"Surfing Uncertainty" on Autism (and Schizophrenia)

Scott Alexander got pretty excited back in September about Andy Clark's "Surfing Uncertainty" (in this post) - but that's because he's a psychiatrist and Clark's model has some insightful things to say about both Autism (Asperger's Syndrome) and Schizophrenia.

Amazon link

I read the book and found Clark's approach (that biological agents, aka 'animals', cognitively function through a combination of top-down model-based prediction and bottom-up sensor-based verification) highly plausible, though not that new. Still he pushes the model quite a way - the details are instructive.

My main problem with the text is that the proposed model is really an architectural/engineering one, yet Clark is a philosopher. He writes in that over-abstract, bloated and padded style which people like Daniel Dennett have made so famous.

Somewhere in there, good ideas are trying to extricate themselves from the gloop.

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Anyway, here's how Scott Alexander, channelling Andy Clark, talks about Autism.

"Various research in the PP [Predictive Processing] tradition has coalesced around the idea of autism as an unusually high reliance on bottom-up rather than top-down information, leading to “weak central coherence” and constant surprisal as the sensory data fails to fall within pathologically narrow confidence intervals.

Autistic people classically can’t stand tags on clothing – they find them too scratchy and annoying. Remember the example from Part III about how you successfully predicted away the feeling of the shirt on your back, and so manage never to think about it when you’re trying to concentrate on more important things? Autistic people can’t do that as well.

Even though they have a layer in their brain predicting “will continue to feel shirt”, the prediction is too precise; it predicts that next second, the shirt will produce exactly the same pattern of sensations it does now. But realistically as you move around or catch passing breezes the shirt will change ever so slightly – at which point autistic people’s brains will send alarms all the way up to consciousness, and they’ll perceive it as “my shirt is annoying”.

Or consider the classic autistic demand for routine, and misery as soon as the routine is disrupted. Because their brains can only make very precise predictions, the slightest disruption to routine registers as strong surprisal, strong prediction failure, and “oh no, all of my models have failed, nothing is true, anything is possible!”

Compare to a neurotypical person in the same situation, who would just relax their confidence intervals a little bit and say “Okay, this is basically 99% like a normal day, whatever”. It would take something genuinely unpredictable – like being thrown on an unexplored continent or something – to give these people the same feeling of surprise and unpredictability."

As an AQ high-scorer, I relate to this. In many a social situation I'm walking on eggshells, never quite knowing how people will respond. I'll say something which seems amusing within my own private model of the subject of discourse, only to be met with incomprehension - or worse, consternation - as my poor unconscious predictive model of other people's likely response fails again.

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The very next section (11) summarises the story on Schizophrenia:

"Schizophrenia. Converging lines of research suggest this also involves weak priors, apparently at a different level to autism and with different results after various compensatory mechanisms have had their chance to kick in.

One especially interesting study asked neurotypicals and schizophrenics to follow a moving light, much like the airplane video in Part III above. When the light moved in a predictable pattern, the neurotypicals were much better at tracking it; when it was a deliberately perverse video specifically designed to frustrate expectations, the schizophrenics actually did better.

This suggests that neurotypicals were guided by correct top-down priors about where the light would be going; schizophrenics had very weak priors and so weren’t really guided very well, but also didn’t screw up when the light did something unpredictable. ...

The exact route from this sort of thing to schizophrenia is really complicated, and anyone interested should check out Section 2.12 and the whole of Chapter 7 from the book. But the basic story is that it creates waves of anomalous prediction error and surprisal, leading to the so-called “delusions of significance” where schizophrenics believe that eg the fact that someone is wearing a hat is some sort of incredibly important cosmic message.

Schizophrenics’ brains try to produce hypotheses that explain all of these prediction errors and reduce surprise – which is impossible, because the prediction errors are random. This results in incredibly weird hypotheses, and eventually in schizophrenic brains being willing to ignore the bottom-up stream entirely – hence hallucinations.

All this is treated with antipsychotics, which antagonize dopamine, which – remember – represents confidence level. So basically the medication is telling the brain “YOU CAN IGNORE ALL THIS PREDICTION ERROR, EVERYTHING YOU’RE PERCEIVING IS TOTALLY GARBAGE SPURIOUS DATA” – which turns out to be exactly the message it needs to hear.

An interesting corollary of all this – because all of schizophrenics’ predictive models are so screwy, they lose the ability to use the “adjust away the consequences of your own actions” hack discussed in Part 5 of this section.

That means their own actions don’t get predicted out, and seem like the actions of a foreign agent. This is why they get so-called “delusions of agency”, like “the government beamed that thought into my brain” or “aliens caused my arm to move just now”. And in case you were wondering – yes, schizophrenics can tickle themselves."

My overall take-home message from this book was that tabula rasa, blank slate paradigms of so much contemporary AI may suffice for crafting smart and powerful classificatory tools, but they won't hack it when we try to build socially-competent agents. In facial recognition and playing Go we're already superhuman; chatbots not so much.

Three links for Thursday

This is a typically lengthy and insightful essay from Scott Alexander posted three years ago:

I CAN TOLERATE ANYTHING EXCEPT THE OUTGROUP.

Somehow it reads as if from yesterday. Scott writes about the American incarnation of his Red/Blue/Gray tribes - but of course they're universal.

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As a Gray Tribe member, I score utilitarian rather than compassionate. My BS detectors are thus powered up when I read another liberal, hand-wringing diatribe against torture ("It doesn't work!").

Bruce Schneier is paid-up Blue Tribe and uncritically recommends this lengthy article:

"The scientists persuading terrorists to spill their secrets"

which is actually unfailingly fascinating.

But it's The Guardian: the underlying liberal agenda sets up a false interrogation dichotomy: ham-handed brutality vs. sophisticated, empathic 'rapport'. No contest as to which wins there.

The article is forced to concede that it does take two to do rapport:

"Irish paramilitaries were trained to focus their gaze on a spot on the wall and remain utterly silent. Some suspects give only monosyllabic answers, or stick to scripted responses, or simply turn their chair around, presenting the interviewer with the back of their head."

If you're prepared to (competently) torture it can presumably work. Thankfully most bad guys are not sufficiently well-trained or hardcore to resist the highly-effective social-engineering described in the article. There are very good utilitarian reasons not to legitimise torture, whether it works or not.

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I'm reading Duncan Foley's excellent primer on Capital.

PDF link

Foley is a clear and creative thinker who is prepared to bring some simple mathematics to the table. He's interested in presenting the conceptual apparatus of Marxism in an orderly manner rather than simply providing a slimmed-down exegesis of the books themselves. His approach is very much rooted in applying Marxism to the present day economy, which informs both his appraisal and his examples.

He reconstructs in mathematical form the circulation of capital and Marx's simple and expanded reproduction equations before moving on to the 'transformation problem', crisis theories and Marx's concept of socialism. Here's the table of contents:

Contents

1 On Reading Marx: Method                            1
2 The Commodity: Labor, Value, Money        12
3 The Theory of Capital and Surplus Value    31
4 Production under Capitalism                        49
5 The Reproduction of Capital                         62
6 The Equalization of the Rate of Profit           91
7 The Division of Surplus Value                     105
8 The Falling Rate of Profit                            125
9 The Theory of Capitalist Crisis                    141
10 Socialism                                                   158
Suggested Readings                                      173
References                                                     177
Index                                                              181

In addition as you can see, this introductory book is quite short.

A book abandoned

Cool cover art.

 Amazon link

I read Scott Alexander's extensive review and tried to cancel but too late: the very next day the Amazon parcel arrived. Alexander's review is an easier read than the book itself, which is written in a 'flat' academic style akin to a succession of Wikipedia mini-articles.

I wouldn't have minded if the content had been as described in the back cover quotes ('mind-blowing', 'fascinating', 'stimulating') .. but the ideas are relatively pedestrian, what you would expect if you thought about it a bit; many of Hanson's assertions are plausible without being that compelling.

So after a while of mentally chewing on cardboard, I abandoned.

If a society of brains-emulated-in-hardware-and-software is truly your thing, then it's a lot more fun reading Greg Egan's sublime Permutation City.

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Back yesterday from a couple of days camping on the heights above Minehead where we also took in the Civil War reenactment at Dunster Castle.

Clare fronting the view of Minehead from the campsite

Dunster Castle: the women spin and cook behind the cannon

The pikemen and musketeers assemble

I'd anticipated a mass mêlée, a pitched battle of The Sealed Knot - but what you see in the pictures was what we got.

The fighting persons in close-up

I especially liked Ginger Baker (above) who gave us a one-person marching drum solo after the obligatory team musket discharges and pike-drill.

A polygenic risk for autism spectrum disorders

The full title of the paper in the news today is "Genetic risk for autism spectrum disorders and neuropsychiatric variation in the general population" authored by a cast of thousands. It's published in Nature Genetics - here's the abstract.

"Almost all genetic risk factors for autism spectrum disorders (ASDs) can be found in the general population, but the effects of this risk are unclear in people not ascertained for neuropsychiatric symptoms. Using several large ASD consortium and population-based resources (total n > 38,000), we find genome-wide genetic links between ASDs and typical variation in social behavior and adaptive functioning.

"This finding is evidenced through both LD score correlation and de novo variant analysis, indicating that multiple types of genetic risk for ASDs influence a continuum of behavioral and developmental traits, the severe tail of which can result in diagnosis with an ASD or other neuropsychiatric disorder. A continuum model should inform the design and interpretation of studies of neuropsychiatric disease biology."

At some level this is not too surprising, there's not a 'gene for autism or Asperger Syndrome' any more than there's a gene for height or intelligence. Instead a number of alleles of small effect push the genome towards or away from autism spectrum traits, with de novo negative mutations adding a sprinkling of gratuitous damage.

There is a dataset of families where one family member has an ASD (autism spectrum disorder) while the the rest are not so classified. This is the Simons Simplex Collection (SSC):

"The Simons Simplex Collection (SSC) is a core project and resource of the Simons Foundation Autism Research Initiative (SFARI). The SSC achieved its primary goal to establish a permanent repository of genetic samples from 2,600 simplex families, each of which has one child affected with an autism spectrum disorder, and unaffected parents and siblings."

There is a test, similar to an IQ test, which measures the level of difficulty experienced by people with an ASD. It's called the Vineland Adaptive Behavior Rating Scale (VABS):

"Raw scores are converted to IQ-type standard scores (mean: 100 sd: 15) for each domain and for the composite adaptive behavior score. Score ranges are as follows:

• 70-80 borderline adaptive functioning; 
• 51-55 -70: mildly deficient adaptive functioning ; 
• 35-50: moderately deficient adaptive behavior; 
• 20-35: severely deficient adaptive behavior; 
• less than 20: markedly or profoundly deficient adaptive behavior. 

Scores above 80 are classified in approximately the same ranges (low average, average, above average, superior) as IQ scores."

When you test the SSC non-ASD people (controls) vs. SSC people with ASD (cases) using the VABS, this is what you see:

Figure 2 from the Nature Genetics paper 

You plainly observe the overlap between non-ASD and ASD people on a scale designed to measure degrees of autistic behaviour.

While this histogram does not directly exhibit the underlying genetic analysis, it's exactly what you expect to see from a polygenic syndrome.

Feeling black holes collide from close-up

As soon as I heard about that LIGO thing, first thing I thought of, what would it have felt like if you'd been there, maybe an AU away from those coalescing black holes?

Eventually the Internet got around to telling me.

"As I read the historic news, there’s one question that kept gnawing at me: how close would you need to have been to the merging black holes before you could, you know, feel the distortion of space?  I made a guess, [...] you’d need to be very close.

"Even if you were only as far from the black-hole cataclysm as the earth is from the sun, I get that you’d be stretched and squished by a mere ~50 nanometers (this interview with Jennifer Ouellette and Amber Stuver says 165 nanometers, but as a theoretical computer scientist, I try not to sweat factors of 3).

Even if you were 3000 miles from the black holes—New-York/LA distance—I get that the gravitational waves would only stretch and squish you by around a millimeter. Would you feel that? Not sure. At 300 miles, it would be maybe a centimeter—though presumably the linearized approximation is breaking down by that point.

[...]

"Now, the black holes themselves were orbiting about 200 miles from each other before they merged.  So, the distance at which you could safely feel their gravitational waves, isn’t too far from the distance at which they’d rip you to shreds and swallow you!

In summary, to stretch and squeeze spacetime by just a few hundred nanometers per meter, along the surface of a sphere whose radius equals our orbit around the sun, requires more watts of power than all the stars in the observable universe give off as starlight.

"People often say that the message of general relativity is that matter bends spacetime “as if it were a mattress.”  But they should add that the reason it took so long for humans to notice this, is that it’s a really friggin’ firm mattress, one that you need to bounce up and down on unbelievably hard before it quivers, and would probably never want to sleep on."

From Scott Aaronson's blog, a post appealingly titled "The universe has a high (but not infinite) Sleep Number", h/t SSC.

Victor Toth writes:

"A gravitational wave is like a passing tidal force. It squeezes you in one direction and stretches you in a perpendicular direction. If you are close enough to the source, you might feel this as a force. But the effect of gravitational waves is very weak. For your body to be stretched by one part in a thousand, you’d have to be about 15,000 kilometers from the coalescing black hole.

"At that distance, the gravitational acceleration would be more than 3.6 million g-s, which is rather unpleasant, to say the least. And even if you were in a freefalling orbit, there would be strong tidal forces, too, not enough to rip your body apart but certainly enough to make you feel very uncomfortable (about 0.25 g-forces over one meter.) So sensing a gravitational wave would be the least of your concerns.

"But then… you’d not really be sensing it anyway. You would be hearing it. Most of the gravitational wave power emitted by GW150914 was in the audio frequency range. A short chip rising in both pitch and amplitude. And the funny thing is… you would hear it, as the gravitational wave passed through your body, stretching every bit a little, including your eardrums."

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I'm reading "The Welfare Trait: How State Benefits Affect Personality" by Dr Adam Perkins of King's College, London. He talks about the employment-resistant personality and how such people feature disproportionately on welfare. There they tend to have lots of children, both for increased benefits and because they're rather feckless, (A-, C-, in the five-factor jargon).

Amazon Link

Dr Perkins is worried about dysgenic consequences - plainly the potential is there - but how big is the effect? I'm waiting to see whether Dr Perkins gets quantitative, but if he does, he'll be using the Breeder's Equation.

Time for a quick review from West Hunter - this is the Breeder's Equation:

"R = h²S.

"R is the response to selection, S is the selection differential, and h² is the narrow-sense heritability. This is the workhorse equation for quantitative genetics. The selective differential S, is the difference between the population mean and the mean of the parental population (some subset of the total population).

"For example, imagine a set of parents with IQs of 120, drawn from a population with an average IQ of 100. Suppose that the narrow-sense heritability (in that population, in that environment) is 0.5 . The average IQ of their children will be 110. That’s what is usually called regression to the mean.

"Do the same thing with a population whose average IQ is 85. We again choose parents with IQs of 120, and the narrow-sense heritability is still 0.5. The average IQ of their children will be 102.5 – they regress to a lower mean.

"You can think of it this way. In the first case, the parents have 20 extra IQ points. On average, 50% of those points are due to additive genetic factors, while the other 50% is is the product of good environmental luck. By the way, when we say ‘environmental” we mean “something other than additive genetics”. It doesn’t look as if the usual suspects – the way in which you raise your kids – contributes much to this ‘environmental’ variance, at least for adult IQ. In fact we know what it’s not, but not much about what it is, although it must include factors like test error and being hit on the head.

"The kids get the good additive genes, but have average ‘environmental’ luck – so their average IQ is 110. The luck (10 pts worth) goes away

"The 120-IQ parents drawn from the IQ-85 population have 35 extra IQ points, half of which are from good additive genes and half from good environmental luck. But in the next generation, the luck goes away… so they drop 17.5 points.

"The next point is that the luck only goes away once. If you took those kids from the first group, with average IQs of 110, and dropped them on an uninhabited but friendly island, they would presumably get around to mating eventually – and the next generation would also have an IQ of 110. With tougher selection, say by kidnapping a year’s worth of National Merit Finalists, you could create a new ethny with far higher average intelligence than any existing. Eugenics is not only possible, it’s trivial."

Dysgenics too: as personality has similar heritability to intelligence (0.5), still mulling over the application of this to the profligate underclass ...

You might also want to take a look at this.

Quotes

Quote from Andrew Ng, Chief Scientist at Chinese search giant, Baidu:

"Worrying about AI evil superintelligence today is like worrying about overpopulation on the planet Mars."

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An anonymous comment at Scott Alexander's Slate Star Codex:

“Slate Star Codex is 140 IQ discussion about 105 IQ issues.”

(Ouch! That post has more amusing and cringe-inducing stuff).

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Watch out for the LIGO announcement tomorrow that the coalescence of two orbiting black holes has been observed through their gravitational wave signature:

"The masses of the black holes will be 36 and 29 solar masses at the beginning; and 62 for the resulting black hole. The reconstructed orbital speed will be almost exactly the speed of light. As a bonus, they will also observe the "ringdown to Kerr"

More here.

SSC SNP picks

er, ... no ... .

I mentioned in my previous post that you could link a SNP (eg rs4570625) to your own 23andMe results using a link like this:

https://www.23andme.com/you/explorer/snp/?snp_name=rs4570625

Scott Alexander at the almost-always-reliable* Slate Star Codex wrote (November 2014) this amusing post "How To Use 23andMe Irresponsibly" describing his favourite SNPs.

Well, now they're my favourites too and I copy his (lightly edited) thoughts below, but with the SNP references switched from his choice - SNPedia - to my choice, 23andMe.

Quick reminder: most traits in life are quantitative, they come in degree, not kind. In the human genome they are polygenic - many SNPs are involved (and other genetic mechanisms too) .. so one SNP is hardly going to be decisive. In most cases.

--- How To Use 23andMe Irresponsibly - (from SSC)  ---

"rs909525 is linked to the so-called “warrior gene” which I blogged about in the last links roundup. People with the normal four or five repeat version of these gene are less violent than people with the three-repeat version, and people with the two-repeat version are massively overrepresented among violent criminals. ... Although this SNP isn’t the warrior gene itself, it’s linked to it closely enough to be a good predictor.

"This is on the X chromosome, so men will only have one copy (I wonder how much of the increased propensity to violence in men this explains). It’s also one of the minus strand ones, so it’ll be the reverse of what SNPedia is telling you. If you’ve got T, you’re normal. If you’ve got C, you’re a “warrior”. I’ve got C, which gives a pretty good upper limit on how much you should trust these SNPs, since I’m about the least violent person you’ll ever meet. But who knows? Maybe I’m just waiting to snap. Post something dumb about race or gender in the open thread one more time, I dare you…"

I'm T and my mother, Beryl Seel was (T;T), both .. normally unwarlike.

"rs53576 in the OXTR gene is related to the oxytocin receptor, which frequently gets good press as “the cuddle hormone” and “the trust hormone”. Unsurprisingly, the polymorphism is related to emotional warmth, gregariousness versus loneliness, and (intriguingly) ability to pick out conversations in noisy areas.

"23andMe reads this one off the plus strand, so your results should directly correspond to SNPedia’s – (G;G) means more empathy and sociability and is present in 50% of the population, anything else means less. I’m (A;G), which I guess explains my generally hateful and misanthropic outlook on life, plus why I can never hear anyone in crowded bars."

We're both (G;G) which makes us kind and empathic ... .

"rs4680 is in the COMT gene, which codes for catechol-o-methyltransferase, an enzyme that degrades various chemicals including dopamine. Riffing on the more famous “warrior gene”, somebody with a terrible sense of humor named this one the “worrier gene”.

"One version seems to produce more anxiety but slightly better memory and attention; the other version seems to produce calm and resiliency but with a little bit worse memory and attention. (A;A) is smart and anxious, (G;G) is dumb and calm, (A;G) is in between. if you check the SNPedia page, you can also find ten zillion studies on which drugs you are slightly more likely to become addicted to. ..."

Both of us are (A;G) which makes us average and average.

"rs7632287, also in the oxytocin receptor, has been completely proportionally and without any hype declared by the media to be “the divorce gene”. To be fair, this is based on some pretty good Swedish studies finding that women with a certain allele were more often to have reported “marital crisis with the threat of divorce” in the past year (p = 0.003, but the absolute numbers were only 11% of women with one allele vs. 16% of women with the other). This actually sort of checks out, since oxytocin is related to pair bonding. If I’m reading the article right (G;G) is lower divorce risk, (A;A) and (A;G) are higher – but this may only apply to women."

Both my mother and I are (A;G) which makes her a bit .. flighty?

"rs11174811 is in the AVPR1A gene, part of a receptor for a chemical called vasopressin which is very similar to oxytocin. In case you expected men to get away without a divorce gene, this site has been associated with spousal satisfaction in men. Although the paper is extremely cryptic, I think (A;A) or (A;C) means higher spousal satisfaction than (C;C). But if I’m wrong, no problem – another study got the opposite results."

I'm (C;C) as was my mother, Beryl Seel, which means .. probably nothing.

"rs25531 is on the serotonin transporter. It's Overhyped Media Name is “the orchid gene”, on the basis of a theory that children with one allele have higher variance – that is, if they have nice, happy childhoods with plenty of care and support they will bloom to become beautiful orchids, but if they have bad childhoods they will be completely screwed up. The other allele will do moderately well regardless. (T;T) is orchid, (C;C) is moderately fine no matter what. There are rumors going around that 23andMe screwed this one up and nearly everybody is listed as (C;C)."

For my mother and myself, 23andMe did not report on this one.

"rs1800955 is in DRD4, a dopamine receptor gene. It's overhyped media name is The Adventure Gene, and supposedly one allele means you’re much more attracted to novelty and adventure. And by “novelty and adventure”, they mean lots and lots of recreational drugs. This one has survived a meta-analytic review. (T;T) is normal, (C;C) is slightly more novelty seeking and prone to drug addiction."

I was not genotyped at this location and my mother, Beryl Seel was (C;T) which made her a little bit adventurous with lots of use of recreational sherry.

"rs2760118, in a gene producing an obscure enzyme called succinate semialdehyde dehydrogenase, is a nice polymorphism to have. According to this article, it makes you smarter and can be associated with up to fifteen years longer life (warning: impressive result means almost certain failure to replicate). (C;C) or (C;T) means you’re smarter and can expect to live longer; (T;T) better start looking at coffins sooner rather than later."

I'm (T;T) and my mother, Beryl Seel was (C;T) which makes me resigned to an early grave. She lived to 92.

"rs6311 is not going to let me blame the media for its particular form of hype. The official published scientific paper on it is called “The Secret Ingredient for Social Success of Young Males: A Functional Polymorphism in the 5HT2A Serotonin Receptor Gene”.

"Boys with (A;A) are less popular than those with (G;G), with (A;G) in between – the effect seems to be partly mediated by rule-breaking behavior, aggression, and number of female friends. Now it kind of looks to me like they’re just taking proxies for popularity here, but maybe that’s just what an (A;A) nerd like me would say. Anyway, at least I have some compensation – the popular (G;G) guys are 3.6x more likely to experience sexual side effects when taking SSRI antidepressants."

I'm (G;G) and my mother, Beryl Seel was (G;A) which makes me out to be some kind of bad boy!? I must remember to keep off those SSRI tablets.

"rs6265, known as Val66Met to its friends, is part of the important depression-linked BDNF system. It’s a bit depressing itself, in that it is linked to an ability not to become depressed when subjected to “persistent social defeat”. The majority of whites have (G;G) – the minority with (A;A) or (A;G) are harder to depress, but more introverted and worse at motor skills."

I predicted I would be (A;A) based on poor motor skills and in fact I'm (A;G). My mother, Beryl Seel was the normal (G;G) which is consistent with her not-bad motor skills (except at driving).

"rs41310927 is so cutting-edge it’s not even in SNPedia yet. But these people noticed that a certain version was heavily selected for in certain ethnic groups, especially Chinese, and tried to figure out what those ethnic groups had in common.

"The answer they came up with was “tonal languages”, so they tested to see if the gene improved ability to detect tones, and sure enough they claimed that in experiments people with a certain allele were better able to distinguish and understand them. Usual caveats apply, but if you want to believe, (G;G) is highest ability to differentiate tones, (A;A) is lowest ability to differentiate tones. (A;G) is in between.

Sure enough, I’m (A;A). All you people who tried to teach me Chinese tonology, I FRICKIN’ TOLD YOU ALL OF THE WORDS YOU WERE TELLING ME SOUNDED ALIKE."

Both of us test (A;G) so I'm sure we would have struggled with Mandarin, a daily requirement in Bristol.

So, just to reiterate, if you have a 23andMe account, click on the rs... links and see how you scored.

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* If you care, I don't share his worries about the existential threat of the 'new AI'.