers looking at retinas, also
       | withstood external validation on an independent dataset of
       | patients with different baseline demographics Although not likely
       | to be clinically useful, this finding hints at the future
       | potential of deep learning for the discovery of novel
       | associations through unbiased modelling of high-dimensional data.
       | 
       | If we had a way to detect trans children, for sure that would be
       | clinically useful!
       | 
       | Edit: as always, thanks for the downvotes, but please also
       | educate me where I am wrong.
        
       | phnofive wrote:
       | The link points to some sort of viewer which lagged badly for me
       | - here's the PDF:
       | 
       | https://www.nature.com/articles/s41598-021-89743-x.pdf
        
       | sxg wrote:
       | (My mistake, missed their external validation)
        
         | Isinlor wrote:
         | They did external validation.
         | 
         | > External validation was performed on the Moorfields dataset.
         | This dataset differed from the UK Biobank development set with
         | respect to both fundus camera used, and in sourcing from a
         | pathology-rich population at a tertiary ophthalmic referral
         | center. The resulting sensitivity, specificity, PPV and ACC
         | were 83.9%, 72.2%, 78.2%, and 78.6% respectively
        
       | fxtentacle wrote:
       | Some women have 4 types of color rods, all men have only 3.
        
         | galangalalgol wrote:
         | Don't all women have 6 types but usually they all have very
         | similar or even identical frequency response? Only when they
         | have a colorblind gene are they noticeably different.
        
           | fxtentacle wrote:
           | I meant this one: https://en.wikipedia.org/wiki/Tetrachromacy
           | 
           | "Tetrachromacy is the condition of possessing four
           | independent channels for conveying color information, or
           | possessing four types of cone cell in the eye."
           | 
           | https://jov.arvojournals.org/article.aspx?articleid=2191517
           | 
           | "12% of women are carriers of [..] anomalous trichromacy."
        
             | galangalalgol wrote:
             | Yes, it says it is from carrying a colorblind gene, usually
             | red-green. But they have six copies of rhodopsin encoding
             | dna, usuall 3 of them are duplicates. In red green
             | colorblind only two are duplicates, but there are other
             | types of colorblind. Theoretically they could be
             | hexachromatic
        
             | YeGoblynQueenne wrote:
             | From the wikipedia page linked in your comment:
             | 
             |  _One study suggested that 15% of the world 's women might
             | have the type of fourth cone whose sensitivity peak is
             | between the standard red and green cones, giving,
             | theoretically, a significant increase in color
             | differentiation.[23] Another study suggests that as many as
             | 50% of women and 8% of men may have four photopigments and
             | corresponding increased chromatic discrimination compared
             | to trichromats.[24]_
             | 
             | It's not just women.
        
               | wearywanderer wrote:
               | Nor is color blindness exclusively a male phenomena; in
               | Northern Europeans, 8% of males are colorblind while 0.5%
               | of females are.
               | 
               | Suppose a few more sexual dimorphic traits like this
               | exist in the eyes; perhaps differences that have no
               | practical effect on human vision and have consequently
               | gone unnoticed by clinicians. If the ML model is picking
               | up a few of these dimorphic traits, it could perhaps
               | classify sex with more accuracy than anybody looking at a
               | single trait could. This is pretty standard Bayesian
               | stuff; it's the way basic "Plan for Spam" style Bayesian
               | spam filters work.
        
       | drcode wrote:
       | Keep in mind ML models are really great at cheating to get
       | answers: Maybe it's detecting that women have to tilt their head
       | up more to reach the retinal photography machine, because they're
       | shorter on average. Maybe, some of the images come from an
       | optometrist that specializes in women's glass frames, and his
       | retinal photography machine has a slightly dimmer bulb. Maybe,
       | men are more likely to get a retinograph only when they have more
       | severe disease already, so the retinas look different for that
       | reason.
        
         | max_ wrote:
         | Thank you very much for this comment.
         | 
         | My problem with modern scientific publications is that they
         | focus more on the "discovery" instead of describing the logical
         | rigor as to why their "discovery" could be true or false.
        
         | ed25519FUUU wrote:
         | Reproducibility is one thing I like about AI research. If they
         | provide the model, I can take on my own computer and test it
         | against whatever I want and judge it.
         | 
         | Most things in science is almost impossible to reproduce
         | because of cost or specialized equipment.
        
         | Baeocystin wrote:
         | To wit- the apocryphal Tank story:
         | 
         | https://www.gwern.net/Tanks
        
           | B1FF_PSUVM wrote:
           | """
           | 
           | Once upon a time--I've seen this story in several versions
           | and several places, sometimes cited as fact, but I've never
           | tracked down an original source--once upon a time, I say, the
           | US Army wanted to use neural networks to automatically detect
           | camouflaged enemy tanks.
           | 
           | The researchers trained a neural net on 50 photos of
           | camouflaged tanks amid trees, and 50 photos of trees without
           | tanks. Using standard techniques for supervised learning, the
           | researchers trained the neural network to a weighting that
           | correctly loaded the training set--output "yes" for the 50
           | photos of camouflaged tanks, and output "no" for the 50
           | photos of forest.
           | 
           | Now this did not prove, or even imply, that new examples
           | would be classified correctly. The neural network might have
           | "learned" 100 special cases that wouldn't generalize to new
           | problems. Not, "camouflaged tanks versus forest", but just,
           | "photo-1 positive, photo-2 negative, photo-3 negative,
           | photo-4 positive..." But wisely, the researchers had
           | originally taken 200 photos, 100 photos of tanks and 100
           | photos of trees, and had used only half in the training set.
           | The researchers ran the neural network on the remaining 100
           | photos, and without further training the neural network
           | classified all remaining photos correctly. Success confirmed!
           | 
           | The researchers handed the finished work to the Pentagon,
           | which soon handed it back, complaining that in their own
           | tests the neural network did no better than chance at
           | discriminating photos. It turned out that in the researchers'
           | data set, photos of camouflaged tanks had been taken on
           | cloudy days, while photos of plain forest had been taken on
           | sunny days. The neural network had learned to distinguish
           | cloudy days from sunny days, instead of distinguishing
           | camouflaged tanks from empty forest.
           | 
           | """
        
           | sgt101 wrote:
           | apocryphal ehh?
        
         | X6S1x6Okd1st wrote:
         | Yup. I learned this the hard way on the last model I trained at
         | scale. It was evaluating fit between two heterogeneous classes
         | I sampled training & test split off of a large time window and
         | got to work. It performed extremely well on test & training.
         | Too good.
         | 
         | I pulled a third sample from a completely different time window
         | and it performed terribly.
         | 
         | It turned out that both datasets were dominated by class A
         | being sorted into always selecting great fit or poor fit, so
         | the ML model learned to memorize the class A instances.
         | 
         | This problem when away when I subselected down to only
         | instances of class A that had examples of both good fit and
         | poor fit.
        
         | acituan wrote:
         | Their use of an external validation dataset eliminates many, if
         | not all, of those concerns.
         | 
         | Regarding external validation set:
         | 
         | > This dataset differed from the UK Biobank development set
         | with respect to both fundus camera used, and in sourcing from a
         | pathology-rich population at a tertiary ophthalmic referral
         | center.
         | 
         | Regarding UK Biobank set (training set)
         | 
         | > UK Biobank dataset, which is an observational study in the
         | United Kingdom that began in 2006 and has recruited over
         | 500,000 participants--85,262 of which received eye imaging38.
         | Eye imaging was obtained at 6 centers in the UK and comprises
         | over 10 terabytes of data39. Participants volunteered to
         | provide data including other medical imaging, laboratory
         | results, and detailed subjective questionnaires.
        
           | nerdponx wrote:
           | Still, until we have a better sense of what features the
           | model is extracting, it's a surprising result and ought to be
           | treated with caution.
        
         | robocat wrote:
         | Slight reflections of eyelashes? Especially if blurred?
        
       | Kliment wrote:
       | Here's a similar study from three years ago that tried to do the
       | same with clinically relevant measures and got somewhat better
       | results
       | https://scihubtw.tw/https://www.nature.com/articles/s41551-0...
        
       | fastaguy88 wrote:
       | Sexy title, but it is unclear that clinicians can't classify sex
       | from the retina, its just that they haven't bothered to. And the
       | classification is not that great (<80% PPV on independent data).
       | Clinicians will certainly get much higher sensitivity,
       | specificity, and PPV just by looking at the subject ;)
        
       | 988747 wrote:
       | Clinicians don't care, so they never learn to distinguish. It's
       | that simple.
        
       | StreamBright wrote:
       | ML model can't explain how it classifies retinal photographs,
       | clinicians can.
        
       | Causality1 wrote:
       | Fascinating. I had no idea retinas were sexually dimorphic. I
       | wonder if the difference serves a purpose or is just a
       | consequence of some other adaptation.
        
         | esyir wrote:
         | There's also the risk of severe overfitting to some latent
         | variable. I haven't quite dug into the work itself yet, but it
         | does bring back memories of some case of perfect diagnosis due
         | to hospital documentation process though.
        
         | slibhb wrote:
         | Neither did doctors apparently. If everything is kosher,
         | they've proved some level of sexual dimorphism and now they can
         | investigate and perhaps find out what it is.
         | 
         | This is an interesting use of machine learning. We (or at least
         | I) normally think of these models as replacing or complementing
         | humans. But using them as a driver for research is cool.
        
       | cerved wrote:
       | This doesn't seem terribly well framed. Classifying the sex from
       | a retinal photograph is useless. Obviously clinicians aren't
       | going to be good at it. At which point I've lost interest
        
         | spuz wrote:
         | The paper is about 4 pages long - it takes about as long as it
         | to you to write that comment as it does to skim through and
         | learn that what you mentioned is exactly why they did the
         | study:
         | 
         | > While our deep learning model was specifcally designed for
         | the task of sex prediction, we emphasize that this task has no
         | inherent clinical utility. Instead, we aimed to demonstrate
         | that AutoML could classify these images independent of salient
         | retinal features being known to domain experts, that is, retina
         | specialists cannot readily perform this task.
         | 
         | It always amazes me how people spend 5 seconds reading a
         | headline but think they know more than someone who has spent
         | days and months on the same topic.
        
           | cerved wrote:
           | It's just an honest take. If I was more interested in the
           | subject maybe I would skim more but I'm not interested
           | enough.
           | 
           | Not trying to shit on anyone, it's just a brutally honest
           | opinion
        
             | spuz wrote:
             | Sorry I misinterpreted then. I thought you were dismissing
             | it out of negativity but actually it's worse - you actually
             | made a judgement that you knew more than the authors of the
             | study.
        
               | cerved wrote:
               | The only judgement I made was to not read the whole
               | paper. I read up until the paper stated that classifying
               | sex based on retinal pictures was unlikely to be
               | clinically useful. At which point I lost interest.
               | 
               | Why wasn't the ML model and clinician classifying
               | something that actually is clinically useful?
               | 
               | If it has no clinical significance, what's the relevance
               | of the classification of the clinicians?
               | 
               | How is it any more spectacular than beating a random
               | classifier?
               | 
               | Had these points been addressed at this point I might
               | have continued reading
        
             | scarnak wrote:
             | Why on earth are you even bothering to comment on the post
             | then? If you're not interested enough to even skim the
             | paper why do you think anyone would be interested to hear
             | what your opinion of it is? You're not "brutally honest",
             | you're just ignorant.
        
               | cerved wrote:
               | Because I had already spent time reading and maybe
               | someone could enlighten me as to why it in fact is
               | interesting. That and I was also hoping to get insulted
        
         | Klinky wrote:
         | I'd agree that if clinicians haven't been trained on this for
         | their line work, then the comparison is not fair, but I
         | wouldn't go so far as to say it's "useless".
        
           | cerved wrote:
           | They wrote in the paper it's useless
        
             | Klinky wrote:
             | Not having obvious clinical utility at the moment doesn't
             | mean it's outright useless.
        
               | cerved wrote:
               | No, you're right. But since there's a whole field on the
               | subject I figured they could have chosen something with
               | clinical utility and I don't really understand why they
               | didn't
        
       | Scoundreller wrote:
       | I remember a researcher doing some early research on compressing
       | diagnostic imaging and was happy about all the hard disk space
       | saved. They did some research to find out what level of
       | compression they could go with that wouldn't result in different
       | clinicians reaching different conclusions from the same images.
       | 
       | It really upset me. We probably threw away decades of training
       | data that a computer could have used for early detection.
       | 
       | Fine for broken arms of whatever, but for cancer diagnostics,
       | ugh. The computer might have been able to see the tumour before a
       | clinician.
        
       | [deleted]
        
       | amelius wrote:
       | What network topology did they use? I couldn't find it in the
       | paper.
        
         | kevinventullo wrote:
         | In the section Model Training:
         | 
         | "Our deep learning model was trained using code-free deep
         | learning (CFDL) with the Google Cloud AutoML platform ... the
         | CFDL platform provides the option of image upload via shell-
         | scripting utilizing a .csv spreadsheet containing labels ...
         | Automated machine learning was then employed, which entails
         | neural architecture search and hyperparameter tuning."
         | 
         | Earlier, in the Limitations section:
         | 
         | "The design of the CFDL model was inherently opaque due to the
         | framework's automated nature with respect to model architecture
         | and hyperparameters. While this opacity is not unique to CFDL,
         | there is potential to further reduce ML explainability due to
         | lack of insight of model architectures and parameters
         | employed."
         | 
         | Maybe there's a whitepaper somewhere on how Google's AutoML
         | works?
        
       | maCDzP wrote:
       | I am going to drop a thought here to see what happens. If there
       | is a difference between male/female retinas. Could this affect
       | our perception of reality?
        
         | stirfish wrote:
         | If it were to affect our perception of reality, what
         | differences could we find?
         | 
         | I'm guessing that it would affect our perception of reality in
         | the same way eye color would.
        
         | LeoPanthera wrote:
         | Surely not any more than my terrible eyesight does. I don't
         | think my spectacles are altering my perception of reality.
        
           | Hoasi wrote:
           | Mine certainly do, because without them I would be blind.
        
         | [deleted]
        
         | wearywanderer wrote:
         | > _If there is a difference between male /female retinas_
         | 
         | Is this even an "if"? It's well established that men are more
         | likely to be colorblind, and it's likely many women are
         | tetrachromats (most people are mere trichromats). The genes for
         | the extra cone pigments are in the X chromosome, and are
         | seemingly expressed more often when somebody has two X
         | chromosomes. Similarly, people with two X chromosomes are less
         | likely to be colorblind because most forms of colorblindness
         | are caused by defects in genes in X chromosomes.
         | 
         | https://en.wikipedia.org/wiki/Tetrachromacy#Humans
         | 
         | https://en.wikipedia.org/wiki/Color_blindness#Genetics
         | 
         | Perhaps most men and women, men and women with normal
         | trichromatic vision, have identical retinas. But with genes so
         | important to eyeballs residing in the X chromosome, who knows.
         | But I'm left wondering why experts are particularly surprised
         | by this result.
        
         | BurningFrog wrote:
         | My guess: Only in trivial ways.
         | 
         | The fact that women see the world from a ~20cm lower point
         | probably has real impact.
         | 
         | For one thing, guys, your nose hair is very visible from that
         | height.
        
           | NaturalPhallacy wrote:
           | A few funny anecdotes in that vein.
           | 
           | A woman complained that her very tall boyfriend had hung a
           | mirror in the bathroom. She took a picture of it. It was her
           | reflection holding the camera level with the top of her head,
           | and little else.
           | 
           | One that happened to me personally. I asked my then gf (5'1")
           | what it was like being a small person, do you feel like a
           | normal sized person in a land of giants? "Yes" was the
           | instant response.
           | 
           | One very tall guy once remarked: "The tops of your fridges
           | are fucking disgusting."
        
             | xorfish wrote:
             | > A woman complained that her very tall boyfriend had hung
             | a mirror in the bathroom. She took a picture of it. It was
             | her reflection holding the camera level with the top of her
             | head, and little else.
             | 
             | As a tall guy, there is a surprising number of bathroom
             | mirrors where my reflection doesn't include my head.
        
         | hervature wrote:
         | I don't like philosophical questions like this. Let's say male
         | blue is female red and vice versa. Our perception of the world
         | is different yet it doesn't change anything as to how we
         | understand and interact with "reality".
        
           | vmception wrote:
           | I would argue that it does and that we conform behaviors to a
           | standard, but there are alot of assumptions we make that lead
           | us to not understand each other at all
           | 
           | There is a shared experience isolated to one sex that the
           | other cannot perceive
        
           | CyanBird wrote:
           | It is well backed up by science that women can see or at
           | least perceive/brainlog a stronger variety of colors than
           | men, and then this is expressed on women having a stronger
           | beefier vocabulary when it comes to naming and identifying
           | colors
           | 
           | So yeah, that's a thing
           | 
           | Also, what you are describing is called Qualia, and that is
           | intangible qualities of how the brain processes data, such as
           | the "yellowness of a lemon", or the "foot pain of stepping on
           | unexpected rock shoeless"
           | 
           | Qualia can't be verbalized or compared between people because
           | it is an inherent "brainfeel", you just need to expect others
           | to have "at least similar-ish" qualias
        
             | hervature wrote:
             | Right, and children hear much higher frequencies than the
             | rest of us. Just because you see more doesn't fundamentally
             | change how we perceive reality. Like if someone says there
             | is a color between eggshell white and snow white, I believe
             | them because there is obviously a gradient there. I don't
             | need to see their reality to agree on the state of it.
        
               | bobthechef wrote:
               | What's "fundamental" in this respect?
               | 
               | If someone is colorblind, and another isn't, does that
               | entail a change in perception? Sure. It means the
               | colorblind guy can't discern things that people with
               | normal vision can.
               | 
               | A person born blind can't see anything and never has.
               | They don't even imagine visual images (only images
               | informed by the remaining senses). Their perception is
               | unimaginable to me and mine to them.
               | 
               | So if women can discern more colors than men, it follows
               | that they experience more colors which seems like a
               | matter of perception. Have you never argued with a woman
               | about the color of a sweater?
        
           | maCDzP wrote:
           | Yeah - you are right. I thought about it and I guess since we
           | can interact our perception can't be to far off - otherwise
           | we wouldn't be able to procreate. It would be something out
           | of the hitchhikers guide to the galaxy. A specie that because
           | of a retinal differences between sexes is unable to mate.
        
         | slver wrote:
         | No
        
         | matheuss-leonel wrote:
         | Holy shit
        
       | almog wrote:
       | Just throwing a guess here about one factor that partitions
       | photos based on sex might: height (I'm assuming males are
       | generally taller).
       | 
       | Looking at how a retinal photography machine looks like, I'd
       | guess the height at which the photo is taken might slightly
       | affect the POV angle, which in turn might be just enough to get
       | caught by the ML model.
        
         | hellbannedguy wrote:
         | I had a Ph.D instructor in psychology.
         | 
         | She said, women are actually taller than men when all cultures
         | are studied.
         | 
         | I don't care enough to dig deeper, but always stuck with me.
        
           | jan_Inkepa wrote:
           | That's an unexpected (to me at least) claim to make - https:/
           | /onlinelibrary.wiley.com/doi/abs/10.1002/ajpa.1330530... - I
           | always thought of sexual dimoprhism (men taller than women on
           | average) as a given and this paper backs up my claim
           | specifically in the context of human societies (where it
           | gives a 10cm height advantage in average in men over women,
           | comparing 216 different societies ). There might be some way
           | of counting in which the converse is true, but not in any way
           | I know. I understand you don't want to dig deeper, but
           | thought I'd flag it in case anyone else unwittingly digests
           | this (possibly wrong) knowldge.
           | 
           | https://www.quantamagazine.org/males-are-the-taller-sex-
           | estr... is an example of a pop-sci article assuming the same
           | basis (written by a biology phd).
        
           | username90 wrote:
           | People with Ph.D's often makes up facts and believes in
           | nonsense just like everybody else.
           | 
           | Edit: This includes those with STEM degrees as well. You
           | really shouldn't trust someone more just because they have a
           | research degree. I knew a professor who claimed to have
           | solved some famous problems but that the peer reviewers just
           | didn't want to accept that he solved it and therefore
           | rejected his papers.
        
             | make3 wrote:
             | like you did just now. That person made something up. Let's
             | not put all Ph.Ds in a bag just for that.
        
           | Erik816 wrote:
           | She appears to have made that up:
           | https://www.worlddata.info/average-bodyheight.php
        
       | sojournerc wrote:
       | I'm curious if the a difference in cone density or distribution
       | could be the differentiator.
       | 
       | https://theneurosphere.com/2015/12/17/the-mystery-of-tetrach...
        
       | DoubleDerper wrote:
       | "EK is a consultant for Google Health. PAK has received speaker
       | fees from Heidelberg Engineering, Topcon, Haag-Streit, Allergan,
       | Novartis and Bayer. PAK has served on advisory boards for
       | Novartis and Bayer, and is a consultant for DeepMind, Roche,
       | Novartis and Apellis. KB has received research grants from
       | Novartis, Bayer. Heidelberg and Roche. KB has received speaker
       | fees from Novartis, Bayer, TopCon, Heidelberg, Allergan, Alimera.
       | KB is a consultant for Novartis, Bayer and Roche. AK is a
       | consultant to Aerie, Allergan, Novartis, Google Health, Reichert
       | and Santen. All other co-authors have no competing interests to
       | declare."
       | 
       | Worth noting.
        
       | mahathu wrote:
       | This is a really impressive result and an interesting result to
       | apply ML to. Thank you for sharing, OP. I'm just wondering if
       | there are any real world applications of why you'd want to tell
       | the sex of a person by a retinal photograph? It seems like a bit
       | of a useless skill to have?
        
         | qayxc wrote:
         | I think this more an example how black-box models are basically
         | useless for clinical research.
         | 
         | The authors aren't aware of any distinguishing retinal features
         | between male and female eyes and the model itself has no
         | explanatory power.
         | 
         | Could be a Clever Hans situation where the model exploits meta
         | information of some kind in the absence of actual features. It
         | could just as well mean that there are indeed distinguishing
         | features that are compromised in the presence of foveal
         | pathology.
         | 
         | The authors note that another study using manually selected
         | features identified three features that are indicative of
         | genetical sex. These features yielded about 0.78 AUROC accuracy
         | measure. Compared to the presented model's AUROC accuracy of
         | 0.93 that's only 19% worse and these 19% additional accuracy
         | may point to a combination of the already identified features
         | or one or more additional features.
         | 
         | I personally find this paper rather pointless. It stops at the
         | point where actual progress could be made and things would get
         | interesting - why didn't the authors evaluate the previously
         | known features on the model's matches to measure their
         | significance?
         | 
         | This could have told them whether their black-box was relying
         | on the same set of features as the ones identified by previous
         | work, for example.
        
       | zephyr____ wrote:
       | This is a step backwards for LGBTQI rights.
       | 
       | It is scientifically proven that there are no differences between
       | men and women.
       | 
       | I hope the inevitable retraction gets as much attention on HN.
        
         | stirfish wrote:
         | >It is scientifically proven that there are no differences
         | between men and women.
         | 
         | https://en.m.wikipedia.org/wiki/Sexual_dimorphism
        
         | rs999gti wrote:
         | > It is scientifically proven that there are no differences
         | between men and women.
         | 
         | XY and XX chromosomes don't matter? Then what are all those
         | fertility doctors doing?
        
         | claudiawerner wrote:
         | Don't feed the troll.
        
       | Traster wrote:
       | >Clinicians are currently unaware of distinct retinal feature
       | variations between males and females, highlighting the importance
       | of model explainability for this task.
       | 
       | If I'm reading this correctly what they're saying is that since
       | we don't currently know the difference between male and female
       | retinas, being able to explain what the ML black box is doing is
       | important. But from what I can see in the paper they basically
       | don't know what the black box is doing, they really don't
       | understand what features their tool has isolated. I might be
       | misunderstanding though?
        
         | NieDzejkob wrote:
         | Yes, they are highlighting the importance of research towards
         | model explainability.
        
           | slver wrote:
           | I believe that's impossible.
        
             | TaylorAlexander wrote:
             | ML explainability is a wide field with a lot of success.
             | For example you can discover what features are activating
             | which detections. You comment, taken literally, suggests
             | that research in this field is impossible. That is not the
             | case.
        
               | sigstoat wrote:
               | when the activated feature in an image recognition net
               | looks like a lovecraftian horror, that doesn't explain
               | how the net came up with "turtle".
               | 
               | explainability is going to have a rough time for the same
               | reason ai alignment is going to have a rough time. people
               | think they can explain decisions (technical and moral)
               | far more effectively than they actually can.
        
         | oogabooga123 wrote:
         | Your question is confusing, it might be that you are using
         | "feature" in an ML sense and the quote refers to human
         | describable distinctions we know about? But I still don't know
         | how to parse your question.
         | 
         | The model can predict male vs female retinas but they don't
         | understand why. What exactly are you asking?
        
           | TaylorAlexander wrote:
           | ML models have layers, and neurons in a given layer detect
           | "features" in the image or in the previous layer. So yes I
           | believe the person meant which structures in the image are
           | activating the network. Which is a well studied area so it is
           | surprising the authors didn't explore that.
        
         | thaumasiotes wrote:
         | I don't really understand your confusion?
         | 
         | They say the following:
         | 
         | - This model can distinguish photographs of a male retina from
         | photographs of a female retina.
         | 
         | - We don't know, ourselves, how to do that.
         | 
         | - We would like to be able to determine, from looking at the
         | model, what features it's using to draw the distinction.
         | 
         | What's weird?
        
           | mattkrause wrote:
           | > We don't know, ourselves, how to do that.
           | 
           | Have we actually tried?
           | 
           | There is a cursory discussion about how this is
           | "inconceivable to those who spent their careers looking at
           | retinas". However, if it's not clinically useful (as the next
           | sentence says), those experts probably haven't spent much--if
           | any--training themselves to try.
           | 
           | Humans can learn to detect surprisingly subtle features. For
           | example, the right training regime can make you _much_ better
           | are reporting a tile of a line, but it requires practice and
           | feedback, just like the network got.
        
           | Traster wrote:
           | What I'm confused by is that they say this is important to
           | do, but then don't actually seem to do it?
        
             | JabavuAdams wrote:
             | Important to do next.
        
             | make3 wrote:
             | future work is almost always discussed in publications
        
             | joe_the_user wrote:
             | They don't give an explanation because they don't know how
             | to give an explanation - many if not most ML model lack an
             | easy explanation presently, they just spit out answers.
             | 
             | They are saying "someone should do this because it's
             | important even though we don't (presently) know how to do
             | this".
        
               | aaron-santos wrote:
               | I'm open to learning why class activation maps (CAM)
               | would or wouldn't be a good place to start.
        
         | hervature wrote:
         | We're not at the point of explaining complicated models with a
         | straight face. Based on the saliency maps, it looks like the
         | model has learned something around the bright circles (or is it
         | the blind spot? Not an ophthalmologist). Makes me think the
         | network can reverse engineer distortions in the light to get
         | curvature of the lens which might be indicative of gender
         | differences.
        
       | contrarian_5 wrote:
       | thats going to be one of the biggest shocks to society going
       | forward when it comes to the changes that AI bring. there are
       | mountains of data everywhere that is completely overlooked simply
       | because the cost of processing the data is too high. too high to
       | discover patterns/correlation and too high to process in any
       | case.
       | 
       | human beings filter out most of what goes on around them. they
       | dont see the world as it is and their minds dont keep track of
       | physical primitives. their minds abstract the world into larger
       | conceptual parts and track those parts. its not just a question
       | of processing power, its a question of intuitive access. and
       | nobody realizes this yet because the only sentient beings who are
       | around to demonstrate any of this have those filters in place.
       | when the AI comes with all that horse power and with no filters,
       | it will see things all around that we are blind to. it will seem
       | as though it can make impossible predictions. it will seem god-
       | like, even before it graduates to doing something other than
       | simply observing the world.
        
       | wizzwizz4 wrote:
       | Odds on it detecting mascara or eyelashes or some other makeup?
       | Retinal photos have to go through the front of the eye, after
       | all.
        
         | terramex wrote:
         | If there ever was mascara on your retina you better be going to
         | the hospital quickly.
        
           | [deleted]
        
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